A method, apparatus, equipment, and storage medium for calculating surrounding rock pressure in loess shield tunnels.

Abstract

This specification discloses a method, apparatus, equipment, and storage medium for calculating the surrounding rock pressure of a loess shield tunnel, relating to the field of tunnel engineering technology. The scheme includes: acquiring several sets of working condition data for the loess shield tunnel, the working condition data being used to characterize the water content of the loess layer and the tunnel burial depth; inputting each set of working condition data into a numerical simulation model of surrounding rock stress to obtain surrounding rock stress data for each set of working condition data; the numerical simulation model of surrounding rock stress is established using experimental data from loess shield tunnel model tests combined with finite element software; determining the surrounding rock pressure type of each set of working condition data based on the surrounding rock stress data; and calculating the surrounding rock pressure of the loess shield tunnel based on all surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types, thereby improving the accuracy of the surrounding rock pressure calculation for the loess shield tunnel and providing accurate guidance for the design of loess shield tunnels.

Description

Technical Field

[0001] This application relates to the field of tunnel engineering technology, and in particular to a method, apparatus, equipment and storage medium for calculating the surrounding rock pressure of a loess shield tunnel. Background Technology

[0002] Surrounding rock pressure is the pressure generated at the contact surface between the support and the surrounding rock during the stress redistribution process caused by the disturbance of the rock mass. It is the force that causes deformation or damage to the surrounding rock mass and support in the underground excavation space.

[0003] In related technologies, the calculation method for surrounding rock pressure in loess tunnels is based on that used for mountain tunnels. However, due to significant differences between loess tunnels and mountain tunnels in terms of the timing of shield tunneling support, construction disturbance, and cross-sectional shape, the accuracy of surrounding rock pressure calculation in loess shield tunnels cannot be guaranteed, thus failing to accurately guide the design of loess shield tunnels. Summary of the Invention

[0004] This specification provides an embodiment of a method for calculating the surrounding rock pressure of loess shield tunnels, in order to solve the problem that the existing technology cannot guarantee the accuracy of the surrounding rock pressure of loess shield tunnels and cannot accurately guide the design of loess shield tunnels.

[0005] To solve the above-mentioned technical problems, the embodiments in this specification are implemented as follows:

[0006] Firstly, the embodiments of this specification provide a method for calculating the surrounding rock pressure of a loess shield tunnel, including:

[0007] Several sets of working condition data for loess shield tunnels are obtained, and the working condition data are used to characterize the water content of the loess layer and the tunnel burial depth of the loess shield tunnel.

[0008] Each set of working condition data is input into the surrounding rock stress numerical simulation model to obtain the surrounding rock stress data for each set of working condition data; the surrounding rock stress numerical simulation model is established by combining the test data of the loess shield tunnel model test with finite element software;

[0009] Based on the surrounding rock stress data, determine the type of surrounding rock pressure for each set of working condition data;

[0010] The surrounding rock pressure of the loess shield tunnel is calculated based on all the surrounding rock pressure algorithms corresponding to all the aforementioned surrounding rock pressure types.

[0011] Secondly, the embodiments of this specification provide a device for calculating the surrounding rock pressure of a loess shield tunnel, comprising:

[0012] The working condition data acquisition module is used to acquire several sets of working condition data for the loess shield tunnel. The working condition data is used to characterize the water content of the loess layer and the tunnel burial depth of the loess shield tunnel.

[0013] The surrounding rock stress data determination module is used to input each set of working condition data into the surrounding rock stress numerical simulation model to obtain the surrounding rock stress data for each set of working condition data; the surrounding rock stress numerical simulation model is established by combining the test data of the loess shield tunnel model test with finite element software;

[0014] The surrounding rock pressure type determination module is used to determine the surrounding rock pressure type of each set of working condition data based on the surrounding rock stress data.

[0015] The surrounding rock pressure calculation module is used to calculate the surrounding rock pressure of the loess shield tunnel according to all the surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

[0016] Thirdly, the embodiments of this specification provide a device for calculating the surrounding rock pressure of a loess shield tunnel, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the method for calculating the surrounding rock pressure of a loess shield tunnel in Scheme 1.

[0017] Fourthly, the embodiments of this specification provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for calculating the surrounding rock pressure of the loess shield tunnel in Scheme 1.

