A method and system for evaluating the toughness of a super-large diameter shield tunneling under an airport runway based on differential settlement and dynamic settlement rules, a terminal device, and a medium

Abstract

The application discloses a kind of method, system, terminal equipment and medium based on difference settlement and dynamic settlement law of super diameter shield under airport runway toughness evaluation, it is related to shield engineering technical field.The method includes: obtaining engineering information and post-construction settlement and post-construction difference settlement control standard;Build three-dimensional finite element model containing multiple simulation conditions, multiple key characteristic sections and reflecting the interaction of soil and structure;Simulate the sequential excavation of shield, obtain dynamic settlement data and final settlement value, and calculate the difference settlement amount;Dynamic toughness value and evolution curve are obtained by substituting dynamic settlement data into toughness performance function;Based on dynamic toughness value, calculate the final state toughness index, and determine the toughness grade by combining control standard and pre-set grade division standard.The application realizes runway toughness dynamic and final state quantitative evaluation and grade determination, and clarifies the performance degradation law of structure, which provides scientific basis for construction control optimization and engineering decision.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) engineering technology, and in particular to a method, system, terminal equipment, and medium for assessing the toughness of ultra-large diameter TBMs passing under airport runways based on differential settlement and dynamic settlement laws. Background Technology

[0002] With economic development, the construction scope of civil airports has expanded, leading to a surge in demand for tunnel projects that pass under airport flight zones to improve traffic around airports and create integrated transportation hubs. Ultra-large diameter shield tunneling technology has become a key development direction for urban underground engineering due to its significant advantages in alleviating traffic pressure and reducing surface disturbance. However, airport runways are extremely sensitive to settlement, and improper control can easily lead to accidents such as cracking and shutdowns. Furthermore, the ground disturbance caused by ultra-large diameter shield tunnels is stronger than that caused by small diameter tunnels, resulting in more prominent risks and hidden dangers.

[0003] Existing research largely focuses on numerical simulations and settlement analyses of small-diameter shield tunnels passing under runways, such as verifying model effectiveness and analyzing settlement variation patterns. It also tends to focus on overall settlement after construction, with less attention paid to differential settlement at different locations and dynamic settlement throughout the construction process. Furthermore, research on ultra-large diameter shield tunnels passing under runways is scarce, and there is a lack of toughness assessment methods to quantify the degree of runway structural performance degradation under construction disturbances, making it difficult to scientifically evaluate the effectiveness of control measures.

[0004] Therefore, there is an urgent need for a toughness assessment method for ultra-large diameter shield tunnels passing under airport runways, based on differential settlement and dynamic settlement laws and incorporating toughness theory, to fill the gap in existing technologies. Summary of the Invention

[0005] The technical problem this invention aims to solve is that in the field of ultra-large diameter shield tunneling projects under airport runways, the ground disturbance is strong during these tunneling operations. The runways are sensitive to settlement and prone to safety accidents. Furthermore, there is a lack of attention to differential settlement and dynamic settlement throughout the construction process, as well as a lack of toughness assessment methods to quantify the degradation of runway structural performance, making it difficult to scientifically evaluate the effectiveness of control measures. Therefore, an effective solution is urgently needed to address these technical problems.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, the method comprising:

[0008] Obtain engineering information on the project of an ultra-large diameter shield tunnel passing under an airport runway, and determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications.

[0009] Based on the engineering information, a three-dimensional finite element model is constructed to simulate the dynamic tunneling process of a shield tunnel. The three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation working conditions and several key feature sections.

[0010] The three-dimensional finite element model was constructed to simulate the sequential tunneling process of the shield tunnel and obtain the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed.

[0011] Based on the dynamic settlement data, the differential settlement between each section under each simulated working condition is calculated.

[0012] Substituting the dynamic settlement data into the toughness performance function, the dynamic toughness value of the airport runway structure under each simulated working condition during the entire construction process is calculated, and the corresponding toughness evolution curve is obtained. The toughness evolution curve represents the toughness change state of the airport runway structure at each construction stage.

[0013] Based on the dynamic toughness value, the final toughness index is calculated, and the toughness level is determined for the final settlement value, the differential settlement amount, and the final toughness index according to the control standard and the preset toughness level classification standard. The final toughness index characterizes the overall performance recovery capability of the structure.

[0014] In one implementation, obtaining engineering information for the ultra-large diameter shield tunnel project under an airport runway includes:

[0015] Obtain the stratigraphic distribution and physical and mechanical parameters of the soil and rock mass at the engineering site;

[0016] Obtain the design parameters of the tunnel boring machine, including the diameter, shell thickness, and mechanical parameters of the tunnel boring machine;

[0017] Obtain tunnel design parameters, including tunnel burial depth, lining thickness, and material properties;

[0018] Obtain construction parameters, including target support force, grouting pressure and range;

[0019] Obtain the structural parameters of the airport runway, including the runway's dimensions and material properties.

[0020] Obtain the relative spatial relationship between the tunnel and the runway.

[0021] In one implementation, constructing a three-dimensional finite element model simulating the dynamic tunneling process of a shield machine based on the engineering information includes:

[0022] Mohr-Coulomb constitutive simulations were performed on the soil and rock masses involved in the project.

[0023] Elastic constitutive simulation and elastic concrete layer simulation of airport runways;

[0024] Plate unit simulation of the tunnel boring machine shell;

[0025] Concrete material simulation was performed on the segment lining of the shield tunnel.

[0026] In one implementation, the simulated working conditions include a foundation working condition, an increased burial depth working condition, and a grouting reinforcement working condition. The key feature sections include the left side section, the middle section, and the right side section of the airport runway surface. The three-dimensional finite element model is configured with several simulated working conditions and several key feature sections, including:

[0027] The basic working condition is set as the design burial depth working condition without reinforcement measures;

[0028] The increased burial depth condition is set as a condition that increases the burial depth by 1D or 2D on the basis of the design burial depth, where D is the diameter of the tunnel boring machine;

[0029] The grouting reinforcement condition is set to either 180° range grouting reinforcement or 360° range grouting reinforcement.

[0030] In one implementation, the shield tunnel is a double-track shield tunnel. The constructed three-dimensional finite element model simulates the sequential tunneling process and obtains dynamic settlement data of key characteristic sections under various simulated conditions throughout the tunneling process, as well as the final settlement value after tunnel completion. This includes:

[0031] The three-dimensional finite element model was run to simulate the entire process of sequential tunneling of the shield double-track tunnel under various simulated working conditions. During the simulation, dynamic settlement data of three key characteristic sections of the airport runway surface—the left, middle, and right sections—were monitored and extracted in real time.

[0032] After the two tunnels of the shield tunnel are completed, the final settlement value is obtained based on the dynamic settlement data.

[0033] In one implementation, substituting the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, and obtaining the corresponding toughness evolution curve, includes:

[0034] Substituting the dynamic settlement data into the toughness performance function yields the dynamic toughness value, wherein the toughness performance function is:

[0035]

[0036] in, This is the dynamic toughness value. This represents the maximum allowable deformation of an airport runway when its structural performance fails. This refers to the actual deformation of the airport runway structure over time.

[0037] Based on the calculated dynamic toughness values, the corresponding toughness evolution curves are plotted.

[0038] In one implementation, the step of calculating the final-state toughness index based on the dynamic toughness value, and determining the toughness level of the final settlement value, the differential settlement amount, and the final-state toughness index according to the control standard and the preset toughness level classification standard, includes:

[0039] Based on the dynamic toughness value, the final-state toughness index is calculated. The calculation formula is:

[0040]

[0041] in, for The integral value within the preset time interval, As the baseline settlement impact, The length of the preset time interval;

[0042] Based on the control criteria, a preliminary toughness assessment is made of the final settlement value and the differential settlement amount.

[0043] Based on the preset toughness level classification standard and the preliminary toughness judgment result, the final toughness index is divided into high toughness, medium toughness, low toughness, and no toughness.

[0044] Secondly, embodiments of the present invention also provide a toughness assessment system for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, the system comprising:

[0045] The data acquisition module is used to acquire engineering information on the project of ultra-large diameter shield tunnel passing under the airport runway, and to determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications.

[0046] The three-dimensional finite element model construction module is used to construct a three-dimensional finite element model simulating the dynamic tunneling process of a shield tunnel based on the engineering information. The three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation working conditions and several key feature sections.

[0047] The dynamic settlement data and final settlement value acquisition module is used to simulate the sequential tunneling process of the shield tunnel through the constructed three-dimensional finite element model, and to acquire the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed.

[0048] The differential settlement calculation module is used to calculate the differential settlement between each section under each simulated working condition based on the dynamic settlement data.

[0049] The toughness evolution curve calculation module is used to substitute the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition during the entire construction process, and obtain the corresponding toughness evolution curve. The toughness evolution curve represents the toughness change state of the airport runway structure at each construction stage.

[0050] The final-state toughness index calculation and grade determination module is used to calculate the final-state toughness index based on the dynamic toughness value, and to determine the toughness level of the final settlement value, the differential settlement amount, and the final-state toughness index according to the control standard and the preset toughness level classification standard. The final-state toughness index characterizes the overall performance recovery capability of the structure.

[0051] Thirdly, embodiments of the present invention also provide a terminal device, the terminal device including a memory, a processor, and a toughness assessment program for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws stored in the memory and executable on the processor. When the processor executes the toughness assessment program for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws, it implements the steps of the toughness assessment method for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws as described in any of the above schemes.

