Parameter simulation calculation method and device for soft rock tunnel face advance reinforcement system

Abstract

The present disclosure provides a method and device for simulating and calculating the parameters of the advance reinforcement system of a soft rock tunnel face, which belongs to the field of data processing technology. The method includes: dividing the tunnel surrounding rock from the elastic-plastic boundary inward into second concentric rings until the tunnel excavation radius; starting from the first second concentric ring, calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; wherein, if the inner diameter of the second concentric ring is less than or equal to the grouting depth, adjusting the mechanical parameters of the tunnel surrounding rock based on the grouting reinforcement parameters; if the second safety factor is less than or equal to the set threshold, adjusting the parameters of the advance reinforcement system, and returning to the step of calculating the second extrusion deformation; if the second safety factor is greater than the set threshold, outputting the calculation results of the parameters of the advance reinforcement system. The method and device for simulating and calculating the parameters of the advance reinforcement system of a soft rock tunnel face provided by the present disclosure are helpful to improve the stability of the tunnel face and the safety of construction.

Description

Technical Field

[0001] The present invention belongs to the field of data processing technology, and more specifically, relates to a method and device for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system. Background Art

[0002] Due to the high-energy geological environment and the special mechanical properties of soft rock in high-geo-stress soft rock tunnel projects, the stability control of the tunnel face is quite difficult. However, the stability of the tunnel face has a crucial impact on the construction safety and progress of the entire tunnel project. Therefore, the stability control of the tunnel face in high-geo-stress soft rock tunnels is a major engineering problem that tunnel practitioners and scientific researchers need to solve urgently.

[0003] Glass fiber anchor bolts (hereinafter referred to as face anchor bolts), face grouting, and face shotcrete are the most commonly used face stability pre-reinforcement measures. The three are combined to form a tunnel face pre-reinforcement system, which has been increasingly used in actual projects of high-ground stress soft rock tunnels. However, the current application and promotion of the tunnel face pre-reinforcement system has the following two shortcomings: (1) The parameters of the tunnel face pre-reinforcement system are mostly determined by engineering experience or engineering analogy, resulting in the inability to reasonably quantitatively evaluate the reinforcement effect of the tunnel face pre-reinforcement system; (2) Most of the existing face pre-reinforcement stability evaluation methods are based on static equilibrium theory and are mainly applicable to soil or broken surrounding rock strata, but have limited applicability to high-ground stress soft rock tunnels.

[0004] Therefore, it is urgent to propose a parameter design method for the tunnel face advance reinforcement system suitable for high-ground stress soft rock, to achieve quantitative design and evaluation of the parameters of the tunnel face advance reinforcement system, to provide theoretical guidance and suggestions for actual tunnel engineering, and to help improve the stability of the tunnel face and construction safety. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system, which can realize quantitative design and evaluation of the parameters of the face advance reinforcement system, provide theoretical guidance and suggestions for actual tunnel engineering, and help improve the stability of the tunnel face and construction safety.

[0006] In a first aspect of the disclosed embodiment, a method for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system is provided, comprising: dividing the tunnel surrounding rock from the elastic-plastic boundary inward into A second concentric ring, until the radius of the tunnel excavation;

[0007] Starting from the first of the second concentric circles, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; the second extrusion deformation is the extrusion deformation of the tunnel face under the advanced reinforcement condition;

[0008] Among them, if The inner diameter of the second concentric ring is less than or equal to the grouting depth, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters; the mechanical parameters of the tunnel surrounding rock belong to the geological data of the tunnel site; the second safety factor is calculated based on the second extrusion deformation; the second safety factor is used to characterize the stability of the tunnel face under the condition of advanced reinforcement of the tunnel face;

[0009] If the second safety factor is less than or equal to the set threshold, adjust the parameters of the advance reinforcement system and return to the step of calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters starting from the first of the second concentric rings; if the second safety factor is greater than the set threshold, output the calculation results of the advance reinforcement system parameters; the advance reinforcement system parameters include the anchor reinforcement parameters and the grouting reinforcement parameters.

[0010] A second aspect of the embodiments of the present disclosure provides a device for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system, comprising:

[0011] The first calculation module is used to divide the tunnel surrounding rock from the elastic-plastic boundary into A second concentric ring, until the radius of the tunnel excavation;

[0012] The second calculation module is used to calculate the second extrusion deformation amount starting from the first of the second concentric rings based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; the second extrusion deformation amount is the extrusion deformation amount of the tunnel face under the advanced reinforcement condition;

[0013] Among them, if The inner diameter of the second concentric ring is less than or equal to the grouting depth, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters; the mechanical parameters of the tunnel surrounding rock belong to the geological data of the tunnel site; a third calculation module is used to calculate a second safety factor based on the second extrusion deformation; the second safety factor is used to characterize the stability of the tunnel face under the condition of advanced reinforcement of the tunnel face;

[0014] Parameter output module, if the second safety factor is less than or equal to the set threshold, adjust the parameters of the advance reinforcement system, return to execute the step of calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters starting from the first second concentric ring; if the second safety factor is greater than the set threshold, output the calculation results of the advance reinforcement system parameters; the advanced reinforcement system parameters include the anchor reinforcement parameters and the grouting reinforcement parameters.

[0015] The beneficial effects of the method and device for simulating and calculating parameters of the advance reinforcement system of the soft rock tunnel face provided by the embodiments of the present disclosure are:

[0016] In the disclosed embodiment, taking into account that the evolution mechanism of deformation, instability and failure of the heading face of high-ground stress soft rock tunnels is significantly different from the evolution mechanism of deformation, instability and failure of the heading face of tunnels in soil strata or broken strata, the heading face extrusion deformation is used as the basis for judging the stability of the heading face of high-ground stress soft rock tunnels. Compared with the existing judgment basis based on static equilibrium theory, it is more suitable for the quantitative design of the advanced reinforcement system of the heading face of high-ground stress soft rock tunnels.

[0017] At the same time, the embodiment of the present disclosure takes into account that in the advanced reinforcement system, the three reinforcement methods have different action areas. Taking the advanced reinforcement system composed of the anchor reinforcement method and the grouting reinforcement method as an example, starting from the elastic-plastic boundary and calculating inward, it is possible to reach the anchor reinforcement area first and then the grouting reinforcement area. Therefore, the second extrusion deformation is first iteratively calculated according to the anchor reinforcement condition. If the iteration reaches a certain position (for example, the first The second concentric ring), The inner diameter of the second concentric ring is less than or equal to the grouting depth, indicating that the iteration has reached the grouting depth. When continuing to iterate downward, the influence of the grouting reinforcement method on the mechanical parameters of the tunnel surrounding rock is considered, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters. The second extrusion deformation is calculated based on the adjusted mechanical parameters. The above calculation method takes into account the combined effect of the reinforcement methods, which is conducive to the accurate calculation of the second extrusion deformation and the second safety factor, and then uses the second safety factor as an evaluation standard to calculate the parameters of the advance reinforcement system, which can obtain accurate calculation results, thereby realizing the quantitative design and evaluation of the parameters of the advance reinforcement system of the face, providing theoretical guidance and suggestions for actual tunnel engineering, and helping to improve the stability of the tunnel face and construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, 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 of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic flow chart of a method for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system provided in an embodiment of the present disclosure;

