Method, device and equipment for calculating surrounding rock pressure of loess shield tunnel and storage medium

Abstract

The embodiment of the invention discloses a surrounding rock pressure calculation method, device and equipment of a loess shield tunnel and a storage medium, and relates to the technical field of tunnel engineering. According to the scheme, the method comprises the steps that a plurality of sets of working condition data of the loess shield tunnel are obtained, wherein the working condition data are used for representing the moisture content and the tunnel burial depth of a loess layer of the loess shield tunnel; inputting each group of working condition data into a surrounding rock stress numerical simulation model to obtain surrounding rock stress data of each group of working condition data; the surrounding rock stress numerical simulation model is established by combining test data of a loess shield model test with finite element software; determining the surrounding rock pressure type of each group of working condition data according to the surrounding rock stress data; according to all the surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types, the surrounding rock pressure of the loess shield tunnel is calculated, and therefore the accuracy of the surrounding rock pressure of the loess shield tunnel is improved, and accurate guidance is provided for design of the loess shield tunnel.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel engineering, and in particular to a method, device, equipment and storage medium for calculating the surrounding rock pressure of a loess shield tunnel. Background Art

[0002] The surrounding rock pressure is the pressure generated on the contact surface between the support and the surrounding rock when the surrounding rock deformation is blocked by the support structure during the process of stress redistribution caused by the disturbance of the rock mass. It is the force that causes deformation or destruction of the rock mass and support around the underground excavation space.

[0003] In related technologies, the calculation of surrounding rock pressure of loess tunnels refers to the calculation method of surrounding rock pressure of mountain tunnels. Since factors such as the timing of shield support construction, construction disturbance, and cross-sectional shape of mountain tunnels are significantly different from those of loess tunnels, the accuracy of surrounding rock pressure of loess shield tunnels cannot be guaranteed, and thus the design of loess shield tunnels cannot be accurately guided. Summary of the invention

[0004] The embodiments of this specification provide a method for calculating the surrounding rock pressure of a loess shield tunnel to solve the problem that the accuracy of the surrounding rock pressure of a loess shield tunnel cannot be guaranteed in the prior art and the design of the loess shield tunnel cannot be accurately guided.

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

[0006] In a first aspect, an embodiment of this specification provides a method for calculating the surrounding rock pressure of a loess shield tunnel, comprising:

[0007] Acquire several groups of working condition data of a loess shield tunnel, wherein the working condition data is used to characterize the moisture content of the loess layer of the loess shield tunnel and the buried depth of the tunnel;

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

[0009] Determining the surrounding rock pressure type of each group of working condition data according to the surrounding rock stress data;

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

[0011] In a second aspect, an embodiment of the present specification provides a surrounding rock pressure calculation device for a loess shield tunnel, comprising:

[0012] A working condition data acquisition module, used to acquire several groups of working condition data of a loess shield tunnel, wherein the working condition data is used to characterize the moisture content of the loess layer of the loess shield tunnel and the buried depth of the tunnel;

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

[0014] A surrounding rock pressure type determination module, used to determine the surrounding rock pressure type of each group of working condition data according to 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 surrounding rock pressure algorithms corresponding to all surrounding rock pressure types.

[0016] In a third aspect, an embodiment of the present specification provides 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, wherein the processor executes the computer program to implement the method for calculating the surrounding rock pressure of a loess shield tunnel in scheme one.

[0017] In a fourth aspect, an embodiment of the present specification provides 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 a loess shield tunnel in scheme one.

