A deformation detection method and system for foundation pit construction adjacent to an existing line

Abstract

The application discloses a kind of deformation detection method and system for foundation pit construction adjacent to existing line, the method comprises: the finite element simulation of deep foundation pit construction is carried out to the retaining structure of foundation pit adjacent to existing line during construction, the predicted displacement of the foundation pit adjacent to existing line at a position point under current permeability coefficient is extracted by finite element model, wherein the current permeability coefficient dynamically changes with construction behavior;Obtain the measured displacement of the foundation pit adjacent to existing line at a position point, the difference between the measured displacement and the predicted displacement is used as error tensor, simultaneously, obtain the pore water pressure change rate of the foundation pit adjacent to existing line at a position point, groundwater level gradient, and the comprehensive risk intensity index of the foundation pit adjacent to existing line at a position point is calculated in combination with the error tensor;Set multiple risk type labels, and the all position points of the foundation pit adjacent to existing line are clustered into corresponding risk type label according to comprehensive risk intensity index to complete risk identification.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of deep foundation pit construction risk point identification, and more particularly relates to a foundation pit construction deformation detection method and system for adjacent existing lines. BACKGROUND

[0002] Deep foundation pit refers to the underground engineering construction area with a large excavation depth, usually more than 5 meters (7 meters or more in some areas according to the specification), which is widely used in urban subway stations, underground garages, high-rise building basements, comprehensive pipe galleries and other projects. Its main function is to provide construction operation surface and space conditions for underground structures in limited ground space, which is the premise of realizing underground structure construction. Since deep foundation pit excavation can significantly change the stress state and balance system of the surrounding soil, it may cause a series of geological and structural safety problems such as surrounding ground subsidence, adjacent building deformation, and underground water level changes, so strict supporting structures (such as underground continuous walls, bored piles, steel support systems, etc.) and deformation monitoring means need to be taken during design and construction to ensure construction safety and stability of the surrounding environment. Deep foundation pit engineering is not only an important part of urban underground space development, but also a typical representative of the cross-fusion of engineering geology, structural mechanics, construction technology and risk control, which has important significance for improving urban space utilization efficiency and infrastructure construction capacity.

[0003] Therefore, there is an urgent need for a technical solution that can intelligently identify the risk points of deep foundation pit construction adjacent to existing lines, so as to avoid construction safety problems. SUMMARY

[0004] To solve the above technical problems, the present application provides a foundation pit construction deformation detection method for adjacent existing lines, comprising:

[0005] Performing finite element simulation of the deep foundation pit construction of the surrounding structure of the foundation pit adjacent to the existing line during construction, and extracting the predicted displacement of the foundation pit adjacent to the existing line at a certain position point under the current permeability coefficient through the finite element model, wherein the current permeability coefficient changes dynamically with the construction behavior;

[0006] Obtaining the measured displacement of the foundation pit adjacent to the existing line at a certain position point, taking the difference between the measured displacement and the predicted displacement as an error tensor, and simultaneously obtaining the pore water pressure change rate and underground water level gradient of the foundation pit adjacent to the existing line at a certain position point, and calculating the comprehensive risk intensity index of the foundation pit adjacent to the existing line at a certain position point in combination with the error tensor;

[0007] Setting multiple risk type labels, clustering all position points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification.

[0008] Further, the current permeability coefficient dynamically changing with construction progress comprises:

[0009]

[0010] wherein K(x, y, z, t) is the current permeability coefficient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, K0 is the initial permeability coefficient, κ is the adjustment factor of the local permeability disturbance factor, ξ(x, y, z, t) is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, β is the adjustment factor of the local stress disturbance factor, t0 is the integral starting time, χ σ (x, y, z, τ) is the local stress disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ due to the construction behavior.

[0011] Further, the local stress disturbance factor χ σ (x, y, z, τ) of the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ due to the construction behavior comprises:

[0012]

[0013] wherein σ(x, y, z, τ) is the current stress of the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ, σ0(x, y, z) is the initial stress of the foundation pit adjacent to the existing line at the position point (x, y, z).

[0014] Further, the calculation of the comprehensive risk intensity index of the foundation pit adjacent to the existing line at a position point comprises:

[0015]

[0016] wherein Υ(x, y, z, t) is the comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ1 is the weight of the error tensor, Δu K (x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the change rate of the pore water pressure, Δp(x, y, z, t) is the change rate of the pore water pressure of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, is the groundwater level gradient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t.