[0018] One embodiment of this specification achieves the following beneficial effects: by inputting the working condition data characterizing the water content of the loess layer and the tunnel burial depth of the loess shield tunnel into the experimental data based on the loess shield tunnel model test and the numerical simulation model of surrounding rock stress established by finite element software, surrounding rock stress data is obtained. Based on the surrounding rock stress data, the type of surrounding rock pressure of the loess shield tunnel is determined. By using the surrounding rock pressure algorithm corresponding to the type of surrounding rock pressure of the loess shield tunnel, the surrounding rock pressure of the loess shield tunnel is calculated, thereby improving the accuracy of the surrounding rock pressure of the loess shield tunnel and providing accurate guidance for the design of loess shield tunnels. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1A flowchart illustrating a method for calculating the surrounding rock pressure of a loess shield tunnel, provided as an embodiment of this specification;

[0021] Figure 2 This is a schematic diagram showing the relative position of the bearing area and the ground surface as provided in the embodiments of this specification;

[0022] Figure 3 A schematic diagram of the elastic-plastic stress state of the surrounding rock provided in the embodiments of this specification;

[0023] Figure 4 This is an illustration of an application scenario of a method for calculating the surrounding rock pressure of a loess shield tunnel provided in the embodiments of this specification;

[0024] Figure 5 This is a schematic diagram summarizing the model test stress data and numerical simulation stress data presented in the embodiments of this specification;

[0025] Figure 6 A schematic diagram of the structure of a surrounding rock pressure calculation device for a loess shield tunnel provided in the embodiments of this specification;

[0026] Figure 7 This is a schematic diagram of the structure of a rock pressure calculation device for a loess shield tunnel, provided as an embodiment of this specification. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of one or more embodiments of this specification clearer, the technical solutions of one or more embodiments of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of one or more embodiments of this specification.

[0028] Loess layers possess characteristics such as strong structural integrity and water sensitivity. Moisture content is a crucial factor determining the surrounding rock load, while burial depth is a significant factor affecting tunnel structural safety. Therefore, under the combined effects of different moisture contents and burial depths, the zoning of the surrounding rock zone, characterizing the degree of disturbance during shield tunneling, is rather ambiguous. This makes it difficult to determine the appropriate formula for calculating the surrounding rock pressure in loess shield tunnels under different working conditions, resulting in poor accuracy of the obtained surrounding rock pressure readings.

[0029] In order to overcome the deficiencies in the prior art, the technical solutions provided by the various embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0030] The method for calculating the surrounding rock pressure of a loess shield tunnel, as provided in the embodiments of the specification, will be explained in detail with reference to the accompanying drawings.

[0031] Figure 1 This is a flowchart illustrating a method for calculating surrounding rock pressure in a loess shield tunnel, as provided in an embodiment of this specification. From a programming perspective, the entity executing the process can be a program hosted on an application server or an application client. From a hardware perspective, the entity executing the process can be a terminal device; this embodiment does not impose any particular limitation on this.

[0032] like Figure 1 As shown, the process may include the following steps:

[0033] Step 110: Obtain several sets of working condition data for the loess shield tunnel, which are used to characterize the water content of the loess layer and the tunnel burial depth.

[0034] In the embodiments of this specification, the working condition data may include soil moisture content, tunnel burial depth, shield material properties, segment material properties, etc., wherein material properties may include cohesion, internal friction angle, etc.

[0035] In practical applications, the working parameters of loess shield tunnels are determined comprehensively based on specific geological survey results, design requirements, and construction conditions.

[0036] Step 120: Input each set of working condition data into the surrounding rock stress numerical simulation model to obtain the surrounding rock stress data for each set of working condition data; the surrounding rock stress numerical simulation model is established by combining the test data of the loess shield tunnel model test with finite element software.

[0037] In the embodiments of this specification, the water content and burial depth parameters in the finite element model are adjusted according to the selected working condition data. A set of data is selected as input, the adjusted model is run in the finite element software, the surrounding rock stress is calculated, and the surrounding rock stress data in the calculation results is extracted and saved. The surrounding rock stress data can be obtained quickly and accurately through the numerical simulation model of surrounding rock stress.

[0038] Step 130: Determine the type of surrounding rock pressure for each set of working condition data based on the surrounding rock stress data.

[0039] In the embodiments of this specification, the types of surrounding rock pressure in tunnels mainly include loosening pressure, deformation pressure, expansion pressure, and impact pressure.

[0040] In practical applications, the surrounding rock stress data corresponding to each set of working condition data can be analyzed manually or using analysis software. The surrounding rock stress data can include radial stress and circumferential stress. Based on the surrounding rock stress data, the deformation characteristics of the surrounding rock can be preliminarily determined. For example, if the radial stress of the surrounding rock decreases significantly while the circumferential stress increases, it may indicate that the surrounding rock is undergoing shear failure or tensile failure, which is usually related to loosening pressure. If the stress state of the surrounding rock is relatively stable but gradually increases over time, it may indicate that the surrounding rock is undergoing plastic deformation, which is usually related to deformation pressure.