[0020] Figure 2 A schematic flow chart of a method for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system provided by another embodiment of the present disclosure;

[0021] Figure 3 A schematic diagram of calculating the equivalent circle of a horseshoe section provided in one embodiment of the present disclosure;

[0022] Figure 4 A schematic diagram of tunnel surrounding rock differentials provided by an embodiment of the present disclosure;

[0023] Figure 5 A schematic diagram of the relationship between the anchor rod length and the surrounding rock plastic zone provided in an embodiment of the present disclosure; wherein, Figure 5 (a) is a schematic diagram of anchor length = plastic zone radius. Figure 5 (b) is a schematic diagram of anchor length > plastic zone radius. Figure 5 (c) is a schematic diagram of anchor length < plastic zone radius;

[0024] Figure 6 A schematic diagram of a graphical method provided for an embodiment of the present disclosure;

[0025] Figure 7 A structural block diagram of a parameter simulation and calculation device for a soft rock tunnel face advance reinforcement system provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present disclosure. However, it should be clear to those skilled in the art that the present disclosure may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obstructing the description of the present disclosure with unnecessary details.

[0027] In order to make the purpose, technical solutions and advantages of the present disclosure more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0028] The following is an introduction to the technical terms involved in this embodiment.

[0029] Elastic-plastic boundary: In tunnel excavation, foundation treatment and other projects, the elastic-plastic properties of rock and soil need to be considered to evaluate the stability and safety of the project. Therefore, the concept of elastic-plastic boundary is often used. The elastic-plastic boundary refers to the boundary position where the material changes from the elastic state to the plastic state. At the elastic-plastic boundary, the stress of the material reaches the yield stress (that is, the critical stress value for the material to change from the elastic state to the plastic state). At the elastic-plastic boundary, the strain of the material will also change. In the elastic stage, the strain of the material is reversible. When unloaded, the material can return to its original shape and size; in the plastic stage, the strain of the material is irreversible. Even after unloading, the material will retain a certain permanent deformation.

[0030] Excavation radius: The excavation radius is the radius of the circular or arc area formed by excavation work in the construction of tunnels, mines, foundation projects, etc. In tunnel excavation, the excavation radius usually refers to the radius of the tunnel cross section.

[0031] Plastic zone radius: In geotechnical engineering, tunnel excavation will cause stress redistribution in the surrounding rock and soil. When the stress exceeds the yield strength of the rock and soil, a plastic zone will be formed around the tunnel. The plastic zone radius refers to the size of the area where the material undergoes plastic deformation under the action of force.

[0032] Please refer to Figure 1-Figure 2 , Figure 1 A flow chart of a method for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system provided in an embodiment of the present disclosure, the method comprising:

[0033] S101: The tunnel surrounding rock is divided into A second concentric ring is formed until the radius of the tunnel excavation.

[0034] In this embodiment, based on the sphere theory, the tunnel face excavation process is considered as the excavation process of a hollow sphere. The cross-sectional shapes of soft rock tunnels are mainly horseshoe-shaped and circular. For non-circular sections, the equivalent circle radius calculation is required.

[0035] Please refer to Figure 3 , the radius of the equivalent circle obtained by the calculation method of the radius of the horseshoe equivalent circle ( ) is the height of the horseshoe section ( ) and span ( ) is 1 / 4 of the sum of . The specific calculation formula is as follows:

[0036]

[0037] On this basis, the tunnel surrounding rock is subjected to differential and radius normalization processing: the surrounding rock is divided into multiple second concentric rings from the elastic-plastic boundary to the tunnel excavation radius, and the confining pressure (i.e. radial stress) and plastic deviatoric strain of each second concentric ring are substituted into the soft rock mechanical parameter evolution model to calculate the corresponding mechanical parameters; and, according to symmetry, the mechanical parameters at different angles of the same ring are the same. Figure 4 As shown, Figure 4 Reference numeral 41 indicates a tunnel face, and reference numeral 42 indicates an elastic-plastic boundary.

[0038] The radius of the surrounding rock ring is normalized and the radius of the plastic zone is assumed to be , the expression of the normalized radius of the annulus is as follows.

[0039]

[0040] in, Indicates The normalized radius of the second concentric ring, Indicates The inner diameter of the second concentric ring; the normalized radius of the first second concentric ring (i.e. the first ring) is .

[0041] S102: Starting from the first second concentric ring, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; the second extrusion deformation is the extrusion deformation of the tunnel face under the advanced reinforcement condition.

[0042] Among them, if The inner diameter of the second concentric ring is less than or equal to the grouting depth, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting depth; the mechanical parameters of the tunnel surrounding rock belong to the geological data of the tunnel site;

[0043] In this embodiment, the geological data of the tunnel site include ground stress, mechanical parameters of surrounding rock (such as elastic modulus, Poisson's ratio, cohesion, internal friction angle, etc.), which determine the deformation and failure characteristics of the surrounding rock under stress. Tunnel section data include tunnel section shape (such as circular, elliptical or horseshoe), section size (including specific values ​​such as tunnel height, width, radius, etc.). Anchor rod parameters include anchor rod length, anchor rod diameter, anchor rod spacing, etc. Grouting parameters include grouting material type (such as cement slurry, chemical slurry), material strength (including compressive strength, tensile strength, etc.), grouting pressure, grouting depth, grouting volume, etc. The geological data of the tunnel site and the tunnel section data can be obtained through actual measurement, and the anchor rod parameters and grouting parameters can be parameters pre-selected based on experience.

[0044] Considering that the three reinforcement methods have different action areas in the advanced reinforcement system, taking the advanced reinforcement system composed of anchor reinforcement and grouting reinforcement as an example, starting from the elastic-plastic boundary and calculating inward, it is possible to reach the anchor reinforcement area first and then the grouting reinforcement area. Therefore, the second extrusion deformation is iteratively calculated according to the anchor reinforcement condition. If the iteration reaches a certain position (for example, the first The second concentric ring), The inner diameter of the second concentric ring is less than or equal to the grouting depth, indicating that the iteration has reached the grouting depth. When continuing to iterate downward, the influence of the grouting reinforcement method on the mechanical parameters of the tunnel surrounding rock is considered, the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters, and the second extrusion deformation is calculated based on the adjusted mechanical parameters.

[0045] At the same time, considering the characteristics of the evolution of soft rock mechanical parameters, based on sphere theory, elastic-plastic theory and finite difference theory, a method for calculating the second extrusion deformation based on the geological data of the tunnel site, tunnel section data and anchor reinforcement parameters is proposed. This method is subject to the following assumptions:

[0046] (1) Based on the sphere theory, the tunnel face excavation process is considered as the excavation process of a hollow sphere, where the sphere radius is the tunnel face excavation radius. According to existing research results, the radial deformation of the hollow sphere is approximately equal to the extrusion deformation of the tunnel face. Therefore, the calculation of the extrusion deformation of the tunnel face (also known as the second extrusion deformation) is transformed into the calculation of the radial deformation of the hollow sphere.

