A tunnel lining load determination method, system, device and medium

Abstract

The application discloses a tunnel lining load determination method, system, equipment and medium, and comprises the following steps: acquiring basic design parameters of a subway tunnel; the basic design parameters of the subway tunnel comprise a tunnel outer diameter, a tunnel buried depth, a specific weight of surrounding rock soil, a friction angle of the surrounding rock soil and a cohesion of the surrounding rock soil; determining a design included angle between a tunnel strike line and a ground fissure strike line; calculating an equivalent coefficient of a surrounding rock soil rupture angle on both sides of the tunnel and the surrounding rock soil rupture angle on both sides of the tunnel according to the basic design parameters of the subway tunnel; calculating external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active according to the surrounding rock soil rupture angle on both sides of the tunnel; and obtaining the maximum load of the subway tunnel lining according to the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining. The application fully considers the influence of the ground fissure activity on the subway tunnel, determines the maximum lining load required in the subway engineering design crossing the ground fissure, and ensures the structural safety of the subway tunnel.

Description

Technical Field

[0001] This invention belongs to the field of tunnel engineering technology, and specifically relates to a method, system, equipment and medium for determining tunnel lining load. Background Technology

[0002] Ground fissures are a discontinuous or faulty phenomenon in the soil and rock media that develops on the surface of the earth's crust. As a geological hazard that is closely related to the subsidence of pumped-out surfaces, basement structure, and active tectonics, it affects human production and life, and the direct or indirect losses caused have reached billions of yuan.

[0003] Existing research indicates that ground fissures can cause uneven settlement and deformation of strata, imposing additional loads on subway tunnels that cross them, leading to structural deformation and the risk of structural breakage. This is particularly true in recent years with the rapid development of urban rail transit, as many newly constructed subway lines face the inability to avoid ground fissures. Therefore, during the tunnel structural design phase, it is crucial to carefully determine the lining design loads to address the adverse effects of ground fissures and ensure the safe operation of the subway system in the future.

[0004] Typically, the design phase of tunnel lining requires determining various types of structural loads, including primary loads, secondary loads, and special loads, all guided by the maximum load value. Special additional loads caused by ground fissure activity should be considered in the design to guide and optimize lining design and reinforcement calculations. Structural measures should be taken near the intersection of the tunnel and the ground fissure to ensure the structural safety of the subway tunnel. However, due to the complex and variable geological conditions and the complex activity of ground fissures, existing subway design codes do not address this load, and there is currently a lack of corresponding methods to determine this additional load. Therefore, to guide the structural design of subway tunnels crossing ground fissures and ensure the safety of subway operation, the impact of ground fissure activity on the subway lining needs to be considered, and the problem of determining the load on the subway tunnel lining in ground fissure sites urgently needs to be solved. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the present invention provides a method, system, equipment and medium for determining tunnel lining load, in order to solve the technical problem that the prior art fails to consider the impact of ground fissure activity on subway tunnels and makes it difficult to determine the maximum lining load required in the design of subway projects that cross ground fissures.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for determining tunnel lining loads, used in the process of determining the lining loads of subway tunnels in ground fissure sites; wherein, the method for determining tunnel lining loads includes:

[0008] Obtain the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil;

[0009] The design angle between the tunnel alignment and the ground fissure alignment is determined. Based on the projection rules and the stress equivalence principle, and according to the basic design parameters of the subway tunnel, the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel are calculated.

[0010] Based on the fracture angle of the surrounding rock and soil on both sides of the tunnel, the external force exerted by the surrounding rock on the subway tunnel lining during ground fissure activity is calculated.

[0011] Based on the principle of force balance of the lining on the cross section of the subway tunnel, the maximum load on the subway tunnel lining is calculated according to the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the ground fissure is active.

[0012] Furthermore, the design angle between the tunnel alignment and the ground fissure alignment is determined based on projection rules and the stress equivalence principle. In the process of calculating the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel according to the basic design parameters of the subway tunnel, the following formula is used.

[0013]

[0014]

[0015]

[0016]

[0017] 0°<β≤90°

[0018] in, The friction angle of the surrounding rock and soil; h is the tunnel depth; d is the tunnel outer diameter; K a ω is the lateral earth pressure coefficient; β is the fracture angle of the surrounding rock and soil on both sides of the tunnel when the subway tunnel and the ground fissure are orthogonal; α is the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel when the subway tunnel and the ground fissure are orthogonal; α1 is the equivalent coefficient of the fracture angle of the surrounding rock and soil on one side of the tunnel when the subway tunnel and the ground fissure are oblique; α2 is the equivalent coefficient of the fracture angle of the surrounding rock and soil on the other side of the tunnel when the subway tunnel and the ground fissure are oblique; ω is the design angle between the tunnel alignment line and the ground fissure alignment line; β1 is the fracture angle of the surrounding rock and soil on one side of the tunnel when the subway tunnel and the ground fissure are oblique; β2 is the fracture angle of the surrounding rock and soil on the other side of the tunnel when the subway tunnel and the ground fissure are oblique.

[0019] Furthermore, based on the fracture angle of the surrounding rock and soil on both sides of the tunnel, the external force exerted by the surrounding rock on the subway tunnel lining during the activity of ground fissures is calculated as follows:

[0020] When the subway tunnel is perpendicular to the ground fissure, the external force exerted by the surrounding rock on both sides of the tunnel lining during ground fissure activity is:

[0021]

[0022] Where T is the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the subway tunnel is orthogonal to the ground fissure and the ground fissure is active; γ is the unit weight of the surrounding rock and soil; and c is the cohesion of the surrounding rock and soil.

