Safety management system for shield tunneling

Abstract

The present invention relates to a safety management system for shield tunneling, which can arrange monitoring points for collecting characteristic parameters that can characterize the deformation of structures during on-site construction, and establish a monitoring center, wherein the monitoring center can output monitoring data fed back by the monitoring points and can be used to evaluate the actual safety assessment of the safety of the structure. The system can arrange different monitoring points at different locations based on numerical analysis results, so as to implement targeted monitoring at the locations, which is conducive to monitoring the deformation of the structure, thereby adjusting the construction parameters; and can arrange monitoring points with different monitoring densities / different monitoring numbers according to the stress / displacement level of the numerical analysis reaction, so as to implement key monitoring of key parts.

Description

[0001] The present invention is a divisional application with application number 201911091899.1, application date November 11, 2019, application type invention, and application name a deformation control method and evaluation system for a structure under a shield tunnel. Technical Field

[0002] The invention relates to the technical field of tunnel engineering, and in particular to a safety management system for shield tunneling. Background Art

[0003] As an important part of urban underground space, urban subways have achieved large-scale development in my country. In addition to underground railways, major cities are successively building various underground tunnels such as urban highway tunnels, railway tunnels, municipal tunnels, civil air defense tunnels and power cable tunnels to solve the increasingly serious problem of urban space congestion. However, in the process of urban tunnel construction, due to the limitations of geological conditions and construction technology, shield machine excavation will inevitably disturb the surrounding environment, thereby endangering the safety and normal use of adjacent structures (such as surface structures, pile foundations, underground pipelines, foundation pits and adjacent built pipelines). The problem of damage to structures around tunnels is becoming increasingly prominent.

[0004] Beijing Subway is one of the symbols of urban transportation in my country. Since the construction of the subway began in 1965, it has been developed for nearly 55 years. It has a large scale, a fast development speed, and a revolutionary breakthrough in construction technology. Beijing Subway Line 12 is the North Third Ring Road, which is an encrypted line in northern Beijing. Sanyuanqiao Station is located on the east side of the Airport Expressway. Among them, the design direction of Xibahe Station-Sanyuanqiao Station is: laid southeast along the North Third Ring Road East, the left line increases the line spacing to 35m with a set of R-1200m reverse curves, bypasses both sides of Sanyuan West Bridge, and adjusts the line direction with R-400m curves on the left line and R-400m curves on the right line before the Airport Expressway, and reduces the line spacing to 17.2m. After passing under the Sanyuanqiao ramp bridge, turn to the east side of the Capital Airport Expressway and arrive at Xibahe Station. As the country's political and cultural center and a major city for subway development and construction, Beijing is particularly sensitive and prominent in the safety benefits of shield construction. Therefore, it is of great significance and urgency to strengthen the research on risk management and safety control technology of Beijing subway shield construction.

[0005] At present, shield construction management has basically established a systematic and scientific control of shield construction risks, including identification of shield construction hazards, risk assessment of shield construction systems, and risk control; from the owner to the construction unit, a centralized and vertical risk management system has been established in the shield construction process, and a comprehensive risk management system covering all shield engineering risks has been established, and an enterprise internal control and operation mechanism that effectively balances risk and return management capabilities has been established; from a technical perspective, relying on the existing shield risk management and control platform, it is possible to basically realize information collection, processing, and control of the entire shield construction process. However, for a single line and a certain section, only basic information can be read from the information platform, and there is only a planar position relationship for various types of crossing risk source areas, lacking the supplement of their spatial and temporal relationships. The function of the platform mainly relies on the transmission of existing monitoring data. Taking settlement monitoring as an example, a large number of monitoring personnel are required, and it is impossible to predict and warn of the crossing process, and the information reserve for the construction crossing process is lagging behind.

[0006] During the shield construction process, due to soil loss, changes in surrounding pore water pressure and lining deformation, the original stress of the soil is redistributed, and the original soil balance state is destroyed, resulting in sinking deformation, tilt deformation, curvature deformation, horizontal movement deformation and discontinuous deformation of the surface. When the movement and deformation of the surface are large, it often causes safety problems such as cracking, settlement and tilting of adjacent structures above or below the ground. For example,

[0007] 1. The impact of shield construction on ground structures is mainly manifested in:

[0008] (1) Surface subsidence will cause the structure to sink as a whole;

[0009] (2) Uneven settlement will cause the ground surface to tilt, which will easily lead to structural damage and cracks in structures;

[0010] (3) Soil deformation will cause the ground surface to form a curved surface and produce curvature. The curvature of the ground surface will cause large settlement in the middle of the structure and small settlement at the ends. The central part of the structure will be suspended and the ends will be sheared.

[0011] (4) The structure is sensitive to surface tensile deformation. When the foundation side is subjected to outward horizontal thrust, cracks are likely to form in weak parts. At the same time, door and window openings will deform, the roof will bulge, and the longitudinal walls or fences will be wrinkled.

[0012] 2. Impact of shield construction on underground pipelines

[0013] (1) It causes transverse and longitudinal bending of the pipeline, and the degree of transverse bending is much greater than that of longitudinal bending.

[0014] (2) It is easy to cause the pipeline to twist or even crack.

[0015] (3) Excessive stretching and compression can cause pipe joints to leak or even come loose.

[0016] (4) Large axial shear force or bending moment will cause transverse cracks in the pipeline.

[0017] Therefore, the issue of preventing structures from being damaged during tunnel construction has become a core research topic for many experts and engineers in this field.

[0018] For example, a Chinese patent with publication number CN102996136B discloses a deformation control method for shield tunneling under a composite foundation structure at a close distance. The method includes: determining the construction characteristics of the structure under the tunnel, the construction characteristics include the protection registration of the structure and the foundation form, and according to the construction characteristics, pre-protection facilities are mainly reinforced for the existing structure foundation and foundation of the structure; three-dimensional finite element simulation analysis is performed on the construction sequence and method during the shield tunneling, and the structural weak area of ​​the structure is found and the preliminary shield tunneling plan is determined; construction monitoring of the structure is performed, including vertical settlement monitoring and crack observation of the building, surrounding surface settlement profile monitoring, and adjusting the preliminary shield tunneling plan to obtain an improved plan; the shield tunneling is used to advance the construction using the improved advancement plan during the shield tunneling under the structure; secondary grouting and support structure construction are performed after the shield tunneling under the tunneling, and the support structure construction is to construct a support structure for the soil outside the segment from the corresponding segment below the structure after the shield tunneling passes through the upper structure.

