Seismic design method for rigid panel reinforced earth retaining wall in railway engineering

Abstract

The invention provides a railway engineering rigid panel reinforced soil retaining wall aseismic design method, which belongs to the technical field of roadbed engineering, and comprises the following steps of: determining design conditions of a reinforced soil retaining wall, determining a structural form and used materials of the reinforced soil retaining wall, preliminary design of the reinforced soil retaining wall is carried out; based on a double-wedge theory, calculating a rib material strength design value of the reinforced earth retaining wall and a resultant force applied behind the reinforced earth retaining wall, checking and calculating safety, usability and repairability, judging whether the reinforced earth retaining wall meets performance requirements required by design or not according to checking and calculating results, if yes, performing detailed design of the reinforced earth retaining wall, and if not, returning to preliminary design of the reinforced earth retaining wall. The problems that an existing railway engineering rigid panel reinforced earth retaining wall only controls strength and stability in design and lacks deformation control standards and aseismic design, so that large-scale application in high-speed railway engineering with millimeter-level deformation control and high-intensity earthquake areas is difficult are solved.

Description

Technical Field

[0001] This invention belongs to the field of roadbed engineering technology, and in particular relates to a seismic design method for rigid panel reinforced soil retaining walls in railway engineering. Background Technology

[0002] Driven by breakthroughs in high-speed rail technology, the maximum operating speed of trains has increased to 350 km / h, and in the future, it will continue to move towards being "faster, more stable, safer, and more environmentally friendly." As a key load-bearing structure of the track, the optimization and upgrading of roadbed engineering plays a decisive role in ensuring the safe and stable operation of trains. Among them, rigid panel reinforced soil retaining walls have become an important structural form in roadbed engineering due to their significant advantages such as being eco-friendly, saving land, and having excellent seismic performance. This structure has achieved remarkable results in the construction of the Japanese Shinkansen, maintaining good performance even after undergoing multiple strong earthquakes, fully demonstrating its applicability in high-intensity seismic areas.

[0003] However, the application of this type of structure has long been limited in my country, especially in high-speed railway projects with large loads, strict deformation control, and extremely high requirements for line safety and durability. The design and selection of such structures have been cautious. The main reasons include: firstly, reinforced soil retaining walls are flexible structures that rely on the coordinated deformation of the panel, reinforcement, and backfill to achieve vibration reduction and energy dissipation. However, this deformation can cause significant displacement, affecting the smoothness and safe operation of the railway line. Secondly, existing reinforced soil retaining wall designs often use the allowable stress method, focusing only on strength and stability as control indicators, without clear deformation control standards and a lack of seismic design methods. With the accelerated expansion of railway projects into high-intensity seismic zones in western my country, to promote the large-scale application of reinforced soil retaining walls in these areas, it is urgent to construct a performance design method for reinforced soil retaining walls under seismic loading that integrates multiple performance objectives for coordinated control, combines strength and deformation standards, and is tailored to my country's specific railway conditions. Summary of the Invention

[0004] To address the aforementioned shortcomings in existing technologies, this invention provides a seismic design method for rigid panel reinforced soil retaining walls in railway engineering. This method solves the problem that existing designs for rigid panel reinforced soil retaining walls in railways only control strength and stability, lack deformation control standards and seismic design, making large-scale application difficult in high-speed railway engineering and high-intensity earthquake zones where millimeter-level deformation control is required.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a seismic design method for rigid panel reinforced soil retaining walls in railway engineering, comprising the following steps: Determine the design conditions for reinforced soil retaining walls, including performance requirements for safety level, safety, usability, and repairability; Determine the structural type and materials of the reinforced soil retaining wall, and carry out the preliminary design of the reinforced soil retaining wall; Based on the double-wedge theory, the design value of the reinforcement strength and the resultant force behind the slab of the reinforced soil retaining wall are calculated. Based on the design strength values ​​of the reinforcement materials of the reinforced soil retaining wall and the resultant force behind the slab, the safety, usability, and repairability of the reinforced soil retaining wall are checked, and the check results are obtained. Based on the calculation results, determine whether the reinforced soil retaining wall meets the performance requirements of the design. If so, carry out the detailed structural design of the reinforced soil retaining wall; otherwise, carry out the preliminary design of the reinforced soil retaining wall again.

[0006] Furthermore, the expression for the tensile strength of the reinforcing bar is as follows:

[0007] in, This represents the characteristic value of the tensile strength of the reinforcing bar. The standard value of the ultimate tensile strength of the reinforcing bar, as measured by a tensile test. This is a material correction factor. .

[0008] Furthermore, the expression for the pull-out strength of the reinforcing bar is as follows:

[0009]

[0010]

[0011]

[0012]

[0013] in, For the pull-out strength of the reinforcing bar, For the filling material and the load on the top of the wall acting on the first Total vertical stress on the reinforcement layer For the cohesive force of the filler, The angle of friction of the packing material. This is the pull-out reduction factor for the reinforcing steel. For the first Length of anchorage section of layered reinforcement The vertical stress on the reinforcement of the reinforced soil retaining wall due to the backfill soil, track and train loads. The vertical stress on the reinforcing steel caused by strip loads such as tracks and trains acting on the roadbed surface. For the packing density, This is the vertical distance from the top of the wall to the reinforcing steel. For strip loads such as tracks and trains acting on the roadbed surface, The width of the strip load distribution above the roadbed surface. The width of the earth pressure distribution caused by the load. The distance from the load above the roadbed surface to the inner surface of the panel. The vertical distance from the load to the reinforcing bar. The stress diffusion angle, The slope ratio of the fill above the top of the wall. The unit weight of the fill soil above the top of the wall. For the height of the wall, This refers to the height of the backfill above the top of the wall. It is the horizontal distance from the top of the wall to the toe of the embankment slope to the back of the slab.

[0014] Furthermore, the expression for the design strength value of the reinforcement in the reinforced soil retaining wall is as follows:

[0015] in, For reinforced soil retaining wall Design strength values ​​of the reinforcement in the layer To obtain the characteristic value of tensile strength of reinforcing steel With pull-out strength of reinforcing bars The minimum value.

[0016] The aforementioned further beneficial effects are: the auxiliary reinforced soil retaining wall design method is transformed from the anchored wedge method to the double wedge method, while avoiding excessive structural design redundancy caused by excessively long reinforcement materials.

[0017] Furthermore, the expression for the resultant force acting on the back of the plate is as follows:

[0018]

[0019]

[0020]

[0021]

[0022] in, The net force acting on the back of the plate. For the height of the wall, These represent the horizontal loads at different heights behind the slab. The earth pressure generated by the fill material at different heights behind the panel is distributed in a triangular pattern, with zero earth pressure at the top and a magnitude of [missing value] at the bottom. , The earth pressure generated at different heights behind the slab by the backfill soil and the top strip load through the stress diffusion angle is distributed across a width of [missing information]. The magnitude of the earth pressure is , The earth pressure generated at different heights behind the slab by the inertial forces produced by the horizontal load on the top of the wall and the load on the wedge under seismic action is distributed in an inverted triangular pattern. The earth pressure at the top of the panel is... The earth pressure at the bottom is 0. For earth pressure calculation coefficients, For the packing density, The angle between the back of the board and the vertical direction. The angle of friction of the packing material. The width of the strip load distribution. For the loads of the superfill and rail trains, etc. Horizontal seismic intensity The width of the load distribution on the upper part of the wedge is defined as .