[0047] (2) The tunnel surrounding rock is regarded as an isotropic and homogeneous material, and its mechanical parameters (including elastic modulus, Poisson's ratio, friction angle and cohesion) obey the soft rock mechanical parameter evolution model. The soft rock mechanical parameter evolution model is as follows:

[0048]

[0049] in, represents the plastic deviatoric strain, represents the strength stress ratio ( ), represents the confining pressure, Indicates the uniaxial compressive strength of the rock sample; represents the plastic deviatoric strain ratio, represents the critical plastic deviatoric strain; represents the dimensionless value of the elastic modulus, Indicates the real-time value of the elastic modulus, represents the elastic modulus of soft rock in the elastic stage under uniaxial conditions, represents the dimensionless value of Poisson's ratio, represents the real-time value of Poisson's ratio, represents the Poisson's ratio of soft rock in elastic stage under uniaxial condition, represents the dimensionless value of the friction angle, Indicates the real-time value of the friction angle, represents the friction angle of soft rock in elastic stage under uniaxial condition, is the dimensionless value of cohesion, Indicates cohesion, represents the cohesion of soft rock in the elastic stage under uniaxial conditions, Represents exponential operation with constant e as base; is a proportional parameter, which is obtained by fitting the triaxial compression test data of soft rock under cyclic loading and unloading conditions under different confining pressures.

[0050] The soft rock mechanical parameter evolution model used in this embodiment can fully characterize the change process of mechanical parameters of soft rock in different deformation stages (elastic stage, softening stage, residual stage) with confining pressure and plastic deviatoric strain. In addition, the above-mentioned soft rock mechanical parameter evolution model fully considers the coupling effect of confining pressure and plastic strain, and can accurately characterize the evolution process of soft rock mechanical parameters under the coupling effect of confining pressure and plastic strain, making the numerical simulation calculation results more accurate.

[0051] (3) The surrounding rock obeys the Mohr-Coulomb yield criterion, which is expressed as follows.

[0052]

[0053] in, is the radial stress, is the tangential stress, is the friction angle, For cohesion.

[0054] S103: Calculating a second safety factor based on the second extrusion deformation; the second safety factor is used to characterize the stability of the tunnel face under the condition of advanced face reinforcement.

[0055] In this embodiment, considering that different tunnel faces can withstand different ultimate extrusion deformations, the ultimate extrusion deformation of the tunnel face ( ) and the second extrusion deformation ( ) as the second safety factor , the specific formula is as follows:

[0056]

[0057] Second safety factor It can intuitively characterize the stability of the tunnel face under the condition of face grouting reinforcement.

[0058] Among them, the calculation of the extreme extrusion deformation of the tunnel face of high-in-situ stress soft rock tunnel can be carried out by numerical simulation method, and numerical simulation analysis can be carried out according to the specific high-in-situ stress soft rock tunnel engineering example to obtain the extreme extrusion deformation of the tunnel face corresponding to this engineering example. If the above numerical simulation method is not used, combined with the existing research results, it can be selected according to the span of the high-in-situ stress soft rock tunnel (as shown in Table 1) and the extrusion deformation control standard of the railway tunnel face in my country (as shown in Table 2).

[0059] Table 1 Classification standards for railway tunnel spans in my country

[0060]

[0061] Table 2 my country's railway tunnel face extrusion deformation control standards

[0062]

[0063] S104: If the second safety factor is less than or equal to the set threshold, adjust the parameters of the advance reinforcement system and return to the step of calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters starting from the first second concentric ring; if the second safety factor is greater than the set threshold, output the calculation results of the advanced reinforcement system parameters.

[0064] In this embodiment, by comparing the second safety factor under the advance reinforcement condition with the set threshold of the tunnel face safety factor, the safety and stability of the tunnel face of a high ground stress soft rock tunnel after advance reinforcement can be evaluated. If the second safety factor is greater than the set threshold, the tunnel face is safe and stable, and the parameter calculation is completed; if the second safety factor is less than or equal to the set threshold, the tunnel face is unstable, and the tunnel face advance reinforcement parameters need to be adjusted until the safety factor requirements are met.

[0065] Considering the complex geological conditions and construction factors, it is recommended to set the threshold to 1.5. If the surrounding rock conditions are poor and the ground stress level is high, the selection can be enlarged according to the actual situation to ensure a more adequate safety reserve.

[0066] From the above, it can be concluded that this embodiment takes into account that the evolution mechanism of deformation, instability and failure of the heading face of high-ground stress soft rock tunnels is significantly different from the evolution mechanism of deformation, instability and failure of the heading face of tunnels in soil strata or broken strata. The heading face extrusion deformation is used as the basis for judging the stability of the heading face of high-ground stress soft rock tunnels. Compared with the existing judgment basis based on static equilibrium theory, it is more suitable for the quantitative design of the advanced reinforcement system of the heading face of high-ground stress soft rock tunnels.

[0067] At the same time, this embodiment takes into account that the three reinforcement methods have different action areas in the advanced reinforcement system. Taking the advanced reinforcement system composed of anchor reinforcement and grouting reinforcement as an example, starting from the elastic-plastic boundary and calculating inward, it is possible to reach the anchor reinforcement area first and then the grouting reinforcement area. Therefore, the second extrusion deformation is iteratively calculated according to the anchor reinforcement condition. If the iteration reaches a certain position (for example, the first A second concentric ring, is a natural number, and ) The inner diameter of the second concentric ring is less than or equal to the grouting depth, indicating that the iteration has reached the grouting depth. When iterating further, the influence of the grouting reinforcement method on the mechanical parameters of the tunnel surrounding rock is considered, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters. The second extrusion deformation is calculated based on the adjusted mechanical parameters. The above calculation method takes into account the combined effect of the reinforcement methods, which is conducive to the accurate calculation of the second extrusion deformation and the second safety factor. Then, the second safety factor is used as an evaluation standard to calculate the parameters of the advance reinforcement system, which can obtain accurate calculation results, thereby improving the advance reinforcement effect of the face.

[0068] In one embodiment of the present disclosure, the advanced reinforcement system parameters also include shotcrete reinforcement parameters, and the second extrusion deformation is calculated based on the tunnel site geological data, tunnel section data and anchor reinforcement parameters, including:

[0069] Jordi The inner diameter of the second concentric ring is greater than the shotcrete depth, and the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters;

[0070] Jordi The inner diameter of the second concentric ring is less than or equal to the shotcrete depth, an extrusion deformation curve is drawn based on the anchor reinforcement parameters and the grouting reinforcement parameters, and a shotcrete reinforcement curve is drawn based on the shotcrete reinforcement parameters; and the intersection of the extrusion deformation curve and the shotcrete reinforcement curve is determined as the second extrusion deformation amount;

[0071] Among them, the extrusion deformation curve is used to characterize the extrusion deformation of the tunnel face under different support reaction forces, and the shotcrete reinforcement curve is used to characterize the extrusion deformation of the tunnel face under different concrete support reaction forces.