[0017] Further, before clustering all position points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification, the method further comprises: obtaining a current settlement rate and a permeable connectivity value of all position points;

[0018] For a current position point, a spatial neighborhood radius is defined, a number of neighborhood points of the current position point within the spatial neighborhood radius is counted, and an average permeable connectivity value and an average settlement rate of all position points within the spatial neighborhood radius are calculated, if the number of neighborhood points of the current position point exceeds a minimum number threshold, and the average permeable connectivity value is greater than or equal to an average permeable connectivity threshold, and the average settlement rate is greater than or equal to an average settlement rate threshold, the current position point is marked as a core point, and all position points within the spatial neighborhood radius are classified into the same class of position points, and all position points are classified into multiple classes by traversing all position points.

[0019] Further, the risk type labels comprise: a short-term burst risk area, a medium-term settlement risk area and a stable area.

[0020] Further, the method further comprises: obtaining a comprehensive risk intensity index, a peak settlement rate and the average permeable connectivity value of each class of position points;

[0021] If the comprehensive risk intensity index of a certain class of position points is greater than a first risk intensity threshold, the peak settlement rate is greater than a settlement rate threshold, and the average permeable connectivity value is greater than a permeable connectivity threshold, the certain class of position points is marked as a short-term burst risk area.

[0022] If the comprehensive risk intensity index of the certain class of position points is less than or equal to the first risk intensity threshold and greater than a second risk intensity threshold, and the peak settlement rate is less than the settlement rate threshold, the certain class of position points is marked as a medium-term settlement risk area.

[0023] If the comprehensive risk intensity index of the certain class of position points is less than or equal to the second risk intensity threshold, the certain class of position points is marked as a stable area.

[0024] The application further provides a foundation pit construction deformation detection system for a foundation pit adjacent to an existing line, comprising:

[0025] A finite element simulation module is configured to perform finite element simulation of a deep foundation pit construction of a support structure of the foundation pit adjacent to the existing line during construction, and to extract a predicted displacement of the foundation pit adjacent to the existing line at a position point under a current permeability coefficient through a finite element model, wherein the current permeability coefficient dynamically changes with construction behavior.

[0026] The risk intensity index calculation module is used for obtaining a measured displacement at a position point of the foundation pit adjacent to the existing line, taking a difference between the measured displacement and the predicted displacement as an error tensor, simultaneously, obtaining a pore water pressure change rate and a groundwater level gradient at the position point of the foundation pit adjacent to the existing line, and combining the error tensor to calculate a comprehensive risk intensity index at the position point of the foundation pit adjacent to the existing line.

[0027] The risk identification module is used for setting a plurality of risk type labels, clustering all position points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification.

[0028] Further, the current permeability coefficient dynamically changes with construction progress, and the current permeability coefficient K(x, y, z, t) at the position point (x, y, z) of the foundation pit adjacent to the existing line at time t is calculated according to the following formula:

[0029]

[0030] Wherein, K(x, y, z, t) is the current permeability coefficient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, K0 is the initial permeability coefficient, κ is the adjustment factor of the local permeability disturbance factor, ξ(x, y, z, t) is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, β is the adjustment factor of the local stress disturbance factor, t0 is the integral starting time, χ σ (x, y, z, τ) is the local stress disturbance factor of the construction behavior to the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ.

[0031] Further, the local stress disturbance factor χ σ (x, y, z, τ) of the construction behavior to the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ includes:

[0032]

[0033] Wherein, σ(x, y, z, τ) is the current stress received by the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ, and σ0(x, y, z) is the initial stress received by the foundation pit adjacent to the existing line at the position point (x, y, z).

[0034] Overall, compared with the prior art, the above technical scheme of the present application has the following beneficial effects:

[0035] Through the above technical scheme, the present application can intelligently identify the safety point of the deep foundation pit during construction, especially the construction risk point under the foundation pit adjacent to the existing line, greatly improving the construction safety and improving the construction efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1is a method flowchart of embodiment 1 of the present application.

[0037] Figure 2 is a system structure diagram of embodiment 2 of the present application. DETAILED DESCRIPTION

[0038] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0039] The method provided by the present application can be implemented in a terminal environment, which can include one or more of the following components: a processor, a storage medium and a display screen. Among them, the storage medium stores at least one instruction, which is loaded and executed by the processor to realize the method described in the following embodiments.

[0040] The processor can include one or more processing cores. The processor connects various parts in the entire terminal through various interfaces and lines, and performs various functions and processes data of the terminal by running or executing instructions, programs, code sets or instruction sets stored in the storage medium, and calling data stored in the storage medium.

[0041] The storage medium can include random access memory (RAM) and read-only memory (ROM). The storage medium can be used to store instructions, programs, codes, code sets or instructions.

[0042] The display screen is used to display the user interface of each application program.

[0043] In addition, those skilled in the art can understand that the structure of the above terminal does not constitute a limitation on the terminal, and the terminal can include more or fewer components, or combine certain components, or different component arrangements. For example, the terminal also includes radio frequency circuit, input unit, sensor, audio circuit, power supply and other components, which will not be described here.