[0019] For example, a Chinese patent with publication number CN102733816B discloses a method for controlling deformation when a shield machine passes through a structure at close range. First, a numerical analysis method is used to analyze the impact of shield tunneling on strata and structures under different support pressure ratios and different grouting effects, and the optimal support stress ratio and requirements for slurry performance are proposed; secondly, the stability control of the shield excavation face is strengthened, and the slag in the pressure chamber can be improved into a fluid plastic state by improving the slag, reducing the fluctuation of pressure control, and controlling over-excavation by comparing the actual slag quality of the measured slag with the theoretical slag quality; finally, the performance control of the grouting liquid behind the wall should be strengthened, and a high-density, thixotropic slurry should be used to prevent the loss of slurry and achieve immediate filling of the shield tail gap. During the shield tunneling process, safety monitoring should also be strengthened, and the shield tunneling parameters should be adjusted in time to ensure the safety of nearby buildings.

[0020] For example, a Chinese patent with publication number CN103334763B discloses a method for controlling the impact of a shield tunneling through a hard rock formation on an adjacent pile foundation. The method includes: step one, establishing a finite element numerical analysis model for shield tunneling, analyzing the impact of the thrust and torque of the shield tunneling in the hard formation on the adjacent pile foundation, and evaluating the degree of impact; step two, vertically slotting the pile foundation adjacent to the shield tunneling side, the slotting depth is 2 to 3 meters from the top of the pile foundation to the bottom of the shield tunneling tunnel, placing an inclinometer tube in the slot and extending it out of the ground, filling the slot with soft materials, and covering the top of the slot for protection; step three, the shield tunnels at a low speed, using the side inclined tube to monitor the horizontal displacement of the pile foundation and adjust the shield tunneling parameters based on the monitoring data.

[0021] For example, a Chinese patent with publication number CN102312673B discloses a construction method for a shield machine to pass through an already operating subway tunnel at close range under complex working conditions. The specific steps are: 1. Analysis of the mathematical model of the crossing working conditions; 2. Setting construction parameters; 3. Establishing monitoring during the shield machine's crossing and monitoring of the tunnel and surrounding environment; 4. Shield machine construction: construction parameter control, synchronous grouting, and dual-liquid grouting. The method provided by this patent enables the shield machine to successfully pass through an already operating subway tunnel, ensuring the safe operation of subway trains.

[0022] For example, a Chinese patent with publication number CN107092802A discloses a risk analysis method for surface deformation during shield tunneling based on HAZOP-accuracy. It includes: determining the standard value and range of risk factors in shield tunnel construction; obtaining the actual monitoring value of risk factor parameters, analyzing the shield tunnel construction situation, obtaining the deviation of risk factor parameters, basic accuracy, total accuracy and consequence analysis; summarizing the deviation of risk factor parameters, basic accuracy, total accuracy and consequence analysis to obtain the cause of risk. The risk analysis method for surface deformation during shield construction based on HAZOP-accuracy established by this invention is simple to operate and plays a guiding role in the risk prevention of surface deformation during the shield tunneling stage.

[0023] For example, a Chinese patent with publication number CN102900441B discloses a Chinese tunnel construction method based on complete deformation control of surrounding rock. The implementation steps of this method are: (1) Geological determination: comprehensive evaluation of tunnel engineering geological survey and surrounding rock physical and mechanical properties, determine tunnel surrounding rock classification and physical and mechanical parameters; (2) Standard formulation: predict tunnel surrounding rock deformation, formulate surrounding rock deformation control standards and preliminary design plans that meet safety and economy; (3) Countermeasure formulation: formulate detailed deformation control countermeasures for the entire deformation process, and decompose the surrounding rock deformation control target into each construction process in the construction drawing design; (4) Process measurement: monitor and measure and feedback information throughout the construction process, focus on monitoring key construction locations and key construction processes, judge the safety of the project and respond in time; (5) Status evaluation: timely evaluate the status of the support structure, evaluate the long-term stability of the tunnel surrounding rock structure, and if necessary, make reasonable reinforcement plans for each location.

[0024] In the prior art, the arrangement of monitoring points is mainly based on the shield scale and hydrogeological conditions to determine the length of the observation line, and the monitoring points are arranged along the tunnel axis (longitudinal section) and the vertical tunnel axis (cross section). For example, the length between the monitoring points arranged along the tunnel excavation direction is generally not greater than the length of the shield machine, and generally the distance between the two measuring points is 3 to 5 meters. The spacing of the monitoring cross section is generally 20 to 30 meters. In the monitoring cross section, the measuring points are arranged from both sides of the center line of the interval according to the increasing spacing of the measuring points (2 to 5 meters), and the arrangement range is 2 to 3 times the outer diameter of the shield. However, under different engineering conditions, the types and risks of damage to the structure are different. The arrangement of monitoring points based on experience often cannot monitor the most dangerous parts. Therefore, the existing technical means still have the following deficiencies in the risk identification of structures: the monitoring effect of the weak parts of the structure is not good or the structure has been damaged but has not been monitored (such as cracks in the corners).

[0025] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the inventor studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0026] In view of the shortcomings of the prior art, the present invention provides a method for controlling the deformation of a structure under a shield tunnel, comprising:

[0027] A numerical analysis model for shield tunneling is established, and the preliminary safety assessment and construction parameters that can be used to evaluate the safety of the structure are output based on the numerical analysis results. The numerical analysis results can show the stress, strain and displacement of the structure (and the adjacent soil) during the shield tunneling process. The dangerous points of the structure can be known from the stress cloud map, strain cloud map and displacement cloud map. Based on the stress cloud map, strain cloud map and displacement cloud map, a preliminary safety assessment for evaluating the structure during the shield tunneling process can be output. Secondly, after the physical model of the numerical analysis is established, only by adjusting its boundary conditions (for example, construction parameters such as cutterhead speed, propulsion speed, grouting pressure and formation parameters), the safety impact of different construction parameters and different formation parameters on the structure during the shield tunneling process can be analyzed. In addition, combined with the orthogonal experiment principle, sensitive factors that affect the safety status of the structure can be determined for specific engineering objects. Therefore, according to the numerical analysis results, the construction parameters can be preliminarily formulated, especially the early identification of sensitive factors.

