A method for determining the stability of ground-connected walls based on distributed optical fiber monitoring

Abstract

The present invention proposes a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, including: S1 analyzing the disturbance law of the ground deformation caused by foundation pit excavation on the ground-connected wall; S2 establishing a ground-connected wall instability determination calculation model based on the disturbance law in S1 and the calculation model of the elastic foundation beam; S3 establishing the boundary conditions of the ground-connected wall instability determination calculation model based on the ground-connected wall instability determination calculation model in S2; S4 establishing the mechanical equilibrium equation of the ground-connected wall instability determination calculation model, solving the mechanical equilibrium equation based on the boundary conditions of the ground-connected wall instability determination calculation model, and obtaining the ground-connected wall instability deformation control equation; S5 arranging distributed optical fibers in the ground-connected wall to obtain the deformation curve of the ground-connected wall; S6 comparing the deformation curve in S5 with the calculation curve corresponding to the instability deformation control equation in S4, and determining the stability of the ground-connected wall based on the comparison result. The present invention provides an objective and accurate basis for data analysis and determination of ground-connected walls measured by optical fibers.

Description

Technical Field

[0001] The invention relates to the technical field of monitoring ground-connected walls constructed in foundation pits of water conservancy projects, and in particular to a method for determining the stability of ground-connected walls based on distributed optical fiber monitoring. Background Art

[0002] Ground-connected walls are widely used in foundation pit excavation projects due to their strong integrity, good water-proofing and durability. By constructing ground-connected walls, not only can the safe construction of foundation pits be ensured, but also the waste of water resources can be reduced, and loss reduction, water conservation and green construction can be achieved. However, the disturbance caused by foundation pit excavation can easily change the stress environment of the ground-connected wall, and it is easy to tilt and damage to the goaf under the action of lateral water pressure.

[0003] Traditional monitoring methods include indirect monitoring and point monitoring. Indirect monitoring cannot reflect the deformation of the ground-connected wall, and point monitoring may miss detection. Distributed fiber optic sensing technology has developed rapidly and has been gradually applied to foundation pit excavation projects. It has the advantages of being distributed, highly sensitive, anti-electromagnetic interference, small in size, and long in durability, and can achieve distributed monitoring of kilometer-deep holes. Therefore, distributed fiber optic sensing technology has great potential in monitoring the stability of ground-connected walls.

[0004] Prior to the present invention, the invention patent with patent number 202210089110.4 proposed a system and method for monitoring building settlement. The patented technical solution obtains the spatial settlement model of the building by arranging fiber gratings in the longitudinal and transverse directions of the building. However, the patented technical solution only obtains the deformation of the building through testing, which can provide guidance for the monitoring of the ground-connected wall, but the patented technical solution cannot determine whether the ground-connected wall is unstable. When the patented technical solution monitors a large deformation, there is no basis for determining whether the ground-connected wall is unstable. Therefore, the patented technical solution cannot provide a reference for the stability judgment of the ground-connected wall. Summary of the invention

[0005] In view of this, it is necessary to propose a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring to address the above-mentioned problems, so as to overcome some shortcomings in the above-mentioned background technology and solve the following technical problems: how to efficiently and accurately determine the stability of the ground-connected wall through the measured data of the ground-connected wall obtained by distributed optical fiber monitoring.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention proposes a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, comprising steps S1-S5 performed sequentially:

[0008] S1, analyze the disturbance law of ground deformation caused by foundation pit excavation on the ground-connected wall;

[0009] S2, based on the disturbance law obtained in S1 and combined with the calculation model of the elastic foundation beam, a calculation model for determining the instability of the ground-connected wall is established;

[0010] S3, according to the calculation model for determining instability of the ground-connected wall obtained in S2, establishing the boundary conditions of the calculation model for determining instability of the ground-connected wall;

[0011] S4, establishing a mechanical equilibrium equation of a ground-connected wall instability discrimination calculation model, solving the mechanical equilibrium equation according to the boundary conditions of the ground-connected wall instability discrimination calculation model, thereby obtaining a ground-connected wall instability deformation control equation;

[0012] S5, arranging distributed optical fibers on the ground-connected wall to obtain a deformation curve of the ground-connected wall;

[0013] S6, comparing the deformation curve obtained in S5 with the calculation curve corresponding to the instability deformation control equation obtained in S4, and determining the stability of the ground-connected wall according to the comparison result.