[0044] Embodiment 1

[0045] As Figure 1 , the present embodiment proposes a deformation detection method for foundation pit construction adjacent to existing lines, which comprises:

[0046] Step 101, finite element simulation of deep foundation pit construction is performed on the enclosure structure of the foundation pit adjacent to the existing line during construction, and the predicted displacement of the foundation pit adjacent to the existing line at a certain position point under the current permeability coefficient is extracted through the finite element model, wherein the current permeability coefficient changes dynamically with the construction behavior;

[0047] Preferably, the present embodiment inputs construction drawings, adjacent existing line foundation exploration data, construction log, etc. into finite element software (e.g. Plaxis 2D / 3D or FLAC 3D) to perform finite element simulation.

[0048] Specifically, the dynamic change of the current permeability coefficient with construction progress comprises:

[0049]

[0050] wherein K(x, y, z, t) is the current permeability coefficient of the adjacent existing line foundation at position point (x, y, z) at time t, K0 is the initial permeability coefficient, κ is the adjustment factor of the local permeability disturbance factor, ξ(x, y, z, t) is the local permeability disturbance factor of the adjacent existing line foundation at position point (x, y, z) at time t, β is the adjustment factor of the local stress disturbance factor, t0 is the integral starting time, χ σ (x, y, z, τ) is the local stress disturbance factor of the adjacent existing line foundation at position point (x, y, z) at time τ due to construction behavior.

[0051] Preferably, the present embodiment obtains the adjustment factor β of the local stress disturbance factor by the following way:

[0052] obtaining the measured permeability coefficients of the same position point at multiple time points t1, t2,..., t n , such as through field double ring method, PPT test or well group test back calculation;

[0053] According to the calculation formula of the current permeability coefficient, the calculated permeability coefficient is obtained, according to the least square method, the calculation formula of the current permeability coefficient is fitted according to the measured permeability coefficient, and the optimal β value is regressed, and similarly, the initial optimal κ value can be regressed together.

[0054] Preferably, the local permeability disturbance factor ξ(x, y, z, t) of the adjacent existing line foundation at position point (x, y, z) at time t reflects the local permeability performance change trend caused by construction influence, structure deformation or hydraulic redistribution, and the present embodiment obtains ξ(x, y, z, t) by the following way:

[0055] Original data preparation: arrange osmometers at different depths / positions, and automatically record the measured osmotic pressure value p measured (x, y, z, t) at time t, the seepage field simulation result based on the initial permeability coefficient K0, the osmotic pressure prediction value p predicted (x, y, z, t) calculated by finite element software, and the measured osmotic pressure value p measured (x, y, z, t) and the osmotic pressure prediction value p predicted(x, y, z, t) is the osmotic pressure error Δp(x, y, z, t) between the measured value of the osmotic pressure p(x, y, z, t) and the predicted value of the osmotic pressure p(x, y, z, t), and the osmotic pressure error Δp(x, y, z, t) is divided by the measured value of the osmotic pressure p(x, y, z, t) measured (x, y, z, t) is the osmotic pressure error Δp(x, y, z, t) between the measured value of the osmotic pressure p(x, y, z, t) and the predicted value of the osmotic pressure p(x, y, z, t), and the osmotic pressure error Δp(x, y, z, t) is divided by the measured value of the osmotic pressure p(x, y, z, t)

[0056] Preferably, the embodiment considers the dynamic change of the permeability coefficient with the construction progress, and aims to describe the process of gradual deterioration of the permeability coefficient with time, representing the reconstruction or deterioration mechanism of the permeability of the stratum under the influence of construction.

[0057] Specifically, the local stress disturbance factor χ(x, y, z, τ) of the foundation pit adjacent to the existing line at the position point (x, y, z) under the construction behavior at time τ is σ (x, y, z, t) includes:

[0058]

[0059] wherein σ(x, y, z, τ) is the current stress of the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ, and σ0(x, y, z) is the initial stress of the foundation pit adjacent to the existing line at the position point (x, y, z).

[0060] In step 102, the measured displacement of the foundation pit adjacent to the existing line at a certain position point is obtained, the difference between the measured displacement and the predicted displacement is taken as an error tensor (preferably, the error tensor is an absolute value), at the same time, the change rate of the pore water pressure and the groundwater level gradient of the foundation pit adjacent to the existing line at a certain position point are obtained, and the comprehensive risk intensity index of the foundation pit adjacent to the existing line at a certain position point is calculated in combination with the error tensor;

[0061] Specifically, calculating the comprehensive risk intensity index of the foundation pit adjacent to the existing line at a certain position point in combination with the error tensor includes:

[0062]

[0063] wherein Υ(x, y, z, t) is the comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ1 is the weight of the error tensor, Δu(x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the change rate of the pore water pressure, Δp(x, y, z, t) is the change rate of the pore water pressure of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, K (x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the change rate of the pore water pressure, Δp(x, y, z, t) is the change rate of the pore water pressure of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, is the groundwater level gradient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t.