[0041] Step 140: Calculate the surrounding rock pressure of the loess shield tunnel according to all the surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

[0042] In the embodiments of this specification, the surrounding rock pressure algorithm corresponding to the type of surrounding rock pressure is selected. The specific parameters of the loess shield tunnel (such as the unit weight of the surrounding rock, the tunnel burial depth, the mechanical properties of the loess, etc.) are input into the selected algorithm for calculation, which can accurately obtain the surrounding rock pressure of the loess shield tunnel and provide accurate guidance for the design of loess shield tunnels.

[0043] It should be understood that the order of some steps in the methods described in one or more embodiments of this specification may be interchanged according to actual needs, or some steps may be omitted or deleted.

[0044] In the embodiments of this specification, the working condition data characterizing the water content of the loess layer and the tunnel burial depth of the loess shield tunnel are input into the test data based on the loess shield tunnel model test and combined with the surrounding rock stress numerical simulation model established by the finite element software to calculate the surrounding rock pressure of the loess shield tunnel. The accuracy of the surrounding rock pressure of the loess shield tunnel is improved by the surrounding rock stress numerical simulation model, thereby providing accurate guidance for the design of loess shield tunnels.

[0045] based on Figure 1 In addition to the method described in the embodiments of this specification, some specific implementation schemes of the method are also provided, which will be described below.

[0046] Optionally, before inputting each set of working condition data into the numerical simulation model of surrounding rock stress as described in the embodiments of this specification, the method may further include:

[0047] A test chamber for constructing a model test of a loess shield tunnel;

[0048] Pressure data of the loess shield tunnel is obtained based on the pressure sensors installed inside the test chamber;

[0049] The pressure data is combined with finite element software to obtain the numerical simulation model of the surrounding rock stress.

[0050] In the embodiments of this specification, a test soil sample similar to the strata traversed by loess shield tunnels in actual engineering can be used, prepared with a ratio of quartz sand: remolded loess: quicklime: kaolin = 0.9:0.07:0.01:0.02. The test soil sample is filled into a test chamber, and pressure sensors are simultaneously placed in the test soil sample to monitor changes in surrounding rock stress. Then, a shield excavation test is conducted using an indoor shield tunneling device.

[0051] Based on the characteristics and simulation requirements of loess shield tunnels, appropriate finite element software, such as ANSYS and ABAQUS, is selected. The software is configured and set as necessary, such as material properties and boundary conditions. The pressure data is imported into the finite element software, and a corresponding three-dimensional model, namely the numerical simulation model of surrounding rock stress, is constructed in the finite element software according to the actual structure and size of the loess shield tunnel.

[0052] In practical applications, the distribution of surrounding rock pressure in loess shield tunnels varies under different working conditions. Specifically, the surrounding rock pressure changes with tunnel depth and loess moisture content. Therefore, loess shield tunneling model tests are conducted for different working conditions. The tests simulate the tunneling process of a shield machine in loess by using a servo-driven tunneling system to excavate within a test chamber. By comparing and verifying the stress data obtained from the loess shield tunneling model tests with those from the surrounding rock stress numerical simulation model, the parameters of the surrounding rock stress numerical simulation model can be optimized, ensuring its accuracy.

[0053] The parameters of the numerical simulation model for surrounding rock stress include data on surrounding rock, shield shell properties, and segment properties. The Drucker-Prager (DP) strength criterion is used for the strata, and the elastic constitutive model is used for the segments. Loess shield tunneling model tests are conducted, and the model test parameters are shown in Table 1.

[0054] Table 1 Model Test Parameters

[0055]

[0056] Optionally, the method of determining the type of surrounding rock pressure for each set of working condition data based on the surrounding rock stress data in the embodiments of this specification may specifically include:

[0057] The surrounding rock stress data is divided according to a preset surrounding rock zoning algorithm to obtain the surrounding rock zoning for each set of working condition data; wherein, the surrounding rock zoning includes at least one of loosening zone, plastic zone, elastic zone and original rock stress zone, and the preset surrounding rock zoning algorithm includes surrounding rock zoning criteria;

[0058] Based on the surrounding rock zoning, determine the surrounding rock pressure type for each set of working condition data.

[0059] In the embodiments of this specification, the type of surrounding rock pressure for each set of working condition data is determined based on the identified surrounding rock zoning. Different zoning can characterize the degree of disturbance of the surrounding rock. The surrounding rock zoning may include plastic zone I (loosening zone), plastic zone II (plastic zone), elastic zone and original rock stress zone.

[0060] The boundary of the loosened zone is the distance from the boundary of the tunnel excavation chamber to the intersection of the circumferential stress and the original rock stress; the boundary of the plastic zone is the distance from the boundary of the tunnel excavation chamber to the extreme point of the circumferential stress; and the boundary of the elastic zone is the distance from the boundary of the excavation chamber to the point where the circumferential stress recovers to the original rock stress.