[0052] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a toughness assessment program for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws. When the processor executes the toughness assessment program for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws, it implements the steps of the toughness assessment method for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws as described in any of the above schemes.

[0053] Beneficial Effects: This invention discloses a method, system, terminal equipment, and medium for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws. It relates to the field of shield tunneling engineering technology. The method first acquires engineering information for an ultra-large diameter shield tunnel passing under an airport runway and determines the control standards for post-construction settlement and differential settlement of the airport runway based on engineering specifications. Then, based on the engineering information, a three-dimensional finite element model simulating the dynamic tunneling process of the shield is constructed. This three-dimensional finite element model reflects the interaction between soil and structure and includes several simulation conditions and several key feature sections. Next, the sequential tunneling process of the shield tunnel is simulated using the constructed three-dimensional finite element model, and the dynamic settlement data of each key feature section under each simulation condition during the entire tunneling process and the final settlement value after tunnel completion are obtained. Subsequently, based on the dynamic settlement data, the differential settlement between each section under each simulation condition is calculated. Subsequently, the dynamic settlement data is substituted into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, obtaining the corresponding toughness evolution curve. The toughness evolution curve characterizes the toughness change state of the airport runway structure at each construction stage. Finally, based on the dynamic toughness value, the final-state toughness index is calculated. According to the control standard and the preset toughness level classification standard, the final settlement value, the differential settlement amount, and the final-state toughness index are used to determine the toughness level. The final-state toughness index characterizes the overall performance recovery capability of the structure. This invention acquires engineering information and post-construction settlement and differential settlement control standards, constructs a three-dimensional finite element model containing multiple simulated working conditions and key characteristic sections, simulates shield tunneling to obtain settlement data, calculates differential settlement, dynamic toughness values ​​and evolution curves, and then calculates the final-state toughness index and determines the level. This allows for dynamic and final-state quantitative assessment of runway toughness, clarifies the structural performance degradation law, scientifically evaluates the effectiveness of control measures, provides a basis for construction optimization and engineering decision-making, and effectively addresses the safety assessment challenges of ultra-large diameter shield tunnels passing under runways. Attached Figure Description

[0054] Figure 1 This is a flowchart illustrating a specific implementation method for assessing the toughness of ultra-large diameter shield tunnels crossing airport runways based on differential settlement and dynamic settlement patterns, as provided in this invention.

[0055] Figure 2 This is a schematic diagram of the numerical models for working conditions one, two, and three in the method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws provided in this embodiment of the invention.

[0056] Figure 3 This is a schematic diagram of the numerical model for working conditions four and five in the toughness assessment method for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws provided in the embodiments of the present invention.

[0057] Figure 4 This is a schematic diagram of the dynamic settlement curves of the left, middle and right sides of the runway at different burial depths in the toughness assessment method for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws provided in an embodiment of the present invention.

[0058] Figure 5 The diagram shows the dynamic settlement curves of the left, middle, and right sides of the runway under different reinforcement measures in the toughness assessment method for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws provided in this embodiment of the invention.

[0059] Figure 6 The diagram shows the dynamic settlement of the runway under single and double-line excavation conditions one, three and five in the toughness assessment method for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws provided in the embodiments of the present invention.

[0060] Figure 7 This is a schematic diagram of the dynamic curves of runway toughness under single and double-line excavation conditions one, three and five in the toughness assessment method for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws provided in the embodiments of the present invention.

[0061] Figure 8 This is a schematic diagram of the principle of the ultra-large diameter shield tunneling toughness assessment device for airport runway underpass based on differential settlement and dynamic settlement law, provided in an embodiment of the present invention.

[0062] Figure 9 This is a block diagram illustrating the internal structure of the terminal device provided in an embodiment of the present invention. Detailed Implementation

[0063] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0064] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content, operations, or steps, nor does it require execution in the described order. For example, some operations or steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0065] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0066] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. For example, the first control information and the second control information are only used to distinguish different control information and do not limit their order.

[0067] Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or the order of execution, and that the words "first" and "second" do not necessarily imply that they are different.

[0068] It should also be understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0069] With economic development, the scale of civil airport construction has expanded, but early airport construction mostly did not consider reserving space for subway or highway underpasses. To improve traffic conditions around airports and create important transportation hubs, the demand for tunnels passing under airport flight zones has surged. Ultra-large diameter shield tunneling technology, due to its significant advantages in alleviating traffic congestion and reducing surface disturbance, has become a key development direction for urban underground engineering. However, airport runways are extremely sensitive to settlement; inadequate settlement control can easily lead to runway cracking, shutdowns, and other accidents. Moreover, the ground disturbance caused by ultra-large diameter shield tunnels is stronger than that caused by small diameter shield tunnels, making the risks and hidden dangers more prominent.

[0070] Significant progress has been made in numerical simulation and settlement analysis of shield tunneling under airport runways and related existing structures. Specifically, some studies have combined three-dimensional finite element numerical simulation to analyze the runway settlement caused by small-diameter shield tunneling under double-track tunnels and compared the results with on-site monitoring data. Other studies have focused on the spatial variability of soil parameters, using random field theory to analyze the influence of construction parameters and soil / rock parameters on the airport runway during shield tunneling. Still other studies have conducted numerical analysis of the construction process of small-diameter shield tunnels under airport runways, verifying the model's effectiveness and deriving the settlement variation patterns of the runway and underlying soil layers during excavation. Finally, some studies have combined numerical simulation with model testing to study the deformation patterns of airport runways and existing tunnels during construction, or to analyze the settlement of airport runways caused by parallel shield and open-cut tunnel construction. The study also examines the laws governing surface settlement and deformation. Furthermore, it includes numerous studies focusing on specific engineering cases. For example, three-dimensional finite element models considering high-speed railway subgrades, cement-fly ash-gravel pile reinforcement areas, and double-shield tunnels are used to verify the rationality of numerical results. Three-dimensional centrifuge tests and numerical inversion analysis are employed to study the development law of subgrade surface settlement when a shield tunnel passes under an intercity railway. A novel physical modeling system is proposed to capture the behavior of longitudinal settlement troughs and circumferential joints in shield tunnels. Studies are also conducted on the laws governing surface settlement and tunnel deformation under different curvature radii of hyperbolic tunnels and subsequent construction effects. Additionally, research is undertaken on shallow-buried shield tunnel construction schemes based on the engineering geological characteristics of karst areas, and three-dimensional refined numerical models are established to analyze the impact of shield tunneling on airport runways.

[0071] In the area of ​​construction control and analysis for shield tunneling under airport runways and existing buildings, some studies have also explored related aspects. Specifically, some studies have effectively controlled the deformation of maglev bridge piers caused by tunnels through construction control methods such as synchronous grouting and shield state adjustment; some studies have analyzed the development of tunnel settlement and the internal borehole grouting repair process using specific subway engineering cases, and explored the impact of increasing tunnel diameter and thickness on improving the deformation resistance of tunnel structures; some studies have used multi-objective evolutionary algorithms to optimize structural parameters and verify the high accuracy of existing tunnel deformation prediction models; some studies have taken the construction of ultra-large diameter shallow-buried shield tunnels as an example to discover the soil-carrying effect in shield construction and explore its mechanism and disturbance characteristics; some studies have proposed construction technologies such as pre-support of the tunnel perimeter pipe jacking and multi-tunnel sectional excavation support to solve the problem of pavement settlement control; and some studies have studied shield construction parameters through field propulsion tests. The study explored various methods to regulate settlement and ensure it meets airport runway control requirements. Some research outlines a framework for settlement control of shield tunnels passing under airports, encompassing the determination of settlement control indicators, theoretical calculations and numerical analysis, and construction measures. Other studies developed new single-liquid grouts to improve soil deformation and tunnel waterproofing stability in rail transit shield tunneling projects under airport runways. Still others improved rail shield tunneling technology by combining specific regional sedimentary geological characteristics. Some studies optimized tunneling parameters through test sections, adopted mud-efficiency methods and automated monitoring technology, and modified supplementary grouting techniques to achieve successful shield tunneling under airport runways. Finally, research employed new synchronous grouts to ensure stable and controllable settlement over one year, achieving the goal of minimally disturbed tunneling under airport main runways in soft soil areas.

[0072] However, existing research still has significant shortcomings. First, most studies focus on small-diameter shield tunnels (less than 10m), neglecting the special scenario of ultra-large diameter shield tunnels passing under airport runways, thus failing to address the stronger ground disturbance characteristics of ultra-large diameter shield tunnels. Second, existing research primarily focuses on the overall settlement of the runway after construction, paying insufficient attention to differential settlement at different locations on the runway, the dynamic settlement patterns throughout the construction process, and rarely studies the location and variation patterns of the maximum runway settlement, making it difficult to fully grasp the impact of construction on the runway. Third, current technology lacks a toughness assessment method that can quantitatively evaluate the degree of structural performance degradation of airport runways under construction disturbances, making it impossible to scientifically evaluate the effectiveness of different control measures in improving the toughness of the runway structure. Furthermore, current shield tunnel projects passing under airport runways are all small-diameter tunnels (less than 10m), with no actual engineering cases of ultra-large diameter shield tunnels, making it difficult to meet the safety assessment and construction control requirements for ultra-large diameter shield tunnel projects passing under airport runways.