[0023] Furthermore, based on the principle of force balance of the lining on the cross-section of the subway tunnel, and according to the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity, the maximum load on the subway tunnel lining is calculated as follows:

[0024] When the subway tunnel is perpendicular to the ground fissure, the maximum load on the subway tunnel lining is:

[0025]

[0026] Where q1 is the maximum load on the subway tunnel lining when the subway tunnel is orthogonal to the ground fissure; θ is the friction angle between the tunnel roof and the surrounding rock and soil on both sides.

[0027] Furthermore, the formula for calculating the friction angle θ between the tunnel roof and the surrounding rock on both sides is as follows:

[0028]

[0029] in, The friction angle of the surrounding rock and soil.

[0030] Furthermore, based on the fracture angle of the surrounding rock and soil on both sides of the tunnel, the external force exerted by the surrounding rock on the subway tunnel lining during the activity of ground fissures is calculated as follows:

[0031] When a subway tunnel intersects a ground fissure at an oblique angle, the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity are:

[0032]

[0033]

[0034] Wherein, T1 is the external force exerted on the subway tunnel lining by the surrounding rock and soil on one side of the tunnel when the ground fissure is active, and T2 is the external force exerted on the subway tunnel lining by the surrounding rock and soil on the other side of the tunnel when the ground fissure is active.

[0035] Furthermore, based on the principle of force balance of the lining on the cross-section of the subway tunnel, and according to the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity, the maximum load on the subway tunnel lining is calculated as follows:

[0036] When the subway tunnel intersects the ground fissure at an oblique angle, the maximum load on the subway tunnel lining is:

[0037]

[0038] Where q2 is the maximum load on the subway tunnel lining when the subway tunnel intersects the ground fissure obliquely.

[0039] This invention also provides a tunnel lining load determination system for determining the lining load of subway tunnels in ground fissure sites; wherein, the tunnel lining load determination system includes:

[0040] The basic design parameter acquisition module is used to acquire the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil.

[0041] The first calculation module is used to determine the design angle between the tunnel alignment and the ground fissure alignment. Based on the projection rules and stress equivalence principle, and according to the basic design parameters of the subway tunnel, it calculates the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel.

[0042] The second calculation module is used to calculate the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the ground fissures are active, based on the fracture angle of the surrounding rock and soil on both sides of the tunnel.

[0043] The third calculation module is used to calculate the maximum load on the subway tunnel lining based on the principle of force balance of the lining on the cross-section of the subway tunnel and the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the ground fissure is active.

[0044] The present invention also provides a device for determining tunnel lining load, comprising:

[0045] Memory, used to store computer programs;

[0046] A processor is used to implement the steps of the method for determining the tunnel lining load when executing the computer program.

[0047] The present invention also provides a computer-readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the steps of the method for determining the tunnel lining load.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0049] This invention provides a method and system for determining tunnel lining load. Based on the Bierbaumer and Terzaghi theories, it uses the limit equilibrium form of the stratum bearing principle as the basis for calculating the maximum load on the tunnel lining when a subway tunnel crosses a ground fissure. Based on the deformation and motion mode of the ground fissure-subway tunnel-surrounding rock, combined with the projection rule, stress equivalence principle and the force balance principle of the lining on the cross section of the subway tunnel, and according to the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity, the maximum load on the subway tunnel lining is calculated. This method considers the impact of ground fissure activity on the subway tunnel, and can determine the maximum lining load required in the design stage of subway engineering crossing ground fissures, ensuring the safe operation of the subway tunnel structure.

[0050] Furthermore, considering the intersection relationship between the ground fissure and the subway tunnel, calculation formulas were constructed for the maximum load on the lining when the subway tunnel perpendicularly crosses the ground fissure and for the maximum load on the lining when the subway tunnel obliquely crosses the ground fissure. This allows for the calculation and determination of the maximum load on the tunnel lining when the subway tunnel obliquely crosses the ground fissure at any angle, filling a gap in the method for determining the additional load on the subway tunnel lining caused by ground fissure activity. It provides structural designers in similar subway projects with ideas and methods for determining the maximum load, which can be used to adjust and optimize structural measures, ensuring the safety of subway tunnel operation in ground fissure sites in the later stages. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the basic model for calculating the lining load when a subway tunnel passes through a ground fissure in this invention.

[0052] Figure 2 This is a schematic diagram of the deformation and movement mode of the ground fissure-subway tunnel-surrounding rock in this invention;

[0053] Figure 3 This is a schematic diagram showing the position of the subway tunnel when it is orthogonal to the ground fissure in this invention;

[0054] Figure 4 This is a schematic diagram showing the location of the subway tunnel when it intersects the ground fissure at an oblique angle in this invention;

[0055] Figure 5 This is a schematic diagram of the calculation model for the orthogonality between the subway tunnel and the ground fissure in this invention;

[0056] Figure 6 This is a force analysis model diagram of the subway tunnel and the ground fissure being orthogonal in this invention;

[0057] Figure 7 This is a schematic diagram of the calculation model for the oblique intersection of the subway tunnel and the ground fissure in this invention;

[0058] Figure 8 This is a force analysis model diagram of the subway tunnel and the ground fissure intersecting at an oblique angle in this invention;

[0059] Figure 9 This is a schematic diagram of the calculation sub-model for the fracture angle of the surrounding rock and soil on both sides of the tunnel in this invention;

[0060] Figure 10 This is a comparison chart of the measured and calculated values ​​of tunnel lining loads in Examples 1-3. Detailed Implementation

[0061] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0062] This invention provides a method for determining tunnel lining loads, used in the process of determining the lining loads of subway tunnels in ground fissure sites; wherein, the method for determining tunnel lining loads includes:

[0063] Step 1: Obtain the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter d, the tunnel burial depth h, the unit weight γ of the surrounding rock and soil, and the friction angle of the surrounding rock and soil. And the cohesion c of the surrounding rock and soil.