[0028] Based on the numerical analysis results, monitoring points for collecting parameters that can characterize the deformation of the structure are arranged at the construction site, and a monitoring center is established. In the present invention, the arrangement of the monitoring points is based on the numerical analysis results. Since the numerical analysis is established based on actual working conditions, the arrangement of the monitoring points is not based on empirical judgment. According to this method, the present invention also has the following advantages: 1. The monitoring point can collect mechanical parameters of the most vulnerable parts of the structure based on the dangerous points of the structure reflected by the stress cloud map, the strain cloud map and the displacement cloud map, which is conducive to the monitoring of weak links in the shield tunneling process; 2. The monitoring point can use different types of data acquisition devices based on the different types of dangerous points of the structure reflected by the stress cloud map, the strain cloud map and the displacement cloud map. For example, for the parts with greater stress or greater stress concentration, the monitoring point can use a strain sensor. For another example, for the parts with greater displacement, the monitoring point can use a displacement sensor. This mainly enables the real collected data to effectively monitor the types that are prone to damage in a targeted manner based on the numerical analysis results; 3. The monitoring data fed back by the monitoring point can be processed by the monitoring center and output as an actual safety assessment for evaluating the safety of the structure. The actual safety assessment can complement and verify each other with the preliminary safety assessment, and is mainly used to optimize or adjust the construction parameters based on the monitoring results and the numerical simulation results, so that the structure is in a controllable and / or safe state during the shield tunneling construction process.

[0029] According to a preferred embodiment, the numerical analysis results can at least be used to determine the types of arranged monitoring points and / or the relative positional relationship of the monitoring points, wherein the types of monitoring points at least include displacement monitoring points for monitoring structural displacement, and the arrangement positions of the displacement monitoring points are at least determined based on the displacement cloud map and / or strain cloud map in the numerical analysis results; and / or the monitoring spacing of the adjacent monitoring points is arranged in a manner that is negatively correlated with the displacement value in the displacement cloud map and / or the strain value in the strain cloud map.

[0030] According to a preferred embodiment, when the change over time of the feedback data of the monitoring point is greater than or equal to the deformation rate threshold set based on the numerical analysis result, the monitoring frequency of the monitoring point is set based on the rate of change of the feedback data over time; or when the change over time of the feedback data of the monitoring point is less than the threshold set based on the numerical analysis result, the monitoring frequency of the monitoring point is set based on the numerical analysis result.

[0031] According to a preferred embodiment, when the distance between the shield machine and the structure is less than a distance threshold set based on numerical analysis results, the monitoring frequency of the monitoring points is increased; and / or the number of arranged monitoring points is increased and the monitoring distance between adjacent monitoring points is reduced.

[0032] According to a preferred embodiment, in combination with different underpass sections, risky underpass sections are identified based on numerical analysis results and settlement control quantities. When the shield machine passes through the risky underpass section, the monitoring method of the monitoring points constructs a topological monitoring network in the following manner: increasing the monitoring frequency of the monitoring points; and / or increasing the number of arranged monitoring points; and / or increasing the arrangement density of the monitoring points; and / or changing the arrangement method of the monitoring points.

[0033] According to a preferred embodiment, the deformation rate threshold can be set at least in the following manner: based on the numerical analysis results, a sinking curve of the structure in the simulated shield penetration process is obtained, and the sinking curve can be divided into an early sinking curve, a mid-term sinking curve and a late sinking curve according to the travel path of the shield cutter head and the law of the sinking curve, wherein an early deformation rate threshold is set based on the early sinking curve; a mid-term deformation rate threshold is set based on the mid-term sinking curve; and a late deformation rate threshold is set based on the late sinking curve; wherein the early sinking curve corresponds to the stage where the shield cutter head has not passed through the structure, the mid-term sinking curve corresponds to the stage where the shield cutter head is passing through the structure, and the late sinking curve corresponds to the stage where the shield cutter head has passed through the structure.

[0034] According to a preferred embodiment, the influence of the physical properties of the strata around the tunnel to be built on the deformation of the structure is preliminarily analyzed based on the numerical analysis model, and a mechanical configuration plan and / or a support reinforcement plan are preliminarily formulated in combination with the control of settlement, wherein the physical properties of the strata refer to the constitutive model of the strata, which at least includes the internal friction angle, Poisson's ratio and / or elastic modulus.

[0035] According to a preferred embodiment, the construction parameters include at least soil bin pressure, shield thrust, single-disk torque and / or excavation speed; wherein the numerical analysis model can be used to analyze the correlation between the soil bin pressure, the shield thrust, the single-disk torque and / or the excavation speed and the deformation of the structure, so that the control method can select sensitive factors affecting the deformation of the structure from the soil bin pressure, the shield thrust, the single-disk torque and / or the excavation speed based on the numerical analysis results.

[0036] According to a preferred embodiment, a deformation assessment system for a structure under a shield tunnel comprises: a numerical analysis platform for establishing a numerical analysis model of shield underpass excavation, the assessment system also comprising monitoring points and a monitoring center arranged at a construction site based on the numerical analysis results for collecting parameters that can characterize the deformation of the structure, the monitoring center outputting an actual safety assessment that can be used to evaluate the safety of the structure based on monitoring data fed back by the monitoring points; the numerical analysis results of the numerical analysis model can be used to evaluate a preliminary safety assessment and a first construction parameter of the safety of the structure; when at least one safety parameter in the actual safety assessment is within a danger threshold, the preliminary safety assessment and the actual safety assessment are used to adjust the first construction parameter, and the adjusted construction parameters can make the structure in a controllable and / or safe state during the shield underpass construction process.