[0023] The aforementioned further beneficial effects are: it specifies the distribution of earth pressure behind the slab, assists in the transformation of my country's reinforced soil retaining wall design method from the anchored wedge method to the double wedge method, and serves as the basis for subsequent safety, usability, and repairability checks.

[0024] Furthermore, the safety calculation includes anti-sliding stability calculation, anti-overturning stability calculation, overall stability calculation, overall tensile strength calculation of reinforcement, overall pull-out strength calculation of reinforcement, and foundation bearing capacity calculation; The expression for the anti-slip stability check is as follows:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] in, This is the design value for the horizontal resistance to sliding. This represents the effect value of the horizontal sliding force. For the first The horizontal resistance of the layered reinforcement is designed to be high. This refers to the friction between the wall and the foundation. This is the sum of the vertical loads acting on the bottom surface of the panel. The coefficient of friction between the base and the foundation. For the panel's gravity, For the vertical load at the top of the panel, Let F be the earth pressure exerted by the wedge on the panel. The angle of friction of the packing material. The angle between the back of the board and the vertical direction. The horizontal component of the resultant earth pressure is... The inertial force on the panel under earthquake action, The resultant horizontal force acting on the top of the panel, Horizontal seismic intensity For the horizontal load on the top of the panel, For the earth pressure action partial factor in the anti-sliding stability check, The partial factors for the self-weight of the wall and the resistance of the track load are used in the anti-sliding stability check.

[0032] The expression for the overturning stability check is as follows:

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041] in, This is the design value for the overturning moment. This represents the effect value of the overturning moment. For the first The overturning moment generated by the layered reinforcement The stabilizing moment generated by the wall's own weight. for and The stabilizing torque generated by the vertical component difference, The stabilizing moment generated by the vertical earth pressure component on the back of wedge B. From the bottom of the retaining wall to the first Vertical distance at the location of the reinforcement layer. The horizontal distance from the wall toe to the center of gravity of the panel. The net force acting on the back of the plate. The resultant earth pressure of wedge B on wedge F. Vertical earth pressure difference Horizontal distance to the toe of the wall Vertical earth pressure component on the back of wedge B Horizontal distance to the toe of the wall for The overturning moment generated by the horizontal component of the force. This refers to the torque generated by the inertia of the panel during an earthquake. The overturning moment is generated by the external force at the top of the panel. For the wall toe perpendicular distance from the point of application Horizontal seismic intensity This is the vertical distance from the wall toe to the center of gravity of the panel. For the horizontal load on the top of the panel, The vertical distance from the wall toe to the top of the panel. For the vertical load at the top of the panel, The horizontal distance from the toe of the wall to the top of the panel where the vertical load is applied is denoted as . The partial factors for the self-weight of the wall and the resistance of the track load are used in the overturning stability check. For the earth pressure resistance partial factor in the overturning stability check, The earth pressure factor is used in the overturning stability check. The expression for the overall stability check is as follows:

[0042]

[0043]

[0044]

[0045]

[0046]

[0047] in, This is the design value for the overall stability resistance torque. This represents the overall stability effect value of the sliding torque. The resisting moment generated by the soil and the load. The resisting torque generated by the reinforcing material, The sliding moment generated by the soil and the load. The sliding moment generated by the panel and the load. For soil strips Soil cohesion at the slip surface For soil strips The length of the bottom edge of the sliding surface, For soil strips gravity and soil strips Permanent loads on, For soil strips Variable loads on For soil strips The angle between the normal force at the center of the sliding surface and the vertical line. Soil strips under seismic action gravity and load The generated inertial force For soil strips The angle of friction of the soil at the slip surface. The radius of the arc. Horizontal seismic intensity For the first Design strength value of the reinforcement layer, For the first The angle formed by the intersection of the layer of reinforcing material and the arc-shaped smooth surface The horizontal distance from the center of gravity of the panel to the center of the circle. The horizontal distance from the point of application of the horizontal load at the top of the panel to the center of the circle. This is the vertical distance from the center of gravity of the panel to the height of the center of the circle. It is the vertical distance from the point of application of the vertical load at the top of the panel to the height of the center of the circle. This is the vertical distance from the point of application of the horizontal force on the soil strip to the height of the center of the circle. This is the resistance partial factor for the resisting moment generated by cohesion in the overall stability check. This is the resistance partial factor for the resisting moment generated by the self-weight of permanent loads in the overall stability check. This is the resistance partial factor for the resisting moment generated by variable loads in the overall stability check. This is a partial factor for the effect of the sliding moment caused by the self-weight of the permanent load in the overall stability check. The partial factor for the effect of sliding moment caused by variable load in the overall stability check; The expression for the foundation bearing capacity check is as follows:

[0048] In the formula: This represents the effect value of the foundation bearing capacity. The total vertical load acting on the base is calculated using the most unfavorable values ​​obtained from the anti-sliding stability and anti-overturning stability measures. The base width, The eccentricity of the resultant force of the base is denoted as .

[0049] The further beneficial effects mentioned above are as follows: Soil and rock structures often experience significant deformation upon failure, which is fundamentally different from reinforced concrete building structures. Directly applying deformation control criteria based on building structures to design roadbeds and retaining walls for earthquake resistance during major earthquakes lacks rationality. Therefore, for the seismic design of reinforced soil retaining walls, this design abandons traditional deformation control criteria and adopts strength control criteria, directly verifying its strength and stability under rare earthquake conditions. This ensures the structure achieves the seismic fortification goal of "not collapsing under major earthquakes," overcoming the limitations of the traditional anchoring wedge method under seismic conditions.

[0050] Furthermore: the usability and repairability assessment includes surface settlement assessment, panel appearance and damage assessment, and reinforcement damage assessment; The expression for the surface settlement calculation is as follows:

[0051] in, This represents the effect value of surface settlement. The permanent vertical displacement caused by different load combinations. This refers to permanent vertical displacement caused by the deterioration of structural materials. The expressions for panel appearance and damage detection are as follows:

[0052]

[0053] In the formula: The values ​​represent the bending moment effect at different heights of the panel section. These represent the shear force effect values ​​at different heights of the panel section. This represents the horizontal displacement of the panel at different height positions. The bending stiffness of the panel section; The expression for calculating the reinforcement damage is as follows:

[0054]

[0055] in, This represents the strain effect value of the reinforcing material. This is the additional factor for the peak strain of the reinforcing material. This represents the elongation of the reinforcing steel. For the first Length of free section of layered reinforcement, This represents the effect value of tensile force on a single reinforcing bar. This is the tensile modulus of the reinforcing bar.