[0014] Furthermore, in S1, the disturbance factors of stratum deformation on the ground-connected wall include total stratum settlement, horizontal displacement of stratum in any direction, stratum settlement deformation caused by foundation pit excavation, and stratum settlement deformation caused by aquifer drainage;

[0015] The disturbance law complies with the following formula (1):

[0016]

[0017] In formula (1), W(x, y, z) is the total settlement of the formation; Any stratum Direction: horizontal displacement, W1(x,y,z) is the ground settlement deformation value caused by foundation pit excavation, W2(x,y,z) is the ground settlement deformation value caused by aquifer drainage, b1 is the ground horizontal movement coefficient caused by excavation, b2 is the ground horizontal movement coefficient caused by aquifer drainage, r1 is the radius of the main influence of the stratum caused by excavation, r2 is the radius of the main influence of the stratum caused by aquifer drainage.

[0018] Furthermore, in S2, it is assumed that the ground-connected wall complies with the Winkler foundation assumption, that is, it complies with the following formula (2):

[0019] R(x)=kω(x) (2)

[0020] In formula (2), R(x) is the foundation pressure, k is the Winkler foundation coefficient, and ω(x) is the foundation settlement.

[0021] Furthermore, in S3, the boundary conditions of the calculation model for determining the instability of the ground-connected wall are expressed as the following formula (3) or formula (4) through the deflection and the derivative of the deflection:

[0022]

[0023]

[0024] In formula (3), the deflection and rotation of the rock beam at x = 0 are 0, and the shear force and bending moment at x = l are 0; x is the vertical coordinate axis; l is the height of the ground-connected wall; ω1 is the deflection equation of the disturbed section; ω2 is the deflection equation of the non-disturbed section;

[0025] In formula (4), at the point where the boundary condition changes, i.e. x=x1, the deflection, rotation, bending moment and shear force of the beam are all equal.

[0026] Furthermore, in S4, the flexural differential equation corresponding to the mechanical equilibrium equation is the force equilibrium equation. Combining the boundary conditions, the mechanical equilibrium equation in S4 can be obtained. The flexural differential equation is:

[0027]

[0028] In equation (5), E is the elastic modulus of the rock beam, I is the moment of inertia of the rock beam section; the lateral water pressure load increases gradually from top to bottom, k is the foundation coefficient of the safety model, x2 is the disturbance height caused by excavation; the lateral water pressure is trapezoidal, the top load is q0, the bottom load is h2q0, the lateral water pressure in the deformation zone is h1q0, ω(x) is the foundation settlement, ω (4) is the fourth derivative of ω, ω is the deflection of the ground-connected wall, the first derivative of the deflection of the ground-connected wall is the rotation angle, the second derivative is the bending moment, the third derivative is the shear force, and the fourth derivative is the load; x is the vertical coordinate axis, x1 is the disturbance height, q0 is the lateral water pressure at the top of the ground-connected wall, l is the height of the ground-connected wall, and h2 is the calculation parameter of the lateral water pressure;

[0029] Solving differential equation (5), 0≤x≤x1 and x1≤x≤l, we can obtain the deflection equation (6) of the rock beam. The deflection equation (6) of the rock beam is the deflection control equation of the ground-connected wall 5 in S4. The deflection equation (6) of the rock beam is as follows:

[0030]

[0031]

[0032] In equation (6a) and equation (6b), C1, C2, C3, C4 and D1, D2, D3, D4 are constants.

[0033] According to the 8 continuity conditions in formula (4) and equation (5), 8 unknown quantities can be solved, namely constants C1~C4, D1~D4.