[0073] Therefore, with the increasing demand for tunnels passing under airport runways, ultra-large diameter shield tunneling technology has become the preferred solution. However, it causes stronger ground disturbances, and airport runways are extremely sensitive to settlement. Improper settlement control can lead to major safety accidents, making the engineering safety risks significantly higher than in small-diameter shield tunneling scenarios. These limitations of existing technologies make it difficult to quantify the degree of runway structural performance degradation and scientifically evaluate the effectiveness of control measures in ultra-large diameter shield tunneling projects under airport runways. This hinders reliable support for engineering construction optimization and safety decision-making, and fails to meet the actual needs of engineering safety assessment and construction control. Therefore, effective solutions are urgently needed to overcome these technical bottlenecks.

[0074] Based on this, a method for evaluating the toughness of airport runways is proposed, aiming to solve the problem that existing technologies are unable to quantify the degree of performance degradation of runway structures under construction disturbances. This method reveals the differential settlement law through numerical simulation and innovatively introduces toughness theory to dynamically and ultimately evaluate the performance of runway structures. First, basic engineering data and control standards are collected. Specifically, basic information on ultra-large diameter shield tunnels passing under airport runways is collected, including: the geological strata distribution and physical and mechanical parameters of the soil and rock mass at the project site, shield machine design parameters (such as diameter and shell thickness), tunnel design parameters (such as burial depth, lining thickness, and material properties), construction parameters (such as target support force, grouting pressure and range), airport runway structural parameters (such as dimensions and material properties), and the relative spatial relationship between the tunnel and the runway. Simultaneously, post-construction settlement and post-construction differential settlement control standards for the airport runway are determined according to relevant engineering specifications. Then, a three-dimensional finite element model is constructed and construction conditions are set. Based on the collected parameters, a three-dimensional finite element model capable of simulating the dynamic tunneling process of the shield machine is established; the model should accurately reflect the interaction between soil and structure. Subsequently, various simulation conditions were set, including at least the design depth foundation condition without reinforcement, the increased foundation depth condition, and the grouting reinforcement condition, to compare and analyze the effects of different control measures. Then, the construction process was simulated and differential settlement data of the runway was extracted. The established model was run to simulate the entire process of sequential tunneling of the shield-driven twin-track tunnel. During the simulation, dynamic settlement data of three key characteristic sections on the left, middle, and right sides of the airport runway surface were monitored and extracted in real time, with particular attention paid to the final settlement value after the twin tracks were connected, and the differential settlement between each section was calculated. Finally, the toughness index of the runway structure was calculated and its grade was evaluated. Based on the extracted dynamic settlement data of the key runway sections, it was substituted into the toughness performance function to calculate the dynamic toughness value of the runway structure throughout the construction process, and a toughness evolution curve was plotted. Simultaneously, the final-state toughness index, characterizing the overall performance recovery capability of the structure, was calculated based on the final settlement value. According to the preset toughness grade classification standard, the toughness performance of the runway structure was quantitatively evaluated and graded, thereby scientifically evaluating the effectiveness of the control measures and providing a basis for engineering decisions.

[0075] This embodiment provides a method for assessing the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement patterns. Figure 1 As shown, the specific steps include the following:

[0076] Step S100: Obtain engineering information for the ultra-large diameter shield tunnel project under the airport runway, and determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications.

[0077] In this embodiment, the underpass tunnel project for the second runway of an airport in City A is taken as an example. This project uses a shield tunneling method to pass under the airport in City A. The total length of the shield tunnel is approximately 3.9 km, with a closed section of 3127 m. Two horizontal curves are set along the entire route, each with a radius of 1000 m. The shield tunnel uses a twin-tube shield, with six lanes in both directions and a soil cover thickness of 34 to 38 m. The shield section on one side is planned to have an outer diameter of 14.5 m and a lining thickness of 600 mm. The interior has three lanes in one direction, with a road width of 3.5 m + 3.5 m + 3.5 m, a clearance height of 4.50 m, and the extra space under the shield can be used for the layout of a comprehensive utility tunnel according to actual pipeline needs.

[0078] This project involves an airport complex including connecting corridors, terminals, aprons, and runways. These structures exhibit varying sensitivities to settlement, with runways being particularly sensitive to ground settlement control requirements. Currently, there are no unified standards for this, necessitating the establishment of reasonable settlement control standards. Furthermore, measures to control settlement caused by the tunnel boring machine (TBM) passing under the runway need to be proposed. In this embodiment, two measures are employed: increasing the depth of the new tunnel and reinforcing the area around the new tunnel with grouting. The main construction challenge of this project focuses on passing under the existing airport runway structures, where the maximum width of the runway is 70m. The tunneling length under the airport is nearly 900m, with approximately 38m of overburden, and the TBM is situated in moderately weathered rock. Passing under the airport's east runway and adjacent taxiways carries inherent risks. Runways and taxiways are crucial for aircraft takeoffs, landings, and taxiing; if construction disturbances cause settlement in these areas, it will affect the airport's normal operations.

[0079] Civil aviation standards indicate that aircraft operation and uneven settlement of the pavement foundation can lead to increased surface unevenness, severely hindering aircraft operations. Generally, isolated unevenness with a deviation of 2.5cm to 3cm within a 45m distance is acceptable, i.e., pavement smoothness: 2.5cm to 3.0cm (within 45m). Civil airport engineering specifications state that the limits are within the design service life, with settlement primarily characterized by uniform settlement. The design of tunnels crossing the airport flight area mainly considers the impact of pavement settlement during tunnel construction on safe aircraft operation. Therefore, based on relevant specifications, the specific requirements for post-construction settlement and post-construction differential settlement within the design service life of airport runways are: post-construction settlement less than -20mm and post-construction differential settlement less than 1‰, with the horizontal distance for measuring post-construction differential settlement being 50m.

[0080] In one implementation, obtaining engineering information for a large-diameter shield tunnel passing under an airport runway specifically includes the following steps:

[0081] Step S110: Obtain the stratigraphic distribution and physical and mechanical parameters of the soil and rock mass at the engineering site;

[0082] Step S120: Obtain the shield machine design parameters, which include the shield machine's diameter, shell thickness, and mechanical parameters;

[0083] Step S130: Obtain tunnel design parameters, including tunnel burial depth, lining thickness and material properties;

[0084] Step S140: Obtain construction parameters, including target support force, grouting pressure and range;

[0085] Step S150: Obtain the structural parameters of the airport runway, including the dimensions and material properties of the airport runway.

[0086] Step S160: Obtain the relative spatial relationship between the tunnel and the runway.

[0087] In this embodiment, engineering information on the ultra-large diameter shield tunnel passing under an airport runway, obtained through methods such as data collection, sampling, and information gathering, is used for subsequent model construction and simulation of the impact of the actual shield tunneling process on the airport runway. The engineering information specifically includes data on the geological strata distribution and physical and mechanical parameters of the soil and rock mass at the project site, shield machine design parameters, tunnel design parameters, construction parameters, airport runway structural parameters, and the relative spatial relationship between the tunnel and the runway. The collected engineering information includes soil constitutive model parameters and other experimental material parameters used for subsequent model construction.

[0088] Specifically, through drilling sampling and indoor geotechnical tests, the strata were divided into five layers: artificial fill, clay, slightly dense gravel, medium dense gravel, and dense gravel. The physical and mechanical parameters of each layer are shown in Table 1. Subsequently, based on the tunnel boring machine design documents, tunnel design drawings, and runway completion data, the core material parameters were obtained, as shown in Table 2. Construction parameters such as target support force and grouting pressure were determined with reference to similar project experience and local stratum conditions. The relative position of the tunnel and runway is such that the tunnel passes under the runway along its length, and the runway centerline intersects the central axis of the tunnel group perpendicularly.

[0089] Table 1 includes mechanical parameters such as the internal friction angle, which is used to express the shear strength generated by inter-particle friction in soil. φ Cohesion, which expresses the shear strength generated by the cementation between soil particles. c The weight of a unit volume of soil (including natural water content) used to calculate ground stress and settlement load. γ The elastic modulus, which expresses the ratio of stress to strain in soil during the elastic stage. E Poisson's ratio is used to express the ratio of transverse strain to longitudinal strain in soil. ν The mechanical parameters involved in Table 2 include the unit weight of concrete, which expresses the weight of the concrete per unit volume. γ The elastic modulus, which expresses the ability of the shield machine's outer shell material to resist elastic deformation. E Shear modulus is used to express a material's ability to resist shear deformation. G Poisson's ratio is used to express the lateral deformation capability of shell materials. ν Structural thickness used to express the thickness of the outer shell of a tunnel boring machine or the thickness of the segment lining. d .

[0090] Table 1

[0091]

[0092] Table 2

[0093]

[0094] Step S200: Based on the engineering information, construct a three-dimensional finite element model to simulate the dynamic tunneling process of a shield tunnel. The three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation working conditions and several key feature sections.