[0056] The aforementioned further beneficial effects are: the usability and repairability of reinforced soil retaining walls have been verified; a multi-parameter collaborative verification mechanism with surface settlement as the core control index and supplemented by panel crack width, bending moment and shear force and reinforcement strain has been established; and the functional reliability and post-earthquake recoverability of the structure under various levels of earthquake action have been systematically guaranteed.

[0057] Furthermore: the security checks, usability checks, and repairability checks include: The safety check adopts the ultimate limit state design, and the expression for the safety check is as follows:

[0058] in, For structural importance coefficients, This represents the structural effect value. This is the design value for structural resistance; Usability and repairability checks are performed using the normal serviceability limit state design. The expressions for usability and repairability checks are as follows:

[0059] in, These are the limits for the structure under normal operating conditions.

[0060] The beneficial effects of this invention are: (1) A performance design method for rigid panel reinforced soil retaining walls for railway engineering was constructed, clarifying the performance requirements of reinforced soil retaining walls in terms of safety, usability and repairability. A design method based on dual control standards of strength and deformation was proposed, and a graded control standard for track top surface settlement directly related to train speed was formulated. This method enables multi-performance target collaborative design of reinforced soil retaining walls, rather than the single strength control of conventional methods. (2) The present invention discloses a seismic design method for rigid panel reinforced soil retaining walls in railway engineering, which can be used for performance verification methods that meet the strict deformation control requirements of railway engineering, and ensures that the structure will not collapse under major earthquakes through strength control criteria. In terms of safety, a stability and bearing capacity verification method based on double wedge theory is established, which overcomes the limitations of the traditional anchored wedge method under seismic conditions; in terms of usability and repairability, a multi-parameter collaborative verification mechanism is established with surface settlement as the core control index, supplemented by panel stress state, crack width and reinforcement strain, etc., which systematically ensures the functional reliability and post-earthquake recoverability of the structure under various levels of earthquake action. Attached Figure Description

[0061] Figure 1 A flowchart illustrating a seismic design method for rigid panel reinforced soil retaining walls in railway engineering. Figure 2 The diagram is a calculation based on the double wedge theory. Figure 3 A schematic diagram illustrating the calculation of the vertical stress on the reinforcing steel under the loads of the backfill, track, and train on the top of the reinforced soil retaining wall. Figure 4 This is a schematic diagram for calculating the vertical stress on the reinforcing steel under strip loads such as tracks and trains acting on the roadbed surface. Figure 5 A schematic diagram of the pressure distribution behind the reinforced soil retaining wall; Figure 6 This is a schematic diagram for anti-slip stability calculation; Figure 7 This is a schematic diagram for calculating the overturning stability. Figure 8 This is a schematic diagram for overall stability calculation; Figure 9 This is a schematic diagram for calculating reinforcement damage. Figure 10 Schematic diagram of the cross-section design for reinforced soil retaining wall; Figure 11 Schematic diagram of surface settlement under different combinations of effects; Figure 12 Schematic diagram of bending moment and shear force distribution on the lower panel section under different load combinations; Figure 13 This is a schematic diagram illustrating the extent to which the performance of the reinforcing steel is utilized. Detailed Implementation

[0062] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0063] Example 1 like Figure 1 As shown, this invention provides a seismic design method for rigid panel reinforced soil retaining walls in railway engineering, comprising the following steps: Determine the design conditions for reinforced soil retaining walls, including performance requirements for safety level, safety, usability, and repairability; Determine the structural type and materials of the reinforced soil retaining wall, and carry out the preliminary design of the reinforced soil retaining wall; Based on the double-wedge theory, the design value of the reinforcement strength and the resultant force behind the slab of the reinforced soil retaining wall are calculated. Based on the design strength values ​​of the reinforcement materials of the reinforced soil retaining wall and the resultant force behind the slab, the safety, usability, and repairability of the reinforced soil retaining wall are checked, and the check results are obtained. Based on the calculation results, determine whether the reinforced soil retaining wall meets the performance requirements of the design. If so, carry out the detailed structural design of the reinforced soil retaining wall; otherwise, carry out the preliminary design of the reinforced soil retaining wall again.

[0064] Existing reinforced soil retaining wall design methods employ strength and stability control criteria. Internal stability calculations use the anchored wedge method, prohibiting reinforcement breakage or pull-out. External stability calculations treat the reinforced area along with the panel as a solid wall, performing sliding stability, overturning stability, and foundation checks, using gravity retaining wall design methods. However, existing reinforced soil retaining wall design methods lack clear structural deformation control standards and calculation methods, and also lack seismic design checks. This invention, starting with millimeter-level deformation control of high-speed railway subgrades, draws on the three-level fortification concept in building seismic design, clarifying the performance requirements of reinforced soil retaining walls in terms of safety, usability, and repairability, and proposing corresponding performance indicators and check items. Based on existing rigid panel reinforced soil retaining wall design methods for railway engineering, this invention optimizes the safety level classification of reinforced soil retaining walls, proposes a design principle based on dual strength and deformation control standards, and establishes a graded control standard for track top surface settlement directly related to train speed, realizing a system transformation from single strength control to multi-performance target collaborative control.

[0065] Before designing reinforced soil retaining walls, it is necessary to determine the performance design system, including: (1) Clarify the basis for classifying the safety level of reinforced soil retaining walls; (2) The performance requirements of reinforced soil retaining walls are divided into safety, usability and repairability, and the performance requirements of reinforced soil retaining walls under different load conditions are specified. (3) Set the corresponding performance check items and corresponding performance indicators according to the performance requirements of reinforced soil retaining walls; (4) Determine the corresponding control equations for the verification based on the performance requirements of the reinforced soil retaining wall in terms of safety, usability and repairability; (5) Formulate standards for classifying the deformation and damage levels of reinforced soil retaining walls to determine the performance status of the structure.

[0066] In one embodiment of the present invention, the rigid panel reinforced soil retaining wall is suitable for roadbed retaining engineering in areas with limited land use, weak foundations, and earthquakes. The wall height should not exceed 10m. According to the panel construction process, it can be divided into integral rigid panel reinforced soil retaining walls and composite rigid panel reinforced soil retaining walls, etc. According to my country's "Unified Standard for Reliability Design of Railway Engineering Structures (GB 50216-2019)," the structural safety level is divided into three levels based on the severity of the consequences of its failure: Safety Level I, Safety Level II, and Safety Level III, as shown in Table 1. Table 1

