Pre-disintegration soft rock filling body non-uniform settlement determination method based on reinforcement control

Abstract

The invention discloses a method for determining non-uniform settlement of a pre-disintegrated soft rock filling body based on reinforcement control. The method comprises the following steps: firstly, sampling in a pre-disintegration soft rock filling body, carrying out a static triaxial creep test, and establishing a permanent strain estimation model; a filling body is divided into nodes, the initial creep quantity of each node is determined, then the geogrid is added, and the total settlement value of each node, the settlement difference value between the nodes and the deformation length of the geogrid are calculated. And then, evaluating the variable quantity of the soil body below the geogrid, iteratively calculating the settlement value of each node until the strain difference of the geogrid subjected to continuous two iterations is reduced to be within 3%, and finally outputting a stable settlement value to realize the prediction and control of the non-uniform settlement deformation. According to the method, the settlement amount can be accurately predicted, deformation control can be effectively implemented, and the defects in the prior art are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of roadbed engineering, and in particular relates to a method for determining non-uniform settlement of pre-collapsed soft rock filling bodies based on reinforcement control. Background Art

[0002] Uneven settlement of roadbed is one of the common problems in road engineering, and its potential harm is extensive and far-reaching. First, uneven settlement will cause different degrees of bulge or depression on the road surface, which not only reduces the driving comfort, but also significantly increases the incidence of traffic accidents. Secondly, this settlement phenomenon will directly act on the roadbed structure, causing cracks and deformation. In extreme cases, it can cause the destruction of the roadbed structure, seriously affecting the overall stability and load-bearing performance of the road. Furthermore, the roadbed settlement changes the original drainage design, which is easy to cause local water accumulation, accelerate the aging and damage of the pavement material, and shorten the service life of the road. In addition, for roads equipped with bridges and culverts, uneven settlement will also threaten the stability of these structures, which may lead to serious consequences such as structural tilt, cracking and even collapse. Finally, in order to deal with various problems caused by settlement, more frequent road maintenance and repair work is often required, which undoubtedly increases the cost burden of road management. Therefore, the research and prevention of uneven road settlement has important engineering practical significance and economic effects.

[0003] In view of the problem of uneven settlement of roadbed, although a variety of treatment measures such as soil replacement cushion method, dynamic compaction method and composite foundation method have been proposed and applied, these methods can effectively control and alleviate the impact of uneven settlement of roadbed to a certain extent. However, they also have significant limitations and shortcomings. For example, the soil replacement cushion method may lead to poor long-term effect due to improper material selection or poor construction technology; the dynamic compaction method may be limited due to its greater impact on the surrounding environment; although the composite foundation method can provide better support, its design and construction process are relatively complex and the cost is relatively high. The two existing technologies, a high steep embankment reinforcement structure to prevent uneven settlement (publication number CN106192652A) and a method for calculating the creep deformation of high embankment after construction (publication number CN116108540A), although they have made contributions in specific aspects, have also exposed obvious shortcomings. Although the former proposed a reinforcement scheme for high and steep embankments to prevent uneven settlement, it did not involve how to accurately predict the amount of uneven settlement, and the high cost of implementing the scheme limited its widespread application. The latter focused on providing a method to calculate the post-construction creep deformation of high embankments, which is helpful for evaluating the long-term stability of embankments, but failed to provide effective measures to control the actual deformation of embankments, making the method limited in practical application.

[0004] In summary, the existing technologies for solving the problem of uneven roadbed settlement either lack effective deformation prediction methods, or the deformation control measures provided are not perfect, or the implementation costs are too high, making it difficult to meet the requirements of safety, economy, practicality and other aspects in actual engineering. Summary of the invention

[0005] The purpose of the embodiment of the present invention is to provide a method for determining non-uniform settlement of pre-collapsed soft rock fill based on reinforcement control, which can accurately predict the non-uniform settlement deformation of the pre-collapsed soft rock fill while controlling the non-uniform settlement deformation of the roadbed.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is a method for determining the non-uniform settlement of pre-collapsed soft rock filling body based on reinforcement control, which is specifically carried out in the following steps:

[0007] S1. Sampling is carried out in the pre-disintegrated soft rock fill section;

[0008] S2, conduct static triaxial creep tests on the samples obtained in S1 to establish a model for estimating permanent strain of the compacted mass under static stress;

[0009] S3, meshing the compacted body to obtain a plurality of nodes; determining the node position through a rectangular coordinate system, determining the creep amount of each compacted body node, and then substituting the creep amount of each compacted body node into the node;