[0061] In practical applications, if the surrounding rock zoning corresponding to the same set of working condition data contains multiple regions (such as both loosened and plastic zones), the influence of these regions needs to be considered comprehensively to determine the final type of surrounding rock pressure.

[0062] Optionally, the method of determining the surrounding rock pressure type for each set of working condition data based on the surrounding rock zoning described in the embodiments of this specification may specifically include:

[0063] Determine whether the surrounding rock zoning includes the loosened zone;

[0064] If so, then the surrounding rock pressure type of each set of working condition data is determined to be loosened surrounding rock pressure;

[0065] If not, then the surrounding rock pressure type of each set of working condition data is determined to be deformation surrounding rock pressure.

[0066] In the embodiments of this specification, it is determined whether these partitions include loosened areas. Loosened areas usually indicate that the surrounding rock has undergone significant loosening and damage, and are areas with poor surrounding rock stability.

[0067] If the surrounding rock zoning includes a loosened zone, it can be determined that the surrounding rock pressure type corresponding to this set of working conditions is loosened surrounding rock pressure. Loosened surrounding rock pressure is mainly caused by the loosening and failure of the surrounding rock, and usually requires strengthening of the support structure to ensure the stability of the tunnel.

[0068] If the surrounding rock zoning does not include a loose zone, it can be determined that the type of surrounding rock pressure corresponding to this set of working conditions is deformation surrounding rock pressure. Deformation surrounding rock pressure is mainly caused by the plastic deformation of the surrounding rock, and this deformation usually stabilizes gradually under the action of the support structure.

[0069] Based on the surrounding rock zoning, the type of surrounding rock pressure in each set of working condition data is determined, providing strong technical support for the construction and support design of loess shield tunnels.

[0070] In practical applications, the stress of the surrounding rock before excavation is taken as the original rock stress, which is the initial stress. If the circumferential stress output by the numerical simulation model of surrounding rock stress is consistently less than the initial stress, it is considered that the surrounding rock has a plastic zone I, i.e., a loosened zone, and the type of surrounding rock pressure is considered to be loosened surrounding rock pressure. If the circumferential stress output by the numerical simulation model of surrounding rock stress is consistently greater than the initial stress, it is considered that the surrounding rock has not formed a plastic zone I, i.e., there is no loosened zone, and the type of surrounding rock pressure is considered to be deformed surrounding rock pressure.

[0071] Further, optionally, in the embodiments of this specification, if the surrounding rock zoning includes the plastic zone and / or the elastic zone, the plastic zone and the elastic zone are taken as the bearing zone, and the determination of the surrounding rock pressure type of each set of working condition data as deformation surrounding rock pressure may specifically include:

[0072] Determine whether the bearing zone of the surrounding rock partition penetrates the ground surface;

[0073] If so, then the surrounding rock pressure type of each set of working condition data is determined to be shallow buried loosened surrounding rock pressure;

[0074] If not, then the surrounding rock pressure type of each set of working condition data is determined to be deep-buried loosened surrounding rock pressure.

[0075] In the embodiments of this specification, the specific location, range and depth of the plastic zone and elastic zone as the bearing zone can be determined according to the preset surrounding rock zoning algorithm. Whether the bearing zone penetrates the ground surface is determined by comparing the top position of the bearing zone with the position of the ground surface.

[0076] Figure 2 This is a schematic diagram showing the relative position of the bearing area and the ground surface as provided in the embodiments of this specification.

[0077] like Figure 2 As shown, if the bearing zone penetrates the surface, it means that there is not enough overburden above the tunnel to provide sufficient pressure support. Therefore, the surrounding rock around the tunnel may be more susceptible to loosening and damage. It can be determined that the type of surrounding rock pressure corresponding to this set of working conditions is shallow buried loosened surrounding rock pressure.

[0078] If the bearing zone does not penetrate the surface, it means that there is enough overburden above the tunnel to provide pressure support, and the surrounding rock around the tunnel may be relatively stable. It can be determined that the type of surrounding rock pressure corresponding to this set of working conditions is deep-buried loosened surrounding rock pressure.

[0079] Based on the preset surrounding rock zoning algorithm, the location, extent, and relative position of each zoning zone with respect to the tunnel can be obtained. Furthermore, the regional boundary values ​​of each surrounding rock zoning zone can be obtained. Table 2 shows the boundary values ​​of the loosened zone, plastic zone, and elastic zone of the surrounding rock under different working conditions. In this table, D represents the tunnel cross-section width, "∞" indicates that the bearing zone has developed to the surface, L represents the boundary value of the loosened zone, P represents the boundary value of the plastic zone, and E represents the boundary value of the elastic zone.

[0080] Table 2 Boundary values ​​of loosened zone, plastic zone, and elastic zone of surrounding rock under different working conditions.