[0037] According to a preferred embodiment, the numerical analysis results can at least be used to determine the types of arranged monitoring points and / or the relative positional relationship of the monitoring points, wherein the types of monitoring points at least include displacement monitoring points for monitoring structural displacement, and the displacement monitoring points are at least determined based on the displacement cloud map and / or strain cloud map in the numerical analysis results; and / or the spacing between the adjacent monitoring points is arranged in a manner that is negatively correlated with the displacement value in the displacement cloud map and / or the strain value in the strain cloud map.

[0038] The present invention provides a method for controlling deformation of a structure under a shield tunnel, which has at least the following advantages:

[0039] (1) The monitoring data fed back by the monitoring points arranged based on the numerical analysis results can be processed by the monitoring center and output as an actual safety assessment for evaluating the safety of the structure. The actual safety assessment can complement and verify the preliminary safety assessment and is mainly used to optimize or adjust the construction parameters based on the monitoring results and numerical simulation results so that the structure is in a controllable and / or safe state during the shield tunneling construction process.

[0040] (2) Different monitoring points can be arranged at different locations based on the results of numerical analysis, so as to implement targeted monitoring at the location, which is beneficial to the deformation monitoring of the structure, so as to adjust the construction parameters; and different monitoring densities / different monitoring numbers of monitoring points can be arranged according to the stress / displacement level reflected by the numerical analysis, so as to implement key monitoring of key parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flow chart of a method for controlling deformation of a structure under a shield tunnel provided by the present invention; and

[0042] Figure 2 The present invention provides a schematic diagram of the arrangement of monitoring points for a shield tunneling. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1 , 2 Provide detailed explanation.

[0044] Example 1

[0045] The numerical analysis model is a mathematical model based on the finite element method simulation and is widely used in engineering fields such as water conservancy engineering, civil engineering, mechanical engineering, bridge engineering and metallurgical engineering. It is mainly a numerical technology for solving approximate solutions to boundary value problems of partial differential equations. Since most practical problems are difficult to obtain accurate solutions, and the finite element method not only has high calculation accuracy, but also can adapt to various complex shapes, it has become an effective engineering analysis method. For example, in the shield tunneling, the numerical analysis method can simulate the influence of different tunneling speeds of the shield machine 300 on the disturbance of the adjacent soil. Numerical analysis can use existing numerical analysis platforms, such as ANSYS, ABAQUS, FLAC-3D, LS-Dyna and MIDAS / GTS and other finite element analysis platforms.

[0046] This embodiment provides a method for controlling the deformation of a structure 200 that a shield machine passes through, as shown in the attached figure. Figure 1 As shown, including:

[0047] S1: Establish a numerical analysis model for shield tunneling. The steps of the numerical analysis model mainly include the establishment of a physical model, the establishment of boundary conditions and meshing. The physical model includes a tunnel geotechnical geometry model, a physical model of the structure 200, a physical model of the shield machine 300 and the spatial relationship between the structure 200 and the tunnel. The establishment of boundary conditions includes the mechanical model of the geotechnical structure, the mechanical model of the shield machine 300, the mechanical model of the structure 200, the tunneling parameters of the shield section and the definition of the interaction relationship between the shield machine 300 and the geotechnical structure. Meshing is to discretize the tunnel geotechnical physical model, the physical model of the structure 200 and the physical model of the shield machine 300.

[0048] S2: In the present invention, the numerical analysis results can be used to preliminarily evaluate the safety of the structure 200 and to analyze the impact of the construction parameters on the safety of the structure 200.

[0049] S3: Based on the numerical analysis results, monitoring points 100 are arranged at the construction site for collecting parameters that can characterize the deformation of the structure 200, and a monitoring center is established. The numerical analysis results mainly include stress cloud maps, strain cloud maps, displacement cloud maps of rock and soil, and stress cloud maps, strain cloud maps and displacement cloud maps of the structure 200. The stress cloud map, strain cloud map and displacement cloud map of rock and soil mainly reflect the disturbance of the surrounding soil during the shield tunneling process. The stress cloud map, strain cloud map and displacement cloud map of the structure 200 mainly reflect the inclination rate of the structure 200 and whether strength failure will occur during the shield tunneling process. The monitoring point 100 and the monitoring center can be wired communication methods, such as optical fiber communication. The monitoring point 100 and the monitoring center can also be wireless communication methods, such as Bluetooth communication, 4G communication, NB-loT communication, EnOcean communication, etc. The monitoring point 100 can actually be at least one of the monitoring equipment such as displacement sensor, strain sensor, electronic level, house inclinometer, etc. For example, a certain number of displacement monitoring points 100 may be arranged at the location with the maximum displacement according to the displacement cloud diagram, while a number of displacement monitoring points 100 less than the number may be arranged at other locations.

[0050] S4: The monitoring center outputs the actual safety assessment that can be used to evaluate the safety of the structure 200 based on the monitoring data fed back by the monitoring point 100. The monitoring data fed back by the monitoring point 100 mainly include displacement and stress. The actual safety assessment is mainly obtained by analyzing the displacement level and the stress level. The displacement level is used to analyze the surface settlement, and the surface settlement is directly related to the deformation of the structure 200. The stress level can be used to analyze the stress condition of the structure 200, and can also be used to analyze the stress condition of the stratum.

[0051] S5: In the construction project, if at least one safety parameter in the actual safety assessment is at a dangerous threshold, the construction parameters can be adjusted in combination with the preliminary safety assessment and the actual safety assessment so that the structure 200 can be in a controllable and / or safe state when the shield passes under. The preliminary safety assessment may include an analysis of the impact of various construction parameters on the deformation of the structure 200. The actual safety assessment is an actual engineering assessment conducted through construction parameters and feedback monitoring data. For example, when the displacement exceeds the dangerous threshold, the sensitivity parameters in the construction parameters can be adjusted. The sensitivity parameters mainly come from the preliminary safety assessment. The controllable state means that the deformation of the structure 200 is in a state that can be improved by construction methods such as support, while the safe state means that the deformation of the structure 200 is within the safety threshold set by the project.