[0010] S4, adding geogrids to the compacted mass; determining the creep value of each compacted mass node, and substituting the creep value of each compacted mass node after adding the geogrids into the node; adding the creep values ​​of each column of compacted mass nodes under the geogrids to obtain the total settlement value under each compacted mass node at the geogrids;

[0011] S5. Determine the settlement difference between each fill node at the geogrid and the length of the geogrid between the fill nodes after deformation;

[0012] S6. Determine the change in soil mass below the geogrid;

[0013] S7. Determine the second settlement value of each fill node at the geogrid;

[0014] S8. Repeat the process of S5 to S7 until the difference in the strain of the geogrid between the nodes of the fill body is reduced to within 3% after two consecutive iterations; output the final settlement value.

[0015] Furthermore, the prediction model of permanent strain of the compacted body under static stress of S2 is specifically:

[0016]

[0017]

[0018] Where: ε is the creep value of soil, ε0 is the initial plastic strain of soil; K is the compaction degree of fill soil; e is the base of natural logarithm; P a is the standard atmospheric pressure; σ 11 is the axial pressure; 31 is the confining pressure; f(ε) is the normal distribution function; σ is the standard deviation of the function; μ is the mean value of the function.

[0019] Furthermore, the creep amount h of each fill node in S3 is 1ij Specifically:

[0020]

[0021] Where: h 1ij It is the creep deformation between two adjacent filling nodes under the action of self-weight stress; is the average strain between two adjacent nodes of the vertical section under the action of self-weight stress; h is the vertical distance between the nodes.

[0022] Furthermore, in S4, the total settlement value H below each fill node at the geogrid is 1i Specifically:

[0023] H 1i =∑h 1ij (4)

[0024] h 1ij It is the creep deformation between two adjacent compacted volumes under the action of self-weight stress.

[0025] Furthermore, the settlement difference ΔH between the nodes of the fill body at the geogrid in S5 is 1i The length of the geogrid between the nodes of the fill body after deformation Δl 1i Specifically:

[0026] ΔH 1i =|H 1i -H 1(i+1) | (5)

[0027]

[0028] Among them, H 1i is the total settlement value below each fill node at the geogrid; ΔH 1i is the settlement difference between the nodes of the fill at the geogrid; Δl 1i is the deformed length of the geogrid between the nodes of the fill body; l is the horizontal interval of the nodes; i is the horizontal coordinate number.

[0029] Furthermore, the change in the soil mass below the S6 geogrid is determined in the following steps:

[0030] S601. First, determine the deformation of the geogrid between the nodes of the fill body, and multiply it by the elastic modulus of the geogrid to obtain the stress on the geogrid; then multiply the stress by the cross-sectional area of ​​the geogrid to obtain the tensile force on the geogrid:

[0031]

[0032] σ 1i =E·ε 1i (8)

[0033] f 1i =σ 1i ·A' (9)

[0034] Among them, ε 1i is the geogrid strain between fill nodes; σ 1i is the tensile stress on the geogrid; E is the elastic modulus of the geogrid; f 1i is the tensile force on the geogrid; A' is the cross-sectional area of ​​the geogrid, Δl 1i is the length of the geogrid between the nodes of the fill after deformation; l is the horizontal spacing of the nodes;

[0035] S602, determine the component force of the geogrid in the vertical direction, and then determine the stress of the nodes of the fill body at the geogrid; then determine the strain of the fill body under the geogrid in combination with the permanent strain estimation model of the fill body under the static stress; finally, determine the change amount of the soil under the geogrid based on the strain:

[0036] F 1i =f 1(i-1) ·sinα 1(i-1) +f 1i ·sinα 1i (10)

[0037]

[0038]

[0039]

[0040] Δh=h2·ε′ 1i (14)

[0041] Among them: F 1i is the vertical force on the nodes of the fill at the geogrid; α 1i is the angle between the geogrid and the horizontal direction after the change; σ′ 1iis the stress on the node of the fill at the geogrid; A0 is the area of ​​the geogrid per unit area; γ is the weight of the fill soil; h1 is the height of the soil above the geogrid; Δh is the change of the soil below the geogrid; h2 is the height of the soil below the geogrid; ε′ 1i is the strain of the fill below the geogrid; i is the horizontal coordinate number; j is the vertical coordinate number; ΔH 1i is the settlement difference between the nodes of the fill at the geogrid; Δl 1i is the length of the geogrid between the nodes of the fill after deformation; f 1i is the tensile force on the geogrid; ε is the soil creep value, ε0 is the initial plastic strain of the soil; K is the compaction degree of the fill soil; e is the base of the natural logarithm; P a is the standard atmospheric pressure; σ 11 is the axial pressure; 31 is the confining pressure; f(ε) is the normal distribution function; σ is the standard deviation of the function; μ is the mean value of the function.