[0081]

[0082]

[0083] By determining whether the surrounding rock zoning includes a loosened zone and whether the bearing zone of the surrounding rock zoning penetrates the surface, the type of surrounding rock pressure can be determined. Based on the boundary values ​​of the loosened zone, plastic zone, and elastic zone of the surrounding rock under different working conditions in Table 2, the type of surrounding rock pressure under different working conditions can be determined.

[0084] Table 3. Types of surrounding rock pressure under different working conditions

[0085] Operating conditions 1.5D 2.25D 3D 3.75D 9.6％ Deformation surrounding rock pressure Deformation surrounding rock pressure Pressure of deeply buried loose surrounding rock Pressure of deeply buried loose surrounding rock 18.6％ Pressure of shallowly buried loosened surrounding rock Pressure of shallowly buried loosened surrounding rock Pressure of deeply buried loose surrounding rock Pressure of deeply buried loose surrounding rock 27.6％ Pressure of shallowly buried loosened surrounding rock Pressure of shallowly buried loosened surrounding rock Pressure of deeply buried loose surrounding rock Pressure of deeply buried loose surrounding rock

[0086] In practical applications, the stress data of both the plastic zone II and the elastic zone are higher than the initial stress, so they are collectively referred to as the bearing zone. When the circumferential stress output by the numerical simulation model of surrounding rock stress is always greater than the initial stress, the surrounding rock is considered to always be in the bearing zone. When the burial depth is relatively shallow and the outer boundary of the bearing zone has reached the surface, the bearing zone is considered to have developed to the surface, that is, the type of surrounding rock pressure is shallow-buried loosened surrounding rock pressure.

[0087] Optionally, before calculating the surrounding rock pressure of the loess shield tunnel according to all surrounding rock pressure algorithms corresponding to all the aforementioned surrounding rock pressure types as described in the embodiments of this specification, the method may further include:

[0088] Establish the correspondence between the surrounding rock pressure type and the surrounding rock pressure algorithm, wherein the surrounding rock pressure algorithm includes at least one of the Fenner formula, the soil column formula and the Beer Bowman formula.

[0089] In the embodiments of this specification, for each type of surrounding rock pressure, a suitable surrounding rock pressure algorithm needs to be selected or determined for calculation. Based on the output results of the numerical simulation model of surrounding rock stress, the correspondence between the surrounding rock pressure type and the surrounding rock pressure algorithm can be established in advance.

[0090] The deformation-induced surrounding rock pressure can be calculated using the modified Fenner formula, which is:

[0091]

[0092] Where P is the surrounding rock pressure; P0 is the initial stress; and c is the surrounding rock cohesion. R is the internal friction angle; R0 is the tunnel excavation radius; R p The radius of the plastic zone.

[0093] The soil column formula can be used to calculate the pressure of shallowly buried loose surrounding rock. The soil column formula is as follows:

[0094] P = γH, where γ is the unit weight of the surrounding rock and H is the tunnel depth.

[0095] The pressure of deeply buried loosened surrounding rock can be calculated using the Beer-Bauman formula, which is as follows:

[0096]

[0097] in,

[0098] D is the tunnel cross-sectional width, H t This refers to the tunnel cross-sectional height.

[0099] Furthermore, when the surrounding rock pressure type is deep-buried loosened surrounding rock pressure, the choice can be made whether to superimpose the surrounding rock pressure algorithm based on the water content in the working condition data. The natural water content can be used as a benchmark; water content greater than the natural water content is considered high water content, and water content equal to or less than the natural water content is considered low water content. For example, using 18.6% as the natural water content benchmark, 9.6% in Table 3 is considered low water content, and 27.6% is considered high water content.

[0100] The pressure of deeply buried loosened surrounding rock under low water content can be calculated using the Beer-Bauman formula, while the pressure under high water content can be calculated using a superposition formula. The superposition formula is as follows:

[0101] P = P l +P i P l =γ×R l

[0102] ,, Among them, R l The radius of the loosened area, α and k are the material parameters of the DP criterion.

[0103] Furthermore, when the tunnel is buried at a greater depth, such as more than 3D, and the moisture content reaches the natural moisture content, a superposition formula can be used.

[0104] By identifying the correspondence between the type of surrounding rock pressure and the algorithm for surrounding rock pressure, the algorithm for surrounding rock pressure can be determined. Based on the type of surrounding rock pressure under different working conditions in Table 3, the corresponding algorithm for surrounding rock pressure can be determined.