[0034] Further, S5 includes the following steps S51-S55 performed in sequence:

[0035] S51, encapsulating the optical fiber into an optical cable, and implanting it into the ground connection wall through vertical drilling. During the lowering process of the optical cable 8, the optical cable is in an overall stretched state;

[0036] S52, grouting and sealing the holes, and the grouting material for sealing the holes is the same as the casting material of the ground-connected wall, so as to ensure that the optical cable can reflect the deformation of the ground-connected wall;

[0037] S53, establishing a monitoring station on the ground and setting up a cloud and a PC terminal that communicate with the monitoring station, collecting and processing monitoring data, and sending the monitoring data to the cloud and the PC terminal;

[0038] S54, obtaining a deformation curve of the ground-connected wall;

[0039] S55, a deformation warning value is established according to the instability deformation control equation of the ground-connected wall 5 obtained in S4, and the deformation curve of the ground-connected wall 5 obtained in S54 is compared with the deformation warning value, and an alarm is issued when the deformation of the ground-connected wall reaches the deformation warning value.

[0040] Further, in S6, the deformation curve of the ground-connected wall obtained in S5 is compared with the deformation curve obtained by equation (6), and when the deformation curves of equation (6) and S5 do not match, it is determined that the ground-connected wall is stable;

[0041] The deformation curve obtained by equation (6) is compared with the curve characteristics of the deformation information of the ground-anchored wall obtained in S5 and the deformation value of the deformation information of the ground-anchored wall obtained in S5. When the deformation curve obtained by equation (6) is the same as the curve characteristics of the deformation information of the ground-anchored wall obtained in S5 and the deformation value of the deformation information of the ground-anchored wall obtained in S5 is less than the deformation value of equation (6), the ground-anchored wall is judged to have an unstable trend; when the deformation curve obtained by equation (6) is the same as the curve characteristics of the deformation information of the ground-anchored wall obtained in S5 and the deformation value of the deformation information of the ground-anchored wall obtained in S5 is greater than or less than the deformation value of equation (6), the ground-anchored wall is judged to be in an unstable state.

[0042] The present invention further proposes a device for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, comprising:

[0043] The disturbance law analysis module is used to analyze the disturbance law of the ground deformation caused by foundation pit excavation on the ground-connected wall;

[0044] The calculation model for determining the instability of the ground-connected wall is established based on the disturbance law obtained by the disturbance law analysis module and combined with the calculation model of the elastic foundation beam;

[0045] A boundary condition establishment module is used to establish the boundary conditions of the ground-connected wall instability determination calculation model according to the ground-connected wall instability determination calculation model;

[0046] A module for establishing the control equation of instability deformation of the ground-connected wall is used to establish the mechanical equilibrium equation of the ground-connected wall instability discrimination calculation model, and solve the mechanical equilibrium equation according to the boundary conditions of the ground-connected wall instability discrimination calculation model, so as to obtain the control equation of instability deformation of the ground-connected wall;

[0047] Distributed optical fibers arranged in the ground-connected wall are used to obtain the deformation curve of the ground-connected wall;

[0048] The stability analysis and judgment module of the ground-connected wall is used to compare the deformation curve obtained by the distributed optical fiber with the calculation curve corresponding to the instability deformation control equation obtained by the ground-connected wall instability deformation control equation establishment module, and judge the stability of the ground-connected wall according to the comparison result.

[0049] The present invention further proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring as described in any one of the above items are implemented.

[0050] The present invention further proposes an electronic device, comprising a storage device, a processor, and a computer program stored in the storage device and executable by the processor. When the processor executes the computer program, the steps of the method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring as described in any one of the above items are implemented.

[0051] The beneficial effects of the present invention are:

[0052] The present invention establishes an instability model of the ground-connected wall and provides a deformation control equation when the ground-connected wall is unstable, which provides an objective and accurate basis for the data analysis and judgment of the ground-connected wall measured by optical fiber, and provides a reference for the stability judgment of the ground-connected wall. The present invention provides a theoretical basis for the judgment of the instability of the ground-connected wall, provides guidance for the analysis of the monitoring data of the ground-connected wall, can judge the disturbance height of the ground-connected wall caused by excavation, and can also reflect the influence of geological parameters on the deformation of the ground-connected wall, providing guidance for the design of the ground-connected wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A flowchart of a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring according to the present invention;

[0054] Figure 2 It is a diagram of the excavation disturbance mechanism of a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring according to the present invention;

[0055] Figure 3 A calculation model diagram of a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring according to the present invention;

[0056] Figure 4 It is a schematic diagram of the optical cable arrangement of a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring according to the present invention;

[0057] Figure 5 The invention relates to a ground-connected wall stability determination method based on distributed optical fiber monitoring;

[0058] Description of reference numerals:

[0059] 1-stratum; 2-aquifer; 3-underlying rock stratum; 4-foundation pit; 5-ground-anchored wall; 6-stable state of ground-anchored wall; 7-instability state of ground-anchored wall; 8-optical cable; 9-drilling hole. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further clearly and completely described in combination with the embodiments of the present invention. It should be noted that 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 making creative work are within the scope of protection of the present invention.