[0064] Step 103, setting multiple risk type labels, the risk type labels including: short-term burst risk area, medium-term settlement risk area and stable area, clustering all location points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification.

[0065] Specifically, before clustering all location points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification, it further includes: obtaining the current settlement rate and the permeable connectivity value of all location points.

[0066] For a current location point, a spatial neighborhood radius is defined, the number of neighborhood points of the current location point is counted within the spatial neighborhood radius, and the average permeable connectivity value and the average settlement rate of all location points within the spatial neighborhood radius are calculated, if the number of neighborhood points of the current location point exceeds a minimum number threshold, and the average permeable connectivity value is greater than or equal to an average permeable connectivity threshold, and the average settlement rate is greater than or equal to an average settlement rate threshold, the current location point is marked as a core point, and all location points within the spatial neighborhood radius are classified into the same class of location points, all location points are traversed, and all location points are divided into multiple classes.

[0067] Preferably, the permeable connectivity value of all location points is obtained by the following method:

[0068] According to the formula:

[0069]

[0070] A three-dimensional permeability coefficient distribution field is constructed, which represents the spatial variation distribution of the permeability of each point in the fine sand layer.

[0071] Setting a hydraulic source (starting point) and an evaluation point (end point): the hydraulic source point set (such as the foundation pit periphery, the groundwater head high area): set as the starting point of the seepage path;

[0072] The evaluation point (such as the settlement monitoring point, the displacement meter point): as the end point of the path;

[0073] K -1 (x, y, z, t) is regarded as the propagation time consumption, the arrival time calculation is performed on the entire field from the water source, that is, the permeable connectivity value of all location points can be defined as:

[0074]

[0075] Wherein, C i is the permeable connectivity value of the i-th location point, T i is the minimum propagation time from the water source point to the i-th location point, and ε is a small constant to avoid division by zero.

[0076] Preferably, the purpose of clustering the position points is to find local risk abnormal concentration area in the construction area plane (such as the bottom of the foundation pit, the vicinity of the retaining wall), and most of the actual engineering monitoring points (such as settlement points, stress meters, pore pressure meters) are distributed on a certain elevation level or profile line (for example, the bottom of the foundation pit, the middle of the supporting pile, the wall back), so when the position points are clustered in this embodiment, all points are assumed to be at a known engineering elevation, thereby omitting the height coordinate of the position points, that is, the z mentioned above.

[0077] Specifically, the comprehensive risk intensity index, the peak settlement rate and the average permeable connectivity value of each type of position point are obtained;

[0078] If the comprehensive risk intensity index of a certain type of position point is greater than the first risk intensity threshold, the peak settlement rate is greater than the settlement rate threshold, and the average permeable connectivity value is greater than the permeable connectivity threshold, the certain type of position point is marked as a short-term sudden risk area, which prompts that acute events such as water inrush and collapse may occur;

[0079] If the comprehensive risk intensity index of the certain type of position point is less than or equal to the first risk intensity threshold and greater than the second risk intensity threshold, and the peak settlement rate is less than the settlement rate threshold, the certain type of position point is marked as a medium-term settlement risk area, which prompts that long-term settlement or structure stress aggregation may occur;

[0080] If the comprehensive risk intensity index of the certain type of position point is less than or equal to the second risk intensity threshold, the certain type of position point is marked as a stable area, which does not need immediate intervention and can be continuously observed.

[0081] Embodiment 2

[0082] As shown in Figure 2 The embodiment provides a deformation detection system for a foundation pit construction adjacent to an existing line, which comprises:

[0083] A finite element simulation module is configured to perform finite element simulation on a deep foundation pit construction of a retaining structure of a foundation pit adjacent to an existing line during construction, and to extract a predicted displacement of the foundation pit adjacent to the existing line at a position point under a current permeability coefficient through a finite element model, wherein the current permeability coefficient dynamically changes with construction behavior.

[0084] Specifically, the current permeability coefficient dynamically changes with construction progress, which comprises:

[0085]

[0086] wherein K(x, y, z, t) is the current permeability coefficient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, K0 is the initial permeability coefficient, κ is the adjustment factor of the local permeability disturbance factor, ξ(x, y, z, t) is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, β is the adjustment factor of the local stress disturbance factor, t0 is the integral starting time, χ σ (x, y, z, t) is the local stress disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t.

[0087] Specifically, the local stress disturbance factor χ σ (x, y, z, t) of the construction behavior of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t includes:

[0088]

[0089] wherein σ(x, y, z, t) is the current stress received by the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, σ0(x, y, z) is the initial stress received by the foundation pit adjacent to the existing line at the position point (x, y, z).