[0042] Furthermore, the second settlement value H of each fill node at S7 geogrid is 2i Specifically

[0043] H 2i =H 1i +Δh (15)

[0044] Among them, H 1i is the total settlement value below each fill node at the geogrid; Δh is the creep change of the soil below the geogrid.

[0045] Compared with the prior art, the beneficial effects of the present invention include the following points:

[0046] 1. By introducing the static triaxial creep test, the present invention establishes a permanent strain prediction model for fill soil; it not only provides necessary parameter support for iterative calculation, but also fully considers the actual deformation of the soil and the influence of its own weight on creep, making the prediction results more accurate and intuitive. The model can more realistically reflect the behavior of the soil under long-term load, thus providing a reliable design basis for road engineering.

[0047] 2. The present invention uses geogrid as the main material to control the settlement of the fill, which has significant cost advantages compared with traditional treatment methods such as soil replacement cushion method and dynamic tamping method. It not only saves materials and construction time, but also reduces the impact on the surrounding environment, achieving the effect of saving time and labor. This solution is particularly suitable for road engineering projects that require rapid response and low-cost maintenance.

[0048] 3. The present invention provides a new method for calculating the settlement of reinforced compacted structures, which not only solves the problem of insufficient prediction accuracy commonly found in the prior art, but also provides a complete theoretical framework for guiding practical operations. This helps to improve the safety and stability of compacted structures while reducing construction costs.

[0049] 4. In view of the limitations of traditional methods when faced with complex geological conditions, the present invention proposes a more flexible and adaptable technical solution; in terms of the reinforcement of high-steep fill or the calculation of the creep deformation of high fill after construction, the present invention can not only accurately predict the settlement but also effectively implement deformation control, thus overcoming the defects existing in the prior art.

[0050] In summary, the present invention not only fills the gap in the existing technology in deformation prediction and control, but also greatly improves the engineering efficiency and economy through technological innovation, and provides a more complete and feasible solution to the problem of uneven roadbed settlement. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0052] Figure 1 This is the node diagram of the geogrid reinforced fill body in this implementation mode;

[0053] Figure 2 Calculation of vertical force at the nodes of the compacted mass in this implementation method;

[0054] Figure 3 The curve showing the variation of the average strain of the roadbed soil layer with depth in this implementation mode;

[0055] Figure 4 It is an iterative flow chart for this implementation. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Example 1

[0058] S1. Sampling in the pre-disintegrated soft rock fill section;

[0059] S2. Perform a static triaxial creep test on the sample of step S1, set different stress ratios and compaction degrees in the test, obtain the permanent axial deformation of the fill body soil under the action of static stress, and establish a permanent strain estimation model for the fill body under the action of static stress.

[0060] The compaction degree of soil samples in the static triaxial creep test was set to 90%, 93%, and 96%; the confining pressure was set to 10kPa, 20kPa, 30kPa, 40kPa, and 50kPa; the ratio of axial pressure to confining pressure was set to 1.2:1.0, 1.4:1.0, 1.6:1.0, 1.8:1.0, and 2.0:1.0. The natural water content was used.

[0061] When establishing the permanent strain estimation model of the compacted body, the degree of compaction, confining pressure, and the ratio of axial pressure to confining pressure are taken into consideration as variables in the model, and the permanent strain estimation model of the compacted body under stress is established:

[0062]

[0063]

[0064] Where: ε is the creep value of soil, ε0 is the initial plastic strain of soil (compaction degree is 96%, confining pressure is 30 kPa, stress ratio is 1.6:1.0); K is the compaction degree of fill soil; e is the base of natural logarithm; P a is standard atmospheric pressure,

[0065] P a =101.4kPa;σ 11 is the axial pressure; 31 for confining pressure; is the stress ratio; f(ε) is the normal distribution function; σ is the standard deviation of the function; μ is the mean value of the function, which is 0.