[0018] An embodiment of the present specification realizes the following beneficial effects: by inputting the working condition data characterizing the moisture content of the loess layer of the loess shield tunnel and the tunnel burial depth into the surrounding rock stress numerical simulation model established according to the test data of the loess shield model test combined with finite element software, the surrounding rock stress data is obtained, and the surrounding rock pressure type of the loess shield tunnel is determined according to the surrounding rock stress data. The surrounding rock pressure of the loess shield tunnel is calculated by a surrounding rock pressure algorithm corresponding to the surrounding rock pressure type of the loess shield tunnel, thereby improving the accuracy of the surrounding rock pressure of the loess shield tunnel, and further providing accurate guidance for the design of loess shield tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1A schematic flow chart of a method for calculating surrounding rock pressure of a loess shield tunnel provided in an embodiment of this specification;

[0021] Figure 2 A schematic diagram of the relative position of the bearing area and the ground surface 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 An application scenario of a method for calculating surrounding rock pressure of a loess shield tunnel provided in an embodiment of this specification is intended to illustrate the present invention;

[0024] Figure 5 A schematic diagram summarizing the model test stress data and numerical simulation stress data proposed 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 an embodiment of this specification;

[0026] Figure 7 A schematic diagram of the structure of a surrounding rock pressure calculation device for a loess shield tunnel provided in an embodiment of this specification. DETAILED DESCRIPTION

[0027] In order to make the purpose, 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 combination with the specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of one or more embodiments of this specification.

[0028] The loess layer has strong structural and water-sensitive characteristics. The water content is an important factor that determines the surrounding rock load, and the burial depth is an important factor that affects the safety of the tunnel structure. Therefore, under the superposition of different water content and burial depth, the surrounding rock zoning that characterizes the degree of disturbance of the surrounding rock under the disturbance of the shield construction is relatively vague, and it is difficult to determine the calculation formula for the surrounding rock pressure of the loess shield tunnel under different working conditions, resulting in poor accuracy of the surrounding rock pressure of the loess shield tunnel.

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

[0030] A method for calculating the surrounding rock pressure of a loess shield tunnel provided in the embodiment of the specification is specifically described in conjunction with the accompanying drawings.

[0031] Figure 1 A flowchart of a method for calculating surrounding rock pressure of a loess shield tunnel provided in an embodiment of this specification is provided. From a program perspective, the execution subject of the process can be a program or application client installed on an application server. On the other hand, from a hardware perspective, the execution subject of the process can be a terminal device, which is not particularly limited in this embodiment.

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

[0033] Step 110: Acquire several groups of working condition data of the loess shield tunnel, wherein the working condition data are used to characterize the moisture content of the loess layer of the loess shield tunnel and the tunnel burial depth.

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

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

[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 of each set of working condition data; the surrounding rock stress numerical simulation model is established by combining the test data of the loess shield model test with finite element software.

[0037] In the embodiments of the present 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 are extracted and saved. The surrounding rock stress data can be obtained quickly and accurately through the surrounding rock stress numerical simulation model.

[0038] Step 130: Determine the surrounding rock pressure type of each set of operating condition data according to the surrounding rock stress data.

[0039] In the embodiments of this specification, in a tunnel, the types of surrounding rock pressure 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 by analysis software. The surrounding rock stress data can include radial stress and hoop stress. Based on the surrounding rock stress data, the deformation characteristics of the surrounding rock can be preliminarily judged. For example, if the radial stress of the surrounding rock decreases significantly, while the hoop 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 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 surrounding rock pressure type is selected, and the specific parameters of the loess shield tunnel (such as surrounding rock density, tunnel burial depth, mechanical properties of loess, etc.) are input into the selected algorithm for calculation. The surrounding rock pressure of the loess shield tunnel can be accurately obtained, providing 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 can be interchanged according to actual needs, or some steps can be omitted or deleted.

[0044] In the embodiments of the present specification, the surrounding rock pressure of the loess shield tunnel is calculated by inputting the working condition data characterizing the moisture content of the loess layer of the loess shield tunnel and the tunnel burial depth into a surrounding rock stress numerical simulation model established according to the test data of the loess shield model test combined with finite element software. The accuracy of the surrounding rock pressure of the loess shield tunnel is improved through the surrounding rock stress numerical simulation model, thereby providing accurate guidance for the design of loess shield tunnels.

[0045] based on Figure 1 The method in this specification also provides some specific implementation plans of the method, which are described below.