[0090] The risk intensity index calculation module is configured to acquire a measured displacement at a position point of the foundation pit adjacent to the existing line, take a difference between the measured displacement and the predicted displacement as an error tensor, acquire a pore water pressure change rate and a groundwater level gradient at the position point of the foundation pit adjacent to the existing line, and calculate a comprehensive risk intensity index at the position point of the foundation pit adjacent to the existing line in combination with the error tensor.

[0091] Specifically, the comprehensive risk intensity index at the position point of the foundation pit adjacent to the existing line in combination with the error tensor includes:

[0092]

[0093] wherein Υ(x, y, z, t) is the comprehensive risk intensity index at the position point (x, y, z) of the foundation pit adjacent to the existing line at time t, λ1 is the weight of the error tensor, Δu K (x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the pore water pressure change rate, Δp(x, y, z, t) is the pore water pressure change rate of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, (x, y, z, t) is the groundwater level gradient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t.

[0094] A risk identification module is configured to set a plurality of risk type labels, including a short-term burst risk area, a medium-term settlement risk area and a stable area, and to cluster all location points of the foundation pit adjacent to the existing line into corresponding risk type labels according to a comprehensive risk intensity index to complete risk identification.

[0095] Specifically, before clustering all location points of the foundation pit adjacent to the existing line into corresponding risk type labels according to a comprehensive risk intensity index to complete risk identification, the method further includes: obtaining a current settlement rate and a permeable connectivity value of each location point.

[0096] For a current location point, a spatial neighborhood radius is defined, the number of neighborhood points of the current location point is counted within the spatial neighborhood radius, and the average permeable connectivity value and the average settlement rate of all location points within the spatial neighborhood radius are calculated.

[0097] Specifically, the comprehensive risk intensity index, the peak settlement rate and the average permeable connectivity value of each class of location points are obtained.

[0098] If the comprehensive risk intensity index of a certain class of location points is greater than a first risk intensity threshold, the peak settlement rate is greater than a settlement rate threshold, and the average permeable connectivity value is greater than a permeable connectivity threshold, the certain class of location points is marked as a short-term burst risk area.

[0099] If the comprehensive risk intensity index of the certain class of location points is less than or equal to the first risk intensity threshold and greater than a second risk intensity threshold, and the peak settlement rate is less than the settlement rate threshold, the certain class of location points is marked as a medium-term settlement risk area.

[0100] If the comprehensive risk intensity index of the certain class of location points is less than or equal to the second risk intensity threshold, the certain class of location points is marked as a stable area.

[0101] Embodiment 3

[0102] The embodiment of the application further provides a storage medium storing a plurality of instructions for implementing the foundation pit construction deformation detection method adjacent to the existing line.

[0103] Optionally, in the embodiment, the storage medium can be located in any one of the computer terminals in the computer terminal group in the computer network, or in any one of the mobile terminals in the mobile terminal group.

[0104] Optionally, in the embodiment, the storage medium is configured to store program code for performing the following method steps: step 101, performing finite element simulation on deep foundation pit construction of the support structure of the foundation pit adjacent to the existing line during construction, and extracting a predicted displacement of the foundation pit adjacent to the existing line at a position point under a current permeability coefficient through a finite element model, wherein the current permeability coefficient dynamically changes with construction behavior;

[0105] Specifically, the current permeability coefficient dynamically changing with construction progress comprises:

[0106]

[0107] wherein K(x, y, z, t) is the current permeability coefficient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, K0 is an initial permeability coefficient, κ is an adjustment factor of a local permeability disturbance factor, ξ(x, y, z, t) is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, β is an adjustment factor of a local stress disturbance factor, t0 is an integral starting time, χ σ (x, y, z, τ) is the local stress disturbance factor of the construction behavior at the position point (x, y, z) of the foundation pit adjacent to the existing line at time τ.

[0108] Specifically, the local stress disturbance factor χ σ (x, y, z, τ) of the construction behavior at the position point (x, y, z) of the foundation pit adjacent to the existing line at time τ comprises:

[0109]

[0110] wherein σ(x, y, z, τ) is a current stress received by the foundation pit adjacent to the existing line at the position point (x, y, z) at time τ, and σ0(x, y, z) is an initial stress received by the foundation pit adjacent to the existing line at the position point (x, y, z).