[0067] The performance requirements for reinforced soil retaining walls are divided into safety, usability, and repairability. Safety refers to the ability of the reinforced soil retaining wall to resist instability, damage, and collapse within its design reference period. It must maintain necessary overall stability during and after accidental events specified in the design, preventing collapse or progressive failure, and avoiding overall failure caused by the damage of individual components or localized areas. Usability refers to the good working performance of the reinforced soil retaining wall under normal service conditions, preventing excessive deformation that affects train operation or structural deterioration and damage that would cause user anxiety. Repairability refers to the ability of the reinforced soil retaining wall to restore its intended function and safety performance after damage caused by factors such as material deterioration, construction defects, and external forces, through technically feasible, economically reasonable, and timely intervention measures. This minimizes the impact of structural failure, extends the structural service life, and ensures that the performance after repair meets design standards. The performance requirements of the reinforced soil retaining wall in this invention incorporate the three-level seismic fortification objectives of architectural design—no damage in minor earthquakes (frequent earthquakes), repairability in moderate earthquakes (fortification earthquakes), and no collapse in major earthquakes (rare earthquakes). The performance requirements of the reinforced soil retaining wall are shown in Table 2: Table 2

[0068] In one embodiment of the present invention, when performing performance checks on reinforced soil retaining walls, corresponding performance check items should be set according to performance requirements, and each performance check item should have a corresponding performance index. The performance check items and performance indexes are related to structural damage, deformation, and failure modes. Structural damage mainly involves damage to the panel and reinforcement, while deformation mainly involves the horizontal displacement of the panel and the vertical displacement of the surface layer. Referring to Table 2, the performance check items and corresponding performance indexes for reinforced soil retaining walls under different combinations of loads are shown in Table 3. Table 3

[0069] Among them, the action combinations are: ① permanent action; ② permanent action + train load; ③ permanent action + variable action (construction / maintenance load); ④ permanent action + train load + frequent earthquake; ⑤ permanent action + train load + design earthquake; ⑥ permanent action + train load + rare earthquake.

[0070] In one embodiment of the present invention, the reinforced soil retaining wall should be reasonably classified into deformation and damage levels, namely deformation level and damage level, to determine the overall performance status of the structure and its components, assist in maintenance and repair decisions, and extend the service life of the structure. Based on the requirements of train operation for track smoothness, the overall performance of the reinforced soil retaining wall should be judged using surface settlement indicators. Based on the magnitude of surface settlement, it is divided into four levels: normal operation, reduced speed operation, maintenance stoppage, and demolition and reconstruction. The performance status of structural components is classified using damage levels. Specific damage indicators are determined based on the materials used in the components and their functions. The panel damage indicator is determined by combining stress and crack size, while the reinforcement damage indicator is determined by combining strength design value and strain. The specific classifications are shown in Table 4 below. Table 4

[0071] Meanwhile, this invention, referring to existing railway engineering subgrade design methods, has formulated track top surface settlement control values ​​that meet train ride comfort requirements, as shown in Table 5 below: Table 5

[0072] Based on the performance design system, the seismic design of rigid panel reinforced soil retaining walls for railway engineering is carried out. In one embodiment of the present invention, the tensile strength, pull-out strength and resultant force on the back of the reinforced soil retaining wall are calculated based on the double wedge theory. like Figure 2 The diagram shown is a calculation diagram based on the double wedge theory. Figure 2 (a) is a calculation diagram. Figure 2 (b) is the force analysis of the wedge, where the force balance equations for wedge B are expressed as follows: The calculation expression is as follows:

[0073]

[0074] The force balance equation expression for wedge F and P F The calculation expression is as follows:

[0075]

[0076] in, For loads such as soil backfill on top of the wall, tracks, and trains (vertical); The load acting on wedge F, The load acting on wedge B, For horizontal earthquake intensity, The horizontal inertial force generated by the load acting on wedge F, The horizontal inertial force generated by the load acting on wedge B, The horizontal load on the top of the panel. This refers to the vertical load on the top of the panel. This refers to the bending moment at the top of the panel; For the weight of the panel, For the gravity of the wedge F, For the gravity of wedge B, The horizontal seismic force caused by the weight of the panel itself. The horizontal seismic force caused by the self-weight of the wedge F. The horizontal seismic force caused by the self-weight of wedge B. The resultant earth pressure force exerted by the wedge F on the panel is... The resultant earth pressure of wedge B on wedge F. The reaction force at the bottom of the wedge-shaped F is... The reaction force is at the bottom of the wedge B. Let F be the angle between the wedge and the horizontal plane. Let B be the angle between the wedge and the horizontal plane. For the cohesive force of the filler, The angle of friction of the packing material. The design strength of a single reinforcing bar. The characteristic value of tensile strength of a single reinforcing bar. The tensile strength of a single reinforcing bar. Let B be the length of the sliding surface of the wedge. Let F be the sliding surface length of the wedge. The reinforcing material, or stiffener, should preferably be selected with low creep, high interfacial friction, and good wear resistance and durability. The expression for the tensile strength of the reinforcing material is as follows:

[0077] in, This represents the characteristic value of the tensile strength of the reinforcing bar. The standard value of the ultimate tensile strength of the reinforcing bar, as measured by a tensile test. The material correction factor is 1.0 for action combination ⑥ and 0.8 for the other action combinations. For material coefficients, the coefficient is 0.4~0.7 for action combination ①, 0.6~0.95 for action combinations ②③④⑤, and 0.7~1.0 for action combination ⑥. The pull-out reduction factor for the reinforcement is 0.50 for action combination ①, 0.67 for action combinations ② and ③, 0.80 for action combinations ④ and ⑤, and 1.0 for action combination ⑥.

[0078] The pull-out strength of reinforced soil retaining walls is determined by factors such as the anchorage length of the reinforcement, the contact area and friction coefficient between the soil and the reinforcement, and the overburden pressure on the reinforcement. The expression for the pull-out strength of the reinforcement is as follows:

[0079] in, For the pull-out strength of the reinforcing bar, This is the pull-out reduction factor for the reinforcing steel. For the filling material and the load on the top of the wall acting on the first Total vertical stress on the reinforcement layer For the first Length of anchorage section of layered reinforcement For the cohesive force of the filler, The angle of friction of the packing material is denoted as φ.

[0080] The total vertical stress on the reinforcing member is calculated using the following expression:

[0081] in, The vertical stress on the reinforcement of the reinforced soil retaining wall due to the backfill soil, track and train loads. The vertical stress on the reinforcing steel caused by strip loads such as tracks and trains acting on the roadbed surface. For the packing density, This is the vertical distance from the top of the wall to the reinforcing steel. Vertical stress on reinforcement of reinforced soil retaining wall by top backfill, track and train loads. The calculation diagram is as follows Figure 3 The diagram shows the vertical pressure on the reinforcement of a reinforced soil retaining wall. The calculation expression for converting the backfill at the top of the wall into an equivalent uniformly distributed backfill load is as follows:

[0082] in, The unit weight of the fill soil above the top of the wall. The slope ratio of the fill above the top of the wall. For the height of the wall, This refers to the height of the backfill above the top of the wall. This is the horizontal distance from the top of the wall, the toe of the embankment slope, to the back of the slab. Figure 3 middle, For the panel thickness, if At that time, take calculate; Vertical stress on reinforcing bars caused by strip loads such as tracks and trains acting on the roadbed surface The calculation diagram is as follows Figure 4 As shown, the calculation is based on the stress diffusion method, and its calculation expression is as follows:

[0083]