[0072] In this embodiment, if the tunnel face advance reinforcement system includes shotcrete reinforcement in addition to anchor reinforcement and grouting reinforcement, the effect of shotcrete reinforcement on the second extrusion deformation should be considered. The inner diameter of the second concentric ring is greater than the shotcrete depth, indicating that the shotcrete reinforcement area has not yet been reached. At this time, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters. A second concentric ring, is a natural number, and ) The inner diameter of the second concentric ring is less than or equal to the shotcrete depth, indicating that the shotcrete reinforcement area has been reached. Figure 6 As shown, the extrusion deformation curve is drawn based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters, and the shotcrete reinforcement curve is drawn based on the shotcrete reinforcement parameters. Then, based on the graphical method, the extrusion deformation characteristic curve and the shotcrete reinforcement curve are drawn in a coordinate system with the support reaction force as the ordinate and the extrusion deformation of the tunnel face as the abscissa. The intersection of the above two curves is determined, and the extrusion deformation of the tunnel face corresponding to the intersection is the extrusion deformation of the tunnel face after the shotcrete reinforcement (that is, the second deformation). Among them, Figure 6 Curve 1 in the middle is the extrusion deformation characteristic curve, and curve 2 is the shotcrete reinforcement curve.

[0073] It can be concluded from the above that this embodiment considers the combined effect of the three reinforcement methods to calculate the second extrusion deformation, which is conducive to the accurate calculation of the second extrusion deformation and the second safety factor.

[0074] In one embodiment of the present disclosure, starting from the first second concentric ring, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters, including:

[0075] If the anchor length is equal to the radius of the plastic zone, starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first second concentric ring is reached. A second concentric ring;

[0076] Based on The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings.

[0077] like Figure 5 As shown in the figure, due to the different lengths of anchor rods, according to the relationship between anchor rod length and plastic zone of surrounding rock, it can be divided into three cases: (1) The first case: anchor rod length = plastic zone radius; (2) The second case: anchor rod length > plastic zone radius; (3) The third case: anchor rod length < plastic zone radius. Therefore, the situation after anchor rod reinforcement should be judged first. It is assumed that the plastic zone radius of surrounding rock after anchor rod reinforcement is equal to the anchor rod length ( ), perform differential calculation based on the anchor length and solve the radial stress That is, starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first By comparing the The radial stress of the second concentric ring and support reaction , determine which of the above three situations the anchor reinforcement belongs to, the judgment method is as follows:

[0078] First case: If ,but ; Anchor length = plastic zone radius;

[0079] Second case: If ,but ; Anchor length > plastic zone radius;

[0080] The third case: If ,but ; Anchor rod length < plastic zone radius.

[0081] Among them, for a circular tunnel under uniform surrounding rock pressure, the support reaction force can be obtained by combining the axisymmetric elastic theory with the tunnel section data. Figure 5 Reference numeral 41 indicates a tunnel face, reference numeral 42 indicates an elastic-plastic boundary, and reference numeral 43 indicates an anchor bolt.

[0082] For the first case: anchor rod length = plastic zone radius, the second extrusion deformation calculation method is as follows:

[0083] (S11) Differential processing within the plastic zone of the surrounding rock. The surrounding rock is divided into From the second concentric ring to the outer radius of the tunnel, the mechanical parameters of the surrounding rock of each ring obey the soft rock mechanical parameter evolution model; and, based on symmetry, the mechanical parameters at different angles of the same ring are the same. It can be taken as 500. The differential step length expression is shown below.

[0084]

[0085] in, represents the width of the second concentric ring, represents the excavation radius of the tunnel face, Indicates the length of the anchor rod.

[0086] (S12) Solving the stress information of the first ring. According to the elastic-plastic boundary conditions, the radial stress and tangential stress at the elastic-plastic boundary (i.e., the first second concentric ring) are solved.

[0087]

[0088] in, represents the radial stress of the first second concentric ring, represents the tangential stress of the first second concentric ring, represents the initial ground stress, represents the yield function, represents the friction angle of the first second concentric ring, Represents the cohesion of the first second concentric ring.

[0089] (S13) Solve the strain information of the first ring. Since it is at the elastic-plastic boundary, based on the plastic increment theory, the strain information generated by plasticity is 0 at this time, so the strain information at the elastic-plastic boundary is as follows:

[0090]

[0091] in, represents the radial strain of the first second concentric ring caused by elasticity, represents the tangential strain of the first second concentric ring generated by elasticity, with the superscript Represents the elastic part, represents the elastic modulus of the first second concentric ring, represents the Poisson's ratio of the first second concentric ring.

[0092] (S14) Solving the anchor force information of the first ring. Assuming that the anchor and the surrounding rock deform cooperatively, the anchor force expression at the elastic-plastic boundary is as follows.

[0093]

[0094] in, Indicates the anchor force information of the first second concentric ring. represents the cross-sectional area of ​​the anchor rod, represents the elastic modulus of the anchor, represents the total radial strain of the first second concentric ring, .

[0095] (S15) Any ring in the middle ( According to the equilibrium equation and yield criterion, any middle ring ( The expression of the ring stress information is as follows:

[0096]

[0097]

[0098] in,

[0099]

[0100]

[0101]

[0102] in, represents the width of the second concentric ring, , represents the excavation radius of the tunnel face, Indicates the anchor length, Indicates The average radius of the second concentric rings, Indicates The strain increment of the second concentric ring is, For the The friction angle of the second concentric ring is, Indicates The cohesion of the second concentric ring, Indicates the vertical spacing of anchor rods (m), Indicates the horizontal spacing of anchor rods (m).

[0103] (S16) Any ring in the middle ( The strain information of any ring in the middle ( The expressions of strain increment caused by elasticity, strain increment caused by plasticity and total strain increment are as follows:

[0104]

[0105] in, The elasticity The radial strain increment of the second concentric ring is, The elasticity The tangential strain increment of the second concentric ring is, Indicates the first The tangential strain increment of the second concentric ring is, represents the shear dilatancy coefficient, Indicates the first The radial strain increment of the second concentric ring is, Indicates The total radial strain of the second concentric ring is, Indicates The total tangential strain of the second concentric ring.

[0106] (S17) Any ring in the middle ( The anchor force information of any intermediate ring is as follows:

[0107] .

[0108] Repeat steps (S15) to (S17) to solve the stress and strain information of the intermediate rings ring by ring until the final ring (the ring).

[0109] (S18) Extrusion deformation of the tunnel face. The calculation expression of the extrusion deformation of the tunnel face after reinforcement (also known as the second deformation) is as shown in the following formula:

[0110]

[0111] in, is the second extrusion deformation, For the The total tangential strain of the second concentric ring is The inner diameter of the second concentric ring is the tunnel face excavation radius .