[0064] Step 2: Determine the design angle ω between the tunnel alignment and the ground fissure alignment. Based on the projection rules and stress equivalence principle, and according to the basic design parameters of the subway tunnel, calculate the equivalent coefficient and the fracture angle of the surrounding rock and soil on both sides of the tunnel. Specifically, the calculation of the equivalent coefficient and the fracture angle of the surrounding rock and soil on both sides of the tunnel is performed according to the following formula.

[0065]

[0066]

[0067]

[0068]

[0069] 0°<β≤90°

[0070] in, The friction angle of the surrounding rock and soil; h is the tunnel depth; d is the tunnel outer diameter; K a ω is the lateral earth pressure coefficient; β is the fracture angle of the surrounding rock and soil on both sides of the tunnel when the subway tunnel and the ground fissure are orthogonal; α is the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel when the subway tunnel and the ground fissure are orthogonal; that is, the equivalent coefficient corresponding to parameter β is parameter α; α1 is the equivalent coefficient of the fracture angle of the surrounding rock and soil on one side of the tunnel when the subway tunnel and the ground fissure are oblique; α2 is the equivalent coefficient of the fracture angle of the surrounding rock and soil on the other side of the tunnel when the subway tunnel and the ground fissure are oblique; ω is the design angle between the tunnel alignment line and the ground fissure alignment line; β1 is the fracture angle of the surrounding rock and soil on one side of the tunnel when the subway tunnel and the ground fissure are oblique; that is, the equivalent coefficient corresponding to parameter β1 is parameter α1; β2 is the fracture angle of the surrounding rock and soil on the other side of the tunnel when the subway tunnel and the ground fissure are oblique; that is, the equivalent coefficient corresponding to parameter β2 is parameter α2.

[0071] Step 3: Based on the fracture angle of the surrounding rock and soil on both sides of the tunnel, calculate the external force exerted by the surrounding rock on the subway tunnel lining when the ground fissures are active; the specific process is as follows:

[0072] When the subway tunnel is perpendicular to the ground fissure, the external force exerted by the surrounding rock on both sides of the tunnel lining during ground fissure activity is:

[0073]

[0074] Where T is the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the subway tunnel is orthogonal to the ground fissure and the ground fissure is active.

[0075] When a subway tunnel intersects a ground fissure at an oblique angle, the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity are:

[0076]

[0077]

[0078] Wherein, T1 is the external force exerted on the subway tunnel lining by the surrounding rock and soil on one side of the tunnel when the ground fissure is active, and T2 is the external force exerted on the subway tunnel lining by the surrounding rock and soil on the other side of the tunnel when the ground fissure is active.

[0079] Step 4: Based on the principle of force balance of the lining on the cross-section of the subway tunnel, and according to the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity, the maximum load on the subway tunnel lining is calculated; the specific process is as follows:

[0080] When the subway tunnel is perpendicular to the ground fissure, the maximum load on the subway tunnel lining is:

[0081]

[0082]

[0083] Where q1 is the maximum load on the subway tunnel lining when the subway tunnel is orthogonal to the ground fissure; θ is the friction angle between the tunnel roof and the surrounding rock and soil on both sides.

[0084] When the subway tunnel intersects the ground fissure at an oblique angle, the maximum load on the subway tunnel lining is:

[0085]

[0086] Where q2 is the maximum load on the subway tunnel lining when the subway tunnel intersects the ground fissure obliquely.

[0087] Explanation of calculation principle:

[0088] In this invention, based on the theories of Bierbaumer and Terzaghi, a limit equilibrium form based on the principle of stratum bearing capacity is proposed as the basis for calculating the lining load when a subway tunnel crosses a ground fissure. According to the deformation and motion mode of the ground fissure-subway tunnel-surrounding rock, the maximum subsidence deformation cross section of the tunnel and surrounding rock is divided into four regions. Using the intersection of the ground fissure and the subway tunnel as a benchmark, and referring to the deformation and stress modes of the tunnel and surrounding rock, the following formulas are constructed: the calculation formula for the maximum lining load when the subway tunnel perpendicularly crosses the ground fissure, and the calculation formula for the maximum lining load when the subway tunnel obliquely crosses the ground fissure at an arbitrary angle ω. Simultaneously, the calculation formula for the fracture angle of the surrounding rock on both sides of the subway tunnel lining caused by ground fissure activity is determined.

[0089] The process for determining the tunnel lining load is as follows:

[0090] As attached Figure 1 As shown, since the activity mode of the ground fissure is that the upper plate sinks while the lower plate remains stationary, it causes the strata to settle and deform, resulting in the deformation of the subway tunnel passing through the ground fissure site. When the ground fissure is active, there will be a significant increase in stress in the upper plate of the ground fissure, that is, the lining load of the tunnel will suddenly increase and reach a peak, and then gradually decrease as it moves away from the ground fissure. Therefore, in the design process of the subway tunnel, the peak load of the lining caused by the activity of the ground fissure must be considered.

[0091] To obtain the peak load on the tunnel lining caused by ground fissure activity, i.e. the external force exerted on the tunnel lining by the surrounding rock and soil during ground fissure activity, a method for determining the load on the subway tunnel lining caused by ground fissure activity is constructed. This fills the gap in the method for determining the additional load on the subway tunnel lining caused by ground fissure activity, and provides ideas and methods for determining the maximum load in the structural design process. This allows for the adjustment and optimization of structural measures to ensure the safety of the subway tunnel in its later operation.