[0084] in, For strip loads such as tracks and trains acting on the roadbed surface, The width of the strip load distribution above the roadbed surface. The width of the earth pressure distribution caused by the load. The distance from the load above the roadbed surface to the inner surface of the panel is [missing information]. Figure 4 middle, The vertical distance from the load to the reinforcing bar. The stress diffusion angle, This refers to the slope ratio of the fill above the wall top, and is based on the diffusion distance of the stress diffusion line. or ; Regarding the minimum reinforcement length requirements, Japanese standards are significantly lower than Chinese standards. This difference stems primarily from two reasons: First, my country uses the anchoring wedge method (mainly the 0.3 H method), which imposes high requirements on reinforcement length. If the reinforcement is too short, it becomes difficult to meet the mandatory requirements for pull-out stability in the specifications. Second, under identical conditions, for the same reinforcement bar, the tensile and pull-out strength design values ​​calculated in Chinese standards are much lower than those in Japanese standards, resulting in a longer required reinforcement length under the same design conditions. The reinforced soil retaining walls designed in Japan have demonstrated excellent seismic performance and have not collapsed in numerous major disasters, including the Hanshin Earthquake (1995), the Niigata Earthquake (2004), and the Great East Japan Earthquake and Tsunami (2011), proving the rationality of their reinforcement strength design value calculation method. In contrast, China's current method is derived from the anchored wedge method and uses "rare earthquakes" rather than "design earthquakes" to ensure structural safety. Continuing to use overly conservative calculation methods would lead to excessive redundancy in structural design. Therefore, the design value of reinforcement strength is calculated with reference to the Japanese method and related coefficients. However, considering the differences in the upper backfill, track, and train loads between the two countries, the total vertical stress acting on the i-th layer of reinforcement by the backfill and wall top loads is calculated. The Chinese calculation method is adopted. The tensile strength of the reinforcing steel is used. With pull-out strength The minimum value is used to determine the first reinforced soil retaining wall. Design value of layered reinforcement strength Its expression is as follows:

[0085] In one embodiment of the present invention, such as Figure 5 The diagram shown is a schematic representation of the pressure distribution behind the reinforced soil retaining wall, including... Figure 5 The resultant earth pressure on the back of the plate in (a) Figure 5(b) Earth pressure generated by the self-weight of the backfill material behind the wall. Figure 5 (c) The earth pressure generated vertically by the load on the top of the wall, Figure 5 (d) refers to the horizontal force of the load at the top of the wall, which is the horizontal action of the inertial force generated under the seismic load within the wedge-shaped area at the top of the wall. Therefore, the resultant force behind the reinforced soil retaining wall is divided into the earth pressure generated by the self-weight of the backfill material, the earth pressure generated by the vertical load at the top of the wall, and the horizontal action of the inertial force generated under the seismic load within the wedge-shaped area at the top of the wall. The expression for the resultant force behind the wall is as follows:

[0086]

[0087]

[0088]

[0089]

[0090] in, The net force acting on the back of the plate. For the height of the wall, These represent the horizontal loads at different heights behind the slab. The earth pressure generated by the fill material at different heights behind the panel is distributed in a triangular pattern, with zero earth pressure at the top and a magnitude of [missing value] at the bottom. , The earth pressure generated at different heights behind the slab by the backfill soil and the top strip load through the stress diffusion angle is distributed across a width of [missing information]. The magnitude of the earth pressure is , The earth pressure generated at different heights behind the slab by the inertial forces produced by the horizontal load on the top of the wall and the load on the wedge under seismic action is distributed in an inverted triangular pattern. The earth pressure at the top of the panel is... The earth pressure at the bottom is 0. For earth pressure calculation coefficients, For the packing density, The angle between the back of the board and the vertical direction. The angle of friction of the packing material. The width of the strip load distribution. For the loads of the superfill and rail trains, etc. Horizontal seismic intensity The width of the load distribution on the upper part of the wedge is defined as .

[0091] In one embodiment of the present invention, the tensile strength, pull-out strength and resultant force on the back of the plate of the reinforcing bar are checked for safety, usability and repairability according to the design conditions, and seismic calculation results are obtained. According to the performance requirements of reinforced soil retaining walls as described in Table 2, the safety calculation of reinforced soil retaining walls includes sliding stability calculation, overturning stability calculation, overall stability calculation, overall tensile strength calculation of reinforcement, overall pull-out strength calculation of reinforcement, and foundation bearing capacity calculation. Since the design value of reinforcement strength is taken as the minimum value of reinforcement tensile strength and pull-out strength, the overall tensile / pull-out strength calculation of reinforcement also meets the requirements if the stability calculation of the reinforced soil retaining wall meets the requirements. The specific calculation methods include: Anti-slip stability calculation includes calculations of the design value of the horizontal resistance to sliding and the effect value of the horizontal sliding force, such as... Figure 6 The figure shows a schematic diagram of the anti-slip stability check. As can be seen from the figure, the expression for the anti-slip stability check is as follows:

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] in, This is the design value for the horizontal resistance to sliding. This represents the effect value of the horizontal sliding force. For the first The horizontal resistance of the layered reinforcement is designed to be high. This refers to the friction between the wall and the foundation. This is the sum of the vertical loads acting on the bottom surface of the panel. The coefficient of friction between the base and the foundation. For the panel's gravity, For the vertical load at the top of the panel, Let F be the earth pressure exerted by the wedge on the panel. The angle of friction of the packing material. The angle between the back of the board and the vertical direction. The horizontal component of the resultant earth pressure is... The inertial force on the panel under earthquake action, The resultant horizontal force acting on the top of the panel, Horizontal seismic intensity For the horizontal load on the top of the panel, For the earth pressure action partial factor in the anti-sliding stability check, the factor is taken as 1.1 for action combinations ①②③ and 1.0 for action combinations ④⑤⑥. For the partial factors of wall self-weight and track load resistance in the anti-sliding stability check, the factor is 1.2 for action combination ①②③ and 1.0 for action combination ④⑤⑥.

[0099] Overturning stability calculation includes calculations of the design value of the overturning moment and the effect value of the overturning moment, such as... Figure 7 The figure shows a schematic diagram of the overturning stability check. As can be seen from the figure, the expression for the overturning stability check is as follows:

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108] in, This is the design value for the overturning moment. This represents the effect value of the overturning moment. For the first The overturning moment generated by the layered reinforcement The stabilizing moment generated by the wall's own weight. for and The stabilizing torque generated by the vertical component difference, The stabilizing moment generated by the vertical earth pressure component on the back of wedge B. From the bottom of the retaining wall to the first Vertical distance at the location of the reinforcement layer. The horizontal distance from the wall toe to the center of gravity of the panel. The net force acting on the back of the plate. The resultant earth pressure of wedge B on wedge F. Vertical earth pressure difference Horizontal distance to the toe of the wall Vertical earth pressure component on the back of wedge B Horizontal distance to the toe of the wall for The overturning moment generated by the horizontal component of the force. This refers to the torque generated by the inertia of the panel during an earthquake. The overturning moment is generated by the external force at the top of the panel. For the wall toe perpendicular distance from the point of application Horizontal seismic intensity This is the vertical distance from the wall toe to the center of gravity of the panel. For the horizontal load on the top of the panel, The vertical distance from the wall toe to the top of the panel. For the vertical load at the top of the panel, The horizontal distance from the toe of the wall to the top of the panel where the vertical load is applied is denoted as . For the overturning stability calculation, the partial factors for the wall's self-weight and track load resistance are taken as 1.25 for action combinations ①②③ and 1.0 for action combinations ④⑤⑥. For the earth pressure resistance partial factor in the overturning stability check, the factor for action combination ①②③ is taken as 1.05, and the factor for action combination ④⑤⑥ is taken as 1.0. For the earth pressure action partial factor in the overturning stability check, the action combination ①②③ is taken as 1.3, and the action combination ④⑤⑥ is taken as 1.0.