[0112] In one embodiment of the present disclosure, if the anchor rod length is greater than the plastic zone radius, the inner end of the anchor rod is determined as the elastic-plastic boundary; starting from the first second concentric ring, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor rod reinforcement parameters, including:

[0113] If the anchor length is greater than the plastic zone radius, the set boundary radial stress is determined as the radial stress of the first second concentric ring. Starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first second concentric ring. A second concentric ring;

[0114] Jordi The radial stress of the second concentric ring is less than the support reaction force, the boundary radial stress is increased, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward;

[0115] Jordi The radial stress of the second concentric ring is greater than the support reaction force, the boundary radial stress is reduced, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward;

[0116] Jordi The radial stress of the second concentric ring is equal to the support reaction force. The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings.

[0117] In this embodiment, for the second case: assuming that the anchor length is greater than the plastic zone length, the calculation method of the extrusion deformation of the tunnel face (that is, the second extrusion deformation) is as follows:

[0118] (S21) Surrounding rock differential processing. The surrounding rock within the length range of the anchor is differentially processed, and the surrounding rock is divided from the inner end of the anchor into From the second concentric ring to the outer radius of the tunnel, the mechanical parameters of the surrounding rock of each ring obey the soft rock mechanical parameter evolution model; and, based on symmetry, the mechanical parameters at different angles of the same ring are the same. It can be taken as 500. The differential step length expression is shown below.

[0119]

[0120] in, represents the width of the second concentric ring, represents the excavation radius of the tunnel face, Indicates the length of the anchor rod.

[0121] (S22) The first ring stress information is solved. Assuming the radial stress at the boundary , and solve the tangential stress according to the following formula.

[0122]

[0123] (S23) Solve the strain information of the first ring. Since it is in an elastic state, based on the plastic increment theory, the strain information generated by plasticity is 0 at this time, so the strain expression at the elastic-plastic boundary is as follows:

[0124]

[0125] in, represents the radial strain of the first second concentric ring caused by elasticity, represents the tangential strain of the first second concentric ring generated by elasticity, with the superscript Represents the elastic part, represents the elastic modulus of the first second concentric ring, represents the Poisson's ratio of the first second concentric ring.

[0126] (S24) Solve the first ring anchor force information. Assuming that the anchor and the surrounding rock deform cooperatively, the anchor force expression at the elastic-plastic boundary is as follows:

[0127]

[0128] in, Indicates the anchor force information of the first second concentric ring. represents the cross-sectional area of ​​the anchor rod, represents the elastic modulus of the anchor, represents the total radial strain of the first second concentric ring, .

[0129] (S25) Any ring in the middle ( According to the equilibrium equation and yield criterion, any middle ring ( The expression of the ring stress information is as follows:

[0130]

[0131] in,

[0132]

[0133] in, represents the width of the second concentric ring, , represents the excavation radius of the tunnel face, Indicates the anchor length, Indicates The average radius of the second concentric rings, Indicates The strain increment of the second concentric ring is, Indicates the vertical spacing of anchor rods (m), Indicates the horizontal spacing of anchor rods (m);

[0134] Discrimination and Relationship, determine whether the surrounding rock is in an elastic or plastic state at this time.

[0135] like Greater than It is still in elastic state. Less than The plastic state.

[0136] If it is elastic,

[0137] .

[0138] in, is the reference value of radial stress, represents the reference value of tangential stress, and The specific value of is based on the stress equilibrium boundary condition, which is:

[0139]

[0140] If it is elastic,

[0141] .

[0142] Any ring in the middle ( The calculation formula for the strain information of the ring) is the same as the calculation formula in step (S16) in the first case.

[0143] If it is a plastic state, let = , update the current ring radius differential expression as follows:

[0144]

[0145]

[0146] in, Indicates The average tangential stress of the second concentric ring, i.e. The average value of the tangential stress of the inner and outer rings of the second concentric ring, Indicates The average radial stress of the second concentric ring, i.e. The average value of the radial stress of the inner and outer rings of the second concentric ring.

[0147] Re-determine and :

[0148]

[0149] .

[0150] Then, using the calculation formula of step (S16) in the first case, calculate the middle arbitrary ring (the ring) strain information.

[0151] (S26) Repeat step (S25) to solve the stress and strain information of the intermediate rings ring by ring until the final ring (the ring).

[0152] (S27) Discrimination and .like Greater than , then increase Then, repeat (S22)~(S26); if Small , then reduce Then, repeat (S22) to (S26) until , and the operation ends.

[0153] (S28) Extrusion deformation of the tunnel face. The calculation expression of the extrusion deformation of the tunnel face after reinforcement (also known as the second extrusion deformation) is as follows:

[0154]

[0155] in, is the second extrusion deformation, For the The total tangential strain of the second concentric ring is The inner diameter of the second concentric ring is the tunnel face excavation radius .

[0156] In one embodiment of the present disclosure, starting from the first second concentric ring, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters, including:

[0157] If the anchor length is less than the plastic zone radius, starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step inward based on the set second plastic zone radius until the first second concentric ring is reached. A second concentric ring;

[0158] Jordi The radial stress of the second concentric ring is less than the support reaction force, the radius of the second plastic zone is increased, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring gradually inward starting from the first second concentric ring;

[0159] Jordi The radial stress of the second concentric ring is greater than the support reaction force, the radius of the second plastic zone is reduced, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward;

[0160] Jordi The radial stress of the second concentric ring is equal to the support reaction force. The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings.

[0161] In this embodiment, for the third case: when the bolt length is less than the plastic zone radius, the calculation method of the extrusion deformation of the tunnel face (that is, the second extrusion deformation) is as follows:

[0162] (S31) Differential processing within the plastic zone of the surrounding rock. Assume that the radius of the plastic zone of the surrounding rock is , the surrounding rock in the plastic zone is differentially processed, and the surrounding rock is divided into From the concentric rings to the outer radius of the tunnel, the mechanical parameters of the surrounding rock of each ring obey the soft rock mechanical parameter evolution model; and, based on symmetry, the mechanical parameters at different angles of the same ring are the same. It can be taken as 500. The differential step length expression is as follows:

[0163]

[0164] in, represents the width of the second concentric ring, Indicates the excavation radius of the tunnel face.

[0165] (S32) Solve the stress information of the first ring. According to the elastic-plastic boundary conditions, solve the radial stress and tangential stress at the elastic-plastic boundary:

[0166]

[0167] in, represents the radial stress of the first second concentric ring, represents the tangential stress of the first second concentric ring, represents the initial ground stress, represents the yield function, represents the friction angle of the first second concentric ring, Represents the cohesion of the first second concentric ring.

[0168] (S33) Solve the strain information of the first ring. Since it is at the elastic-plastic boundary, based on the plastic increment theory, the strain information generated by plasticity is 0 at this time, so the strain information at the elastic-plastic boundary is as follows:

[0169]

[0170] in, represents the radial strain of the first second concentric ring caused by elasticity, represents the tangential strain of the first second concentric ring generated by elasticity, with the superscript Represents the elastic part, represents the elastic modulus of the first second concentric ring, represents the Poisson's ratio of the first second concentric ring.