[0092] Before conducting the stress analysis, it is necessary to analyze the motion and deformation modes among the ground fissure, tunnel, and surrounding rock; as shown in the attached figure. Figure 2 As shown, the maximum settlement deformation in the cross-section of the tunnel and surrounding rock is divided into four regions: the distant surrounding rock, the adjacent surrounding rock on both sides of the tunnel, the tunnel itself, and the surrounding rock above the tunnel. The distant surrounding rock is designated as surrounding rock ①, the adjacent surrounding rock on both sides of the tunnel as surrounding rock ②, the tunnel itself as tunnel ③, and the surrounding rock above the tunnel as surrounding rock ④. When the activity of the ground fissure causes settlement of the hanging wall soil, surrounding rock ① settles first. Due to friction between surrounding rock ② and tunnel ③, the settlement rate of surrounding rock ② is less than that of surrounding rock ①, at which point a fracture surface appears in the soil of surrounding rock ②. Because the subway tunnel has a certain longitudinal stiffness, it can resist a certain degree of ground deformation; therefore, the deformation and settlement rate of tunnel ③ is less than that of surrounding rock ②. Surrounding rock ④ is supported by the lining structure, and its deformation and settlement rate is the slowest. Therefore, the deformation and settlement rates of different regions are specifically: surrounding rock ① > surrounding rock ② > tunnel ③ > surrounding rock ④. Considering that the actual subway tunnel will cross the ground fissure at different angles, as shown in the attached diagram... Figure 3-4 As shown; Appendix Figure 3-4 The diagrams show the locations of the subway tunnel and the ground fissure when they are perpendicular and when they are oblique.

[0093] As attached Figure 5 As shown, based on the cross-section where the tunnel intersects with the ground fissure, a calculation model of the tunnel lining-surrounding rock when the subway tunnel is orthogonal to the ground fissure is established. The calculation model of the tunnel lining-surrounding rock when the subway tunnel is orthogonal to the ground fissure is decomposed and analyzed step by step to establish a stress analysis model for the subway tunnel when it is orthogonal to the ground fissure, as shown in the attached figure. Figure 6 As shown; based on the sine theorem, the expression for the external forces exerted on both sides of the tunnel by the surrounding rock and soil caused by ground fissure activity is obtained:

[0094]

[0095]

[0096] Where T represents the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the subway tunnel is orthogonal to the ground fissure and the ground fissure is active; f t For the resultant force, the resultant force f tThis includes the frictional force f and the cohesion c of the surrounding rock and soil. β is the friction angle of the surrounding rock and soil; β is the fracture angle of the surrounding rock and soil; θ is the friction angle between the tunnel roof and the surrounding rock and soil on both sides, which can be taken as . G2 is the weight of the triangular soil AED; h is the tunnel depth, i.e., the vertical distance from the top of the tunnel to the ground; d is the tunnel outer diameter, i.e., the designed diameter of the tunnel outer contour; γ is the unit weight of the surrounding rock and soil, γ=ρg; ρ is the density of the surrounding rock and soil, and g is the acceleration due to gravity.

[0097] According to soil mechanics theory, the resultant force of frictional force f and cohesion c per unit volume of soil can be expressed by shear strength:

[0098]

[0099] σ h =γhK a (4)

[0100] Where, σ h For horizontal earth pressure; K a The lateral earth pressure coefficient, Where δ is the friction angle between the tunnel lining and the surrounding rock and soil, typically 100°.

[0101] Therefore, for the resultant force f in the triangular soil AED t In this case, integration needs to be performed based on depth, and the calculation formula is as follows:

[0102]

[0103] Substituting equations (2) and (5) into equation (1), the external force T exerted by the surrounding rock on the subway tunnel lining on both sides of the tunnel during the activity of the ground fissure when the subway tunnel is perpendicular to the ground fissure can be written as:

[0104]

[0105] Based on the force system of the soil EFGH, and considering the symmetry of the cross section, the tunnel support force P can be calculated; whereby the tunnel support force P is also the total vertical load of the lining, expressed as:

[0106] P = G1 + 2f t +2Tsinθ (7)

[0107] Where G1 is the gravity of the rectangular soil mass EFGH, expressed as:

[0108] G1=γ·|EF|·|HG|=γhd (8)

[0109] For the resultant force f in the soil mass EFGH tBased on the tunnel burial depth h, the recalculation is as follows:

[0110]

[0111] From the combined equations (6)-(9), we can obtain the lining load per unit length of the tunnel when the subway tunnel orthogonally crosses the ground fissure:

[0112]

[0113] It should be noted that in actual engineering projects, subway tunnels may pass through ground fissures at different angles. The orthogonal configuration described above is only one special case. To be realistic and convenient for engineering applications, it is necessary to construct a calculation model for the lining load when a subway tunnel passes through a ground fissure at any angle, such as... Figure 4 As shown; based on projection rules, the orthogonal case is projected through the angle between the subway tunnel and the ground fissure to obtain the oblique case, at which point the attached... Figure 5 The stress analysis of the tunnel and strata under the influence of ground fissures will change. Specifically, the cross-section of the analysis model now becomes asymmetrical, such as... Figure 7 As shown, the external forces exerted by the surrounding rock and soil on both sides of the tunnel are not equal and need to be calculated separately; the calculation process is as follows:

[0114] The triangular soil masses A'E'D' and B'F'C' on both sides of the tunnel differ from the orthogonal case; firstly, it is necessary to calculate the modified A'E' and B'F'; in Figure 5 The length of AB in the equation can be expressed as:

[0115]

[0116] When the tunnel intersects the ground fissure at an oblique angle, the transformed A'B' can be represented as:

[0117]

[0118] Where ω is the design angle between the tunnel alignment and the ground fissure alignment.

