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CN-122020829-A - Intelligent monitoring test method and equipment for foundation pit

CN122020829ACN 122020829 ACN122020829 ACN 122020829ACN-122020829-A

Abstract

The invention belongs to the technical field of foundation pit engineering monitoring, and relates to an intelligent foundation pit monitoring test method and equipment, wherein the mechanical response parameters of a support and the mechanical response parameters of a medium are constructed into a time sequence aligned multi-physical-quantity monitoring sequence, and a mechanical transmission path is established by combining a space geometric relationship, so that originally scattered monitoring data can be brought into the same transmission link for analysis; the support member-medium coupling response characteristic matrix is constructed by extracting the load transfer coefficient and the constraint stiffness characteristic of each constraint node, a unified characteristic basis is provided for the establishment of a theoretical transfer function, a corresponding integral theoretical response envelope curve is established based on the theoretical transfer function at each constraint node, false alarm or missing report caused by the dependence on a fixed threshold value is avoided, and the abnormal cause is determined by the support member problem, the medium change problem or the support member and medium coupling failure problem through the overrun combination state of the support member response deviation amount and the medium mechanical response deviation amount.

Inventors

  • GAO CHUNJUN

Assignees

  • 合肥工大共达工程检测试验有限公司

Dates

Publication Date
20260512
Application Date
20260416

Claims (10)