[0061] It should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "front", "back", "left", and "right" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0062] The terms "first", "second", "third", "fourth", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the definition of "first", "second", "third", "fourth" features may explicitly or implicitly include one or more of the features.

[0063] Example 1

[0064] like Figure 1-Figure 5 As shown:

[0065] This embodiment proposes a method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, including steps S1-S5 performed sequentially:

[0066] S1, analyzing the disturbance law of the ground diaphragm wall 5 caused by the deformation of the stratum 1 caused by the excavation of the foundation pit 4;

[0067] S2, according to the disturbance law obtained in S1, combined with the calculation model of the elastic foundation beam, establish the calculation model for determining the instability of the ground-connected wall 5;

[0068] S3, according to the calculation model for determining instability of the ground-connected wall 5 obtained in S2, establishing boundary conditions of the calculation model for determining instability of the ground-connected wall 5;

[0069] S4, establishing a mechanical equilibrium equation of the instability determination calculation model of the ground-connected wall 5, solving the mechanical equilibrium equation according to the boundary conditions of the instability determination calculation model of the ground-connected wall 5, thereby obtaining an instability deformation control equation of the ground-connected wall 5;

[0070] S5, arranging distributed optical fibers on the ground-connected wall 5 to obtain a deformation curve of the ground-connected wall 5;

[0071] S6, comparing the deformation curve obtained in S5 with the calculation curve corresponding to the instability deformation control equation obtained in S4, and determining the stability of the ground-connected wall 5 according to the comparison result.

[0072] Specifically, steps S1-S4 are to establish the deformation equation of the ground-connected wall 5 when it is unstable, and the deformation curve (such as Figure 5 As shown); wherein, S1 provides a basis for establishing a calculation model; the optical fiber detection of S5 can measure the deformation curve of the ground-connected wall 5, and based on the equation curve, it can be determined whether the ground-connected wall 5 is unstable during the excavation process; S4 obtains the deformation equation when the ground-connected wall 5 is unstable, and S5 can obtain the real-time data of the deformation of the ground-connected wall 5 during the excavation process, and based on the curve of the deformation equation, the real-time data is analyzed to determine whether the ground-connected wall 5 is unstable.

[0073] Further optimized, in S1, the disturbance factors of the deformation of the stratum 1 on the ground-connected wall 5 include the total settlement of the stratum 1, the horizontal displacement of the stratum 1 in any direction, the settlement deformation of the stratum 1 caused by the excavation of the foundation pit 4, and the settlement deformation of the stratum 1 caused by the drainage of the aquifer 2;

[0074] The disturbance law complies with the following formula (1):

[0075]

[0076] In formula (1), W(x, y, z) is the total settlement value of layer 1; Any for stratum 1 Direction: W1(x, y, z) is the settlement deformation value of stratum 1 caused by excavation of foundation pit 4, W2(x, y, z) is the settlement deformation value of stratum 1 caused by hydrophobicity of aquifer 2, b1 is the horizontal movement coefficient of stratum 1 caused by excavation, b2 is the horizontal movement coefficient of stratum 1 caused by hydrophobicity of aquifer 2, r1 is the radius of main influence of stratum 1 caused by excavation, r2 is the radius of main influence of stratum 1 caused by hydrophobicity of aquifer 2.

[0077] Further optimized, in S2, it is assumed that the ground-connected wall 5 complies with the Winkler foundation assumption, that is, it complies with the following formula (2):

[0078] R(x)=kω(x) (2)

[0079] In formula (2), R(x) is the foundation pressure, k is the Winkler foundation coefficient, and ω(x) is the foundation settlement.