[0095] In this embodiment, the constructed three-dimensional finite element model simulating the dynamic tunneling process of a shield tunnel is based on the engineering information obtained above. It is a visualized and computable engineering simulation model built using finite element analysis software. The goal is to recreate the dynamic interaction between the soil, the shield, and the runway when a large-diameter shield tunnels pass under an airport runway, providing an accurate simulation platform for subsequent settlement data extraction and toughness assessment. The interaction between the soil and the structure reflected in the three-dimensional finite element model refers to the model simulating the force exerted on the structure by soil deformation during construction, as well as the constraint and disturbance effects of the structure on the soil, by precisely defining the constitutive relationships and contact properties of different media. The various simulation conditions are set based on the controlled variable method to compare the impact of different construction control measures on runway settlement, and can cover multiple engineering scenarios. The key feature sections are selected based on the disturbance gradient of the shield tunneling on the runway to accurately capture the differential settlement in different areas of the runway.

[0096] In one implementation, constructing a three-dimensional finite element model simulating the dynamic tunneling process of a shield machine based on the engineering information specifically includes the following steps:

[0097] Step S210: Perform Mohr-Coulomb constitutive simulation on the soil and rock mass involved in the project;

[0098] Step S220: Perform elastic constitutive simulation and elastic concrete layer simulation of the airport runway;

[0099] Step S230: Simulate the shield machine shell using plate units;

[0100] Step S240: Simulate the concrete material for the segment lining of the shield tunnel.

[0101] In this embodiment, the soil and rock mass is simulated using the Mohr-Coulomb constitutive model. Specifically, the soil constitutive parameters in the numerical model in Table 1 are used. The soil shear strength is quantified by the parameters to match the scenario of shear deformation of the strata due to excavation when the ultra-large diameter shield tunnel passes under it. This avoids the defect that other constitutive models cannot simulate the plastic yielding of the soil, and provides a real stratum mechanics basis for subsequent settlement calculations.

[0102] The airport runway stiffness was simulated using an elastic constitutive model, specifically a 70m wide and 2m thick elastic concrete layer, with the relevant parameters from Table 2 used. Airport runways deform minimally under construction disturbances; the elastic constitutive model captures their instantaneous deformation under load and their recoverability after unloading, avoiding the overestimation of permanent runway deformation caused by using a plastic constitutive model, which would affect the accuracy of settlement assessment.

[0103] The shield machine shell is simulated using plate elements, and the relevant parameters in Table 2 are used. The plate elements only need to define the thickness and in-plane mechanical properties, which can simplify the complex internal structure of the shield machine and accurately transmit the extrusion force of the shell on the surrounding strata.

[0104] The lining of the shield tunnel segments was simulated using concrete material units, with the relevant parameters in Table 2 used. Specifically, C40 concrete was used for simulation, and the segments were spatially enclosed by the shield machine shell.

[0105] In one implementation, the simulated working conditions include a foundation working condition, an increased burial depth working condition, and a grouting reinforcement working condition. The key feature sections include the left side section, the middle section, and the right side section of the airport runway surface. The three-dimensional finite element model is configured with several simulated working conditions and several key feature sections, specifically including the following steps:

[0106] Step S250: Set the foundation working condition to the design burial depth working condition without reinforcement measures;

[0107] Step S260: Set the increased burial depth condition to a condition that increases the burial depth by 1D or 2D on the basis of the design burial depth, where D is the diameter of the tunnel boring machine;

[0108] Step S270: Set the grouting reinforcement condition to either 180° range grouting reinforcement or 360° range grouting reinforcement.

[0109] In this embodiment, a three-dimensional finite element model of a large-diameter shield tunnel passing under an airport runway was established using Plaxis-3D software. The model's geometric dimensions are 150m long, 150m wide, and 100m high, with a tunnel depth of 38m. The tunnel spacing is 14.5m, and excavation proceeds along the positive Y-axis, excavating the left tunnel T1 first, followed by the right tunnel T2. The runway is simulated using elastic plate elements with a width of 70m and a thickness of 2m. A schematic diagram of the foundation working conditions is shown below. Figure 2 As shown in case (a) of the model. The boundary conditions of the model are: no horizontal displacement at the vertical boundary, no vertical or horizontal displacement at the bottom boundary, and the top boundary is a free boundary.

[0110] To analyze the settlement impact of airport runways under different tunnel burial depths and different stratum reinforcement measures, five working conditions were designed for analysis. The basic information of the working conditions is shown in Table 3, which summarizes the working condition information.

[0111] Table 3

[0112]

[0113] Working condition 1 is the basic working condition, with a tunnel depth of 38m (2.6D). Working conditions 2 through 5 are based on the basic working condition, with controlled variables. Working condition 2 increases the depth by 1D, to 52.5m (3.6D); working condition 3 increases the depth by 2D, to 67m (3.6D). Working conditions 1 through 3 all involve grouting reinforcement. The numerical models for working conditions 1 through 3 are as follows: Figure 2 (a) Figure 2 (b) Figure 2 As shown in (c) in the figure.

[0114] Conditions four and five involve grouting reinforcement around the existing tunnel. Condition four has the same burial depth as the foundation condition, with an additional 180° grouting reinforcement. Condition five involves 360° grouting reinforcement around the tunnel. The numerical models for conditions four and five are as follows: Figure 3 (a) Figure 3 As shown in (b) in the figure. The colored area represents the grouting reinforcement area.

[0115] Specifically, when analyzing the settlement influence of airport runways at different tunnel burial depths, conditions 1, 2, and 3 were selected for comparison. When analyzing the settlement influence of airport runways under different stratum reinforcement measures, conditions 1, 4, and 5 were selected for comparison.

[0116] Step S300: Using the constructed three-dimensional finite element model, simulate the sequential tunneling process of the shield tunnel, and obtain the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed.

[0117] In this embodiment, before simulating shield tunneling using the constructed model, it is necessary to determine the relevant parameters of shield construction. Specifically, the simulated shield construction process includes the support force applied to the tunnel face to maintain stability, the sequential excavation of the soil within the shield machine, the installation of tunnel segments and grouting in the gap between the lining and the soil, and the tunnel shrinkage applied to the shield machine due to its tapered design. Each construction step of the shield is 2m long. Slurry-balanced shields create a slurry pressure chamber by filling the entire slurry chamber with slurry to balance the water and soil pressure at the excavation face. However, the slurry pressure gradient is often difficult to keep in line with the water and soil pressure value at the working face. Therefore, based on the mechanism of slurry-balanced shield machines, a fixed slurry pressure gradient of 50kPa / m is adopted. Different slurry pressures are applied to the tunnel face and tail gap by adjusting the arch support pressure. Based on experience, the tunnel face support force and grouting pressure should both be slightly greater than the in-situ lateral water and soil pressure of the strata. Based on empirical thrust values ​​from similar projects, the jack thrust in the model is set to 2300 kPa, acting on the segment cross-section in the opposite direction of shield tunneling (-Y direction). The shield tunneling parameters are summarized in Table 4, which shows the shield tunneling construction parameter settings, where the negative sign only indicates direction.

[0118] Table 4

[0119]

[0120] The dynamic settlement data obtained during the simulated tunneling process is specifically defined as the settlement values ​​of three key sections extracted in real time at each step of the simulated tunneling sequence. This data is used to capture the continuous change process of settlement and reveal the cumulative pattern of settlement. The final settlement value after the tunnel is completed is the endpoint value of the dynamic settlement data for the entire tunneling process.

[0121] In one implementation, the shield tunnel is a double-track shield tunnel. The sequential tunneling process of the shield tunnel is simulated by constructing the three-dimensional finite element model, and the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed are obtained. Specifically, the following steps are included:

[0122] Step S310: Run the three-dimensional finite element model to simulate the entire process of sequential tunneling of the shield double-track tunnel under various simulated working conditions, and monitor and extract the dynamic settlement data of the three key feature sections of the airport runway surface—the left section, the middle section, and the right section—in real time during the simulation.

[0123] Step S320: After the two tunnels of the shield tunnel are completed, the final settlement value is obtained based on the dynamic settlement data.

[0124] In this embodiment, the simulation process is divided into three stages: 1) Activating existing structures, such as airport runways; 2) Excavation of the left tunnel T1 of the parallel shield tunnel; 3) Excavation of the right tunnel T2 of the parallel shield tunnel. The entire numerical model consists of 54 calculation steps, of which:

[0125] Phase 1: Initial stress equilibrium; before the start of Phase 2, reset the model strain field and displacement field to zero.

[0126] Phase Two (Steps 1 to 27): Excavation of the left tunnel T1 of the first shield tunnel. The left tunnel T1 was excavated for a total of 150m, with each ring being 2m long, for a total of 75 rings.

[0127] Phase 3 (Steps 28 to 54): Excavation of the right tunnel T2 of the second shield tunnel. The right tunnel T2 was excavated for a total of 150m, with each ring being 2m long, for a total of 75 rings.

[0128] The simulation included a brief overview of the first stage, focusing primarily on the impact of the second and third stages. Therefore, the second and third stages featured detailed simulations of the tunnel boring process, including face pressure, grouting pressure, segment lining support, and jack pressure. The completion of the left tunnel was considered the completion of single-line tunneling, while the completion of both the left and right tunnels was considered the completion of double-line tunneling.

[0129] Based on the above simulation process, the settlement patterns of three key sections of the airport runway at different burial depths were obtained. Specifically, the dynamic settlement curves of the left, middle, and right key sections of the runway at different burial depths under conditions one to three are shown below. Figure 4 (a) Figure 4 (b) Figure 4 As shown in (c) in the figure. The dashed line represents the settlement curve on the left side of the runway when only the left line T1 is excavated, corresponding to the numerical simulation stage 27, i.e., step 27; the solid line represents the settlement curve on the left side of the runway when both the left line T1 and the right line T2 are excavated, corresponding to the numerical simulation stage 54, i.e., step 54.