[0119] Therefore, the transformed A'E' and B'F' can be represented as follows:

[0120]

[0121]

[0122] because Figure 7 The analytical model and Figure 5 The results are quite similar, but note that the calculated cross-sections are asymmetrical and need to be calculated separately; for example... Figure 8As shown, based on the sine theorem, the expressions for the external force T1 exerted by the surrounding rock and soil on one side of the subway tunnel lining when the subway tunnel intersects the ground fissure obliquely and the ground fissure is active, and the external force T2 exerted by the surrounding rock and soil on the other side of the subway tunnel lining when the subway tunnel intersects the ground fissure obliquely and the ground fissure is active, are as follows:

[0123]

[0124]

[0125] Where T1 is the external force exerted on the tunnel lining by the surrounding rock and soil on one side of the tunnel when the ground fissure is active, and T2 is the external force exerted on the tunnel lining by the surrounding rock and soil on the other side of the tunnel when the ground fissure is active, and β1 is the fracture angle of the surrounding rock and soil on one side of the tunnel when the tunnel intersects with the ground fissure; β2 is the fracture angle of the surrounding rock and soil on the other side of the tunnel when the tunnel intersects with the ground fissure; G2 is the gravity of the triangular soil mass A'E'D', and G3 is the gravity of the triangular soil mass B'F'C', expressed as:

[0126]

[0127]

[0128] Substituting equations (17) and (5) into equation (15), and substituting equations (18) and (5) into equation (16), we can obtain the external forces T1 and T2, expressed as follows:

[0129]

[0130]

[0131] Due to changes in external forces on both sides, based on the force system of the soil E'F'G'H', the supporting force P of the tunnel is calculated as follows:

[0132] P = G1 + 2f t '+(T1+T2)sinθ (21)

[0133] Substituting equations (8), (9), (19), and (20) into equation (21), we can obtain the lining load per unit length of the tunnel when the subway tunnel passes through the ground fissure at any angle:

[0134]

[0135] Based on the activity characteristics of ground fissures, the underlying soil is generally stationary, which can be considered the same as a normal site without ground fissures. However, due to the deformation of the upper tunnel caused by ground fissure displacement, a drag effect is exerted on the lower tunnel, causing the lining top of the lower tunnel to tend to separate from the surrounding soil. Therefore, the load on the tunnel top will be somewhat reduced. But in actual engineering, using the weight of the overburden layer to calculate the load can provide a safety margin for the structure; therefore, the formula for calculating the lining load of the lower tunnel is:

[0136]

[0137] Where, γ i and h i These are the unit weight and thickness of the i-th soil layer, respectively.

[0138] Because the calculation of lining load requires the soil fracture angle, and different strata, tunnel depth, and the angle between the subway and the ground fissure all affect this result, it is necessary to analyze the stress state of the calculation section in order to analyze the development of the fracture angle. Figure 9 As shown. When local fissure activity causes soil fracturing, a temporary free surface AD ​​is formed. The stress in the upper soil mass AE'H'I is transferred to the lower soil mass IHD as additional stress. Based on the stress equivalence principle, the area ratio of the two soil masses can be used to calculate the equivalence coefficient α, thus making the stress in soil mass AE'H'I equivalent to that in soil mass IHD, expressed as:

[0139]

[0140] The stress field of the triangular soil mass IDH under additional stress can be equivalently obtained by approximating the vertical stress of the average soil mass AE'H'I, as expressed by:

[0141]

[0142] σ'1=K a σ'3=σ1 (26)

[0143] Where σ1 is the horizontal stress before equivalence; σ3 is the vertical stress before equivalence; σ1' is the horizontal stress after equivalence; and σ3' is the vertical stress after equivalence.

[0144] Since the rupture traces in the soil are assumed to be two straight lines, i.e., the rupture surface is an inclined plane, the soil stress at any point on the inclined plane can be calculated from the stress of the inclined section under two-dimensional stress state. The calculation formula is as follows:

[0145] σ n =σ'1cos 2 β+σ'3sin 2 β (27)

[0146] τ n =(σ'3-σ'1)sinβcosβ (28)

[0147] Where, σ n τ is the normal stress on the fracture surface. n This represents the shear stress on the fracture surface.

[0148] According to the shear strength theory of soil mechanics, the ultimate shear strength at the fracture surface is:

[0149]

[0150] To obtain the fracture angle corresponding to the most dangerous section, a function g(β) needs to be constructed, which is the ultimate shear strength τ at the fracture surface. max and shear stress τ n The difference between them is g(β)=τ max -τ n .

[0151] Substituting equations (24)-(29) into equation (30), we obtain the expression for the function g(β):

[0152]

[0153] Taking the derivative of equation (30) with respect to β and setting its first derivative to 0, we can obtain the fracture angle as follows:

[0154]

[0155]

[0156] Equation (32) is the solution for the fracture angle; however, it should be noted that this equation is an implicit solution and has multiple solutions for β. Therefore, it is necessary to select a unique suitable solution based on the selection criteria, which are:

[0157] 0°<β≤90° (33)

[0158] The fracture angle can be obtained from equations (32) and (33). Then, substitute it into equation (6) or equations (19) and (20) to obtain the external force exerted on the lining by the surrounding rock and soil caused by the ground fissure activity. The maximum lining load of the upper plate when the subway tunnel crosses the ground fissure orthogonally or obliquely is obtained from equation (10) or equation (22). The lining load of the lower plate is obtained from equation (23).

[0159] It should be noted that the fracture traces of the surrounding rock and soil on both sides of the tunnel cross-section caused by the activity of the ground fissure are assumed to be two straight lines; during the slow activity of the ground fissure, the surrounding rock and the tunnel are in a state of limit equilibrium.