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

[0047] Construct a test box for loess shield model testing;

[0048] Obtaining pressure data of the loess shield tunnel according to a pressure sensor arranged inside the test box;

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

[0050] In the embodiments of this specification, a test soil sample similar to the stratum traversed by the loess shield tunnel in the actual project can be used, which is prepared with quartz sand: remolded loess: slaked lime: kaolin = 0.9: 0.07: 0.01: 0.02. The test soil sample is filled into the test box, and a pressure sensor is arranged in the test soil sample to monitor the stress change of the surrounding rock, and then the shield excavation test is carried out through the indoor shield tunneling device.

[0051] According to the characteristics and simulation requirements of the loess shield tunnel, appropriate finite element software, such as ANSYS, ABAQUS, etc., is selected, and necessary configuration and settings are made to the software, such as material properties, boundary conditions, etc. The pressure data is imported into the finite element software. According to the actual structure and size of the loess shield tunnel, the corresponding three-dimensional model is constructed in the finite element software, that is, the numerical simulation model of surrounding rock stress.

[0052] In practical applications, the distribution law of surrounding rock pressure of loess shield tunnels is different under different working conditions, that is, as the tunnel depth and loess moisture content change, the tunnel surrounding rock pressure also changes. Therefore, loess shield model tests are carried out for different working conditions. The test simulates the process of shield machine excavating in loess by excavating in the test box through the servo excavation system. By comparing and verifying the stress data obtained by the loess shield model test with the surrounding rock stress numerical simulation model, the parameters of the surrounding rock stress numerical simulation model can be optimized to ensure the accuracy of the surrounding rock stress numerical simulation model.

[0053] The parameters of the surrounding rock stress numerical simulation model include surrounding rock, shield shell properties, and segment property data. The Drucker-Prager (DP) strength criterion is used for the stratum, and the elastic constitutive model is used for the segment. The loess shield model test is carried out, and the model test parameters are shown in Table 1.

[0054] Table 1 Model test parameters

[0055]

[0056] Optionally, in the embodiments of this specification, determining the surrounding rock pressure type of each group of working condition data according to the surrounding rock stress data may specifically include:

[0057] Divide the surrounding rock stress data according to a preset surrounding rock partitioning algorithm to obtain surrounding rock partitions for each set of working condition data; wherein the surrounding rock partitions include at least one of a loose zone, a plastic zone, an elastic zone, and an original rock stress zone, and the preset surrounding rock partitioning algorithm includes surrounding rock partitioning criteria;

[0058] The surrounding rock pressure type of each group of operating condition data is determined according to the surrounding rock partitioning.

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

[0060] The boundary of the loose zone is the distance from the boundary of the tunnel excavation chamber to the intersection of the hoop 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 hoop stress. The boundary of the elastic zone is the distance from the boundary of the chamber excavation to the point where the hoop stress recovers to the original rock stress.

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

[0062] Optionally, in the embodiments of this specification, determining the surrounding rock pressure type of each group of working condition data according to the surrounding rock partition may specifically include:

[0063] Determining whether the surrounding rock partition includes the loose zone;

[0064] If yes, then determine that the surrounding rock pressure type of each set of working condition data is loose surrounding rock pressure;

[0065] If not, it is determined that the surrounding rock pressure type of each set of operating condition data is deformation surrounding rock pressure.

[0066] In the embodiments of this specification, it is determined whether these partitions include loose areas. The loose areas usually indicate that the surrounding rock has been significantly loosened and damaged, and are areas with poor surrounding rock stability.

[0067] If the surrounding rock partition contains loose areas, it can be judged that the surrounding rock pressure type corresponding to this group of working condition data is loose surrounding rock pressure. Loose surrounding rock pressure is mainly caused by the loosening and damage of the surrounding rock. It is usually necessary to strengthen the support structure to ensure the stability of the tunnel.

[0068] If the surrounding rock partition does not contain loose areas, it can be judged that the surrounding rock pressure type corresponding to this group of working condition data is deformation surrounding rock pressure. The deformation surrounding rock pressure is mainly caused by the plastic deformation of the surrounding rock. This deformation usually gradually stabilizes under the action of the support structure.