[0105] Table 4. Algorithm for surrounding rock pressure under different working conditions

[0106] Operating conditions 1.5D 2.25D 3D 3.75D 9.6％ Fenner's formula Fenner's formula Bill Bowman Formula Bill Bowman Formula 18.6％ soil column formula Bill Bowman Formula Bill Bowman Formula Superposition formula 27.6％ soil column formula Bill Bowman Formula Superposition formula Superposition formula

[0107] In practical applications, the surrounding rock pressure results calculated by the numerical simulation model of surrounding rock stress need to be compared and verified with the test data provided by the loess shield tunnel model test. If the calculation results differ significantly from the actual situation, the algorithm needs to be adjusted or a new algorithm needs to be selected.

[0108] If a tunnel experiences multiple types of surrounding rock pressure simultaneously, each type needs to be calculated separately, taking into account their interactions and influences. The total surrounding rock pressure of the loess shield tunnel can then be obtained by superimposing or comprehensively considering all the pressures. In practical engineering, a combination of methods and approaches can also be used for comprehensive analysis and judgment.

[0109] Optionally, the preset surrounding rock zoning algorithm described in the embodiments of this specification includes standard stress data used to characterize the division basis of the surrounding rock zoning. The step of dividing the surrounding rock stress data according to the preset surrounding rock zoning algorithm to obtain the surrounding rock zoning for each set of working condition data may specifically include:

[0110] Based on the matching results between the surrounding rock stress data and the standard stress data, the surrounding rock zoning for each set of working condition data is obtained.

[0111] In the embodiments described in this specification, based on geomechanical principles, engineering experience, and numerical simulation results, standard stress data is obtained to divide the surrounding rock into different regions to reflect its degree of disturbance and stability. The standard stress data may include the boundary stress values ​​of each surrounding rock zone. By matching the surrounding rock stress data with the standard stress data, the surrounding rock zones for each set of working conditions can be obtained.

[0112] Figure 3 This is a schematic diagram of the elastoplastic stress state of the surrounding rock provided in the embodiments of this specification.

[0113] By matching the stress data output from the numerical simulation model of surrounding rock stress with standard stress data, the surrounding rock can be divided into plastic zone I (loosening zone), plastic zone II (plastic zone), elastic zone, and original rock stress zone. For example... Figure 3 As shown, σ is the stress; r is the partition radius; p0 is the initial stress; σ θ For circumferential stress; σ r This is radial stress.

[0114] The numerical simulation model of surrounding rock stress outputs a data sequence of surrounding rock stress data under working conditions from near to far from the tunnel. The maximum value of the circumferential stress in the data sequence is the stress extremum point. The data sequence is divided into a front data sequence and a back data sequence with the stress extremum point as the dividing point. The first circumferential stress that appears in the back data sequence that is closest to the initial stress is the stress intersection point.

[0115] The region corresponding to the circumferential stress less than or equal to the initial stress in the previous data sequence is designated as the plastic zone I (loosening zone). The region corresponding to the circumferential stress greater than the initial stress but less than or equal to the stress extremum point in the previous data sequence is designated as the plastic zone II (plastic zone). The region corresponding to the circumferential stress less than the stress extremum point but greater than or equal to the stress intersection point in the subsequent data sequence is designated as the elastic zone. The region outside the outer boundary of the elastic zone is designated as the original rock stress zone.

[0116] Figure 4 This is a schematic diagram illustrating an application scenario of a method for calculating the surrounding rock pressure of a loess shield tunnel, as provided in the embodiments of this specification.

[0117] In practical applications, the surrounding rock stress data obtained through loess shield tunneling model tests and numerical simulation models of surrounding rock stress can be compared and verified to ensure the accuracy of the numerical simulation models. Due to the strong structural and water-sensitive characteristics of loess layers, different calculation methods are required for surrounding rock pressure at different water contents and burial depths.

[0118] For ease of understanding, such as Figure 4 As shown, step 401: Test data of surrounding rock stress can be obtained through loess shield tunneling model tests, and a numerical simulation model of surrounding rock stress can be established based on the test data;

[0119] Step 402: The numerical simulation model of surrounding rock stress outputs surrounding rock stress data;

[0120] Step 403: Analyze the surrounding rock stress data according to the preset surrounding rock zoning algorithm to obtain the surrounding rock zoning;

[0121] Step 404: Determine whether the surrounding rock zoning includes a loosened zone;

[0122] Step 405: If not, then determine the type of surrounding rock pressure as deformation surrounding rock pressure;

[0123] Step 406: If yes, then determine the type of surrounding rock pressure as loosened surrounding rock pressure;

[0124] Step 407: Determine whether the bearing area penetrates the ground surface;

[0125] Step 408: If not, then determine the type of surrounding rock pressure as deep-buried loosened surrounding rock pressure;

[0126] Step 409: If yes, then determine the type of surrounding rock pressure as shallowly buried loosened surrounding rock pressure;

[0127] Step 410: Based on the pre-set correspondence between the surrounding rock pressure type and the surrounding rock pressure algorithm, determine the surrounding rock pressure algorithm corresponding to different surrounding rock pressure types, and calculate the surrounding rock pressure of the loess shield tunnel.