[0160] The tunnel lining load determination method described in this invention addresses the structural safety of subway tunnels crossing ground fissures during the design phase. Based on the deformation and movement patterns of the ground fissure-subway-surrounding rock, it constructs calculation formulas for the maximum lining load when the subway tunnel vertically crosses a ground fissure, the maximum lining load when the subway tunnel obliquely crosses a ground fissure at any angle, and the fracture angle of the surrounding rock on both sides of the subway tunnel lining caused by ground fissure activity. The method also provides specific steps for determining the load, effectively filling the gap in methods for determining additional loads on subway tunnel linings caused by ground fissure activity. By obtaining the maximum load required during the structural design phase, it solves the problem of existing technologies failing to consider the impact of ground fissure activity on subway tunnels, thus enabling the determination of the maximum lining load required in the design of subway projects crossing ground fissures. This provides structural designers in similar subway projects with a framework and method for determining the maximum load, allowing for adjustments and optimization of structural measures to ensure the later operational safety of subway tunnels in ground fissure sites.

[0161] This invention also provides a tunnel lining load determination system, including a basic design parameter acquisition module, a first calculation module, a second calculation module, and a third calculation module. The basic design parameter acquisition module is used to acquire the basic design parameters of the subway tunnel, including the tunnel outer diameter, tunnel depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil. The first calculation module is used to determine the design angle between the tunnel's direction line and the ground fissure direction line, and calculates the equivalent coefficient and fracture angle of the surrounding rock and soil on both sides of the tunnel based on projection rules and the stress equivalence principle, and according to the basic design parameters of the subway tunnel. The second calculation module is used to calculate the external force exerted by the surrounding rock on the subway tunnel lining on both sides of the tunnel when the ground fissure is active, based on the fracture angle of the surrounding rock on both sides of the tunnel. The third calculation module is used to calculate the maximum load on the subway tunnel lining based on the principle of force balance of the lining on the cross-section of the subway tunnel and the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active.

[0162] The present invention also provides a device for determining tunnel lining load, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of the method for determining tunnel lining load.

[0163] When the processor executes the computer program, it implements the steps of the above-mentioned method for determining the tunnel lining load, such as: obtaining the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil; determining the design angle between the tunnel direction line and the ground fissure direction line, and calculating the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel based on the projection rules and stress equivalence principle, and according to the basic design parameters of the subway tunnel; calculating the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active based on the fracture angle of the surrounding rock and soil on both sides of the tunnel; and calculating the maximum load of the subway tunnel lining based on the principle of force balance of the lining on the cross section of the subway tunnel and the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active.

[0164] Alternatively, when the processor executes the computer program, it implements the functions of each module in the above system. For example: a basic design parameter acquisition module is used to acquire the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil; a first calculation module is used to determine the design angle between the tunnel direction line and the ground fissure direction line, and calculates the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel based on the projection rules and stress equivalence principle, and according to the basic design parameters of the subway tunnel; a second calculation module is used to calculate the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active, based on the fracture angle of the surrounding rock and soil on both sides of the tunnel; a third calculation module is used to calculate the maximum load of the subway tunnel lining based on the principle of force balance of the lining on the cross-section of the subway tunnel and the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active.

[0165] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a preset function, the instruction segments describing the execution process of the computer program in the tunnel lining load determination device. For example, the computer program can be divided into a basic design parameter acquisition module, a first calculation module, a second calculation module, and a third calculation module. The specific functions of each module are as follows: The basic design parameter acquisition module is used to acquire the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil; The first calculation module is used to determine the design angle between the tunnel alignment line and the ground fissure alignment line, and calculates the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel based on the projection rules and stress equivalence principle, and according to the basic design parameters of the subway tunnel; The second calculation module is used to calculate the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active, based on the fracture angle of the surrounding rock and soil on both sides of the tunnel; The third calculation module is used to calculate the maximum load of the subway tunnel lining based on the principle of force balance of the lining on the cross-section of the subway tunnel and the external force exerted by the surrounding rock on both sides of the tunnel on the subway tunnel lining when the ground fissure is active.

[0166] The tunnel lining load determination device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The tunnel lining load determination device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above are examples of tunnel lining load determination devices and do not constitute a limitation on the tunnel lining load determination device. It may include more components than described above, or combine certain components, or different components. For example, the tunnel lining load determination device may also include input / output devices, network access devices, buses, etc.

[0167] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor, or any conventional processor. The processor is the control center of the tunnel lining load determination device, connecting all parts of the device via various interfaces and lines.

[0168] The memory can be used to store the computer program and / or modules. The processor implements various functions of the tunnel lining load determination device by running or executing the computer program and / or modules stored in the memory and by calling the data stored in the memory.

[0169] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function (such as sound playback, image playback, etc.); the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital cards (SD cards), flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0170] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for determining tunnel lining load.

[0171] If the modules / units integrated in the tunnel lining load determination system are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0172] Based on this understanding, the present invention can implement all or part of the process in the above-described method for determining tunnel lining loads, or it can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the above-described method for determining tunnel lining loads. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or a preset intermediate form, etc.

[0173] The computer-readable storage medium may include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0174] It should be noted that the content contained in the computer-readable storage medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0175] Example 1

[0176] To verify the correctness of the lining load obtained when a subway tunnel orthogonally crosses a ground fissure, this embodiment 1 combines the experimental results from Huang Qiangbing's 2009 doctoral dissertation "Research on the Influence Mechanism and Disease Control of Ground Fissures on Subway Tunnels" and compares and analyzes the tunnel lining load determination method described in this invention with the above test results.

[0177] The basic working conditions of the project are as follows: the stratum in which the subway shield tunnel is located is mainly silty clay layer, and the vertical distance between the top of the tunnel and the ground surface is about 11.5m; the subway tunnel crosses the ground fissure at a 90° orthogonal angle; the outer diameter of the shield segment is 6.0m, and the calculation parameters are shown in Table 1.