[0111] Step 102, obtaining a measured displacement of the foundation pit adjacent to the existing line at the position point, taking a difference between the measured displacement and the predicted displacement as an error tensor, simultaneously, obtaining a pore water pressure change rate and a groundwater level gradient of the foundation pit adjacent to the existing line at the position point, and calculating a comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point in combination with the error tensor;

[0112] Specifically, the comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point calculated in combination with the error tensor comprises:

[0113]

[0114] wherein, Y(x, y, z, t) is the comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ1 is the weight of the error tensor, Δu(x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the change rate of the pore water pressure, Δp(x, y, z, t) is the change rate of the pore water pressure of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, K (x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the change rate of the pore water pressure, Δp(x, y, z, t) is the change rate of the pore water pressure of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, (x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the change rate of the pore water pressure, Δp(x, y, z, t) is the change rate of the pore water pressure of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient,

[0115] Step 103, a plurality of risk type labels are set, the risk type labels include a short-term burst risk area, a medium-term settlement risk area and a stable area, and all position points of the foundation pit adjacent to the existing line are clustered into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification.

[0116] Specifically, before all position points are clustered into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification, the current settlement rate and the permeable connectivity value of all position points are obtained.

[0117] For a current position point, a spatial neighborhood radius is defined, the number of neighborhood points of the current position point is counted within the spatial neighborhood radius, and the average permeable connectivity value and the average settlement rate of all position points within the spatial neighborhood radius are calculated, if the number of neighborhood points of the current position point exceeds a minimum number threshold, and the average permeable connectivity value is greater than or equal to an average permeable connectivity threshold, and the average settlement rate is greater than or equal to an average settlement rate threshold, the current position point is marked as a core point, and all position points within the spatial neighborhood radius are classified into the same class of position points, and all position points are traversed to divide all position points into a plurality of classes.

[0118] Specifically, the comprehensive risk intensity index, the peak settlement rate and the average permeable connectivity value of each class of position points are obtained.

[0119] If the comprehensive risk intensity index of a certain class of position points is greater than a first risk intensity threshold, the peak settlement rate is greater than a settlement rate threshold, and the average permeable connectivity value is greater than a permeable connectivity threshold, the certain class of position points is marked as a short-term burst risk area.

[0120] If the comprehensive risk intensity index of the certain type of position point is less than or equal to the first risk intensity threshold value and greater than the second risk intensity threshold value, and the peak settlement rate is less than the settlement rate threshold value, the certain type of position point is marked as a medium-term settlement risk area.

[0121] If the comprehensive risk intensity index of the certain type of position point is less than or equal to the second risk intensity threshold value, the certain type of position point is marked as a stable area.

[0122] Embodiment 4

[0123] The embodiment of the present application also provides an electronic device, including a processor and a storage medium connected with the processor, the storage medium stores a plurality of instructions, the instructions can be loaded and executed by the processor, so that the processor can execute the deformation detection method for the foundation pit construction adjacent to the existing line.

[0124] Specifically, the electronic device of the embodiment can be a computer terminal, which can include one or more processors and a storage medium.

[0125] The storage medium can be used to store software programs and modules, such as the deformation detection method for the foundation pit construction adjacent to the existing line in the embodiment of the present application, and the corresponding program instructions / modules. The processor executes various functions, applications and data processing by running the software programs and modules stored in the storage medium, that is, implements the deformation detection method for the foundation pit construction adjacent to the existing line. The storage medium can include a high-speed random storage medium, and can also include a non-volatile storage medium, such as one or more magnetic storage systems, flash memories or other non-volatile solid-state storage media. In some examples, the storage medium can further include storage media remotely arranged with respect to the processor, which can be connected to the terminal through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

[0126] The processor can call the information and application programs stored in the storage medium through the transmission system to perform the following steps: step 101, performing finite element simulation of deep foundation construction on the enclosure structure of the foundation pit adjacent to the existing line during construction, and extracting the predicted displacement of the foundation pit adjacent to the existing line at a certain position point under the current permeability coefficient through the finite element model, wherein the current permeability coefficient dynamically changes with the construction behavior;

[0127] Specifically, the current permeability coefficient dynamically changes with the construction progress, including:

[0128]

[0129] wherein K(x, y, z, t) is the current permeability coefficient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, K0 is the initial permeability coefficient, κ is the adjustment factor of the local permeability disturbance factor, ξ(x, y, z, t) is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, β is the adjustment factor of the local stress disturbance factor, t0 is the integral starting time, χ σ (x, y, z, t) is the local stress disturbance factor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t.

[0130] Specifically, the local stress disturbance factor χ σ (x, y, z, t) of the construction behavior of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t includes:

[0131]

[0132] wherein σ(x, y, z, t) is the current stress received by the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, σ0(x, y, z) is the initial stress received by the foundation pit adjacent to the existing line at the position point (x, y, z).