[0109] Overall stability calculation includes calculations of the design value of the overall stability resistance moment and the effect value of the overall stability sliding moment, such as... Figure 8 The figure shows a schematic diagram of the overall stability check. As can be seen from the figure, the expression for the overall stability check is as follows:

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] in, This is the design value for the overall stability resistance torque. This represents the overall stability effect value of the sliding torque. The resisting moment generated by the soil and the load. The resisting torque generated by the reinforcing material, The sliding moment generated by the soil and the load. The sliding moment generated by the panel and the load. For soil strips Soil cohesion at the slip surface For soil strips The length of the bottom edge of the sliding surface, For soil strips gravity and soil strips Permanent loads on, For soil strips Variable loads on For soil strips The angle between the normal force at the center of the sliding surface and the vertical line. Soil strips under seismic action gravity and load The generated inertial force For soil strips The angle of friction of the soil at the slip surface. The radius of the arc. Horizontal seismic intensity For the first Design strength value of the reinforcement layer, For the first The angle formed by the intersection of the layer of reinforcing material and the arc-shaped smooth surface The horizontal distance from the center of gravity of the panel to the center of the circle. The horizontal distance from the point of application of the horizontal load at the top of the panel to the center of the circle. This is the vertical distance from the center of gravity of the panel to the height of the center of the circle. It is the vertical distance from the point of application of the vertical load at the top of the panel to the height of the center of the circle. This is the vertical distance from the point of application of the horizontal force on the soil strip to the height of the center of the circle. For the resistance factor of the resisting moment generated by cohesion in the overall stability check, the factor is 1.25 for action combinations ①②③ and 1.0 for action combinations ④⑤⑥. The resistance factor for the resisting moment generated by the self-weight of permanent loads in the overall stability check is 1.17 for action combinations ①②③ and 1.0 for action combinations ④⑤⑥. For the resistance factor of the resisting moment generated by the variable load in the overall stability check, the factor is 1.25 for action combinations ①②③ and 1.0 for action combinations ④⑤⑥. The partial factor for the sliding moment caused by the self-weight of permanent loads in the overall stability calculation is 1.06 for action combinations ①②③ and 1.0 for action combinations ④⑤⑥. The partial factor for the effect of sliding moment generated by variable load in the overall stability check is 1.1 for action combination ①②③ and 1.0 for action combination ④⑤⑥.

[0116] The expression for calculating the bearing capacity of the foundation is as follows:

[0117] In the formula: This represents the effect value of the foundation bearing capacity. The total vertical load acting on the base is calculated using the most unfavorable values ​​obtained from the anti-sliding stability and anti-overturning stability measures. The base width, The eccentricity (m) of the resultant force at the base is calculated according to the current "Support Code". The eccentricity of the resultant force at the base should not exceed B / 6. Time to take .

[0118] In a specific embodiment of the present invention, the performance calculation of the safety of the reinforced soil retaining wall adopts the ultimate limit state design, the expression of which is as follows:

[0119] in, The structural importance coefficient is used when the safety level is I. When the security level is II When all levels are III , The structural load effect values, in the safety performance calculation, include the horizontal sliding force effect value, the overturning moment effect value, the overall stability sliding moment effect value, and the foundation bearing capacity effect value. The structural resistance design value includes the design value of horizontal resistance to sliding, the design value of overturning moment, and the design value of overall stability resistance moment in the performance verification of safety.

[0120] In one embodiment of the present invention, the usability assessment of the reinforced soil retaining wall includes surface settlement assessment and panel appearance assessment, while the repairability assessment includes surface settlement assessment, panel and reinforcement damage assessment. Therefore, it can be summarized as follows: the usability and repairability assessment includes surface settlement assessment, panel appearance and damage assessment, and reinforcement damage assessment. The specific assessment methods are as follows: Surface settlement calculation for reinforced soil retaining walls can be divided into two parts: one is the permanent vertical displacement caused by different load combinations. Secondly, permanent vertical displacement caused by the deterioration of structural materials (panels, reinforcement, etc.) The expression for surface settlement calculation is as follows:

[0121] in, This represents the effect value of surface settlement. The permanent vertical displacement caused by different load combinations. This refers to permanent vertical displacement caused by the deterioration of structural materials; since it is difficult to accurately predict the extent of damage during the service life of a structure during the design phase, This often requires calculation based on monitoring data during the operation and maintenance period, and a reduction factor can be used to consider it during the design phase. There is a lot of existing technology research on how to obtain it, and existing technologies can be used as a reference for calculation.

[0122] The expressions for panel appearance and damage assessment are as follows:

[0123]

[0124] In the formula: The values ​​represent the bending moment effect at different heights of the panel section. These represent the shear force effect values ​​at different heights of the panel section. This represents the horizontal displacement of the panel at different height positions. The bending stiffness of the panel section; Damage assessment includes the assessment of the strain effect value of reinforcing bars and the tensile force effect value of individual reinforcing bars, such as... Figure 9 The diagram shown illustrates the calculation of reinforcement damage. As can be seen from the diagram, the expression for damage calculation is as follows:

[0125]

[0126] in, This represents the strain effect value of the reinforcing material. This is the additional factor for the peak strain of the reinforcing material, which can be taken as 1.5 to 2.0. For the elongation of the reinforcing steel, if hour, ,like At that time, the reinforcing material in that layer failed. For the first Length of free section of layered reinforcement, This represents the effect value of tensile force on a single reinforcing bar. This refers to the tensile modulus of the reinforcing bar. This refers to the horizontal displacement of the panel at the height of the reinforcing bars. For specific calculation methods, please refer to existing technologies. For the first Length of the anchorage section of the reinforcing bar.

[0127] In a specific embodiment of the present invention, the performance evaluation of usability and repairability adopts a normal use limit state design, and its expression is as follows:

[0128] in, The structural effect value is a limit value for the normal use state of the structure, and is used in the performance verification of usability and repairability. This includes the effect values ​​of surface settlement, strain of reinforcing bars, and tensile force of a single reinforcing bar.