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

[0070] In practical applications, the surrounding rock stress before excavation is taken as the original rock stress, which is the initial stress. When the circumferential stress of the stress data output by the numerical simulation model of surrounding rock stress is always less than the initial stress, it is considered that the surrounding rock has plastic zone I, that is, there is a loose zone, and the surrounding rock pressure type is considered to be loose surrounding rock pressure. When the circumferential stress of the stress data output by the numerical simulation model of surrounding rock stress is always greater than the initial stress, it is considered that the surrounding rock has no plastic zone I, that is, there is no loose zone, and the surrounding rock pressure type is considered to be deformation surrounding rock pressure.

[0071] Further, optionally, in the embodiment of this specification, if the surrounding rock partition includes the plastic zone and / or the elastic zone, the plastic zone and the elastic zone are used as the bearing zone, and the surrounding rock pressure type of each set of working condition data is determined to be deformation surrounding rock pressure, which may specifically include:

[0072] Determining whether the bearing area of ​​the surrounding rock partition penetrates the ground surface;

[0073] If yes, then determine that the surrounding rock pressure type of each set of working condition data is shallow buried loose surrounding rock pressure;

[0074] If not, it is determined that the surrounding rock pressure type of each set of operating condition data is deep-buried loose surrounding rock pressure.

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

[0076] Figure 2 A schematic diagram of the relative position of the bearing area and the ground surface provided in an embodiment of this specification.

[0077] like Figure 2 As shown in Figure 1, if the bearing area runs through the ground surface, it means that there is not enough cover above the tunnel to provide sufficient pressure support, so the surrounding rock around the tunnel may be more susceptible to loosening and damage. It can be judged that the surrounding rock pressure type corresponding to this group of working condition data is shallow buried loose surrounding rock pressure.

[0078] If the bearing area does not penetrate the ground surface, it means that there is enough cover above the tunnel to provide pressure support, and the surrounding rock around the tunnel may be relatively stable. It can be judged that the surrounding rock pressure type corresponding to this set of working condition data is deep buried loose surrounding rock pressure.

[0079] According to the preset surrounding rock partitioning algorithm, the position, range and relative position relationship of each partition with the tunnel can be obtained. Furthermore, the regional boundary value of each surrounding rock partition can be obtained. Table 2 shows the boundary values ​​of the loose zone, plastic zone and elastic zone of the surrounding rock under different working conditions, where D represents the tunnel section width, "∞" represents that the bearing zone has developed to the surface, L represents the boundary value of the loose 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 surrounding rock loose zone, plastic zone and elastic zone under different working conditions

[0081]

[0082]

[0083] The type of surrounding rock pressure can be determined by judging whether the surrounding rock partition contains a loose zone and whether the bearing zone of the surrounding rock partition runs through the surface. According to the boundary values ​​of the loose 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] Working conditions 1.5D 2.25D 3D 3.75D 9.6％ Deformation surrounding rock pressure Deformation surrounding rock pressure Deep buried loose surrounding rock pressure Deep buried loose surrounding rock pressure 18.6％ Shallow buried loose surrounding rock pressure Shallow buried loose surrounding rock pressure Deep buried loose surrounding rock pressure Deep buried loose surrounding rock pressure 27.6％ Shallow buried loose surrounding rock pressure Shallow buried loose surrounding rock pressure Deep buried loose surrounding rock pressure Deep buried loose surrounding rock pressure

[0086] In practical applications, the stress data of the plastic zone II and the elastic zone are higher than the initial stress, so they are collectively called the bearing zone. When the circumferential stress of the stress data output by the surrounding rock stress numerical simulation model is always greater than the initial stress, it is considered that the surrounding rock is always in the bearing zone. When the burial depth is relatively shallow and the outer boundary of the bearing zone has reached the surface, it is considered that the bearing zone has developed to the surface, that is, the surrounding rock pressure type is shallow buried loose 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 surrounding rock pressure types in the embodiments of this specification, the method may further include:

[0088] A corresponding relationship between the surrounding rock pressure type and the surrounding rock pressure algorithm is established, wherein the surrounding rock pressure algorithm includes at least one of the Fenner formula, the soil column formula and the Bill Bowman formula.