[0171] (S34) Solve the first ring anchor force information. Assuming that the anchor and the surrounding rock deform in coordination and have not yet entered the anchor support range, the anchor force expression is as follows:

[0172]

[0173] (S35) Any ring in the middle ( Ring) radius information is solved. and The expression is as follows:

[0174]

[0175]

[0176] (S36) Determine whether anchor rods are involved.

[0177] like > Then the anchor has not yet participated;

[0178] like < Then the anchor rod is already involved.

[0179] (S37) If the anchor is not involved: Determine the differential expression of stress information

[0180]

[0181]

[0182]

[0183]

[0184]

[0185] Using the calculation formula of step (S16) in the first case, calculate the middle arbitrary ring ( ring) strain information.

[0186] (S38) If the anchor rod is already involved: The inner diameter of the second concentric ring Updated to anchor length:

[0187]

[0188]

[0189] Determine Stress information for the second concentric ring:

[0190]

[0191]

[0192]

[0193] Using the calculation formula of step (S16) in the first case, calculate the middle arbitrary ring ( ring) strain information.

[0194] Re-determine and :

[0195]

[0196]

[0197] Based on the re-determination and Calculate the The stress and strain information of the second concentric ring.

[0198] (S39) Repeat steps (S25) to (S38) to solve the stress and strain information of the intermediate rings ring by ring until the final ring (the ring).

[0199] (S3A) Discrimination and .like Greater than , then increase Then, repeat (S31)~(S38); if Less than , then reduce Then, repeat (S31) to (S38) until , and the operation ends.

[0200] (S3B) Calculate the extrusion deformation of the tunnel face after grouting reinforcement. The calculation expression of the extrusion deformation of the tunnel face after reinforcement is as follows:

[0201]

[0202] in, is the second extrusion deformation, For the The total tangential strain of the second concentric ring is The inner diameter of the second concentric ring is the tunnel face excavation radius .

[0203] In one embodiment of the present disclosure, the mechanical parameters of the tunnel surrounding rock include cohesion, and adjusting the mechanical parameters of the tunnel surrounding rock based on the grouting reinforcement parameters includes:

[0204] Jordi The inner diameter of the second concentric ring is less than or equal to the grouting depth. The first cohesion is calculated based on the radial stress of the second concentric ring and the evolution model of soft rock mechanical parameters; the first adjustment parameter is calculated based on the first cohesion and the grouting depth; the first cohesion is adjusted based on the first adjustment parameter to obtain the first The cohesion of a second concentric ring.

[0205] In this embodiment, if The inner diameter of the second concentric ring Less than or equal to grouting depth , that is, it has entered the grouting reinforcement range, and the impact of grouting reinforcement on the tunnel face needs to be considered. The specific calculation method is: first, The radial stress of the second concentric ring By inputting the soft rock mechanical parameter evolution model, the first cohesion can be obtained (without considering the influence of grouting reinforcement); then, it is multiplied by the cohesion increase coefficient (that is, the first adjustment parameter), and get The cohesion of the second concentric ring (considering the influence of grouting reinforcement), on this basis, the radial stress and tangential stress expressions of any subsequent ring are calculated based on the adjusted cohesion, and the cohesion increase coefficient The calculation formula is as follows:

[0206]

[0207] in, is the cohesion of the grouting body (Pa), is the grouting filling rate, is the grouting depth (m), is the tunnel face excavation diameter (m), is the failure angle of the tunnel face (°), which can be calculated by Perform calculations.

[0208] In one embodiment of the present disclosure, drawing an extrusion deformation curve based on anchor reinforcement parameters and grouting reinforcement parameters includes:

[0209] The extrusion deformation under different support reaction forces is calculated based on the anchor reinforcement parameters and grouting reinforcement parameters, and the extrusion deformation curve is drawn based on the mapping relationship between support reaction force and extrusion deformation.

[0210] In this embodiment, the extrusion deformation of the soft rock tunnel face under different support reaction conditions can be calculated based on the anchor reinforcement parameters and the grouting reinforcement parameters; then, the extrusion deformation of the soft rock tunnel face is used as the horizontal coordinate and the support reaction force is used as the vertical coordinate to draw the extrusion deformation characteristic curve of the soft rock tunnel face.

[0211] In one embodiment of the present disclosure, after the face of the tunnel is reinforced with shotcrete, the shotcrete layer fits closely with the surrounding rock and deforms in coordination. The stress and deformation characteristics of the face of the shotcrete layer are consistent with those of the tunnel body section of the shotcrete layer, and can be regarded as a thin-walled plate. Therefore, the face of the tunnel shotcrete reinforcement characteristic curve expression is as follows:

[0212]

[0213] in, , , , They are shotcrete stiffness, support reaction force, extrusion deformation and maximum support force, which can be calculated using the following formulas respectively.

[0214]

[0215] In the formula, E con , v con are the elastic modulus and Poisson’s ratio of shotcrete; is the thickness of shotcrete; R 0 is the excavation radius of the tunnel face.

[0216]

[0217] is the uniaxial compressive strength of shotcrete material.

[0218] The maximum deformation of shotcrete can be calculated using the following formula:

[0219] .

[0220] In one embodiment of the present disclosure, before calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters, the method for simulating and calculating the parameters of the advance reinforcement system of the soft rock tunnel face further includes:

[0221] The first extrusion deformation is calculated based on the geological data of the tunnel site and the tunnel section data; the first extrusion deformation is the extrusion deformation of the tunnel face without reinforcement;

[0222] Calculating a first safety factor based on a first extrusion deformation;

[0223] If the first safety factor is less than or equal to a set threshold, a step of calculating a second extrusion deformation based on the geological data of the tunnel site, the tunnel cross-section data and the anchor reinforcement parameters is executed.

[0224] In this embodiment, before calculating the reinforcement system parameters, the first extrusion deformation of the tunnel face without reinforcement can be calculated based on the geological data of the tunnel site and the tunnel section data, and then the first safety factor can be calculated based on the first extrusion deformation. The stability of the tunnel face without grouting reinforcement is judged based on the first safety factor. When the first safety factor is less than or equal to the set threshold, the reinforcement system parameter calculation operation is performed to determine the appropriate advanced reinforcement system parameters, and the tunnel face is grouting reinforced to improve the stability of the tunnel face. When the first safety factor is greater than the set threshold, there is no need to perform the advanced reinforcement system parameter calculation operation to avoid unnecessary calculation operations.