[0052] Therefore, in the present invention, the arrangement of the monitoring points 100 is based on the results of numerical analysis. Since the numerical analysis is established according to the actual working conditions, the arrangement of the monitoring points 100 is not based on empirical judgment. In this way, the present invention also has the following advantages: 1. The monitoring points 100 can collect the mechanical parameters of the parts of the structure 200 that are most prone to damage based on the dangerous points of the structure 200 reflected by the stress cloud map, strain cloud map and displacement cloud map, which is beneficial to the monitoring of weak links during the shield tunneling process; 2. The monitoring points 100 can use different types of data acquisition devices based on the different types of dangerous points of the structure 200 reflected by the stress cloud map, strain cloud map and displacement cloud map. For example, for parts with greater stress or parts with greater stress concentration, the monitoring points 100 can use strain sensors. For example, for parts with greater stress or parts with greater stress concentration, the monitoring points 100 can use strain sensors. For parts with larger displacement, the monitoring point 100 can use a displacement sensor, which mainly enables the real collected data to be targeted and effectively monitor the types that are prone to damage based on the numerical analysis results; 3. The monitoring data fed back by the monitoring point 100 can be processed by the monitoring center and output as an actual safety assessment for evaluating the safety of the structure 200. The actual safety assessment can complement and verify the preliminary safety assessment, and is mainly used to optimize or adjust the construction parameters based on the monitoring results and numerical simulation results, so that the structure 200 is in a controllable and / or safe state during the shield tunneling construction process.

[0053] Preferably, the numerical analysis results can at least be used to determine the type of monitoring points 100 to be arranged and / or the relative position relationship of the monitoring points 100. For example, the type of monitoring points 100 includes at least displacement monitoring points 100 for monitoring the displacement of the structure 200. The displacement monitoring points 100 can be displacement sensors and / or electronic levels. The displacement monitoring points 100 can be used to monitor the horizontal displacement and / or vertical displacement of the structure 200. For another example, the type of monitoring points 100 can also include strain sensors for monitoring the stress of the structure 200, which can monitor the stress changes of the structure 200 during the shield tunneling process. The arrangement position of the displacement monitoring points 100 is at least determined based on the displacement cloud map and / or strain cloud map in the numerical analysis results. The displacement cloud map is a three-dimensional map composed of the displacement values ​​of each point in the numerical model (it can also be a two-dimensional map formed by selecting the displacement values ​​of each point in a certain section in the form of selecting a section in the numerical platform). Similarly. The strain cloud diagram is a three-dimensional diagram composed of the strain values ​​of each point in the numerical model (it can also be a two-dimensional diagram formed by selecting the strain values ​​of each point in a certain section in the form of selecting a section in the numerical platform). Therefore, engineers can arrange the displacement monitoring points 100 by reading the maximum point, larger point and mutation point of the displacement value in the numerical calculation platform as the arrangement center of the displacement monitoring point 100. The monitoring spacing of the adjacent monitoring points 100 is arranged in a manner that is negatively correlated with the displacement value in the displacement cloud diagram and / or the strain value in the strain cloud diagram. For example, for the location of the maximum point of the displacement value, a displacement monitoring point 100 can be arranged at the maximum point, and other displacement monitoring points 100 can be arranged in a "one" shape with the displacement monitoring point 100 at the maximum point, and the monitoring spacing of the adjacent displacement monitoring points 100 closer to the maximum point is smaller, and the monitoring spacing of the adjacent displacement monitoring points 100 farther from the maximum point is larger. For another example, for the location of the maximum point of the displacement value, a displacement monitoring point 100 can be arranged at the maximum point, and multiple layers of displacement monitoring points 100 are arranged with the displacement monitoring point 100 as the center of the circle. The closer the inner layer of adjacent displacement monitoring points 100 are to the maximum point, the smaller the monitoring spacing (monitoring arc), while the farther the outer layer of adjacent displacement monitoring points 100 are from the maximum point, the larger the monitoring spacing (monitoring arc). In the prior art, the monitoring points 100 for monitoring displacement changes are arranged along the tunnel axis and perpendicular to the tunnel axis. However, this method in the prior art is based on empirical judgment, and each type of project will have at least the following differences: the spatial relationship between the structure 200 and the tunnel to be built is different, the soil around the tunnel to be built is different, and the type of the structure 200 is different. Therefore, the conventional method of arranging monitoring points 100 based on experience cannot truly reflect the displacement of dangerous parts of a specific project, thereby increasing the risk of the project.In this way, the present invention can have at least the following advantages: 1. It can arrange different monitoring points 100 at different positions based on the results of numerical analysis, so as to implement targeted monitoring at the position, which is beneficial to the deformation monitoring of the structure 200, so as to adjust the construction parameters; 2. It can arrange monitoring points 100 with different monitoring densities / different monitoring numbers according to the stress / displacement level reflected by the numerical analysis, and implement key monitoring of key parts.