[0130] Figure 4 (a) Figure 4 (b) Figure 4 Figure (c) shows the dynamic settlement curves of the left, middle, and right sides of the runway at different burial depths. When the single-line excavation of the left line T1 is completed, the peak settlement values ​​of different areas of the runway decrease with increasing burial depth. Under condition one (burial depth 38m, 2.6D), the maximum settlement values ​​of the left, middle, and right sides of the runway are -15.16mm, -14.25mm, and -13.06mm, respectively; under condition two (burial depth 52.5m, 3.6D), they decrease to -12.04mm, -10.93mm, and -9.65mm; under condition three (burial depth 67m, 4.6D), they further decrease to -9.15mm, -8.54mm, and -7.82mm. The peak values ​​of the settlement curves all appear at X=60m (to the left of the left line T1 axis at X=60.5m), indicating that the area of ​​maximum settlement during single-line construction is adjacent to the tunnel axis. After the completion of the dual-track tunnel, the settlement increased significantly and its distribution pattern changed. In Condition 1, the maximum settlement values ​​on the left, center, and right sides of the runway increased to -23.56 mm, -22.11 mm, and -20.47 mm, respectively; in Condition 2, they were -19.60 mm, -18.25 mm, and -16.84 mm; and in Condition 3, they were -15.66 mm, -14.76 mm, and -13.85 mm. The peak settlement location shifted from X=60m in the single-track stage to the range of X=70m to 75m: the peak value in Condition 1 was located at X=70m and X=75m, while the peak values ​​in Conditions 2 and 3 remained stable at X=75m (the runway center area). This shift indicates that the dual-track construction caused the center of the settlement trough to shift 10 to 15m towards the tunnel's central axis.

[0131] The settlement analysis of three key sections of the airport is summarized in Table 5, which shows the maximum settlement value (mm) of the runway at different tunnel depths.

[0132] Table 5

[0133]

[0134] Similarly, based on the above simulation process, the settlement patterns of three key sections of the airport runway under different reinforcement measures were obtained. Specifically, for conditions one, four, and five with the same burial depth and different reinforcement methods, the dynamic settlement curves of the three key sections of the runway (left, center, and right) are shown below. Figure 5 (a) Figure 5 (b) Figure 5 As shown in (c) in the figure.

[0135] When the single-track excavation of the left T1 line was completed, the peak settlement in different areas of the runway decreased as the grouting range expanded. Under condition one (burial depth 38m, 2.6D), the maximum settlement values ​​on the left, middle, and right sides of the runway were -15.16mm, -14.25mm, and -13.06mm, respectively; under condition four (180° grouting reinforcement), they decreased to -14.09mm, -12.54mm, and -11.43mm; under condition five (360° grouting reinforcement), they further decreased to -11.53mm, -9.85mm, and -7.94mm. The peak values ​​of the settlement curves all appeared at X=60m (to the left of the left T1 axis at X=60.5m), indicating that the area of ​​maximum settlement during single-track construction was adjacent to the tunnel axis.

[0136] After the completion of the dual-track tunnels, the runway settlement distribution pattern changed significantly, and the settlement generally increased: in Condition 1 (unreinforced), the peak settlement values ​​on the left, center, and right sides were -23.56 mm, -22.11 mm, and -20.47 mm, respectively; in Condition 4, which was reinforced with 180° grouting, the settlement values ​​decreased to -21.59 mm, -19.52 mm, and -18.00 mm; while in Condition 5, which was reinforced with 360° grouting, the settlement values ​​further decreased to -17.68 mm, -15.94 mm, and -13.97 mm. The location of the peak settlement value shifted from X=60 m in the single-track stage to X=75 m (the runway center area), indicating that the construction of the dual tracks caused the center of the settlement trough to shift towards the central axis of the tunnel group.

[0137] The data are summarized in Table 6, which shows the maximum settlement (mm) of the runway under different reinforcement methods.

[0138] Table 6

[0139]

[0140] Step S400: Based on the dynamic settlement data, calculate the differential settlement between each section under each simulated working condition.

[0141] In this embodiment, the differential settlement patterns of three key sections of the airport runway at different burial depths are first analyzed. Table 6 shows that after double-line excavation, in condition one, the settlement values ​​for the left, middle, and right sides of the runway are -23.56 mm, -22.11 mm, and -20.47 mm, respectively. The differential settlement between the left and middle sections is -1.45 mm, and between the middle and right sections is -1.64 mm. The settlement on the left side of the runway is significantly greater than that on the middle and right sides, indicating a large differential settlement. Furthermore, the maximum settlement at all three key sections exceeds -20 mm, exceeding the settlement control standard; therefore, control measures are required.

[0142] In Condition 2, the settlement values ​​for the left, middle, and right sides of the runway were -19.60 mm, -18.25 mm, and -16.84 mm, respectively. The differential settlement between the left and middle sections was -1.35 mm, and between the middle and right sections was -1.41 mm. Condition 2 increased the burial depth by 1D compared to Condition 1, but the settlement on the left side of the runway was significantly greater than that on the middle and right sides, with a maximum settlement of -19.60 mm, slightly less than the settlement control standard. In Condition 3, the settlement values ​​for the left, middle, and right sides of the runway were -15.66 mm, -14.76 mm, and -13.85 mm, respectively. The differential settlement between the left and middle sections was -0.90 mm, and between the middle and right sections was -0.91 mm. Furthermore, after increasing the burial depth by 2D, the maximum settlement was -15.66 mm on the left side, far less than the control standard, indicating the best control effect.

[0143] The maximum settlement values ​​for all three working conditions occurred on the left side of the runway, with the maximum values ​​for conditions one through three being -23.56 mm, -19.60 mm, and -15.66 mm, respectively. This is because during shield tunnel excavation, the left side of the runway is always subject to greater disturbance first, resulting in greater settlement compared to other sections over time. The section where the maximum settlement value occurred is the most critical section, and according to the specifications, its post-construction settlement and differential settlement must be inspected. The maximum settlement values ​​for the three working conditions are summarized in Table 6 below, and Table 7 shows the post-construction settlement and differential settlement for conditions one, two, and three.

[0144] Table 7

[0145]

[0146] The data above shows that Condition 1 did not meet the control standards, while Conditions 2 and 3 both met them, with Condition 3 achieving the best control effect. Post-construction settlement and differential post-construction settlement decrease with increasing burial depth under different conditions, indicating that increasing burial depth has a significant effect on reducing differential settlement. However, in actual engineering, as the burial depth of newly constructed tunnels increases, the construction difficulty and cost increase significantly. Therefore, from a comprehensive economic perspective, the scheme with an increased burial depth of 1D is more practically meaningful.

[0147] Subsequently, the differential settlement patterns of the three key sections of the airport runway under different reinforcement measures were analyzed using data from Table 8. It was found that after the double-line excavation was completed, in Condition 1, the settlement values ​​for the left, middle, and right sides of the runway were -23.56 mm, -22.11 mm, and -20.47 mm, respectively. The differential settlement between the left and middle sections was -1.45 mm, and between the middle and right sections was -1.64 mm. The settlement on the left side of the runway was significantly greater than that on the middle and right sides, indicating a large differential settlement. Furthermore, the maximum settlement at all three key sections exceeded -20 mm, exceeding the settlement control standard. In Condition 4, the settlement values ​​for the left, middle, and right sides of the runway were -21.59 mm, -19.52 mm, and -18.00 mm, respectively. The differential settlement between the left and middle sections was -2.07 mm, and between the middle and right sections was -1.52 mm. Condition 4, compared to Condition 1, added a 180° grouting reinforcement measure. However, the settlement on the left side of the runway was still significantly greater than that on the middle and right sides, with a maximum settlement of -21.59 mm, slightly less than the settlement control standard. In Condition 5, the settlement values ​​on the left, middle, and right sides of the runway were -17.68 mm, -15.94 mm, and -13.97 mm, respectively. The differential settlement between the left and middle sides was -1.74 mm, and between the middle and right sides was -1.97 mm. Furthermore, after adding 360° grouting reinforcement, the maximum settlement was -17.68 mm on the left side, far less than the control standard, indicating the best control effect.

[0148] The maximum settlement values ​​for all three working conditions occurred on the left side of the runway, with the maximum values ​​for conditions one, four, and five being -23.56 mm, -21.59 mm, and -17.68 mm, respectively. This is because during shield tunnel excavation, the left side of the runway is always subject to greater disturbance first, resulting in greater settlement compared to other sections over time. The section where the maximum settlement value occurred is the most critical section, and according to the specifications, its post-construction settlement and differential settlement must be inspected. The post-construction settlement and differential settlement corresponding to the maximum settlement values ​​for the three working conditions are shown in Table 8, which displays the post-construction settlement and differential settlement for conditions one, four, and five.

[0149] Table 8

[0150]

[0151] As shown in Table 8, the reinforcement measures have a significant effect on reducing differential settlement. However, the post-construction settlement and post-construction differential settlement under different working conditions indicate that neither working condition 1 nor working condition 4 met the control standards. Therefore, in actual engineering, the 360° grouting reinforcement measures have the best effect and can significantly improve the settlement of the airport runway.