[0129] In one embodiment of the present invention, the designed reinforced soil retaining wall is tested for safety, usability and repairability, and the seismic test results are obtained. Based on the test results, it is determined whether the reinforced soil retaining wall meets the performance requirements of the design, and more detailed structural design is carried out according to the actual engineering situation, and the parameters are fine-tuned to make it meet the actual engineering needs.

[0130] Technical effects of the present invention: (1) A performance design method for rigid panel reinforced soil retaining walls for railway engineering was constructed, clarifying the performance requirements of reinforced soil retaining walls in terms of safety, usability and repairability. A design method based on dual control standards of strength and deformation was proposed, and a graded control standard for track top surface settlement directly related to train speed was formulated. This method enables multi-performance target collaborative design of reinforced soil retaining walls, rather than the single strength control of conventional methods. (2) The seismic design method for rigid panel reinforced soil retaining walls in railway engineering disclosed in this invention can be used as a performance verification method for railway engineering with strict deformation control requirements, and the strength control criteria ensure that the structure can "not collapse under major earthquakes". In terms of safety, a stability and bearing capacity verification method based on double wedge theory is established, which overcomes the limitations of the traditional anchored wedge method under seismic conditions. In terms of usability and repairability, a multi-parameter collaborative verification mechanism with surface settlement as the core control index and supplemented by panel stress state, crack width and reinforcement strain is established, which systematically ensures the functional reliability and post-earthquake repairability of the structure under various levels of earthquake action.

[0131] Example 2 This invention provides a seismic design method for rigid panel reinforced soil retaining walls in railway engineering. Based on Example 1, a practical case design is conducted. The proposed railway is a Class I double-track railway for both passenger and freight transport, with a safety level of Class II, ballasted track, and a design speed of 160 km / h. The subgrade adopts an integral rigid panel reinforced soil retaining wall with a subgrade thickness of 2.5 m, including a surface layer thickness of 0.6 m and a bottom layer thickness of 1.9 m. The foundation has a unit weight of 20 kN / m³. 3 The friction angle is 40°, the cohesion is 0, and the foundation bearing capacity is... The area is classified as a Class II site, with a peak ground acceleration of 0.067 g for frequent earthquakes, 0.20 g for design earthquakes, and 0.38 g for rare earthquakes. The main component design parameters of the reinforced soil retaining wall are shown in Table 6. Table 6

[0132] The reinforcement material to be used in this design is EG polypropylene high-strength unidirectional geogrid (EG160B), with a laying length of 1.0 mm. H (Wall height), vertical laying spacing is 0.3m. The design parameters of the main components are shown in Table 6, and the structural cross-sectional layout diagram is shown below. Figure 10 As shown, the dimensions in the figure are in meters.

[0133] To provide a more intuitive feedback on whether the stability check results meet the requirements, the check expression was adjusted to obtain the following result. If the stability coefficient If the calculation meets the requirements, then the calculation is satisfactory. Since action combination ③ is a combination of permanent action and variable action (construction / maintenance load), the specific load magnitude is determined by the equipment required for construction / maintenance operations, so this action combination has not yet been calculated. Detailed calculation results: The anti-sliding stability calculation results are shown in Table 7; the overturning stability calculation results are shown in Table 8; the overall stability calculation results are shown in Table 9; the foundation bearing capacity calculation results are shown in Table 10; the horizontal displacement calculation results are shown in Table 11; the usability and repairability check results are shown in Table 12; and the surface settlement diagram under different action combinations is shown in... Figure 11 The schematic diagrams of bending moment and shear force distribution in the panel section under different combinations of loads are shown below. Figure 12 A schematic diagram showing the degree of performance utilization of the reinforcing material is shown below. Figure 13 The crack and damage calculation of the panel can be carried out according to the bending moment and shear force distribution of the panel section. After the panel is reinforced, the crack and damage calculation is carried out in accordance with the requirements of the "Code for Design of Concrete Structures (GB 50010-2010)". All calculation results meet the design requirements, and the design scheme is feasible.

[0134] Table 7 Calculation results of anti-slip stability

[0135] Table 8 Calculation results of overturning stability

[0136] Table 9 Overall Stability Calculation Results

[0137] Table 10 Calculation results of foundation bearing capacity

[0138] Table 11 Calculation results of horizontal displacement

[0139] Table 12 Usability and Repairability Assessment Results

Claims

1. A seismic design method for rigid panel reinforced soil retaining walls in railway engineering, characterized in that, Includes the following steps: Determine the design conditions for reinforced soil retaining walls, including performance requirements for safety level, safety, usability, and repairability; Determine the structural type and materials of the reinforced soil retaining wall, and carry out the preliminary design of the reinforced soil retaining wall; Based on the double-wedge theory, the design value of the reinforcement strength and the resultant force behind the slab of the reinforced soil retaining wall are calculated. Based on the design strength values ​​of the reinforcement materials of the reinforced soil retaining wall and the resultant force behind the slab, the safety, usability, and repairability of the reinforced soil retaining wall are checked, and the check results are obtained. Based on the calculation results, determine whether the reinforced soil retaining wall meets the performance requirements of the design. If so, carry out the detailed structural design of the reinforced soil retaining wall; otherwise, carry out the preliminary design of the reinforced soil retaining wall again.

2. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 1, characterized in that, The expression for the tensile strength of the reinforcing bar is as follows: in, This represents the characteristic value of the tensile strength of the reinforcing bar. The standard value of the ultimate tensile strength of the reinforcing bar, as measured by a tensile test. This is a material correction factor. This is the tensile reduction factor for reinforcing bars.

3. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 2, characterized in that, The expression for the pull-out strength of the reinforcing bar is as follows: in, For the pull-out strength of the reinforcing bar, For the filling material and the load on the top of the wall acting on the first Total vertical stress on the reinforcement layer For the cohesive force of the filler, The angle of friction of the packing material. This is the pull-out reduction factor for the reinforcing steel. For the first Length of anchorage section of layered reinforcement The vertical stress on the reinforcement of the reinforced soil retaining wall due to the backfill soil, track and train loads. The vertical stress on the reinforcing steel caused by strip loads such as tracks and trains acting on the roadbed surface. For the packing density, This is the vertical distance from the top of the wall to the reinforcing steel. For strip loads such as tracks and trains acting on the roadbed surface, The width of the strip load distribution above the roadbed surface. The width of the earth pressure distribution caused by the load. The distance from the load above the roadbed surface to the inner surface of the panel. The vertical distance from the load to the reinforcing bar. The stress diffusion angle, The slope ratio of the fill above the top of the wall. The unit weight of the fill soil above the top of the wall. For the height of the wall, This refers to the height of the backfill above the top of the wall. It is the horizontal distance from the top of the wall to the toe of the embankment slope to the back of the slab.

4. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 3, characterized in that, The expression for the design strength of the reinforcement in the reinforced soil retaining wall is as follows: in, For reinforced soil retaining wall Design strength values ​​of the reinforcement in the layer To obtain the characteristic value of tensile strength of reinforcing steel With pull-out strength of reinforcing bars The minimum value.

5. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 1, characterized in that, The expression for the resultant force acting on the back of the plate is as follows: in, The net force acting on the back of the plate. For the height of the wall, These represent the horizontal loads at different heights behind the slab. The earth pressure generated by the fill material at different heights behind the panel is distributed in a triangular pattern, with zero earth pressure at the top and a magnitude of [missing value] at the bottom. , The earth pressure generated at different heights behind the slab by the backfill soil and the top strip load through the stress diffusion angle is distributed across a width of [missing information]. The magnitude of the earth pressure is , The earth pressure generated at different heights behind the slab by the inertial forces produced by the horizontal load on the top of the wall and the load on the wedge under seismic action is distributed in an inverted triangular pattern. The earth pressure at the top of the panel is... The earth pressure at the bottom is 0. For earth pressure calculation coefficients, For the packing density, The angle between the back of the board and the vertical direction. The angle of friction of the packing material. The width of the strip load distribution. For the loads of the superfill and rail trains, etc. Horizontal seismic intensity The width of the load distribution on the upper part of the wedge is defined as .

6. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 1, characterized in that, The safety calculation includes anti-sliding stability calculation, anti-overturning stability calculation, overall stability calculation, overall tensile strength calculation of reinforcement, overall pull-out strength calculation of reinforcement, and foundation bearing capacity calculation. The expression for the anti-slip stability check is as follows: in, This is the design value for the horizontal resistance to sliding. This represents the effect value of the horizontal sliding force. For the first The horizontal resistance of the layered reinforcement is designed to be high. This refers to the friction between the wall and the foundation. This is the sum of the vertical loads acting on the bottom surface of the panel. The coefficient of friction between the base and the foundation. For the panel's gravity, For the vertical load at the top of the panel, The earth pressure exerted by the wedge F on the panel. The angle of friction of the packing material. The angle between the back of the board and the vertical direction. The horizontal component of the resultant earth pressure is... The inertial force on the panel under earthquake action, The resultant horizontal force acting on the top of the panel, Horizontal seismic intensity For the horizontal load on the top of the panel, For the earth pressure action partial factor in the anti-sliding stability check, The partial factors for the self-weight of the wall and the resistance of the track load are used in the anti-sliding stability check. The expression for the overturning stability check is as follows: in, This is the design value for the overturning moment. This represents the effect value of the overturning moment. For the first The overturning moment generated by the layered reinforcement The stabilizing moment generated by the wall's own weight. for and The stabilizing torque generated by the vertical component difference, The stabilizing moment generated by the vertical earth pressure component on the back of wedge B. From the bottom of the retaining wall to the first Vertical distance at the location of the reinforcement layer. The horizontal distance from the wall toe to the center of gravity of the panel. The net force acting on the back of the plate. The resultant earth pressure of wedge B on wedge F. Vertical earth pressure difference Horizontal distance to the toe of the wall Vertical earth pressure component on the back of wedge B Horizontal distance to the toe of the wall for The overturning moment generated by the horizontal component of the force. This refers to the torque generated by the inertia of the panel during an earthquake. The overturning moment is generated by the external force at the top of the panel. For the wall toe perpendicular distance from the point of application Horizontal seismic intensity This is the vertical distance from the wall toe to the center of gravity of the panel. For the horizontal load on the top of the panel, The vertical distance from the wall toe to the top of the panel. For the vertical load at the top of the panel, The horizontal distance from the toe of the wall to the top of the panel where the vertical load is applied is denoted as . The partial factors for the self-weight of the wall and the resistance of the track load are used in the overturning stability check. For the earth pressure resistance partial factor in the overturning stability check, The earth pressure factor is used in the overturning stability check. The expression for the overall stability check is as follows: in, The design value for the overall stability resistance torque. This represents the overall stability effect value of the sliding torque. The resisting moment generated by the soil and the load. The resisting torque generated by the reinforcing material, The sliding moment generated by the soil and the load. The sliding moment generated by the panel and the load. For soil strips Soil cohesion at the slip surface For soil strips The length of the bottom edge of the sliding surface, For soil strips gravity and soil strips Permanent loads on, For soil strips Variable loads on For soil strips The angle between the normal force at the center of the sliding surface and the vertical line. Soil strips under seismic action gravity and load The generated inertial force For soil strips The angle of friction of the soil at the slip surface. The radius of the arc. Horizontal seismic intensity For the first Design strength value of the reinforcement layer, For the first The angle formed by the intersection of the layer of reinforcing material and the arc-shaped smooth surface The horizontal distance from the center of gravity of the panel to the center of the circle. The horizontal distance from the point of application of the horizontal load at the top of the panel to the center of the circle. This is the vertical distance from the center of gravity of the panel to the height of the center of the circle. It is the vertical distance from the point of application of the vertical load at the top of the panel to the height of the center of the circle. This is the vertical distance from the point of application of the horizontal force on the soil strip to the height of the center of the circle. This is the resistance partial factor for the resisting moment generated by cohesion in the overall stability check. This is the resistance partial factor for the resisting moment generated by the self-weight of permanent loads in the overall stability check. This is the resistance partial factor for the resisting moment generated by variable loads in the overall stability check. This is a partial factor for the effect of the sliding moment caused by the self-weight of the permanent load in the overall stability check. The partial factor for the effect of sliding moment caused by variable load in the overall stability check; The expression for the foundation bearing capacity check is as follows: In the formula: This represents the effect value of the foundation bearing capacity. The total vertical load acting on the base is calculated using the most unfavorable values ​​obtained from the anti-sliding stability and anti-overturning stability measures. The base width, The eccentricity of the resultant force of the base is denoted as .

7. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 1, characterized in that, The usability and repairability assessment includes surface settlement assessment, panel appearance and damage assessment, and reinforcement damage assessment. The expression for the surface settlement check is as follows: in, This represents the effect value of surface settlement. The permanent vertical displacement caused by different load combinations. This refers to permanent vertical displacement caused by the deterioration of structural materials. The expressions for panel appearance and damage detection are as follows: In the formula: The values ​​represent the bending moment effect at different heights of the panel section. These represent the shear force effect values ​​at different heights of the panel section. This represents the horizontal displacement of the panel at different height positions. The bending stiffness of the panel section; The expression for calculating the reinforcement damage is as follows: in, This represents the strain effect value of the reinforcing material. This is the additional factor for the peak strain of the reinforcing material. This represents the elongation of the reinforcing steel. For the first Length of free section of layered reinforcement This represents the effect value of tensile force on a single reinforcing bar. This is the tensile modulus of the reinforcing bar.

8. The seismic design method for rigid panel reinforced soil retaining walls in railway engineering according to claim 1, characterized in that, The security, usability, and repairability checks include: The safety check adopts the ultimate limit state design, and the expression for the safety check is as follows: in, For structural importance coefficients, This represents the structural effect value. This is the design value for structural resistance; Usability and repairability checks are performed using the normal serviceability limit state design. The expressions for usability and repairability checks are as follows: in, These are the limits for the structure under normal operating conditions.

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