[0225] In one embodiment of the present disclosure, the first extrusion deformation amount is calculated based on the geological data of the tunnel site and the tunnel section data, including:

[0226] The surrounding rock is divided into a plurality of first concentric rings from the first elastic-plastic boundary inwards until the tunnel excavation radius; the first elastic-plastic boundary is the elastic-plastic boundary of the tunnel surrounding rock without reinforcement;

[0227] Starting from the first concentric ring, the stress information and strain information of each first concentric ring are calculated step by step until the first stop condition is met;

[0228] The stress information of the first concentric ring satisfies the stress equilibrium boundary condition, specifically:

[0229]

[0230] in, represents the radial stress of the first concentric ring, represents the tangential stress of the first concentric ring, represents the initial ground stress, represents the yield function, represents the friction angle of the first concentric ring, represents the cohesion of the first concentric ring;

[0231] The strain information of the first concentric ring is:

[0232]

[0233] in, represents the radial strain of the first concentric ring caused by elasticity, represents the tangential strain of the first concentric ring generated by elasticity, with the superscript Represents the elastic part, represents the elastic modulus of the first concentric ring, represents the Poisson's ratio of the first concentric ring;

[0234] No. The stress information of the first concentric ring is:

[0235]

[0236]

[0237]

[0238]

[0239]

[0240] in, is a set constant, indicating the width of the first concentric ring. Indicates The average radius of the first concentric rings, For the The friction angle of the first concentric ring is Indicates The cohesion of the first concentric rings;

[0241] No. The strain information of the first concentric ring is:

[0242]

[0243] in, The elasticity The radial strain increment of the first concentric ring is, The elasticity The tangential strain increment of the first concentric ring is, Indicates the first The tangential strain increment of the first concentric ring is, represents the shear dilatancy coefficient, Indicates the first The radial strain increment of the first concentric ring is, Indicates The total radial strain of the first concentric ring is, Indicates The total tangential strain of the first concentric ring;

[0244] The first stop condition is: The radial stress of the first concentric ring is equal to the support reaction force;

[0245] Based on The radius of the first plastic zone is calculated based on the inner diameter of the first concentric ring. The inner diameter of the first concentric ring and the The first extrusion deformation is calculated based on the total tangential strain of the first concentric rings.

[0246] In this embodiment, the calculation expressions of the first plastic zone radius and the first extrusion deformation amount obtained through the above process are as follows.

[0247]

[0248]

[0249] Among them, when When the radial stress of the first concentric ring meets the first stop condition, The inner diameter of the first concentric ring is the tunnel excavation radius .

[0250] On the basis of obtaining the first extrusion deformation, the upper limit of the extrusion deformation (i.e., the tunnel face limit extrusion deformation ( )) and the first extrusion deformation ( ) as the first safety factor , the specific formula is as follows:

[0251] .

[0252] In summary, this embodiment takes into account that the evolution mechanism of deformation, instability and destruction of the tunnel face in high-ground stress soft rock tunnels is significantly different from that of deformation, instability and destruction of the tunnel face in soil strata or broken strata. Therefore, a stability evaluation model of the tunnel face in high-ground stress soft rock tunnels based on tunnel face extrusion deformation is proposed, and a parameter design method of the tunnel face advance reinforcement system of high-ground stress soft rock tunnels based on tunnel face extrusion deformation is established, which includes three advance reinforcement measures: glass fiber anchors, grouting, and shotcrete. The design method of the tunnel face advance reinforcement system can realize the quantitative design of the parameters of a single reinforcement measure, and can also realize the quantitative design of the combined reinforcement parameters of two or more measures, realizing the quantitative design of the tunnel face advance reinforcement system.

[0253] At the same time, the calculation method for face extrusion deformation proposed in the present invention takes into account the evolution process of soft rock mechanical parameters under high ground stress conditions, making the calculation results more accurate and reasonable, and in line with the actual high ground stress soft rock tunnel engineering.

[0254] Corresponding to the above embodiment, the simulation calculation method of the parameters of the soft rock tunnel face advance reinforcement system is as follows: Figure 7This is a structural block diagram of a soft rock tunnel face advance reinforcement system parameter simulation calculation device provided by an embodiment of the present disclosure. For ease of explanation, only the parts related to the embodiment of the present disclosure are shown. Figure 7 The soft rock tunnel face advance reinforcement system parameter simulation calculation device 20 includes: a first calculation module 21, a second calculation module 22, a third calculation module 23 and a parameter output module 24.

[0255] The first calculation module 21 is used to divide the tunnel surrounding rock from the elastic-plastic boundary into A second concentric ring, until the radius of the tunnel excavation;

[0256] The second calculation module 22 is used to calculate the second extrusion deformation amount starting from the first second concentric ring based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; the second extrusion deformation amount is the extrusion deformation amount of the tunnel face under the advanced reinforcement condition;

[0257] Among them, if The inner diameter of the second concentric ring is less than or equal to the grouting depth, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters; the mechanical parameters of the tunnel surrounding rock belong to the geological data of the tunnel site;

[0258] The third calculation module 23 is used to calculate a second safety factor based on the second extrusion deformation; the second safety factor is used to characterize the stability of the tunnel face under the condition of advanced reinforcement of the tunnel face;

[0259] Parameter output module 24, if the second safety factor is less than or equal to the set threshold, adjust the parameters of the advance reinforcement system, return to the execution starting from the first second concentric ring, and calculate the second extrusion deformation step based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; if the second safety factor is greater than the set threshold, output the calculation results of the advance reinforcement system parameters; the advance reinforcement system parameters include anchor reinforcement parameters and grouting reinforcement parameters.

[0260] In one embodiment of the present disclosure, the second calculation module 22 is specifically used for:

[0261] Jordi The inner diameter of the second concentric ring is greater than the shotcrete depth, and the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters;

[0262] Jordi The inner diameter of the second concentric ring is less than or equal to the shotcrete depth, an extrusion deformation curve is drawn based on the anchor reinforcement parameters and the grouting reinforcement parameters, and a shotcrete reinforcement curve is drawn based on the shotcrete reinforcement parameters; and the intersection of the extrusion deformation curve and the shotcrete reinforcement curve is determined as the second extrusion deformation amount;

[0263] Among them, the extrusion deformation curve is used to characterize the extrusion deformation of the tunnel face under different support reaction forces, and the shotcrete reinforcement curve is used to characterize the extrusion deformation of the tunnel face under different concrete support reaction forces.