[0089] In the embodiments of this specification, for each type of surrounding rock pressure, it is necessary to select or determine a suitable surrounding rock pressure algorithm for calculation. According to the output results of the surrounding rock stress numerical simulation model, the corresponding relationship between the surrounding rock pressure type and the surrounding rock pressure algorithm can be established in advance.

[0090] The deformation 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; c is the surrounding rock cohesion; is the internal friction angle; R0 is the tunnel excavation radius; R p is the radius of the plastic zone.

[0093] The pressure of shallowly buried loose surrounding rock can be calculated using the soil column formula, which is:

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

[0095] The pressure of deep buried loose surrounding rock can be calculated using the Bill Bowman formula, which is:

[0096]

[0097] in,

[0098] D is the tunnel section width, H t is the tunnel section height.

[0099] Furthermore, when the surrounding rock pressure type is deep-buried loose surrounding rock pressure, it is possible to choose whether to superimpose the surrounding rock pressure algorithm according to the water content in the working condition data. The natural water content can be used as a reference, and a water content greater than the natural water content is a high water content, and a water content less than the natural water content is a low water content. For example, 18.6% is used as the natural water content reference, and 9.6% in Table 3 is a low water content, and 27.6% is a high water content.

[0100] The Bill Bowman formula can be used to calculate the deep-buried loose surrounding rock pressure under low water content, and the superposition formula can be used to calculate the deep-buried loose surrounding rock pressure under high water content. The superposition formula is:

[0101] P=P l +P i , P l =γ×R l ,

[0102] Among them, R l is the radius of the loose zone, α and k are DP criterion material parameters.

[0103] Furthermore, when the tunnel burial depth is large, for example, the tunnel burial depth is greater than 3D, when the water content reaches the natural water content, the superposition formula can be used.

[0104] The surrounding rock pressure algorithm can be determined through the correspondence between the surrounding rock pressure type and the surrounding rock pressure algorithm. According to the surrounding rock pressure types under different working conditions in Table 3, the corresponding surrounding rock pressure algorithm can be determined.

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

[0106] Working 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 surrounding rock stress numerical simulation model need to be compared and verified with the test data provided by the loess shield model test. If the calculated results are significantly different from the actual situation, the algorithm needs to be adjusted or reselected.

[0108] If there are multiple types of surrounding rock pressure in the tunnel at the same time, it is necessary to calculate each type of surrounding rock pressure separately, and consider the interaction and influence between them, superimpose or comprehensively consider various surrounding rock pressures to obtain the total surrounding rock pressure of the loess shield tunnel. In actual engineering, a combination of multiple methods and means can also be used for comprehensive analysis and judgment.

[0109] Optionally, the preset surrounding rock partitioning algorithm in the embodiment of this specification includes standard stress data for characterizing the basis for the division of surrounding rock partitions, and the surrounding rock stress data is divided according to the preset surrounding rock partitioning algorithm to obtain the surrounding rock partitions of each group of working condition data, which may specifically include:

[0110] The surrounding rock partition of each group of working condition data is obtained according to the matching result of the surrounding rock stress data and the standard stress data.

[0111] In the embodiments of this specification, based on geomechanics principles, engineering experience, numerical simulation results, etc., standard stress data for dividing surrounding rocks into different regions to reflect their degree of disturbance and stability are obtained. The standard stress data may include boundary stress values ​​of each surrounding rock partition. The surrounding rock stress data is matched with the standard stress data to obtain the surrounding rock partitions for each set of working condition data.

[0112] Figure 3 A schematic diagram of the elastic-plastic stress state of the surrounding rock provided in the embodiments of this specification.

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

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

[0115] The area corresponding to the circumferential stress less than or equal to the initial stress in the previous data sequence is taken as plastic zone I (loose zone), the area corresponding to the circumferential stress greater than the initial stress and less than or equal to the stress extreme point in the previous data sequence is taken as plastic zone II (plastic zone), and the area corresponding to the circumferential stress less than the stress extreme point and greater than or equal to the stress intersection point in the subsequent data sequence is taken as the elastic zone, and the area outside the outer boundary of the elastic zone is the original rock stress zone.