[0054] Since shield construction belongs to shallow drilling construction, it is inevitable to encounter the influence of bad weather, such as rainy days, during the construction process. Shallow strata are mostly susceptible to the influence of water content, so the feedback data of the monitoring point 100 may undergo a large change at this stage that is not conducive to the safety of the structure 200. For this reason, preferably, when the change of the feedback data of the monitoring point 100 over time is greater than or equal to the deformation rate threshold set based on the numerical analysis results, the monitoring frequency of the monitoring point 100 is set based on the change rate of the feedback data over time. In the numerical analysis model, it is a nonlinear simulation process of dynamic simulation, so each cloud map is constantly changing (but within a certain excavation time, the trend of the displacement cloud map, strain cloud map and stress cloud map is roughly unchanged, for example, the maximum displacement point, the maximum strain point and the maximum stress point are roughly unchanged.) The deformation rate threshold set by the numerical analysis result can be obtained as follows: the ratio of the difference between the maximum displacement value and the minimum displacement value of the maximum displacement point within the certain excavation time to the excavation time; or, within the certain excavation time, the ratio of the difference between the maximum displacement value and the average displacement value of the maximum displacement point to the excavation time. For example, when the monitored displacement change rate is greater than or equal to the displacement change rate in the numerical analysis result, the monitoring frequency of monitoring point 100 will increase. For example, the monitoring frequency of monitoring point 100 is 8 times / day. If the monitored displacement change rate is greater than or equal to the displacement change rate in the numerical analysis result, the monitoring frequency of monitoring point 100 will increase to 10 times / day or 12 times / day or even more. The increased monitoring frequency depends on the change rate of the feedback data of the monitoring point 100 over time. The greater the change rate, the more the monitoring frequency is increased. For example, if the deformation rate threshold set based on the numerical analysis result is 1mm / d, and the change rate of the feedback data of the monitoring point 100 over time is 1.1mm / d, the monitoring frequency of the monitoring point 100 will be increased to 10 times / day; if the change rate of the feedback data of the monitoring point 100 over time is 1.2mm / d, the monitoring frequency of the monitoring point 100 will be increased to 12 times / day. In this way, the present invention has at least the following advantages: 1. It can determine the displacement deformation rate of rock and soil / the displacement deformation rate of structure 200 based on actual monitoring data, so that when the displacement deformation rate / the displacement deformation rate of structure 200 is greater than the deformation rate threshold set by the numerical analysis result, the monitoring frequency can be increased, which is conducive to strengthening the implementation of monitoring; 2. The numerical analysis results are often the analysis results for ideal working conditions, and the analysis results can set a certain evaluation index that can be used in actual construction. Therefore, the set deformation rate threshold comes from the numerical analysis results, so that the role of numerical simulation analysis in guiding actual engineering can be achieved, which facilitates the mutual correspondence between the two.

[0055] Preferably, when the distance between the shield machine 300 and the structure 200 is less than the distance threshold set based on the numerical analysis results, the monitoring frequency of the monitoring point 100 increases. The distance between the shield machine 300 and the structure 200 can be defined as: the length of the line segment between the geometric center of the shield machine 300 and the geometric center line of the structure 200, or the length of the line segment between the center of gravity of the cutter head of the shield machine 300 and the center of gravity of the structure 200, or the geometric distance between the foundation surface of the structure 200 and the tunnel under construction. For example, the distance threshold set by the numerical analysis results is 5 to 8 times the radius of the tunnel under construction. For example, when the geometric distance between the foundation surface of the structure 200 and the tunnel under construction is greater than 5 times the radius of the tunnel under construction, the monitoring frequency of the monitoring point 100 is 6 times / d. When the geometric distance between the foundation surface of the structure 200 and the tunnel under construction is less than 5 times the radius of the tunnel under construction, the monitoring frequency of the monitoring point 100 is 8 times / d. And / or, the number of monitoring points 100 arranged increases and the monitoring spacing of adjacent monitoring points 100 decreases. For example, when the geometric distance between the foundation surface of the structure 200 and the tunnel under construction is greater than 5 times the radius of the tunnel under construction, the monitoring spacing of adjacent monitoring points 100 arranged in a "one" shape is 3 to 6 meters. However, when the geometric distance between the foundation surface of the structure 200 and the tunnel under construction is greater than 5 times the radius of the tunnel under construction, the monitoring spacing of adjacent monitoring points 100 arranged in a "one" shape is 1 to 4 meters. Shield tunneling is an engineering event closely related to time. The spatial relationship between the shield machine 300 and the structure 200 changes continuously with the advancement of time, which can be roughly described as: the shield machine 300 gradually approaches the structure 200 until the spacing with the structure 200 is the smallest, and then gradually moves away from the structure 200. Therefore, the physical state (stress level, strain level and position) of the structure 200 is constantly changing. Therefore, this method can effectively evaluate the deformation of the structure 200 while saving engineering resources.

[0056] Preferably, risky underpass sections are identified based on the numerical analysis results and settlement control amounts of different underpass sections. In the present invention, risky underpass sections can be divided into: low-risk underpass sections, medium-risk underpass sections and high-risk underpass sections. For example, risky underpass sections of different risk levels correspond to different levels of the difference between the displacement value and the settlement control amount in the numerical analysis results. Preferably, the settlement control amount can be 20mm. The difference range corresponding to the low-risk underpass section is 10 to 15mm (excluding 10mm). The difference range corresponding to the medium-risk underpass section is 5 to 10mm (excluding 5mm). The difference range corresponding to the high-risk underpass section is 0 to 5mm. When the shield tunnel passes through the risky underpass section, the monitoring method of the monitoring point 100 can construct a topological monitoring network in one or more combinations of the following methods:

[0057] A. Increase the monitoring frequency of monitoring point 100. The monitoring frequencies corresponding to the low-risk underpass section, the medium-risk underpass section, and the high-risk underpass section increase in sequence. For example, when the shield machine 300 passes through the low-risk underpass section, its monitoring frequency is 6 times a day. When the shield machine 300 passes through the medium-risk underpass section, its monitoring frequency is 8 times a day. When the shield machine 300 passes through the high-risk underpass section, its monitoring frequency is 12 times a day.

[0058] B. Increase the number of monitoring points 100. The number of monitoring points corresponding to the low-risk underpass section, the medium-risk underpass section, and the high-risk underpass section increases in sequence. For example, when the shield machine 300 passes through the low-risk underpass section, the number of monitoring points is 6. When the shield machine 300 passes through the medium-risk underpass section, the number of monitoring points is 10. When the shield machine 300 passes through the high-risk underpass section, the number of monitoring points is 16.

[0059] C. Increase the density of monitoring points 100. The density of monitoring points 100 corresponding to low-risk underpass sections, medium-risk underpass sections, and high-risk underpass sections increases in sequence. For example, when the shield machine 300 passes through a low-risk underpass section, the density of monitoring points 100 is one per 4 to 8 meters. When the shield machine 300 passes through a medium-risk underpass section, the density of monitoring points 100 is one per 3 to 6 meters. When the shield machine 300 passes through a high-risk underpass section, the density of monitoring points 100 is one per 2 to 4 meters.

[0060] D. Change the arrangement of the monitoring points 100. Mainly based on the numerical analysis results, analyze the characteristics of the settlement distribution. For example, if the settlement distribution is linear, it can be arranged in a "one" shape. If the settlement distribution is a quadratic function type, it can be arranged in a circumferential direction according to the quadratic function curve.