[0264] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present disclosure, and these modifications or replacements should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system, characterized in that: include: The tunnel surrounding rock is divided into A second concentric ring, until the radius of the tunnel excavation; Starting from the first of the second concentric circles, the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; the second extrusion deformation is the extrusion deformation of the tunnel face under the advanced reinforcement condition; Among them, if The inner diameter of the second concentric ring is less than or equal to the grouting depth, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters; the mechanical parameters of the tunnel surrounding rock belong to the geological data of the tunnel site; Calculating a second safety factor based on the second extrusion deformation; the second safety factor is used to characterize the stability of the tunnel face under the condition of advanced reinforcement of the tunnel face; If the second safety factor is less than or equal to the set threshold, the parameters of the advance reinforcement system are adjusted, and the step of calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters starting from the first of the second concentric rings is returned to execution; if the second safety factor is greater than the set threshold, the calculation results of the parameters of the advance reinforcement system are output; the parameters of the advance reinforcement system include the anchor reinforcement parameters and the grouting reinforcement parameters; The method of calculating the second extrusion deformation amount starting from the first of the second concentric rings based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters includes: Starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first second concentric ring. A second concentric ring; Based on The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings; The advanced reinforcement system parameters also include shotcrete reinforcement parameters. The second extrusion deformation is calculated based on the tunnel site geological data, tunnel section data and anchor reinforcement parameters, including: Jordi The inner diameter of the second concentric ring is greater than the shotcrete depth, and the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; Jordi The inner diameter of the second concentric ring is less than or equal to the shotcrete depth, an extrusion deformation curve is drawn based on the anchor reinforcement parameters and the grouting reinforcement parameters, and a shotcrete reinforcement curve is drawn based on the shotcrete reinforcement parameters; and the intersection of the extrusion deformation curve and the shotcrete reinforcement curve is determined as the second extrusion deformation amount; The extrusion deformation curve is used to characterize the extrusion deformation of the tunnel face under different support reaction forces, and the shotcrete reinforcement curve is used to characterize the extrusion deformation of the tunnel face under different concrete support reaction forces.

2. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: The method of calculating the second extrusion deformation amount starting from the first of the second concentric rings based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters includes: If the anchor length is equal to the radius of the plastic zone, starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first second concentric ring is reached. A second concentric ring; Based on The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings.

3. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: If the anchor length is greater than the radius of the plastic zone, the inner end of the anchor is determined as the elastic-plastic boundary; The method of calculating the second extrusion deformation amount starting from the first of the second concentric rings based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters includes: If the anchor length is greater than the plastic zone radius, the set boundary radial stress is determined as the radial stress of the first second concentric ring. Starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first second concentric ring. A second concentric ring; Jordi The radial stress of the second concentric ring is less than the support reaction force, the boundary radial stress is increased, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward; Jordi The radial stress of the second concentric ring is greater than the support reaction force, the boundary radial stress is reduced, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward; Jordi The radial stress of the second concentric ring is equal to the support reaction force. The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings.

4. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: The method of calculating the second extrusion deformation amount starting from the first of the second concentric rings based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters includes: If the anchor length is less than the plastic zone radius, starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step inward based on the set second plastic zone radius until the first second concentric ring is reached. A second concentric ring; Jordi The radial stress of the second concentric ring is less than the support reaction force, the radius of the second plastic zone is increased, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward; Jordi The radial stress of the second concentric ring is greater than the support reaction force, the radius of the second plastic zone is reduced, and the process returns to the step of calculating the stress information, strain information, and anchor force information of each second concentric ring step by step from the first second concentric ring inward; Jordi The radial stress of the second concentric ring is equal to the support reaction force. The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings.

5. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: The mechanical parameters of the tunnel surrounding rock include cohesion, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting reinforcement parameters, including: Jordi The inner diameter of the second concentric ring is less than or equal to the grouting depth. The first cohesion is calculated based on the radial stress and soft rock mechanical parameter evolution model of the second concentric ring; the first adjustment parameter is calculated based on the first cohesion and the grouting depth; the first cohesion is adjusted based on the first adjustment parameter to obtain the first The cohesion of a second concentric ring.

6. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: The step of drawing an extrusion deformation curve based on the anchor reinforcement parameters and the grouting reinforcement parameters includes: The extrusion deformation under different support reaction forces is calculated based on the anchor reinforcement parameters and the grouting reinforcement parameters, and the extrusion deformation curve is drawn based on the mapping relationship between the support reaction force and the extrusion deformation.

7. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: The step of drawing a shotcrete reinforcement curve based on shotcrete reinforcement parameters includes: By formula , draw the shotcrete reinforcement curve; in, is the shotcrete stiffness, is the shotcrete support reaction force, is the extrusion deformation, is the maximum support force; , is the elastic modulus of shotcrete and Poisson's ratio of shotcrete, is the thickness of shotcrete, is the tunnel face excavation radius, is the uniaxial compressive strength of shotcrete material.

8. The method for simulating and calculating parameters of the soft rock tunnel face advance reinforcement system according to claim 1, characterized in that: Before calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters, the soft rock tunnel face advance reinforcement system parameter simulation calculation method further includes: Calculate the first extrusion deformation based on the geological data of the tunnel site and the tunnel section data; the first extrusion deformation is the extrusion deformation of the tunnel face without reinforcement; Calculating a first safety factor based on the first extrusion deformation; If the first safety factor is less than or equal to a set threshold, the step of calculating the second extrusion deformation based on the tunnel site geological data, tunnel section data and anchor reinforcement parameters is executed.

9. A device for simulating and calculating parameters of a soft rock tunnel face advance reinforcement system, characterized in that: include: The first calculation module is used to divide the tunnel surrounding rock from the elastic-plastic boundary into A second concentric ring, until the radius of the tunnel excavation; The second calculation module is used to calculate the second extrusion deformation amount starting from the first of the second concentric rings based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; the second extrusion deformation amount is the extrusion deformation amount of the tunnel face under the advanced reinforcement condition; Among them, if The inner diameter of the second concentric ring is less than or equal to the grouting depth, and the mechanical parameters of the tunnel surrounding rock are adjusted based on the grouting depth; the mechanical parameters of the tunnel surrounding rock belong to the geological data of the tunnel site, and the grouting depth belongs to the grouting reinforcement parameters; A third calculation module is used to calculate a second safety factor based on the second extrusion deformation; the second safety factor is used to characterize the stability of the tunnel face under the condition of advanced reinforcement of the tunnel face; The parameter output module adjusts the parameters of the advanced reinforcement system if the second safety factor is less than or equal to the set threshold, and returns to the step of calculating the second extrusion deformation based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters starting from the first of the second concentric rings; if the second safety factor is greater than the set threshold, outputs the calculation results of the advanced reinforcement system parameters; The second calculation module is specifically used for: Starting from the first second concentric ring, the stress information, strain information and anchor force information of each second concentric ring are calculated step by step until the first second concentric ring. A second concentric ring; Based on The inner diameter of the second concentric ring and the The second extrusion deformation is calculated based on the total tangential strain of the second concentric rings; Jordi The inner diameter of the second concentric ring is greater than the shotcrete depth, and the second extrusion deformation is calculated based on the geological data of the tunnel site, the tunnel section data and the anchor reinforcement parameters; Jordi The inner diameter of the second concentric ring is less than or equal to the shotcrete depth, an extrusion deformation curve is drawn based on the anchor reinforcement parameters and the grouting reinforcement parameters, and a shotcrete reinforcement curve is drawn based on the shotcrete reinforcement parameters; and the intersection of the extrusion deformation curve and the shotcrete reinforcement curve is determined as the second extrusion deformation amount; The extrusion deformation curve is used to characterize the extrusion deformation of the tunnel face under different support reaction forces, and the shotcrete reinforcement curve is used to characterize the extrusion deformation of the tunnel face under different concrete support reaction forces.

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