[0066] S3. Divide the fill body into a grid and divide it into several nodes. Determine the node positions by using a rectangular coordinate system, such as Figure 1 As shown in the figure, the x-axis represents the width of the compacted body and the y-axis represents the height of the compacted body. The grid shape is a rectangle with a length of 1.0 m and a width of 0.5 m. From the roadbed permanent strain statistical model in step S2 (Equation (1)), the creep amount h of each compacted body node is obtained. 1ij , and then the creep amount h of each fill node 1ij Substitute into the node.

[0067]

[0068] Where: h 1ij It is the creep deformation between two adjacent filling nodes under the action of self-weight stress; is the average strain between two adjacent nodes of the vertical section under the action of self-weight stress; h is the vertical distance between the nodes.

[0069] S4, such as Figure 1 , geogrids are added to the compact so that the creep process of the compact is closely integrated with the geogrid. When the compact creeps, the geogrid is strained, and the force generated further causes the compact to deform. Subsequently, the strain of the geogrid is adjusted accordingly. From then on, the iteration process begins, and the difference in the strain of the geogrid (each segment of the geogrid) between the nodes of the compact is reduced to less than 3% after two consecutive iterations, at which point the iteration ends. Finally, the final creep result of the compact under the action of the geogrid can be obtained.

[0070] The creep value of each node is given by the permanent strain prediction model of the fill in S2, and the creep value of each row of fill nodes under the geogrid is added to obtain the total settlement value H below each fill node at the geogrid. 1i (i is the horizontal coordinate of the node), and the settlement difference between each fill node at the geogrid and the deformed length of the geogrid between the fill nodes are calculated by equations (5) and (6).

[0071] H 1i =∑h 1ij (4)

[0072] ΔH 1i =|H 1i -H 1(i+1) | (5)

[0073]

[0074] Among them, H 1i h is the total settlement value below each fill node at the geogrid; 1ij is the creep amount of each fill node under the geogrid; ΔH 1i is the settlement difference between the nodes of the fill at the geogrid; Δl 1i is the deformed length of the geogrid between the nodes of the fill body; l is the horizontal interval of the nodes; i is the abscissa number; j is the ordinate number, and (i+1) means the abscissa plus 1.

[0075] The strain of the geogrid (each segment of the geogrid) between the nodes of the fill body is obtained by formula (7), and the stress on the geogrid is obtained by multiplying it with the elastic modulus of the geogrid (formula (8)). The tensile force on the geogrid is obtained by multiplying the stress with the cross-sectional area of ​​the geogrid (formula (9)).

[0076]

[0077] σ 1i =E·ε 1i (8)

[0078] f 1i =σ 1i ·A' (9)

[0079] Where: ε 1i is the geogrid strain between fill nodes; σ 1i is the tensile stress on the geogrid; E is the elastic modulus of the geogrid; f 1i is the tension on the geogrid; A' is the cross-sectional area of ​​the geogrid.

[0080] The vertical force component of the geogrid is calculated by equations (10) and (11): Figure 2 As shown. The stress of the fill node at the geogrid is calculated using formula (12), and then the stress is substituted into formula (1) to obtain formula (13), and the strain of the fill below the geogrid is obtained. Finally, the strain is multiplied by the height of the soil below to obtain the change of the soil below the geogrid.

[0081] F 1i =f 1(i-1) ·sinα 1(i-1) +f 1i ·sinα 1i (10)

[0082]

[0083]

[0084]

[0085] Δh=h2·ε′ 1i (14)

[0086] H 2i =H 1i +Δh (15)

[0087] Where: F 1i is the vertical force on the nodes of the fill at the geogrid, with downward force being positive; 1i is the angle between the geogrid and the horizontal direction after the change; σ′ 1i is the stress on the node of the fill at the geogrid, with downward change as positive; A0 is the area of ​​the geogrid per unit area; γ is the weight of the fill soil; h1 is the height of the soil above the geogrid; Δh is the creep change of the soil below the geogrid, with downward change as positive; h2 is the height of the soil below the geogrid; ε1' i H is the fill strain under the geogrid; 2i It is the second settlement value of each fill node at the geogrid.

[0088] Repeat the above formulas (5)-(15), as Figure 4 As shown, until (ε (k-1)i -ε ki ) / ε ki When both are less than 3%, the iteration ends and the final settlement H of the fill is output. ki ; where k is the number of iterations.

[0089] The α that appears in the formula of this embodiment 1i ,σ1' i 、F 1i 、f 1i , ε 1i , σ 1i , H 1(i+1) The subscript of the same symbol is 1i or 1(i+1). When iterating to k, the corresponding change in the following table is ki; that is, α ki ,σ' ki 、F ki 、f ki , ε ki , σ ki , H k(i+1) wait.