[0178] Table 1 Calculation parameters for soil layers and tunnels

[0179]

[0180] Based on the parameters in Table 1, the equivalent coefficient when the subway tunnel and the ground fissure are orthogonal is calculated by equation (24) as α = 1.92tanβ + 7.51, and the soil rupture angle is calculated by equation (32) as β = 32.2°; where, K a=0.4; Substituting into equation (6), we get the external force T = 402kN / m. Finally, we get the maximum lining load of the shield tunnel upper plate from equation (10) as q1 = 472kPa; and we get the lower plate lining load from equation (23) as q = 221kPa.

[0181] Example 2

[0182] To verify the correctness of the lining load obtained when the subway tunnel obliquely crosses the ground fissure, this embodiment 2 combines the experimental results of the paper "Experimental Study on Deformation and Failure Mechanism of Shield Tunnel Crossing Ground Fissure at 60°" published by Hu Zhiping et al. in the Chinese Journal of Rock Mechanics and Engineering in 2010, and compares and analyzes the tunnel lining load determination method described in this invention with the above test results.

[0183] The basic working conditions of the project are as follows: the stratum in which the subway shield tunnel is located is mainly loess, and the vertical distance between the top of the tunnel and the ground surface is about 11.5m; the subway tunnel crosses the ground fissure at a 60° angle; the outer diameter of the shield segment is 6.0m, and the calculation parameters are shown in Table 2.

[0184] Table 2 Calculation parameters for soil layers and tunnels

[0185]

[0186] Based on the parameters in Table 2, the equivalent coefficient α = 1.92tanβ + 7.51 is calculated using equation (24) when the subway tunnel is assumed to be orthogonal to the ground fissure. Then, the corresponding soil rupture angle β = 33.9° is calculated using equation (32). K a =0.4.

[0187] Based on equations (13) and (14), and combined with equation (24), the coefficients on both sides when the subway tunnel intersects the ground fissure are calculated as α1 = 12.17tanβ1 + 1.92 and α2 = 12.46tanβ2 + 1.92, respectively. Thus, the corresponding rupture angles are β1 = 33.8° and β2 = 33.9°.

[0188] Substituting these values ​​into equations (19) and (20) respectively, we obtain external forces T1 = 775 kN / m and T2 = 813 kN / m. Finally, we obtain the maximum lining load of the shield tunnel upper plate as q1 = 467 kPa from equation (22) and the lower plate lining load as q = 228 kPa from equation (23).

[0189] Example 3

[0190] To verify the accuracy of the lining load obtained when a subway tunnel obliquely crosses ground fissures, this embodiment 3 combines the experimental results from the paper "Experimental study on the mechanical response of metro shield tunnels obliquely crossing ground fissures" published by Gou et al. in Tunnelling and Underground Space Technology in 2023, and compares and analyzes the tunnel lining load determination method described in this invention with the above test results.

[0191] The basic working conditions of the project are as follows: the stratum in which the subway shield tunnel is located is mainly loess, and the vertical distance between the top of the tunnel and the ground surface is about 12m; the subway tunnel crosses the ground fissure at a 45° angle; the outer diameter of the shield segment is 6.2m, and the calculation parameters are shown in Table 3.

[0192] Table 3 Calculation parameters for soil layers and tunnels

[0193]

[0194] Based on the parameters in Table 3, the equivalent coefficient α = 1.94tanβ + 7.62 is calculated using equation (24) when the subway tunnel is assumed to be orthogonal to the ground fissure. Then, the corresponding soil rupture angle β = 32.6° is calculated using equation (32). K a =0.4.

[0195] Based on equations (13) and (14), and combined with equation (24), the coefficients on both sides when the subway tunnel intersects the ground fissure are calculated as α1 = 14.5tanβ1 + 1.94 and α2 = 15.3tanβ2 + 1.94, respectively. Thus, the corresponding rupture angles are β1 = 32.4° and β2 = 32.6°.

[0196] Substituting these values ​​into equations (19) and (20) respectively, we obtain external force T1 = 771 kN / m and external force T2 = 851 kN / m. Finally, we obtain the maximum lining load of the shield tunnel upper plate as q1 = 475 kPa from equation (22) and the lower plate lining load as q = 233 kPa from equation (23).

[0197] As attached Figure 10 As shown, attached Figure 10 The attached figure shows a comparison between the measured and calculated values ​​of the tunnel lining load in Examples 1-3; from the attached figure... Figure 10As can be seen, the calculation results in Example 1 are quite close to the maximum measured results, demonstrating the rationality of the tunnel lining load determination method described in this invention. Since the deformation of the hanging wall strata and tunnel caused by ground fissure activity is a complex process, the measurement of the lining load can also be affected by external factors, leading to potential errors between the calculation and measurement results. In practical engineering, safety factors are considered for each load in the design; therefore, the final load obtained from the theoretical calculation value of this method will be greater than the measured value, thus ensuring the safety of the structure.

[0198] From the appendix Figure 10 As can be seen, the calculation results in Example 2 are close to the maximum measured results. When the subway tunnel and the ground fissure intersect obliquely, the intersection angle is an important influencing factor. Although the calculation results deviate from the measured values, for actual engineering, the design will consider the safety factor for each load. Therefore, the final load obtained from the theoretical value calculated by this method will be greater than the measured value, so as to ensure the safety of the structure.

[0199] From the appendix Figure 10 As can be seen from the results, the calculation results in Example 3 are close to the maximum measured results; the lining load of the subway tunnel caused by ground fissure activity will change with the change of the intersection angle, and the smaller the angle, the greater the load; the load of the ground fissure site includes two parts: the load of the overburden itself and the load caused by ground fissure activity. In this invention, the load of the overburden is considered while introducing the external load caused by ground fissure. The calculation results also theoretically prove the conclusion that the smaller the intersection angle, the more unfavorable it is to the tunnel structure.

[0200] In summary, the method for determining tunnel lining loads described in this invention can serve as a reference for lining loads during the design phase, helping designers optimize structural design.