[0152] Analysis using the controlled variable method shows that under different burial depths (condition 1 did not meet the standard, conditions 2 and 3 met the control standards, with condition 3 showing the best effect), and under different reinforcement measures (conditions 1 and 4 did not meet the standard, condition 5, with 360° grouting, significantly reduced settlement and met the standard), the left side of the runway consistently exhibited the largest settlement. However, the above analysis only selected settlement data at two time points: single-line completion (left line completed at T1) and double-line completion (T1 and T2 completed), not covering the entire construction process. To verify the consistent pattern of maximum settlement on the left side of the runway, a dynamic settlement analysis of the entire runway process is necessary. To extract the dynamic settlement of the runway during shield tunneling, conditions with effective control measures need to be selected for comparative analysis with the foundation conditions. Conditions 1, 3, and 5 were selected, and their information is shown in Table 9. The numerical model is as follows. Figure 2 (a) Figure 2 (c) Figure 3 (b) in the middle.

[0153] Table 9

[0154]

[0155] To investigate the dynamic settlement response under three working conditions during single-line excavation, the maximum settlement values ​​of the left, middle, and right sides of the runway were extracted in 10 steps under the case of excavation only on the left line (single line), and summarized in Table 10. Table 10 shows the dynamic settlement (maximum value) of three sections of runways in working conditions one, three, and five during single-line excavation. Specifically, time T1 is when the tunnel has been excavated to ring 6; T2 is when it has been excavated to ring 12; T3 is when it has been excavated to ring 18; T4 is when it has been excavated to ring 24; T5 is when it has been excavated to ring 30; T6 is when it has been excavated to ring 39; T7 is when it has been excavated to ring 48; T8 is when it has been excavated to ring 57; T9 is when it has been excavated to ring 66; and T10 is when it has been excavated to ring 75.

[0156] Table 10

[0157]

[0158] The maximum settlement values ​​occurring in the 10 steps summarized in Table 10 are plotted as a graph or curve, as shown below. Figure 6 As shown in (a) in the figure. For the sake of simplification, the dynamic settlement on the left side of the runway when only single-line excavation is carried out in working condition one is simplified to "working condition one (single) - left".

[0159] Figure 6Figure (a) depicts the dynamic settlement trend of the runway during single-line excavation under conditions 1, 3, and 5, which can be divided into three characteristic regions: Region A (0 to -10 mm) corresponds to the main settlement range of conditions 3 and 5, far below the -20 mm control limit; Region B (-10 to -20 mm) is the settlement stability zone of condition 1, still below the limit; Region C is the over-limit zone, but it was not triggered during single-line construction. The nine curves in the figure clearly show that the settlement response on the left side of the runway under single-line excavation is always significantly higher than that on the middle and right sides, and this difference is particularly prominent in the early stage of construction. Taking condition 1 as an example, the settlement on the left side increases rapidly from -0.77 mm to -15.14 mm in steps T1 to T5, reaching its peak earlier than the middle (reaching -14.25 mm in T8) and the right side (reaching -13.06 mm in T9). This pattern also applies to other operating conditions: in operating condition three, the settlement on the left side increased from -0.88mm to -9.15mm, in the middle from -0.23mm to -8.54mm, and on the right side from -0.13mm to -7.82mm; in operating condition five, the settlement on the left side increased from -0.91mm to -11.53mm, in the middle from -0.19mm to -9.85mm, and on the right side from -0.02mm to -7.94mm.

[0160] To investigate the dynamic settlement response under three working conditions during dual-line excavation, the maximum settlement values ​​of the left side, middle and right side of the runway were extracted in 10 steps under the condition that the left line excavation was completed and the right line was being excavated (dual-line). The results are summarized in Table 11. Table 11 shows the dynamic settlement (maximum value) of the three sections of runways one, three and five under working conditions during dual-line excavation.

[0161] Table 11

[0162]

[0163] The maximum settlement values ​​occurring in the 10 steps summarized in Table 11 are plotted as a graph or curve, as follows: Figure 6 As shown in (b) of the diagram.

[0164] Figure 6 Figure (b) depicts the dynamic settlement trend of the runway under conditions 1, 3, and 5 during double-line excavation. Region A initially settles by approximately 8mm to 10mm; Region B represents the settlement range for conditions 3 and 5; Region C is the over-limit area, where the settlement value in condition 1 exceeds the control threshold during the later stages of right-line excavation. The nine curves in the figure correspond to the settlement responses of the left, middle, and right sides of the runway under double-line excavation. It can be seen that the settlement value on the left side of the runway is significantly higher than that on the middle and right sides in all construction steps, and this difference continues to widen as construction progresses.

[0165] During the dual-track excavation process, the settlement increase on the left side of the runway was the most significant. In Condition 1, the settlement on the left side increased from -15.55 mm to -23.56 mm, while the settlement on the middle and right sides increased from -14.35 mm and -13.16 mm to -22.11 mm and -20.47 mm, respectively. In Condition 3, the settlement on the left side increased from -9.54 mm to -15.66 mm, while the settlement on the middle and right sides increased from -8.62 mm and -7.82 mm to -14.76 mm and -13.85 mm, respectively. In Condition 5, the settlement on the left side increased from -11.99 mm to -17.68 mm, while the settlement on the middle and right sides increased from -10.10 mm and -8.13 mm to -15.94 mm and -13.97 mm, respectively. The results indicate that the settlement increase on the left side of the runway was consistently higher than that on the middle and right sides during construction, making it a key monitoring area requiring strict settlement control measures.

[0166] Step S500: Substitute the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, and obtain the corresponding toughness evolution curve, wherein the toughness evolution curve characterizes the toughness change state of the airport runway structure at each construction stage.

[0167] In this embodiment, the dynamic settlement patterns of the left, center, and right sides of the runway during the excavation of ultra-large diameter shield tunnels were analyzed, revealing the settlement patterns under different burial depths and reinforcement measures. However, settlement itself is not only a measure of displacement but also a direct representation of changes in structural performance. Every settlement caused by proximity construction disturbance inevitably leads to a decrease in the overall performance of the runway structure. To more comprehensively assess the impact of ultra-large diameter shield tunneling on the safe operation of airport runways, it is insufficient to focus solely on settlement values. It is necessary to deeply analyze the actual impact of settlement on runway structural performance and establish corresponding performance characterization formulas, namely dynamic toughness values ​​and toughness evolution curves, to characterize the toughness changes of the airport runway structure at each construction stage.

[0168] In one implementation, substituting the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, and obtaining the corresponding toughness evolution curve, specifically includes the following steps:

[0169] Step S510: Substitute the dynamic settlement data into the toughness performance function to obtain the dynamic toughness value. The toughness performance function is:

[0170]

[0171] in, This is the dynamic toughness value. This represents the maximum allowable deformation of an airport runway when its structural performance fails. This refers to the actual deformation of the airport runway structure over time.

[0172] Step S520: Based on the calculated dynamic toughness value, plot the corresponding toughness evolution curve.

[0173] In this embodiment, the performance of the airport runway structure is first defined, considered as a key indicator for measuring the runway's resistance to deformation. An expression for this performance is derived. From the toughness performance function, it can be seen that when the airport runway structure converges its deformation... hour, This indicates that the airport runway structure has the best performance; with Gradually increase A decrease indicates that the structural performance of the airport runway is gradually deteriorating; when hour, This indicates structural performance failure.

[0174] Based on the toughness performance function, the maximum settlement values ​​for single and double-line excavation in Tables 10 and 11 can be calculated to obtain the toughness performance values, and dynamic toughness curves can be plotted as follows: Figure 7 (a) Figure 7 As shown in (b) of the diagram. Figure 7 (a) Figure 7 Figure (b) shows the dynamic toughness evolution curves of the left, middle, and right sides of the runway under single-track and double-track tunneling conditions (conditions one, three, and five), respectively. The horizontal axis represents the 10 construction steps (T1 to T10) in the tunneling process, and the vertical axis represents the toughness value. , and according to Divided into early warning domains ( ), control domain ( ), failure domain ( The figure shows three regions, with the curves corresponding to the toughness response of each side of the runway under different working conditions, clearly reflecting the dynamic change law of the toughness of the runway structure during the double-track tunnel crossing process.

[0175] During single-line tunneling, the toughness of each working condition continuously decreased with the construction sequence, but the toughness performance differentiated significantly: in Working Condition 1, the toughness of the left and right sides dropped from the warning domain (0.96, 1.00) to the control domain (0.24, 0.35), indicating significant disturbance; in Working Condition 3, all sides remained in the warning domain (0.54, 0.57, 0.61), showing the best stability; in Working Condition 5, the right side dropped to the control domain (0.42), while the left and middle sides remained in the warning domain (0.42, 0.51). During dual-line tunneling, the toughness evolution was more gradual, with all working conditions entering the control domain and the basic Working Condition 1 transitioning to the failure domain. In Working Condition 1, the left and right sides slowly dropped from the control domain (0.22, 0.34) to the failure domain (-0.18, -0.02), indicating that the runway structure had failed and required maintenance measures; in Working Conditions 3 and 5, all sides steadily dropped from the warning domain to the control domain with smaller fluctuations, with Working Condition 3 showing better control than Working Condition 5.