[0133] In step 102, the measured displacement of the foundation pit adjacent to the existing line at a position point is obtained, the difference between the measured displacement and the predicted displacement is taken as an error tensor, at the same time, the pore water pressure change rate and the groundwater level gradient of the foundation pit adjacent to the existing line at a position point are obtained, and the comprehensive risk intensity index of the foundation pit adjacent to the existing line at a position point is calculated in combination with the error tensor;

[0134] Specifically, the comprehensive risk intensity index of the foundation pit adjacent to the existing line at a position point calculated in combination with the error tensor includes:

[0135]

[0136] wherein Υ(x, y, z, t) is the comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ1 is the weight of the error tensor, Δu K (x, y, z, t) is the error tensor of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ2 is the weight of the pore water pressure change rate, Δp(x, y, z, t) is the pore water pressure change rate of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t, λ3 is the weight of the groundwater level gradient, (x, y, z, t) is the groundwater level gradient of the foundation pit adjacent to the existing line at the position point (x, y, z) at time t.

[0137] Step 103, setting multiple risk type labels, the risk type labels including: short-term burst risk area, medium-term settlement risk area and stable area, clustering all location points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification.

[0138] Specifically, before clustering all location points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification, it further includes: obtaining the current settlement rate and the permeable connectivity value of all location points.

[0139] For a current location point, a spatial neighborhood radius is defined, the number of neighborhood points of the current location point is counted within the spatial neighborhood radius, and the average permeable connectivity value and the average settlement rate of all location points within the spatial neighborhood radius are calculated, if the number of neighborhood points of the current location point exceeds a minimum number threshold, and the average permeable connectivity value is greater than or equal to an average permeable connectivity threshold, and the average settlement rate is greater than or equal to an average settlement rate threshold, the current location point is marked as a core point, and all location points within the spatial neighborhood radius are classified into the same class of location points, all location points are traversed and divided into multiple classes.

[0140] Preferably, the permeable connectivity value of all location points is obtained by the following example in the embodiment:

[0141] According to the formula:

[0142]

[0143] A three-dimensional permeability coefficient distribution field is constructed, which represents the spatial variation distribution of the permeability of each point in the fine sand layer;

[0144] Setting a hydraulic source (starting point) and an evaluation point (end point): the hydraulic source point set (such as the foundation pit periphery, the groundwater head high area): set as the starting point of the seepage path;

[0145] The evaluation point (such as the settlement monitoring point, the displacement meter point): as the end point of the path;

[0146] K -1 (x, y, z, t) is regarded as the propagation time consumption, the arrival time calculation is performed on the entire field from the water source, that is, the permeable connectivity value can be defined as:

[0147] Specifically, the comprehensive risk intensity index, the peak settlement rate and the average permeable connectivity value of each class of location points are obtained.

[0148] If the comprehensive risk intensity index of the location point of the certain type is greater than the first risk intensity threshold value, the peak subsidence rate is greater than the subsidence rate threshold value, and the average permeable connectivity value is greater than the permeable connectivity threshold value, the location point of the certain type is marked as a short-term burst risk area;

[0149] If the comprehensive risk intensity index of the location point of the certain type is less than or equal to the first risk intensity threshold value and greater than the second risk intensity threshold value, and the peak subsidence rate is less than the subsidence rate threshold value, the location point of the certain type is marked as a medium-term subsidence risk area.

[0150] If the comprehensive risk intensity index of the location point of the certain type is less than or equal to the second risk intensity threshold value, the location point of the certain type is marked as a stable area.

[0151] The above-mentioned embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0152] In the above-mentioned embodiments of the present application, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0153] In the several embodiments of the present application, it should be understood that the disclosed technology can be implemented in other ways. Of course, the above-mentioned system embodiments are only schematic, for example, the division of units is only a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, unit or module, and can be electrical or other forms.

[0154] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment scheme.

[0155] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0156] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or all or part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0157] Obviously, the above embodiments are only examples for clearly illustrating, but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments do not need to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A deformation detection method for a foundation pit construction adjacent to an existing line, characterized by, The method comprises the following steps: carrying out finite element simulation on a deep foundation pit construction of a foundation pit adjacent to an existing line and a support structure during construction, and extracting a predicted displacement of the foundation pit adjacent to the existing line at a certain position point under a current permeability coefficient through a finite element model, wherein the current permeability coefficient dynamically changes with a construction behavior; the current permeability coefficient dynamically changes with a construction progress, which comprises the following steps: ， wherein is the time is the current permeability coefficient of the foundation pit adjacent to the existing line at the position point , is the initial permeability coefficient, is the adjustment factor of the local permeability disturbance factor, is the time is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point , is the adjustment factor of the local stress disturbance factor, is the integral start time, is the time is the local stress disturbance factor of the foundation pit adjacent to the existing line at the position point due to the construction behavior. Time The construction behavior of the time The local stress disturbance factor of the foundation pit at the position point Comprising: ， wherein, is time the current stress experienced by the foundation pit adjacent to the existing line at the position point , is the initial stress experienced by the foundation pit adjacent to the existing line at the position point ; obtaining a measured displacement of the foundation pit adjacent to the existing line at the certain position point, taking a difference between the measured displacement and the predicted displacement as an error tensor, simultaneously, obtaining a pore water pressure change rate and a groundwater level gradient of the foundation pit adjacent to the existing line at the certain position point, and calculating a comprehensive risk intensity index of the foundation pit adjacent to the existing line at the certain position point in combination with the error tensor; setting a plurality of risk type labels, and clustering all position points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification.