[0116] Figure 4 A schematic diagram of an application scenario of a method for calculating surrounding rock pressure of a loess shield tunnel provided in an embodiment of this specification.

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

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

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

[0120] Step 403: Analyze surrounding rock stress data according to a preset surrounding rock partitioning algorithm to obtain surrounding rock partitions;

[0121] Step 404: determining whether the surrounding rock partition includes a loose area;

[0122] Step 405: If not, determine that the surrounding rock pressure type is deformation surrounding rock pressure;

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

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

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

[0126] Step 409: If yes, determine the surrounding rock pressure type as shallow buried loose surrounding rock pressure;

[0127] Step 410: According to the preset correspondence between the surrounding rock pressure type and the surrounding rock pressure algorithm, the surrounding rock pressure algorithm corresponding to the different surrounding rock pressure types is determined, and the surrounding rock pressure of the loess shield tunnel is calculated.

[0128] Figure 5 This is a schematic diagram summarizing the model test stress data and numerical simulation stress data proposed in the embodiments of this specification.

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

[0130] In practical applications, the surrounding rock stress data is obtained by inputting the working condition data characterizing the moisture content of the loess layer of the loess shield tunnel and the tunnel burial depth into the surrounding rock stress numerical simulation model established according to the test data of the loess shield model test combined with finite element software. The surrounding rock stress data is then used to determine the surrounding rock pressure type of the loess shield tunnel. The surrounding rock pressure of the loess shield tunnel is calculated using the surrounding rock pressure algorithm corresponding to the surrounding rock pressure type of the loess shield tunnel, thereby improving the accuracy of the surrounding rock pressure of the loess shield tunnel and providing accurate guidance for the design of the loess shield tunnel.

[0131] Figure 6 This is a schematic structural diagram 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 of the loess shield tunnel described in the embodiment of this specification may include:

[0133] The working condition data acquisition module 602 is used to acquire several groups of working condition data of the loess shield tunnel, wherein the working condition data is used to characterize the moisture content of the loess layer of the loess shield tunnel and the tunnel burial depth;

[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 of each set of working condition data; the surrounding rock stress numerical simulation model is established by combining the test data of the loess shield model test with finite element software;

[0135] A surrounding rock pressure type determination module 606, configured to determine the surrounding rock pressure type of each set of working condition data according to 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 surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

[0137] Based on the same idea, the embodiments of this specification also provide a device corresponding to the above method.

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

[0139] A surrounding rock pressure calculation device for a loess shield tunnel provided in an embodiment of the present specification may include a memory, a processor, and a computer program stored in the memory, and the processor executes the computer program to implement the surrounding rock pressure calculation method for a loess shield tunnel described in any of the above embodiments.

[0140] An embodiment of the present specification provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for calculating the surrounding rock pressure of a loess shield tunnel described in any of the above embodiments can be implemented.

[0141] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. Figure 7 As for the device shown, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0142] In the 1990s, improvements to a technology could be clearly distinguished as hardware improvements (for example, improvements to the circuit structure of diodes, transistors, switches, etc.) or software improvements (improvements to the method flow). However, with the development of technology, many improvements to the method flow today can be regarded as direct improvements to the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that an improvement in a method flow cannot be implemented using a hardware entity module. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming it themselves, without having to ask a chip manufacturer to design and produce a dedicated integrated circuit chip. Moreover, nowadays, instead of manually making integrated circuit chips, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). There is not only one HDL, but many kinds, 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, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0143] The controller can be implemented in any appropriate manner, for example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (such as software or firmware) that can be executed by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in a purely computer-readable program code manner, the controller can be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included therein for implementing various functions can also be regarded as structures within the hardware component. Or even, the devices for implementing various functions can be regarded as both software modules for implementing the method and structures within the hardware component.