[0176] Step S600: Based on the dynamic toughness value, calculate the final toughness index, and determine the toughness level of the final settlement value, the differential settlement amount, and the final toughness index according to the control standard and the preset toughness level classification standard. The final toughness index characterizes the overall performance recovery capability of the structure.

[0177] In this embodiment, the purpose of calculating the final-state toughness index is to transform the dispersed dynamic toughness data throughout the construction process into a single quantitative indicator, centrally reflecting the overall performance recovery capability of the airport runway structure after the completion of the dual-track tunnel, avoiding the difficulty in summarizing fragmented dynamic data. Its function is to intuitively reflect the final performance state of the runway after construction disturbance, such as determining whether the structure still has the potential to restore safe use performance, providing a core basis for whether subsequent repair measures are needed. The purpose of the grading is to map the abstract final-state toughness index to clear grades, solving the problem that it is difficult to directly judge the structural safety level by only looking at the index value. Its function is to quickly compare the toughness effects of different construction conditions, identify the optimal control measures, and provide clear standards for engineering decisions; for example, without a toughness grade, construction parameters need to be adjusted, while a high toughness grade can verify the effectiveness of measures.

[0178] In one implementation, the step of calculating the final-state toughness index based on the dynamic toughness value, and determining the toughness level of the final settlement value, the differential settlement, and the final-state toughness index according to the control standard and the preset toughness level classification standard, specifically includes the following steps:

[0179] Step S610: Based on the dynamic toughness value, calculate the final-state toughness index, wherein the final-state toughness index... The calculation formula is:

[0180]

[0181] in, for The integral value within the preset time interval, As the baseline settlement impact, The length of the preset time interval;

[0182] Step S620: Based on the control standard, make a preliminary toughness determination on the final settlement value and the differential settlement amount;

[0183] Step S630: Based on the preset toughness level classification standard and the preliminary toughness judgment result, the final toughness index is classified into high toughness, medium toughness, low toughness, and no toughness.

[0184] In this embodiment, the toughness of the runway structure is evaluated based on the calculated dynamic toughness curve. This paper defines the toughness levels for runway structures, as shown in Table 12. Table 12 illustrates the toughness level classification of airport runway structures, where... Defined as the theoretical initial toughness of the runway structure when it is undisturbed ( ), and will , , It is defined as the boundary between high toughness, medium toughness, low toughness, and no toughness. Before classifying toughness levels based on the final-state toughness index, a preliminary toughness assessment of the final settlement value and the differential settlement amount is required based on control standards. If the preliminary assessment indicates no toughness, then the project can be directly considered to have caused structural failure.

[0185] Table 12

[0186]

[0187] The classification of the toughness level of airport runway structures should be determined based on existing practical cases or simulation test results. However, there are currently few comprehensive and systematic records of the structural performance changes of ultra-large diameter shield tunnels passing under airport runways over time, i.e., from initial toughness, to toughness decline, and then to the toughness stabilization stage. This results in a lack of referable engineering test data, making it difficult to provide the classification boundaries of each toughness level of airport runway structures based on actual engineering projects. In this embodiment, a calculation formula for the final state toughness index is specifically designed. Based on this calculation formula, the toughness of the runway is calculated and evaluated, and the toughness values ​​for each working condition are shown in Tables 13 and 14 below. Table 13 shows the toughness value and toughness level of the runway structure when single-line tunneling is completed, and Table 14 shows the toughness value and toughness level of the runway structure when double-line tunneling is completed.

[0188] Table 13

[0189]

[0190] Table 14

[0191]

[0192] Tables 13 and 14 show that the toughness of the runway structure varies significantly under different working conditions and locations. Under the single-line working condition, the right side of the runway exhibits the best toughness, with conditions three and five showing significant improvement compared to the basic working condition one, both achieving a high toughness level. The middle and left sides are mostly of medium toughness, such as the left side of condition one. The initial toughness was low, but due to the control measures in conditions three and five, the toughness recovered to medium toughness. Under the condition of double-line tunneling completion, the toughness values ​​at all locations were significantly lower, and the left side of the runway showed no toughness failure under the foundation condition, indicating the need for effective control measures. The overall toughness level was far worse than when the single-line tunnel was completed. Furthermore, under the same condition, the toughness level of the right side was generally higher than that of the left and middle areas, and the overall toughness of condition three was similar to that of condition five, proving that increasing the burial depth and 360° grouting reinforcement had similar control effects on the airport runway.

[0193] Therefore, the method provided in this embodiment differs from traditional methods. Traditional methods only use static indicators such as settlement amount and differential settlement amount as control standards (e.g., whether it exceeds 20mm). This method innovatively introduces the concept of toughness, using a toughness index... and This method dynamically and quantitatively describes the attenuation impact and recovery capacity of the runway structure's performance throughout the entire construction process, revealing the evolution law of the overall safety performance of the structural system. Furthermore, it provides a more scientific evaluation dimension. This method not only answers the question of the magnitude of settlement, but more importantly, it answers the question of the extent of damage such settlement causes to the runway structure's function, and whether the measures taken effectively restored its performance. It provides a completely new theoretical framework and analytical tool for safety risk assessment in underground engineering.

[0194] Furthermore, this method enables the quantitative comparison and selection of control measures. By simulating various working conditions such as different burial depths and grouting ranges, and evaluating their effectiveness using a unified toughness index, it demonstrates, for example, that 360° grouting is superior to 180° grouting, and that increasing the 2D burial depth yields the best results. This provides engineers with direct data support and decision-making basis for finding the optimal solution between safety, economy, and feasibility. It also guides dynamic control throughout the entire construction process, generating dynamic toughness curves. It can serve as an early warning system, reflecting the cumulative impact of construction steps on structural performance in real time. Once the toughness value is detected to drop rapidly to the warning range, tunneling parameters and grouting pressure can be adjusted promptly, achieving proactive and preventative intelligent construction control to avoid accidents.

[0195] In summary, under the technical solution of the above embodiments, by acquiring engineering information and post-construction settlement and differential settlement control standards, a three-dimensional finite element model containing multiple simulated working conditions and key characteristic sections is constructed. The settlement data is obtained by simulating shield tunneling, and the differential settlement, dynamic toughness value and evolution curve are calculated. Then, the final state toughness index is calculated and the level is determined. This can dynamically and quantitatively evaluate the runway toughness, clarify the structural performance degradation law, scientifically evaluate the effectiveness of control measures, provide a basis for construction optimization and engineering decision-making, and effectively address the safety assessment problem of ultra-large diameter shield tunnels passing under runways.

[0196] like Figure 8 As shown in the figure, this embodiment of the invention provides a toughness assessment system for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws. The system includes: a data acquisition module 10, a three-dimensional finite element model construction module 20, a dynamic settlement data and final settlement value acquisition module 30, a differential settlement calculation module 40, a toughness evolution curve calculation module 50, and a final state toughness index calculation and grade determination module 60.

[0197] Specifically, the data acquisition module 10 is used to acquire engineering information of the ultra-large diameter shield tunnel passing under the airport runway, and to determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications; the three-dimensional finite element model construction module 20 is used to construct a three-dimensional finite element model simulating the dynamic tunneling process of the shield based on the engineering information, wherein the three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation conditions and several key feature sections; the dynamic settlement data and final settlement value acquisition module 30 is used to simulate the sequential tunneling process of the shield tunnel through the constructed three-dimensional finite element model, and to acquire the dynamic settlement data of each key feature section under each simulation condition during the entire tunneling process and the final settlement value after the tunnel is completed; the differential settlement... The settlement calculation module 40 is used to calculate the differential settlement between each section under each simulated working condition based on the dynamic settlement data; the toughness evolution curve calculation module 50 is used to substitute the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, and obtain the corresponding toughness evolution curve, wherein the toughness evolution curve represents the toughness change state of the airport runway structure at each construction stage; the final state toughness index calculation and grade determination module 60 is used to calculate the final state toughness index based on the dynamic toughness value, and determine the toughness level of the final settlement value, the differential settlement, and the final state toughness index according to the control standard and the preset toughness level classification standard, wherein the final state toughness index represents the overall performance recovery capability of the structure.

[0198] Based on the above embodiments, the present invention also provides a terminal device, the principle block diagram of which can be as follows: Figure 9 As shown, the terminal device includes a processor, memory, network interface, display screen, and temperature sensor connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a toughness assessment method for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws. The display screen can be an LCD screen or an e-ink screen. The temperature sensor is pre-installed inside the terminal device to detect the operating temperature of the internal components.

[0199] Those skilled in the art will understand that Figure 9 The schematic diagram shown is only a partial structural diagram related to the present invention and does not constitute a limitation on the terminal device to which the present invention is applied. The specific terminal device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0200] In one embodiment, a terminal device is provided, including a memory and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by one or more processors. The one or more programs include instructions for performing the following operations:

[0201] Obtain engineering information on the project of an ultra-large diameter shield tunnel passing under an airport runway, and determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications.

[0202] Based on the engineering information, a three-dimensional finite element model is constructed to simulate the dynamic tunneling process of a shield tunnel. The three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation working conditions and several key feature sections.

[0203] The three-dimensional finite element model was constructed to simulate the sequential tunneling process of the shield tunnel and obtain the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed.

[0204] Based on the dynamic settlement data, the differential settlement between each section under each simulated working condition is calculated.