[0090] Example 2

[0091] The contact parameters between geogrid and reinforcement soil are shown in Table 1.

[0092] Table 1 Physical parameters of geogrid

[0093]

[0094] After the fill is divided into several cells, the geogrid is inserted into each cell and deforms together with the soil. When the geogrid is strained, it will exert a force on the soil to resist the deformation of the soil. As the deformation of the soil under the geogrid decreases, the strain of the geogrid will also decrease, thereby reducing the force resisting the deformation of the soil. However, this reduced resistance may lead to an increase in the deformation of the soil under the geogrid.

[0095] The lower left corner of the compacted body is taken as the coordinate origin. Each node can be represented by different coordinates. The creep statistical model of the compacted body is used to randomly assign values ​​to each node. The curve of the average strain of the compacted body soil layer changing with depth is shown in Figure 3 The creep amount at each point is shown in Table 2.

[0096] Table 2 Creep amount of each node

[0097]

[0098] Insert the geogrid at the eighth row node. First, consider the geogrid and the soil as a whole. As the lower soil settles, the geogrid will also deform. At each node of the compacted mass, the settlement of the geogrid is consistent with the deformation of the compacted mass nodes. The creep deformation is shown in Table 3.

[0099] Table 3 Total creep of soil under geogrid

[0100]

[0101] According to the data in Table 3, the settlement difference between each fill node is calculated. Combined with formula (6), the deformation length of each section of the geogrid can be obtained. The strain and stress of each section of the geogrid are calculated by formulas (7)-(8) as shown in Table 4.

[0102]

[0103]

[0104] σ 1i =E·ε 1i (8)

[0105] Table 4 Stress and strain of each section of geogrid

[0106]

[0107] Multiply the stress at each point by the cross-sectional area of ​​the geogrid to obtain the force on the node of the fill body. The vertical stress on the node of the fill body is obtained by calculation. The vertical stress is calculated by formula (13) to obtain the vertical strain. Combined with formula (14), the soil change can be obtained as shown in Table 5.

[0108] Table 5 Vertical stress strain at nodes and soil changes

[0109]

[0110] After obtaining the soil change Δh below, add it to the soil settlement in Table 3 and repeat the above process until (ε (k-1)i -ε ki ) / ε ki The iteration ends when the value is less than 3%. Figure 3 shown.

[0111] Table 6 Differences between the last two iteration results of fill joints

[0112] Node i 1 2 3 4 5 6 7 8 9 Iteration result difference (%) 2.683 2.930 2.067 2.180 1.924 2.929 0.408 1.274 1.053

[0113] As shown in Table 6, after 17 iterations, the obtained (ε (k-1)i -ε ki ) / ε kiBoth are less than 3%, so the final settlement and creep deformation of the node is obtained, as shown in Table 7.

[0114] Table 7 Final creep deformation of fill nodes

[0115]

[0116] It can be seen from Table 8 that after iteration, the last strain of the geogrid is significantly reduced compared with the first strain. This shows that this method has a significant effect in improving the uneven settlement of the fill.

[0117] Table 8 Geogrid strain changes

[0118]

[0119] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for determining non-uniform settlement of pre-collapsed soft rock fill based on reinforcement control, characterized in that: Follow these steps: S1. Sampling is carried out in the pre-disintegrated soft rock fill section; S2, conduct static triaxial creep tests on the samples obtained in S1 to establish a model for estimating permanent strain of the compacted mass under static stress; S3, meshing the compacted body to obtain a plurality of nodes; determining the node position through a rectangular coordinate system, determining the creep amount of each compacted body node, and then substituting the creep amount of each compacted body node into the node; S4, adding geogrid to the fill; Then determine the creep amount of each fill node, and substitute the creep amount of each fill node after adding geogrid into the node; Add the creep values ​​of each row of fill nodes under the geogrid to obtain the total settlement value under each fill node at the geogrid; S5. Determine the settlement difference between each fill node at the geogrid and the length of the geogrid between the fill nodes after deformation; S6. Determine the change in soil mass below the geogrid; S7. Determine the second settlement value of each fill node at the geogrid; S8. Repeat the process of S5 to S7 until the difference in the strain of the geogrid between the nodes of the fill body is reduced to within 3% after two consecutive iterations; output the final settlement value.