[0061] Arranging the monitoring scheme of the monitoring point 100 according to the difference between the numerical analysis results and the settlement control amount has at least the following advantages: 1. Focusing on monitoring key sections; 2. Being able to identify risk sources in advance and focus on monitoring risk sources during construction projects.

[0062] Example 2

[0063] This embodiment may be a further improvement and / or supplement to Embodiment 1, and repeated contents will not be repeated. In the case of no conflict or contradiction, the whole and / or part of the preferred implementation modes of other embodiments may be used as a supplement to this embodiment.

[0064] Preferably, the influence of the physical characteristics of the strata around the tunnel to be built on the deformation of the structure 200 is preliminarily analyzed according to the numerical analysis model. During the shield construction process, the strata encountered are mostly loose soil, clay, silt, sand and gravel, etc., or a combination of several. These strata will produce a large displacement after the shield forms the tunnel. Most studies have shown that the stratum factor is one of the more significant factors for the deformation of the structure 200. Therefore, the numerical analysis results of this embodiment will be specifically analyzed for the physical characteristics of the stratum for a specific project. First, the strata encountered in each project are different, and it is necessary to analyze the influence of each stratum parameter on the displacement. Second, since the tunnel is long and narrow, the strata of each underpass section in each project may also be different, and it is also necessary to analyze the influence of the stratum parameters of each underpass section on the displacement. In this embodiment, it is necessary to preliminarily formulate a mechanical configuration plan and / or a support reinforcement plan in combination with the controlled settlement. The mechanical configuration scheme mainly includes the selection of cutterhead, shield unit and panel, grouting pump, grouting pump pipeline setting, etc. The support reinforcement scheme includes spray anchor support, steel-wood support, concrete lining and grouting support, etc.

[0065] Therefore, the present invention can select different mechanical configuration schemes and support reinforcement schemes for different projects by analyzing the numerical analysis results and settlement control values, and can also select different mechanical configuration schemes and support reinforcement schemes for different underpass sections of the same project, thereby avoiding in advance the technical problems of deformation of structure 200 caused by surface displacement caused by formation factors or reducing the risk of deformation of structure 200 caused by surface displacement caused by formation factors.

[0066] In this embodiment, the physical property of the formation refers to the constitutive model of the formation, which at least includes the internal friction angle, Poisson's ratio and / or elastic modulus. The internal friction angle, Poisson's ratio and / or elastic modulus can be determined by sampling the formation and then sent to the measurement, and then input into the numerical analysis model.

[0067] Example 3

[0068] This embodiment may be a further improvement and / or supplement to Embodiments 1 and 2, and repeated contents will not be repeated. In the case of no conflict or contradiction, the whole and / or part of the preferred implementation methods of other embodiments may be used as a supplement to this embodiment.

[0069] The deformation rate threshold can be set at least in the following manner: based on the numerical analysis results, the sinking curve of the structure 200 in the process of simulating the shield tunneling is obtained. In the numerical analysis results, the displacement curve of the center of gravity of the research structure 200 can be obtained. Then, according to the travel path of the shield cutter head and the law of the sinking curve, the sinking curve can be divided into an early sinking curve, a mid-term sinking curve and a late sinking curve. The early sinking curve corresponds to the stage where the shield cutter head has not passed through the structure 200. The mid-term sinking curve includes the stage where the shield cutter head is passing through the structure 200, and may also include the stage where part of the shield cutter head has not passed through the structure 200 (mainly determined by calculating the displacement change rate of the sinking curve, determined according to the inflection point in mathematics) and / or the stage where the structure 200 has been passed (mainly determined by calculating the displacement change rate of the sinking curve, determined according to the inflection point in mathematics). The late sinking curve corresponds to the stage where the shield cutter head has passed through the structure 200. The early deformation rate threshold is set based on the early sinking curve. The mid-term deformation rate threshold is set based on the mid-term sinking curve. The late deformation rate threshold is set based on the late settlement curve. In the actual shield tunneling process, the settlement rate of the structure 200 is different in each of its excavation stages. And, in the process of the shield passing through the structure 200, the settlement rate of the structure 200 is the fastest. Therefore, the early deformation rate threshold and the late deformation rate threshold are smaller than the mid-term deformation rate threshold. In this way, according to the settlement development characteristics of the structure 200 at different stages of the numerical simulation results, the deformation of the structure 200 is monitored in stages and different protection schemes are implemented, and then according to the monitoring results, the corresponding construction parameters and protection schemes are adjusted for the settlement during the construction process, so as to effectively ensure the deformation control of the structure 200 at each underpass stage.

[0070] Example 4

[0071] This embodiment may be a further improvement and / or supplement to Embodiments 1, 2, and 3, and repeated contents will not be repeated. In the case of no conflict or contradiction, the whole and / or part of the preferred implementation methods of other embodiments may be used as a supplement to this embodiment.

[0072] In the present invention, the construction parameters at least include soil bin pressure, shield thrust, single disc torque and / or excavation speed.

[0073] Since the numerical analysis model is established in the numerical analysis platform, the soil bin pressure, shield thrust, single-disk torque and / or excavation speed can be applied as loads in the model, respectively. Therefore, the correlation between different soil bin pressures, shield thrusts, single-disk torques and / or excavation speeds and the deformation parameters of the structure 200 can be analyzed. For example, a single factor analysis method can be used to analyze the changing trend of the deformation parameters of the structure 200 (such as the amount of settlement of the structure 200) with the change of soil bin pressure. For another example, a single factor analysis method can be used to analyze the influence trend of the shield thrust on the deformation parameters of the structure 200 (such as the amount of settlement of the structure 200). Moreover, not only that, the method can also use the orthogonal experimental principle to analyze the soil bin pressure, shield thrust, single-disk torque and / or excavation speed to select sensitive factors that affect the deformation of the structure 200, for example, it can be determined by a 4-factor 3-level orthogonal experimental design. In this way, the present invention can also have the following advantages: 1. It is conducive to identifying sensitive factors that affect the deformation of the structure 200, and is used to guide the formulation of control plans and monitoring plans for sensitive factors in advance; 2. When abnormal monitoring data occurs at the monitoring point 100, an adjustment plan for the sensitive factors can be deployed by focusing on the study of the sensitive factors.