2. The method for detecting deformation of a foundation pit construction facing an existing line according to claim 1, wherein the comprehensive risk intensity index of the foundation pit adjacent to the existing line at the certain position point is calculated in combination with the error tensor, which comprises the following steps: ， wherein, is the time is the integrated risk intensity index of the foundation pit adjacent to the existing line at the position point , is the weight of the error tensor, is the time is the error tensor of the foundation pit adjacent to the existing line at the position point , is the weight of the rate of change of pore water pressure, is the time is the rate of change of pore water pressure of the foundation pit adjacent to the existing line at the position point , is the weight of the groundwater level gradient, is the time is the groundwater level gradient of the foundation pit adjacent to the existing line at the position point .

3. The method for detecting deformation of a foundation pit construction facing an existing line according to claim 1, wherein before clustering all position points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index to complete risk identification, the following steps are further included: obtaining a current settlement rate and a permeability connectivity value of all position points; for a current position point, a spatial neighborhood radius is defined, a number of neighborhood points of the current position point is counted within the spatial neighborhood radius, and an average permeability connectivity value and an average settlement rate of all position points within the spatial neighborhood radius are calculated, if the number of neighborhood points of the current position point exceeds a minimum number threshold, the average permeability connectivity value is greater than or equal to an average permeability connectivity threshold, and the average settlement rate is greater than or equal to an average settlement rate threshold, the current position point is marked as a core point, and all position points within the spatial neighborhood radius are classified into the same class of position points, and all position points are divided into a plurality of classes by traversing all position points.

4. The method for detecting deformation of a foundation pit construction facing an existing line according to claim 3, wherein the risk type labels comprise a short-term sudden risk area, a medium-term settlement risk area and a stable area.

5. The method for detecting deformation of a foundation pit construction facing an existing line according to claim 4, wherein the method further comprises the following steps: obtaining a comprehensive risk intensity index, a peak settlement rate and the average permeability connectivity value of each class of position points; if the comprehensive risk intensity index of a certain class of position points is greater than a first risk intensity threshold, the peak settlement rate is greater than a settlement rate threshold, and the average permeability connectivity value is greater than a permeability connectivity threshold, the certain class of position points is marked as a short-term sudden risk area; if the comprehensive risk intensity index of the certain class of position points is less than or equal to the first risk intensity threshold and greater than a second risk intensity threshold, and the peak settlement rate is less than the settlement rate threshold, the certain class of position points is marked as a medium-term settlement risk area; if the comprehensive risk intensity index of the certain class of position points is less than or equal to the second risk intensity threshold, the certain class of position points is marked as a stable area.

6. A deformation detection system for a foundation pit construction adjacent to an existing line, characterized by ​ A finite element simulation module is configured to perform finite element simulation on a deep foundation pit construction of a foundation pit adjacent to an existing line and a support structure during construction, and to extract a predicted displacement of the foundation pit adjacent to the existing line at a position point under a current permeability coefficient through a finite element model, wherein the current permeability coefficient dynamically changes with a construction behavior; The current permeability coefficient dynamically changes with a construction progress, and includes: ， wherein is the time is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point at the time is the initial permeability disturbance factor is the adjustment factor of the local permeability disturbance factor is the time is the local permeability disturbance factor of the foundation pit adjacent to the existing line at the position point at the time is the adjustment factor of the local stress disturbance factor is the integral start time is the time is the local stress disturbance factor of the foundation pit adjacent to the existing line at the position point at the time Time The construction behavior of a foundation pit adjacent to an existing line at a position point The local stress disturbance factor of the foundation pit comprises: ， wherein, is time the current stress experienced by the foundation pit adjacent to the existing line at the position point , is the initial stress experienced by the foundation pit adjacent to the existing line at the position point . A risk intensity index calculation module is configured to obtain a measured displacement of the foundation pit adjacent to the existing line at the position point, to take a difference between the measured displacement and the predicted displacement as an error tensor, to obtain a pore water pressure change rate and a groundwater level gradient of the foundation pit adjacent to the existing line at the position point, and to calculate a comprehensive risk intensity index of the foundation pit adjacent to the existing line at the position point in combination with the error tensor. A risk identification module is configured to set a plurality of risk type labels, to cluster all position points of the foundation pit adjacent to the existing line into corresponding risk type labels according to the comprehensive risk intensity index, and to complete risk identification.

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