2. The method for determining non-uniform settlement of pre-collapsed soft rock filling mass based on reinforcement control according to claim 1, characterized in that: The S2 permanent strain estimation model of the compacted body under static stress is specifically: Where: ε is the creep value of soil, ε0 is the initial plastic strain of soil; K is the compaction degree of fill soil; e is the base of natural logarithm; P a is the standard atmospheric pressure; σ 11 is the axial pressure; 31 is the confining pressure; f(ε) is the normal distribution function; σ is the standard deviation of the function; μ is the mean value of the function.

3. The method for determining non-uniform settlement of pre-collapsed soft rock filling based on reinforcement control according to claim 1, characterized in that: The creep amount h of each fill node of S3 1ij Specifically: Where: h 1ij It is the creep deformation between two adjacent filling nodes under the action of self-weight stress; is the average strain between two adjacent nodes of the vertical section under the action of self-weight stress; h is the vertical distance between the nodes.

4. The method for determining non-uniform settlement of pre-collapsed soft rock filling based on reinforcement control according to claim 1, characterized in that: In S4, the total settlement value H below each fill node at the geogrid 1i Specifically: H 1i =∑h 1ij (4) h 1ij It is the creep deformation between two adjacent compacted volumes under the action of self-weight stress.

5. The method for determining non-uniform settlement of pre-collapsed soft rock filling mass based on reinforcement control according to claim 1, characterized in that: The settlement difference ΔH between the nodes of the fill body at the geogrid described in S5 1i The length of the geogrid between the nodes of the fill body after deformation Δl 1i Specifically: ΔH 1i =|H 1i -H 1(i+1) | (5) Among them, H 1i is the total settlement value below each fill node at the geogrid; ΔH 1i is the settlement difference between the nodes of the fill at the geogrid; Δl 1i is the deformed length of the geogrid between the nodes of the fill body; l is the horizontal interval of the nodes; i is the horizontal coordinate number.

6. The method for determining non-uniform settlement of pre-collapsed soft rock filling mass based on reinforcement control according to claim 1, characterized in that: The change in soil mass below the S6 geogrid is determined by the following steps: S601. First, determine the deformation of the geogrid between the nodes of the fill body, and multiply it by the elastic modulus of the geogrid to obtain the stress on the geogrid; then multiply the stress by the cross-sectional area of ​​the geogrid to obtain the tensile force on the geogrid: s 1i =E·e 1i (8) f 1i =s 1i ·A' (9) Among them, ε 1i is the geogrid strain between fill nodes; σ 1i is the tensile stress on the geogrid; E is the elastic modulus of the geogrid; f 1i is the tensile force on the geogrid; A' is the cross-sectional area of ​​the geogrid, Δl 1i is the length of the geogrid between the nodes of the fill after deformation; l is the horizontal spacing of the nodes; S602, determine the component force of the geogrid in the vertical direction, and then determine the stress of the nodes of the fill body at the geogrid; then determine the strain of the fill body under the geogrid in combination with the permanent strain estimation model of the fill body under the static stress; finally, determine the change amount of the soil under the geogrid based on the strain: F 1i =f 1(i-1) ·sinα 1(i-1) +f 1i ·sinα 1i (10) Δh=h2·e′ 1i (14) Among them: F 1i is the vertical force on the nodes of the fill at the geogrid; α 1i is the angle between the geogrid and the horizontal direction after the change; σ′ 1i is the stress on the node of the fill at the geogrid; A0 is the area of ​​the geogrid per unit area; γ is the weight of the fill soil; h1 is the height of the soil above the geogrid; Δh is the change of the soil below the geogrid; h2 is the height of the soil below the geogrid; ε′ 1i is the strain of the fill below the geogrid; i is the horizontal coordinate number; j is the vertical coordinate number; ΔH 1i is the settlement difference between the nodes of the fill at the geogrid; Δl 1i f is the length of the geogrid between the nodes of the fill after deformation; 1i is the tensile force on the geogrid; ε is the soil creep value, ε0 is the initial plastic strain of the soil; K is the compaction degree of the fill soil; e is the base of the natural logarithm; P a is the standard atmospheric pressure; σ 11 is the axial pressure; 31 is the confining pressure; f(ε) is the normal distribution function; σ is the standard deviation of the function; μ is the mean value of the function.

7. The method for determining non-uniform settlement of pre-collapsed soft rock filling mass based on reinforcement control according to claim 1, characterized in that: The second settlement value H of each fill node at S7 geogrid 2i Specifically H 2i =H 1i +Δh (15) Among them, H 1i is the total settlement value below each fill node at the geogrid; Δh is the creep change of the soil below the geogrid.

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