[0074] Example 5

[0075] This embodiment discloses a deformation assessment system for a structure 200 passed by a shield machine, which can be used to implement the monitoring methods in Embodiments 1 to 4.

[0076] It includes a numerical analysis platform for establishing a numerical analysis model for shield tunneling.

[0077] The evaluation system further includes monitoring points 100 and a monitoring center arranged at the construction site based on the numerical analysis results and used to collect deformation parameters that can characterize the structure 200 .

[0078] The monitoring center outputs the actual safety assessment that can be used to evaluate the safety of the structure 200 based on the monitoring data fed back by the monitoring point 100 .

[0079] The numerical analysis results of the numerical analysis model can be used to evaluate the preliminary safety assessment and first construction parameters of the safety of the structure 200 .

[0080] When at least one safety parameter in the actual safety assessment is within the danger threshold, the preliminary safety assessment and the actual safety assessment are used to adjust the first construction parameter, and the adjusted construction parameter can make the structure 200 in a controllable and / or safe state during the shield tunneling construction process.

[0081] Preferably, the numerical analysis result can at least be used to determine the type of arranged monitoring points 100 and / or the relative position relationship of the monitoring points 100 .

[0082] The types of monitoring points 100 include at least displacement monitoring points 100 for monitoring the displacement of the structure 200, and the displacement monitoring points 100 are determined based on at least the displacement cloud map and / or the strain cloud map in the numerical analysis result. And / or

[0083] The intervals between adjacent monitoring points 100 are arranged in a manner that is negatively correlated with the displacement value in the displacement cloud diagram and / or the strain value in the strain cloud diagram.

[0084] It should be noted that the above specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention description and its drawings are illustrative and do not constitute a limitation of the claims. The protection scope of the present invention is defined by the claims and their equivalents.

Claims

1. A safety management system for shield tunneling, which can arrange monitoring points (100) for collecting characteristic parameters that can characterize the deformation of a structure (200) during on-site construction, and establish a monitoring center, wherein the monitoring center outputs an actual safety assessment that can be used to evaluate the safety of the structure (200) based on the monitoring data fed back by the monitoring points (100), characterized in that: The system can establish a numerical analysis model for shield tunneling, so as to obtain various cloud maps that are constantly changing through a nonlinear simulation process of dynamic simulation, and output a preliminary safety assessment and construction parameters that can be used to evaluate the safety of the structure (200) based on the numerical analysis results including stress cloud maps, strain cloud maps and displacement cloud maps. The monitoring points (100) determine the types of monitoring points (100) to be arranged and the relative positional relationship of the monitoring points (100) based on the preliminary safety assessment in a manner of obtaining monitoring data of weak points that can characterize the deformation of the structure (200), so that the monitoring center can at least output the actual safety assessment based on the monitoring data when the monitoring data of the weak points fed back by the monitoring points (100) is obtained. The monitoring points (100) are arranged in the actual working condition by combining the preliminary safety assessment including the analysis of the influence of various construction parameters on the deformation of the structure (200) and the actual safety assessment of the actual engineering assessment conducted through the construction parameters and the fed-back monitoring data as the numerical analysis results. The monitoring method of the monitoring points (100) is to construct a topological monitoring network in the following manner when the shield tunnel passes through the risky underpass section: increase the monitoring frequency of the monitoring points (100); and / or increase the number of the monitoring points (100); and / or increase the arrangement density of the monitoring points (100); and / or changing the arrangement of the monitoring points (100), wherein the displacement monitoring points are arranged based on the displacement cloud map and / or the strain cloud map in the numerical analysis results, and / or the monitoring intervals of adjacent monitoring points (100) are arranged in a manner that is negatively correlated with the displacement value in the displacement cloud map and / or the strain value in the strain cloud map, the actual safety assessment can complement and verify the preliminary safety assessment, and in the construction project, if at least one safety parameter in the actual safety assessment is at a dangerous threshold, the construction parameters are optimized or adjusted based on the monitoring results of the actual safety assessment and the numerical simulation results of the preliminary safety assessment, so that the structure (200) is in a controllable and / or safe state during the shield tunneling construction process, When the change over time of the feedback data of the monitoring point (100) is greater than or equal to a deformation rate threshold value set based on the numerical analysis result, the monitoring frequency of the monitoring point (100) is set based on the change over time of the feedback data; or when the change over time of the feedback data of the monitoring point (100) is less than a threshold value set based on the numerical analysis result, the monitoring frequency of the monitoring point (100) is set based on the numerical analysis result, The deformation rate threshold is set at least in the following manner: based on the numerical analysis result, a sinking curve of the structure (200) in the process of simulating shield tunneling is obtained, and the sinking curve is divided into an early sinking curve, a mid-term sinking curve and a late sinking curve according to the travel path of the shield cutter head and the law of the sinking curve, wherein an early deformation rate threshold is set based on the early sinking curve; a mid-term deformation rate threshold is set based on the mid-term sinking curve; and a late deformation rate threshold is set based on the late sinking curve; wherein the early sinking curve corresponds to a stage where the shield cutter head has not passed through the structure (200), the mid-term sinking curve corresponds to a stage where the shield cutter head is passing through the structure (200), and the late sinking curve corresponds to a stage where the shield cutter head has passed through the structure (200).

2. The safety management system according to claim 1, characterized in that: The monitoring point (100) can be at least one of a displacement sensor, a strain sensor, an electronic level, and a building inclinometer monitoring device.

3. The safety management system according to claim 1, characterized in that: The type of monitoring point (100) also includes a strain sensor for monitoring the stress of the structure (200), which can monitor the stress change of the structure (200) during the shield tunneling process.

4. The safety management system according to claim 1, characterized in that: When at least one safety parameter in the actual safety assessment is within a danger threshold, the preliminary safety assessment and the actual safety assessment are used to adjust a first construction parameter, and the adjusted construction parameter enables the structure (200) to be in a controllable and / or safe state during the shield tunneling construction process.

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