[0205] Substituting the dynamic settlement data into the toughness performance function, the dynamic toughness value of the airport runway structure under each simulated working condition during the entire construction process is calculated, and the corresponding toughness evolution curve is obtained. The toughness evolution curve represents the toughness change state of the airport runway structure at each construction stage.

[0206] Based on the dynamic toughness value, the final toughness index is calculated, and the toughness level is determined for the final settlement value, the differential settlement amount, and the final toughness index according to the control standard and the preset toughness level classification standard. The final toughness index characterizes the overall performance recovery capability of the structure.

[0207] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0208] In summary, this invention discloses a method, system, terminal equipment, and medium for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws. This relates to the field of shield tunneling technology. The method first acquires engineering information for an ultra-large diameter shield tunnel passing under an airport runway and determines the control standards for post-construction settlement and differential settlement of the airport runway based on engineering specifications. Then, based on the engineering information, a three-dimensional finite element model simulating the dynamic tunneling process of the shield is constructed. This three-dimensional finite element model reflects the interaction between the soil and the structure and includes several simulation conditions and several key feature sections. Next, the sequential tunneling process of the shield tunnel is simulated using the constructed three-dimensional finite element model, and the dynamic settlement data of each key feature section under each simulation condition during the entire tunneling process and the final settlement value after tunnel completion are obtained. Subsequently, based on the dynamic settlement data, the differential settlement between each section under each simulation condition is calculated. Subsequently, the dynamic settlement data is substituted into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, obtaining the corresponding toughness evolution curve. The toughness evolution curve characterizes the toughness change state of the airport runway structure at each construction stage. Finally, based on the dynamic toughness value, the final-state toughness index is calculated. According to the control standard and the preset toughness level classification standard, the final settlement value, the differential settlement amount, and the final-state toughness index are used to determine the toughness level. The final-state toughness index characterizes the overall performance recovery capability of the structure. This invention acquires engineering information and post-construction settlement and differential settlement control standards, constructs a three-dimensional finite element model containing multiple simulated working conditions and key characteristic sections, simulates shield tunneling to obtain settlement data, calculates differential settlement, dynamic toughness values ​​and evolution curves, and then calculates the final-state toughness index and determines the level. This allows for dynamic and final-state quantitative assessment of runway toughness, clarifies the structural performance degradation law, scientifically evaluates the effectiveness of control measures, provides a basis for construction optimization and engineering decision-making, and effectively addresses the safety assessment challenges of ultra-large diameter shield tunnels passing under runways.

[0209] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0210] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for assessing the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, characterized in that... The method includes: Obtain engineering information on the project of an ultra-large diameter shield tunnel passing under an airport runway, and determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications. Based on the engineering information, a three-dimensional finite element model is constructed to simulate the dynamic tunneling process of a shield tunnel. The three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation working conditions and several key feature sections. The three-dimensional finite element model was constructed to simulate the sequential tunneling process of the shield tunnel and obtain the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed. Based on the dynamic settlement data, the differential settlement between each section under each simulated working condition is calculated. Substituting the dynamic settlement data into the toughness performance function, the dynamic toughness value of the airport runway structure under each simulated working condition during the entire construction process is calculated, and the corresponding toughness evolution curve is obtained. The toughness evolution curve represents the toughness change state of the airport runway structure at each construction stage. Based on the dynamic toughness value, the final toughness index is calculated, and the toughness level is determined for the final settlement value, the differential settlement amount, and the final toughness index according to the control standard and the preset toughness level classification standard. The final toughness index characterizes the overall performance recovery capability of the structure. The construction of a three-dimensional finite element model simulating the dynamic tunneling process of a shield machine based on the engineering information includes: Mohr-Coulomb constitutive simulations were performed on the soil and rock masses involved in the project. Elastic constitutive simulation and elastic concrete layer simulation of airport runways; Plate unit simulation of the tunnel boring machine shell; Concrete material simulation was performed on the segment lining of the shield tunnel.

2. The method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, as described in claim 1, is characterized in that... The acquisition of engineering information for the ultra-large diameter shield tunnel project under the airport runway includes: Obtain the stratigraphic distribution and physical and mechanical parameters of the soil and rock mass at the engineering site; Obtain the design parameters of the tunnel boring machine, including the diameter, shell thickness, and mechanical parameters of the tunnel boring machine; Obtain tunnel design parameters, including tunnel burial depth, lining thickness, and material properties; Obtain construction parameters, including target support force, grouting pressure and range; Obtain the structural parameters of the airport runway, including the runway's dimensions and material properties. Obtain the relative spatial relationship between the tunnel and the runway.

3. The method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, as described in claim 1, is characterized in that... The simulated working conditions include basic working conditions, increased burial depth working conditions, and grouting reinforcement working conditions. The key feature sections include the left, middle, and right sections of the airport runway surface. The three-dimensional finite element model is configured with several simulated working conditions and several key feature sections, including: The basic working condition is set to the design burial depth working condition without reinforcement measures; The increased burial depth condition is set as a condition that increases the burial depth by 1D or 2D on the basis of the design burial depth, where D is the diameter of the tunnel boring machine; The grouting reinforcement condition is set to either 180° range grouting reinforcement or 360° range grouting reinforcement.

4. The method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, as described in claim 3, is characterized in that... The shield tunnel is a double-track shield tunnel. The constructed three-dimensional finite element model simulates the sequential excavation process of the shield tunnel and obtains dynamic settlement data of key characteristic sections under various simulated working conditions throughout the entire excavation process, as well as the final settlement value after tunnel completion. This includes: The three-dimensional finite element model was run to simulate the entire process of sequential tunneling of the shield double-track tunnel under various simulated working conditions. During the simulation, dynamic settlement data of three key characteristic sections of the airport runway surface—the left, middle, and right sections—were monitored and extracted in real time. After the two tunnels of the shield tunnel are completed, the final settlement value is obtained based on the dynamic settlement data.

5. The method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, as described in claim 1, is characterized in that... The process involves substituting the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition throughout the entire construction process, thereby obtaining the corresponding toughness evolution curve, including: Substituting the dynamic settlement data into the toughness performance function yields the dynamic toughness value, wherein the toughness performance function is: in, This is the dynamic toughness value. This represents the maximum allowable deformation of an airport runway when its structural performance fails. This refers to the actual deformation of the airport runway structure over time. Based on the calculated dynamic toughness values, the corresponding toughness evolution curves are plotted.

6. The method for evaluating the toughness of ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, as described in claim 5, is characterized in that... The step of calculating the final-state toughness index based on the dynamic toughness value, and determining the toughness level of the final settlement value, the differential settlement, and the final-state toughness index according to the control standard and the preset toughness level classification standard, includes: Based on the dynamic toughness value, the final-state toughness index is calculated. The calculation formula is: in, for The integral value within the preset time interval, As the baseline settlement impact, The length of the preset time interval; Based on the control criteria, a preliminary toughness assessment is made of the final settlement value and the differential settlement amount. Based on the preset toughness level classification standard and the preliminary toughness judgment result, the final toughness index is divided into high toughness, medium toughness, low toughness, and no toughness.

7. A toughness assessment system for ultra-large diameter shield tunnels crossing airport runways based on differential settlement and dynamic settlement laws, characterized in that, The system, applied to the steps of implementing the toughness assessment method for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws as described in any one of claims 1-6, comprises: The data acquisition module is used to acquire engineering information on the project of ultra-large diameter shield tunnel passing under the airport runway, and to determine the control standards for post-construction settlement and post-construction differential settlement of the airport runway based on engineering specifications. The three-dimensional finite element model construction module is used to construct a three-dimensional finite element model simulating the dynamic tunneling process of a shield tunnel based on the engineering information. The three-dimensional finite element model reflects the interaction between soil and structure, and the three-dimensional finite element model is set with several simulation working conditions and several key feature sections. The dynamic settlement data and final settlement value acquisition module is used to simulate the sequential tunneling process of the shield tunnel through the constructed three-dimensional finite element model, and to acquire the dynamic settlement data of each key feature section under each simulated working condition during the entire tunneling process and the final settlement value after the tunnel is completed. The differential settlement calculation module is used to calculate the differential settlement between each section under each simulated working condition based on the dynamic settlement data. The toughness evolution curve calculation module is used to substitute the dynamic settlement data into the toughness performance function to calculate the dynamic toughness value of the airport runway structure under each simulated working condition during the entire construction process, and obtain the corresponding toughness evolution curve. The toughness evolution curve represents the toughness change state of the airport runway structure at each construction stage. The final-state toughness index calculation and grade determination module is used to calculate the final-state toughness index based on the dynamic toughness value, and to determine the toughness level of the final settlement value, the differential settlement amount, and the final-state toughness index according to the control standard and the preset toughness level classification standard. The final-state toughness index characterizes the overall performance recovery capability of the structure.

8. A terminal device, characterized in that, The terminal device includes a memory, a processor, and a toughness assessment program for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws, stored in the memory and run on the processor. When the processor executes the toughness assessment program for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws, it implements the steps of the toughness assessment method for ultra-large diameter shield tunneling under airport runways based on differential settlement and dynamic settlement laws as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a toughness assessment program for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws. When the processor executes the toughness assessment program for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws, it implements the steps of the toughness assessment method for ultra-large diameter shield tunnels passing under airport runways based on differential settlement and dynamic settlement laws as described in any one of claims 1-6.

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