[0080] Specifically, before the deformation zone disturbs the ground-connected wall 5, the top and bottom of the ground-connected wall 5 are located in the upper and lower rock layers, which can be regarded as constraint boundaries. The right side of the ground-connected wall 5 is subjected to the gradient water pressure load; after the deformation zone disturbs the ground-connected wall 5, the rock layer on the left side of the ground-connected wall 5 in the deformation zone influence range (x1<x<l) provides less support, or even cannot provide support; therefore, a calculation model is established. The bottom of the ground-connected wall 5 is taken as the origin, the vertical direction is the x-axis, and the horizontal direction is the y-axis; assuming that the height of the ground-connected wall 5 is l, the height of the disturbance caused by excavation is x2. The foundation coefficient of the safety model is k, and the foundation coefficient reduction coefficient of the ground-connected wall 5 after the disturbance is β (0≤β<l); the lateral water pressure load gradually increases from top to bottom, the top is q0, the bottom is h2q0, and the boundary position of the deformation zone is h1q0.

[0081] Further optimized, in S3, the boundary conditions of the instability determination calculation model of the ground-connected wall 5 are expressed as the following formula (3) or formula (4) through the deflection and the derivative of the deflection:

[0082]

[0083]

[0084] In formula (3), the deflection and rotation of the rock beam at x = 0 are 0, and the shear force and bending moment at x = l are 0; x is the vertical coordinate axis; l is the height of the ground-connected wall; ω1 is the deflection equation of the disturbed section; ω2 is the deflection equation of the non-disturbed section;

[0085] In formula (4), at the point where the boundary condition changes, i.e. x=x1, the deflection, rotation, bending moment and shear force of the beam are all equal.

[0086] Further optimized, in S4, the flexural differential equation corresponding to the mechanical equilibrium equation is a force equilibrium equation. Combining the boundary conditions, the mechanical equilibrium equation in S4 can be obtained, and the flexural differential equation is:

[0087]

[0088] In equation (5), E is the elastic modulus of the rock beam, I is the moment of inertia of the rock beam section; the lateral water pressure load increases gradually from top to bottom, k is the foundation coefficient of the safety model, x2 is the disturbance height caused by excavation; the lateral water pressure is trapezoidal, the top load is q0, the bottom load is h2q0, the lateral water pressure in the deformation zone is h1q0, ω(x) is the foundation settlement, ω (4) is the fourth derivative of ω, ω is the deflection of the ground-connected wall, the first derivative of the deflection of the ground-connected wall is the rotation angle, the second derivative is the bending moment, the third derivative is the shear force, and the fourth derivative is the load; x is the vertical coordinate axis, x1 is the disturbance height, q0 is the lateral water pressure at the top of the ground-connected wall, l is the height of the ground-connected wall, and h2 is the calculation parameter of the lateral water pressure;

[0089] Solving differential equation (5), 0≤x≤x1 and x1≤x≤l, we can obtain the deflection equation (6) of the rock beam. The deflection equation (6) of the rock beam is the deflection control equation of the ground-connected wall 5 in S4. The deflection equation (6) of the rock beam is as follows:

[0090]

[0091]

[0092] In equation (6a) and equation (6b), C1, C2, C3, C4 and D1, D2, D3, D4 are constants.

[0093] According to the 8 continuity conditions in formula (4) and equation (5), 8 unknown quantities can be solved, namely constants C1~C4, D1~D4.

[0094] Specifically, according to the design parameters of the ground-connected wall 5 and the geological parameters, the deformation curve and deformation value of the ground-connected wall 5 caused by the excavation of the foundation pit 4 can be obtained through equation (6), which can then guide the excavation of the foundation pit 4 and avoid the disaster caused by the destruction of the ground-connected wall 5. This judgment method avoids the influence of subjective factors of personnel and is more objective and accurate; in addition, it can be seen from equation (6) that the deformation of the ground-connected wall 5 is related to the parameters of the stratum 1, and the influence of geological parameters on the deformation of the ground-connected wall 5 can be obtained, which can provide guidance for the parameter design of the ground-connected wall 5.