[0128] Figure 5 This is a schematic diagram summarizing the stress data from model tests and numerical simulations presented in the embodiments of this specification.

[0129] The stress data obtained from loess shield tunneling model tests and surrounding rock stress numerical simulation models under different working conditions can be statistically summarized, compared, and analyzed. Figure 5 It can be seen that the numerical simulation results are in good agreement with the model test, verifying the reliability of using numerical simulation to calculate the surrounding rock pressure of loess shield tunnels.

[0130] In practical applications, by inputting the working condition data characterizing the loess layer moisture content and tunnel burial depth of the loess shield tunnel into the experimental data based on the loess shield tunnel model test and combining it with the numerical simulation model of surrounding rock stress established by finite element software, the surrounding rock stress data is obtained. Based on the surrounding rock stress data, the type of surrounding rock pressure of the loess shield tunnel is determined. By using the surrounding rock pressure algorithm corresponding to the surrounding rock pressure type of the loess shield tunnel, the surrounding rock pressure of the loess shield tunnel is calculated, thereby improving the accuracy of the surrounding rock pressure of the loess shield tunnel and providing accurate guidance for the design of loess shield tunnels.

[0131] Figure 6 This is a schematic diagram of the structure of a surrounding rock pressure calculation device for a loess shield tunnel proposed in an embodiment of this specification.

[0132] The surrounding rock pressure calculation device for loess shield tunnels described in the embodiments of this specification may include:

[0133] The working condition data acquisition module 602 is used to acquire several sets of working condition data for the loess shield tunnel. The working condition data is used to characterize the water content of the loess layer and the tunnel burial depth of the loess shield tunnel.

[0134] The surrounding rock stress data determination module 604 is used to input each set of working condition data into the surrounding rock stress numerical simulation model to obtain the surrounding rock stress data for each set of working condition data; the surrounding rock stress numerical simulation model is established by combining the test data of the loess shield tunnel model test with finite element software;

[0135] The surrounding rock pressure type determination module 606 is used to determine the surrounding rock pressure type of each set of working condition data based on the surrounding rock stress data.

[0136] The surrounding rock pressure calculation module 608 is used to calculate the surrounding rock pressure of the loess shield tunnel according to all the surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

[0137] Based on the same idea, this specification also provides devices corresponding to the above methods in its embodiments.

[0138] Figure 7 This is a schematic diagram of a device for calculating the surrounding rock pressure of a loess shield tunnel, provided as an embodiment of this specification. Figure 7 As shown in the embodiments of this specification, a device for calculating the surrounding rock pressure of a loess shield tunnel includes a memory 730, a processor 710, and a computer program 720 stored in the memory. The processor 710 executes the computer program 720 to implement the method for calculating the surrounding rock pressure of a loess shield tunnel described in any of the above embodiments.

[0139] The embodiments of this specification provide a device for calculating the surrounding rock pressure of a loess shield tunnel, which may include a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the method for calculating the surrounding rock pressure of a loess shield tunnel as described in any of the above embodiments.

[0140] This specification provides a computer-readable storage medium storing a computer program that, when executed by a processor, can implement the method for calculating the surrounding rock pressure of a loess shield tunnel as described in any of the above embodiments.

[0141] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, for... Figure 7 As the device shown is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0142] In the 1990s, improvements to a technology could be clearly distinguished as either hardware improvements (e.g., improvements to the circuit structure of diodes, transistors, switches, etc.) or software improvements (improvements to the methodology). However, with technological advancements, many methodological improvements today can be considered direct improvements to the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved methodology into the hardware circuit. Therefore, it cannot be said that a methodological improvement cannot be implemented using hardware physical modules. For example, a Programmable Logic Device (PLD) (such as a Field Programmable Gate Array (FPGA)) is such an integrated circuit whose logic function is determined by the user programming the device. Designers can program and "integrate" a digital system onto a PLD themselves, without needing chip manufacturers to design and manufacture dedicated integrated circuit chips. Furthermore, nowadays, instead of manually manufacturing integrated circuit chips, this programming is mostly implemented using "logic compiler" software. Similar to the software compiler used in program development, the original code before compilation must be written in a specific programming language, called a Hardware Description Language (HDL). There are many HDLs, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, and RHDL (Ruby Hardware Description Language). Currently, the most commonly used are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should understand that by simply performing some logic programming on the method flow using one of these hardware description languages ​​and programming it into an integrated circuit, the hardware circuit implementing the logical method flow can be easily obtained.