[0201] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A method for determining tunnel lining load, characterized in that, The process for determining the load on the lining of a subway tunnel in a ground fissure site; wherein, the method for determining the tunnel lining load includes: Obtain the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil; The design angle between the tunnel alignment and the ground fissure alignment is determined. Based on the projection rules and the stress equivalence principle, and according to the basic design parameters of the subway tunnel, the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel are calculated. Based on the fracture angle of the surrounding rock and soil on both sides of the tunnel, the external force exerted by the surrounding rock on the subway tunnel lining during ground fissure activity is calculated. Based on the principle of force balance of the lining on the cross section of the subway tunnel, the maximum load on the subway tunnel lining is calculated according to the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the ground fissure is active. The design angle between the tunnel alignment and the ground fissure alignment is determined based on projection rules and the stress equivalence principle. In the process of calculating the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel according to the basic design parameters of the subway tunnel, the following formula is used. in, φ The friction angle of the surrounding rock and soil; h For tunnel burial depth; d The outer diameter of the tunnel; K a This is the coefficient of lateral earth pressure; β The fracture angle of the surrounding rock and soil on both sides of the subway tunnel when the subway tunnel and the ground fissure are perpendicular; α This is the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the subway tunnel when the subway tunnel is orthogonal to the ground fissure; α 1 is the equivalent coefficient of the fracture angle of the surrounding rock and soil on one side of the tunnel when the subway tunnel intersects the ground fissure obliquely; α 2 is the equivalent coefficient of the fracture angle of the surrounding rock and soil on the other side of the tunnel when the subway tunnel intersects the ground fissure obliquely; ω The design angle between the tunnel alignment and the ground fissure alignment; β 1 represents the fracture angle of the surrounding rock and soil on one side of the subway tunnel when it intersects the ground fissure at an angle; β 2 represents the angle of fracture of the surrounding rock and soil on the other side of the subway tunnel when it intersects the ground fissure at an angle; Based on the fracture angles of the surrounding rock and soil on both sides of the tunnel, the external forces exerted by the surrounding rock on the subway tunnel lining during ground fissure activity are calculated as follows: When the subway tunnel is perpendicular to the ground fissure, the external force exerted by the surrounding rock on both sides of the tunnel lining during ground fissure activity is: in, T When the subway tunnel is perpendicular to the ground fissure, the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during the activity of the ground fissure. γ The unit weight of the surrounding rock and soil; c The cohesion of the surrounding rock and soil; It is the friction angle between the tunnel roof and the surrounding rock and soil on both sides.

2. The method for determining tunnel lining load according to claim 1, characterized in that, Based on the principle of force balance of the lining on the cross-section of a subway tunnel, and according to the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity, the maximum load on the subway tunnel lining is calculated as follows: When the subway tunnel is perpendicular to the ground fissure, the maximum load on the subway tunnel lining is: in, q 1 represents the maximum load on the subway tunnel lining when the subway tunnel is perpendicular to the ground fissure.

3. The method for determining tunnel lining load according to claim 2, characterized in that, The friction angle between the tunnel roof and the surrounding rock and soil on both sides θ The calculation formula is: in, φ The friction angle of the surrounding rock and soil.

4. The method for determining tunnel lining load according to claim 1, characterized in that, Based on the fracture angles of the surrounding rock and soil on both sides of the tunnel, the external forces exerted by the surrounding rock on the subway tunnel lining during ground fissure activity are calculated as follows: When a subway tunnel intersects a ground fissure at an oblique angle, the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity are: in, T 1 represents the external force exerted on the subway tunnel lining by the surrounding rock and soil on one side of the tunnel when the ground fissure is active, when the subway tunnel intersects with the ground fissure at an oblique angle. T 2 refers to the external force exerted on the subway tunnel lining by the surrounding rock and soil on the other side of the tunnel when the subway tunnel intersects with the ground fissure at an oblique angle and the ground fissure is active.

5. The method for determining tunnel lining load according to claim 3, characterized in that, Based on the principle of force balance of the lining on the cross-section of a subway tunnel, and according to the external forces exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel during ground fissure activity, the maximum load on the subway tunnel lining is calculated as follows: When the subway tunnel intersects the ground fissure at an oblique angle, the maximum load on the subway tunnel lining is: in, q 2 represents the maximum load on the subway tunnel lining when the subway tunnel intersects obliquely with the ground fissure.

6. A system for determining tunnel lining loads, characterized in that, This method is used to implement the tunnel lining load determination method as described in any one of claims 1-5, specifically for determining the lining load of a subway tunnel in a ground fissure site; wherein the tunnel lining load determination system comprises: The basic design parameter acquisition module is used to acquire the basic design parameters of the subway tunnel; wherein, the basic design parameters of the subway tunnel include the tunnel outer diameter, tunnel burial depth, unit weight of the surrounding rock and soil, friction angle of the surrounding rock and soil, and cohesion of the surrounding rock and soil. The first calculation module is used to determine the design angle between the tunnel alignment and the ground fissure alignment. Based on the projection rules and stress equivalence principle, and according to the basic design parameters of the subway tunnel, it calculates the equivalent coefficient of the fracture angle of the surrounding rock and soil on both sides of the tunnel and the fracture angle of the surrounding rock and soil on both sides of the tunnel. The second calculation module is used to calculate the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the ground fissures are active, based on the fracture angle of the surrounding rock and soil on both sides of the tunnel. The third calculation module is used to calculate the maximum load on the subway tunnel lining based on the principle of force balance of the lining on the cross-section of the subway tunnel and the external force exerted on the subway tunnel lining by the surrounding rock on both sides of the tunnel when the ground fissure is active.

7. A device for determining tunnel lining load, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the method for determining tunnel lining loads as described in any one of claims 1-5.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for determining the tunnel lining load as described in any one of claims 1-5.

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