[0095] Further optimized, S5 includes the following steps S51-S55 performed in sequence:

[0096] S51, encapsulating the optical fiber into an optical cable 8, and implanting it into the ground connection wall 5 through a vertical drilling hole 9. During the lowering process of the optical cable 8, the optical cable 8 is in an overall stretched state;

[0097] S52, grouting and sealing the hole, and the sealing grouting material is the same as the casting material of the ground-connected wall 5, so as to ensure that the optical cable 8 can reflect the deformation of the ground-connected wall 5;

[0098] S53, establishing a monitoring station on the ground and setting up a cloud and a PC terminal that communicate with the monitoring station, collecting and processing monitoring data, and sending the monitoring data to the cloud and the PC terminal;

[0099] S54, obtaining a deformation curve of the ground-connected wall 5;

[0100] S55, a deformation warning value is established according to the instability deformation control equation of the ground-connected wall 5 obtained in S4, and the deformation curve of the ground-connected wall 5 obtained in S54 is compared with the deformation warning value, and an alarm is issued when the deformation of the ground-connected wall 5 reaches the deformation warning value.

[0101] Specifically, a deformation warning value is set in the system, and when the deformation of the diaphragm wall 5 reaches this value, the system issues an alarm.

[0102] Further optimized, in S6, the deformation curve of the ground-connected wall 5 obtained in S5 is compared with the deformation curve obtained by equation (6), and when the deformation curves of equation (6) and S5 do not match, it is determined that the ground-connected wall 5 is stable;

[0103] The deformation curve obtained by equation (6) is compared with the curve characteristics of the deformation information of the ground-anchored wall 5 obtained at S5 and the deformation value of the deformation information of the ground-anchored wall 5 obtained at S5. When the deformation curve obtained by equation (6) is the same as the curve characteristics of the deformation information of the ground-anchored wall 5 obtained at S5 and the deformation value of the deformation information of the ground-anchored wall 5 obtained at S5 is less than the deformation value of equation (6), the ground-anchored wall 5 is determined to have an unstable trend; when the deformation curve obtained by equation (6) is the same as the curve characteristics of the deformation information of the ground-anchored wall 5 obtained at S5 and the deformation value of the deformation information of the ground-anchored wall 5 obtained at S5 is greater than or less than the deformation value of equation (6), the ground-anchored wall 5 is determined to be in an unstable state.

[0104] Specifically, S5 obtains the measured data of the ground-connected wall 5 during the excavation of the foundation pit 4, draws a deformation curve of the ground-connected wall 5, and takes the deformation curve of equation (6) as the warning value. When the measured deformation curve is similar to the result calculated by equation (6) and the deformation value is close, it indicates that the curtain is unstable. It is worth noting that equation (6) is the final instability deformation curve, and curtain instability is a process. Therefore, when the measured deformation curve is similar to the result calculated by equation (6), but the deformation value is less than the result calculated by equation (6), excavation should be stopped.

[0105] like Figure 2-Figure 5 As shown:

[0106] Taking a ground-connected wall 5 as an example, according to the ground-connected wall 5 and geological parameters, the deformation curve of the unstable state of the ground-connected wall 5 is obtained by using Matlab software. The case calculates the deformation characteristics of the unstable state of the ground-connected wall 5 with a disturbance height of 20m (x2=20m).

[0107] Example 2

[0108] This embodiment provides a device for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, comprising:

[0109] The disturbance law analysis module is used to analyze the disturbance law of the ground diaphragm wall caused by the deformation of the stratum 1 caused by the excavation of the foundation pit 4;

[0110] The calculation model for determining the instability of the ground-connected wall is established based on the disturbance law obtained by the disturbance law analysis module and combined with the calculation model of the elastic foundation beam;

[0111] A boundary condition establishment module is used to establish the boundary conditions of the ground-connected wall instability determination calculation model according to the ground-connected wall instability determination calculation model;

[0112] A module for establishing the control equation of instability deformation of the ground-connected wall is used to establish the mechanical equilibrium equation of the ground-connected wall instability discrimination calculation model, and solve the mechanical equilibrium equation according to the boundary conditions of the ground-connected wall instability discrimination calculation model, so as to obtain the control equation of instability deformation of the ground-connected wall;

[0113] Distributed optical fibers arranged in the ground-connected wall are used to obtain the deformation curve of the ground-connected wall;

[0114] The stability analysis and judgment module of the ground-connected wall is used to compare the deformation curve obtained by the distributed optical fiber with the calculation curve corresponding to the instability deformation control equation obtained by the ground-connected wall instability deformation control equation establishment module, and judge the stability of the ground-connected wall according to the comparison result.