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

[0145] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0146] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented 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] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0148] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0149] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions 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] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0152] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules 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 technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0153] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0154] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

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

[0156] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for calculating surrounding rock pressure of a loess shield tunnel, characterized in that: include: Acquire several groups of working condition data of a loess shield tunnel, wherein the working condition data is used to characterize the moisture content of the loess layer of the loess shield tunnel and the buried depth of the tunnel; Input each set of working condition data into the surrounding rock stress numerical simulation model respectively to obtain surrounding rock stress data of each set of working condition data; The surrounding rock stress numerical simulation model is established by combining the test data of the loess shield model test with finite element software; Determining the surrounding rock pressure type of each group of working condition data according to the surrounding rock stress data; The surrounding rock pressure of the loess shield tunnel is calculated according to all surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

2. The method according to claim 1, characterized in that Before inputting each set of working condition data into the surrounding rock stress numerical simulation model, the method further includes: Construct a test box for loess shield model testing; Obtaining pressure data of the loess shield tunnel according to a pressure sensor arranged inside the test box; The pressure data is combined with finite element software to obtain the surrounding rock stress numerical simulation model.

3. The method according to claim 1, characterized in that Determining the surrounding rock pressure type of each set of working condition data according to the surrounding rock stress data specifically includes: Divide the surrounding rock stress data according to a preset surrounding rock partitioning algorithm to obtain surrounding rock partitions for each set of working condition data; wherein the surrounding rock partitions include at least one of a loose zone, a plastic zone, an elastic zone, and an original rock stress zone, and the preset surrounding rock partitioning algorithm includes surrounding rock partitioning criteria; The surrounding rock pressure type of each group of operating condition data is determined according to the surrounding rock partitioning.

4. The method according to claim 3, characterized in that Determining the surrounding rock pressure type of each group of working condition data according to the surrounding rock partition specifically includes: Determining whether the surrounding rock partition includes the loose zone; If yes, then determine that the surrounding rock pressure type of each set of working condition data is loose surrounding rock pressure; If not, it is determined that the surrounding rock pressure type of each set of operating condition data is deformation surrounding rock pressure.

5. The method according to claim 4, characterized in that If the surrounding rock partition includes the plastic zone and / or the elastic zone, the plastic zone and the elastic zone are used as bearing zones, and the type of surrounding rock pressure of each set of working condition data is determined to be deformation surrounding rock pressure, specifically including: Determining whether the bearing area of ​​the surrounding rock partition penetrates the ground surface; If yes, then determine that the surrounding rock pressure type of each set of working condition data is shallow buried loose surrounding rock pressure; If not, it is determined that the surrounding rock pressure type of each set of operating condition data is deep-buried loose surrounding rock pressure.

6. The method according to claim 1, characterized in that Before calculating the surrounding rock pressure of the loess shield tunnel according to all surrounding rock pressure algorithms corresponding to all surrounding rock pressure types, the method further includes: A corresponding relationship between the surrounding rock pressure type and the surrounding rock pressure algorithm is established, wherein the surrounding rock pressure algorithm includes at least one of the Fenner formula, the soil column formula and the Bill Bowman formula.

7. The method according to claim 3, characterized in that The preset surrounding rock partitioning algorithm includes standard stress data for characterizing the basis for the division of surrounding rock partitions. The surrounding rock stress data is divided according to the preset surrounding rock partitioning algorithm to obtain the surrounding rock partitions of each group of working condition data, specifically including: The surrounding rock partition of each group of working condition data is obtained according to the matching result of the surrounding rock stress data and the standard stress data.

8. A device for calculating surrounding rock pressure of a loess shield tunnel, characterized in that: include: A working condition data acquisition module, used to acquire several groups of working condition data of a loess shield tunnel, wherein the working condition data is used to characterize the moisture content of the loess layer of the loess shield tunnel and the buried depth of the tunnel; A 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 of each set of working condition data; The surrounding rock stress numerical simulation model is established by combining the test data of the loess shield model test with finite element software; A surrounding rock pressure type determination module, used to determine the surrounding rock pressure type of each group of working condition data according to 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 surrounding rock pressure algorithms corresponding to all the surrounding rock pressure types.

9. A device for calculating 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 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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