[0143] The controller can be implemented in any suitable manner. For example, it can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicon Labs C8051F320. A memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also recognize that, in addition to implementing the controller in purely computer-readable program code form, the same functionality can be achieved by logically programming the method steps to make the controller take the form of logic gates, switches, ASICs, programmable logic controllers, and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the means included therein for implementing various functions can also be considered as structures within the hardware component. Alternatively, the means for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0144] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0145] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0146] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0147] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0148] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0149] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0150] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0151] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0152] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0153] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0154] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0155] This application can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0156] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for calculating the surrounding rock pressure of a loess shield tunnel, characterized in that, include: Several sets of working condition data for loess shield tunnels are obtained, and the working condition data are used to characterize the water content of the loess layer and the tunnel burial depth of the loess shield tunnel. Each set of working condition data is input into the surrounding rock stress numerical simulation model to obtain the surrounding rock stress data for each set of working condition data. The numerical simulation model of surrounding rock stress was established using experimental data from the loess shield tunnel model test combined with finite element software. Based on the surrounding rock stress data, the surrounding rock pressure type of each set of working condition data is determined; specifically, this includes: dividing the surrounding rock stress data according to a preset surrounding rock zoning algorithm to obtain surrounding rock zoning for each set of working condition data; wherein, the surrounding rock zoning includes at least one of loosened zone, plastic zone, elastic zone, and original rock stress zone, and the preset surrounding rock zoning algorithm includes surrounding rock zoning criteria; and based on the surrounding rock zoning, the surrounding rock pressure type of each set of working condition data is determined. The surrounding rock pressure of the loess shield tunnel is calculated based on all the surrounding rock pressure algorithms corresponding to all the aforementioned surrounding rock pressure types.

2. The method according to claim 1, characterized in that, Before inputting each set of working condition data into the numerical simulation model of surrounding rock stress, the method further includes: A test chamber for constructing a model test of a loess shield tunnel; Pressure data of the loess shield tunnel is obtained based on the pressure sensors installed inside the test chamber; The pressure data is combined with finite element software to obtain the numerical simulation model of the surrounding rock stress.

3. The method according to claim 1, characterized in that, The step of determining the surrounding rock pressure type for each set of working condition data based on the surrounding rock zoning specifically includes: Determine whether the surrounding rock zoning includes the loosened zone; If so, then the surrounding rock pressure type of each set of working condition data is determined to be loosened surrounding rock pressure; If not, then the surrounding rock pressure type of each set of working condition data is determined to be deformation surrounding rock pressure.

4. The method according to claim 3, characterized in that, If the surrounding rock zoning includes the plastic zone and / or the elastic zone, the plastic zone and the elastic zone are taken as the bearing zone. Determining the surrounding rock pressure type of each set of working condition data as deformation surrounding rock pressure specifically includes: Determine whether the bearing zone of the surrounding rock partition penetrates the ground surface; If so, then the surrounding rock pressure type of each set of working condition data is determined to be shallow buried loosened surrounding rock pressure; If not, then the surrounding rock pressure type of each set of working condition data is determined to be deep-buried loosened surrounding rock pressure.

5. The method according to claim 1, characterized in that, Before calculating the surrounding rock pressure of the loess shield tunnel based on all surrounding rock pressure algorithms corresponding to all the aforementioned surrounding rock pressure types, the method further includes: Establish the correspondence between the surrounding rock pressure type and the surrounding rock pressure algorithm, wherein the surrounding rock pressure algorithm includes at least one of the Fenner formula, the soil column formula and the Beer Bowman formula.

6. The method according to claim 1, characterized in that, The preset surrounding rock zoning algorithm includes standard stress data used to characterize the division criteria for surrounding rock zoning. The step of dividing the surrounding rock stress data according to the preset surrounding rock zoning algorithm to obtain the surrounding rock zoning for each set of working condition data specifically includes: Based on the matching results between the surrounding rock stress data and the standard stress data, the surrounding rock zoning for each set of working condition data is obtained.

7. A device for calculating the surrounding rock pressure of a loess shield tunnel, based on the steps of the method described in any one of claims 1-6, characterized in that, include: The working condition data acquisition module is used to acquire several sets of working condition data for the loess shield tunnel. The working condition data is used to characterize the water content of the loess layer and the tunnel burial depth of the loess shield tunnel. The surrounding rock stress data determination module is used to input each set of working condition data into the surrounding rock stress numerical simulation model to obtain the surrounding rock stress data for each set of working condition data. The numerical simulation model of surrounding rock stress was established using experimental data from the loess shield tunnel model test combined with finite element software. The surrounding rock pressure type determination module is used to determine the surrounding rock pressure type of each set of working condition data based on the surrounding rock stress data. The surrounding rock pressure calculation module is used to calculate the surrounding rock pressure of the loess shield tunnel according to all the surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

8. A device for calculating the surrounding rock pressure of a loess shield tunnel, comprising a memory, a processor, and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 6.

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