[0115] Example 3

[0116] This embodiment proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring as described in any technical solution of Example 1 are implemented.

[0117] Example 4

[0118] This embodiment proposes an electronic device, including a storage device, a processor, and a computer program stored in the storage device and executable by the processor. When the processor executes the computer program, the steps of the method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring as described in any technical solution of Example 1 are implemented.

[0119] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, characterized in that: The method comprises steps S1-S5 performed sequentially: S1, analyze the disturbance law of ground deformation caused by foundation pit excavation on the ground-connected wall; S2, based on the disturbance law obtained in S1 and combined with the calculation model of the elastic foundation beam, a calculation model for determining the instability of the ground-connected wall is established; S3, according to the calculation model for determining instability of the ground-connected wall obtained in S2, establishing the boundary conditions of the calculation model for determining instability of the ground-connected wall; S4, establishing a mechanical equilibrium equation of a ground-connected wall instability discrimination calculation model, solving the mechanical equilibrium equation according to the boundary conditions of the ground-connected wall instability discrimination calculation model, thereby obtaining a ground-connected wall instability deformation control equation; S5, arranging distributed optical fibers on the ground-connected wall to obtain a deformation curve of the ground-connected wall; S6, comparing the deformation curve obtained in S5 with the calculated curve corresponding to the instability deformation control equation obtained in S4, and determining the stability of the ground-connected wall according to the comparison result; In S1, the disturbance factors of stratum deformation on the ground-connected wall include total stratum settlement, horizontal displacement of stratum in any direction, stratum settlement deformation caused by foundation pit excavation, and stratum settlement deformation caused by aquifer drainage; The disturbance law complies with the following formula (1): In formula (1), W(x, y, z) is the total settlement of the formation; Any stratum The horizontal displacement in the direction, W1(x, y, z) is the ground settlement deformation value caused by foundation pit excavation, W2(x, y, z) is the ground settlement deformation value caused by aquifer drainage, b1 is the ground horizontal movement coefficient caused by excavation, b2 is the ground horizontal movement coefficient caused by aquifer drainage, r1 is the radius of the main influence of the stratum caused by excavation, and r2 is the radius of the main influence of the stratum caused by aquifer drainage; In S2, it is assumed that the ground-connected wall complies with the Winkler foundation assumption, that is, it complies with the following formula (2): R(x)=kω(x) (2) In formula (2), R(x) is the foundation pressure, k is the Winkler foundation coefficient, and ω(x) is the foundation settlement; In S3, the boundary conditions of the calculation model for determining the instability of the ground-connected wall are expressed by the deflection and the derivative of the deflection as follows: In formula (3), the deflection and rotation of the rock beam at x = 0 are 0, and the shear force and bending moment at x = l are 0; x is the vertical coordinate axis; l is the height of the ground-connected wall; ω1 is the deflection equation of the disturbed section; ω2 is the deflection equation of the non-disturbed section; In formula (4), at the point where the boundary condition changes, that is, x = x1, the deflection, rotation, bending moment and shear force of the beam are all equal; In S4, the flexural differential equation corresponding to the mechanical equilibrium equation is the force equilibrium equation. Combining the boundary conditions, the mechanical equilibrium equation in S4 can be obtained. The flexural differential equation is: In equation (5), E is the elastic modulus of the rock beam, I is the moment of inertia of the rock beam section; the lateral water pressure load increases gradually from top to bottom, k is the foundation coefficient of the safety model, and x2 is the disturbance height caused by excavation; the lateral water pressure is trapezoidal, the top load, that is, the lateral water pressure at the top of the ground-connected wall is q0, the lateral water pressure at the bottom of the ground-connected wall is h2q0, the lateral water pressure in the deformation zone is h1q0, ω(x) is the foundation settlement, ω (4) is the fourth derivative of ω, ω is the deflection of the ground-connected wall, the first derivative of the deflection of the ground-connected wall is the rotation angle, the second derivative is the bending moment, the third derivative is the shear force, and the fourth derivative is the load; x is the vertical coordinate axis, x1 is the disturbance height, l is the height of the ground-connected wall, and h2 is the calculation parameter of the lateral water pressure; Solving differential equation (5), 0≤x≤x1 and x1≤x≤l, we can obtain the deflection equation (6) of the rock beam. The deflection equation (6) of the rock beam is the deflection control equation of the ground-connected wall 5 in S4. The deflection equation (6) of the rock beam is as follows: In equation (6a) and equation (6b), C1, C2, C3, C4 and D1, D2, D3, D4 are constants. According to the 8 continuous conditions in formula (3) and formula (4), 8 unknown quantities can be solved, namely, constant C1, constant C2, constant C3, constant C4, constant D1, constant D2, constant D3, constant D4; S5 includes the following steps S51-S55 performed in sequence: S51, encapsulating the optical fiber into an optical cable, and implanting the optical cable into the ground connection wall through a vertical drilling hole, wherein the optical cable is in an overall stretched state during the lowering process of the optical cable; S52, grouting and sealing the holes, and the grouting material for sealing the holes is the same as the casting material of the ground-connected wall, so as to ensure that the optical cable can reflect the deformation of the ground-connected wall; S53, establishing a monitoring station on the ground and setting up a cloud and a PC terminal that communicate with the monitoring station, collecting and processing monitoring data, and sending the monitoring data to the cloud and the PC terminal; S54, obtaining a deformation curve of the ground-connected wall; S55, establishing a deformation warning value according to the instability deformation control equation of the ground-connected wall obtained in S4, comparing the deformation curve of the ground-connected wall 5 obtained in S54 with the deformation warning value, and issuing an alarm when the deformation of the ground-connected wall reaches the deformation warning value; In S6, the deformation curve of the ground-connected wall obtained in S5 is compared with the deformation curve obtained by equation (6). When the deformation curves of equation (6) and S5 do not match, it is determined that the ground-connected wall is stable. The deformation curve obtained by equation (6) is compared with the curve characteristics of the deformation information of the ground-anchored wall obtained in S5 and the deformation value of the deformation information of the ground-anchored wall obtained in S5. When the deformation curve obtained by equation (6) is the same as the curve characteristics of the deformation information of the ground-anchored wall obtained in S5 and the deformation value of the deformation information of the ground-anchored wall obtained in S5 is less than the deformation value of equation (6), the ground-anchored wall is judged to have an unstable trend; when the deformation curve obtained by equation (6) is the same as the curve characteristics of the deformation information of the ground-anchored wall obtained in S5 and the deformation value of the deformation information of the ground-anchored wall obtained in S5 is greater than the deformation value of equation (6), the ground-anchored wall is judged to be in an unstable state.

2. A device for determining the stability of a ground-connected wall based on distributed optical fiber monitoring, characterized in that: Applying the discrimination method as claimed in claim 1, the discrimination device comprises: The disturbance law analysis module is used to analyze the disturbance law of the ground deformation caused by foundation pit excavation on the ground-connected wall; The calculation model for determining the instability of the ground-connected wall is established based on the disturbance law obtained by the disturbance law analysis module and combined with the calculation model of the elastic foundation beam; A boundary condition establishment module is used to establish the boundary conditions of the ground-connected wall instability determination calculation model according to the ground-connected wall instability determination calculation model; A module for establishing the control equation of instability deformation of the ground-connected wall is used to establish the mechanical equilibrium equation of the ground-connected wall instability discrimination calculation model, and solve the mechanical equilibrium equation according to the boundary conditions of the ground-connected wall instability discrimination calculation model, so as to obtain the control equation of instability deformation of the ground-connected wall; Distributed optical fibers arranged in the ground-connected wall are used to obtain the deformation curve of the ground-connected wall; The stability analysis and judgment module of the ground-connected wall is used to compare the deformation curve obtained by the distributed optical fiber with the calculation curve corresponding to the instability deformation control equation obtained by the ground-connected wall instability deformation control equation establishment module, and judge the stability of the ground-connected wall according to the comparison result.

3. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, the steps of the method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring as claimed in claim 1 are implemented.

4. An electronic device, characterized in that: It includes a storage, a processor, and a computer program stored in the storage and executable by the processor. When the processor executes the computer program, the steps of the method for determining the stability of a ground-connected wall based on distributed optical fiber monitoring as described in claim 1 are implemented.

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