  1. 1. The intelligent foundation pit monitoring test method is characterized by comprising the following steps of: acquiring mechanical response parameters of the support and mechanical response parameters of the medium, and constructing a multi-physical-quantity monitoring sequence with aligned time sequences; Based on the space geometric relation between the foundation pit supporting structure and the medium, a mechanical transmission path is established, and the load transmission coefficient and the constraint stiffness characteristic of each constraint node are extracted; fusing the multi-physical quantity monitoring sequence, the load transfer coefficient and the constraint stiffness characteristic to construct a support-medium coupling response characteristic matrix; determining theoretical transfer functions at all constraint nodes according to the mechanical transfer paths, and constructing an integral theoretical response envelope curve of the mechanical response of the support and the medium in a normal state; Obtaining actually measured mechanical response vectors of all constraint nodes in the support-medium coupling response characteristic matrix at all sampling moments, comparing the actually measured mechanical response vectors with corresponding integral theoretical response envelope curves respectively, and determining support response deviation and medium mechanical response deviation; and determining that the abnormality is caused by a support member problem, a medium change problem or a support member and medium coupling failure problem according to the support member response deviation amount and the medium mechanical response deviation amount.
  2. 2. The intelligent foundation pit monitoring test method according to claim 1, wherein the process of establishing the mechanical transmission path comprises the following steps: constructing a space geometric model according to the space position parameters and the geometric form parameters of the support, and constructing a layered space model according to the space distribution parameters and the interface position parameters of the medium; Carrying out space superposition analysis on the space geometric model and the layered space model, and taking an intersection interval of the support piece and the medium in space as a contact section; and determining the effective action boundary of each contact section according to the stress mode of the support piece in each contact section and the relative position relation between the support piece and the adjacent rock and soil layer.
  3. 3. The method for intelligent monitoring and testing of foundation pit according to claim 2, wherein the process of establishing the mechanical transmission path further comprises: Calculating the change rate of the strain difference value in each contact section along the extension direction of the support, determining a position with the change rate exceeding a preset threshold as a position with abrupt change of the stress state, and determining the position as a constraint position; acquiring space coordinates corresponding to each constraint part as candidate constraint nodes, and determining the main stress direction of each candidate constraint node according to the load acting direction; arranging all candidate constraint nodes according to the sequence from small to large burial depth, determining the candidate constraint node with the smallest burial depth as a load action starting node, acquiring the connecting line direction between the current node and the candidate next node, determining that a force transmission relation exists between the current node and the candidate next node if the included angle between the current node and the main stress direction of the current node is not more than 90 degrees, determining that the direction from the current node to the candidate next node is a transmission direction, skipping the candidate next node if the included angle is more than 90 degrees, and continuously judging the next candidate constraint node; and connecting all candidate constraint nodes confirmed to have a force transmission relation according to the transmission direction to form a mechanical transmission path.
  4. 4. The intelligent foundation pit monitoring test method according to claim 1, wherein the process of extracting the load transfer coefficient and the constraint stiffness characteristics of each constraint node is as follows: The mechanical response parameters of the support piece comprise a strain value and a displacement value of the support piece, the mechanical response parameters of the medium comprise a soil pressure value and a deep level displacement value of the corresponding medium, and the parameters are subjected to time sequence matching; Calculating the ratio of the strain value of the support piece at each constraint node to the pressure value of the medium soil at the same moment, and taking the median of the ratio at a plurality of moments as a load transfer coefficient; Calculating the relative displacement difference between the support member displacement value and the medium deep level horizontal displacement value at the same moment at each constraint node, and determining the interaction force between the support member and the medium according to the node bending moment and the distribution counterforce intensity obtained by converting the support member strain value; Constructing a force-displacement relation curve by using the interaction force and the relative displacement difference, calculating the curvature of the force-displacement relation curve, and extracting the relative displacement difference corresponding to the maximum value of the curvature as inflection point displacement; dividing the intervals by taking inflection point displacement as a boundary, and calculating the average value of the instantaneous rigidity values in each interval to obtain the corresponding constraint rigidity characteristics.
  5. 5. The intelligent foundation pit monitoring test method according to claim 3, wherein the process of constructing the support-medium coupling response characteristic matrix is as follows: Based on the positions of the constraint nodes in the mechanical transmission path, performing node matching on the multi-physical quantity monitoring sequence to obtain node monitoring subsequences corresponding to the constraint nodes; extracting mechanical response parameters and medium mechanical response parameters of the support at each sampling moment according to a preset sampling period; Mapping the load transfer coefficient and the constraint stiffness characteristic of each constraint node to a corresponding node monitoring subsequence, and performing time sequence alignment with the mechanical response parameters of the support piece and the mechanical response parameters of the medium at each sampling time; Normalizing the support mechanical response parameters, the medium mechanical response parameters, the load transfer coefficients and the constraint stiffness characteristics after the time sequence alignment to generate coupling feature vectors of all constraint nodes at all sampling moments; and (3) arranging the coupling feature vectors according to the time sequence and the node sequence of the mechanical transmission path to construct a support-medium coupling response feature matrix.
  6. 6. The intelligent foundation pit monitoring test method of claim 5, wherein the determining the theoretical transfer function at each constraint node comprises: Extracting coupling feature vectors of all constraint nodes in a normal state from a support-medium coupling response feature matrix, and constructing a sample set; And determining upstream associated nodes of all constraint nodes according to the node sequence, taking support mechanical response parameters and medium mechanical response parameters corresponding to the upstream associated nodes as input items, taking support response vectors and medium mechanical response vectors corresponding to the current nodes as output items, and respectively establishing a support theoretical transfer function and a medium theoretical transfer function by combining load transfer coefficients and constraint stiffness characteristics of the current nodes.
  7. 7. The intelligent foundation pit monitoring test method of claim 6, wherein the process of establishing the theoretical response envelope curve of the mechanical response of the support and the medium in the normal state is as follows: Based on theoretical transfer functions at all constraint nodes, calculating theoretical mechanical response parameters of the support and theoretical mechanical response parameters of the medium at all sampling moments in a normal state, and forming a theoretical mechanical response parameter sequence of the support and a theoretical mechanical response parameter sequence of the medium respectively; Counting the two theoretical mechanical response parameter sequences corresponding to each constraint node, respectively taking the maximum value and the minimum value in the theoretical mechanical response parameter sequences of the support piece to construct a theoretical response envelope of the support piece at each constraint node, and taking the maximum value and the minimum value in the theoretical mechanical response parameter sequences of the medium to construct a theoretical response envelope of the medium at each constraint node; And combining theoretical response envelopes corresponding to the constraint nodes according to the node sequence to respectively form theoretical response envelopes of the whole support and the whole medium.
  8. 8. The intelligent foundation pit monitoring test method of claim 7, wherein the process of determining the deviation of the response of the support member and the deviation of the mechanical response of the medium is as follows: acquiring a support actual measurement response vector and a medium mechanics actual measurement response vector of each constraint node in a support-medium coupling response feature matrix at each sampling moment, and comparing the support actual measurement response vector and the medium mechanics actual measurement response vector with corresponding integral theoretical response envelope curves respectively; Judging whether each component of the support member actual measurement response vector and the medium mechanics actual measurement response vector is positioned in a range defined by a corresponding integral theoretical response envelope curve or not respectively; if there is a component exceeding the range of the corresponding integral theoretical response envelope, calculating the difference between each overrun component and the corresponding envelope boundary value, and accumulating the difference between each overrun component to be used as the corresponding support response deviation or the medium mechanical response deviation.
  9. 9. The intelligent foundation pit monitoring test method of claim 8, wherein the determining of the cause of the abnormality is: If the response deviation amount of the support is larger than zero and the response deviation amount of the dielectric mechanics is equal to zero, judging that the abnormality is the problem of the support; if only the medium mechanical response deviation is greater than zero and the support response deviation is equal to zero, judging that the abnormal cause is a medium change problem; If both are greater than zero, the abnormality is determined to be due to failure of the support and the medium coupling.
  10. 10. Foundation ditch intelligent monitoring test equipment, its characterized in that includes: the acquisition and construction module acquires the mechanical response parameters of the support and the mechanical response parameters of the medium and constructs a multi-physical-quantity monitoring sequence with aligned time sequences; The path characteristic module is used for establishing a mechanical transmission path based on the space geometric relation between the foundation pit supporting structure and the medium and extracting the load transmission coefficient and the constraint stiffness characteristic of each constraint node; The matrix construction module is used for fusing the multi-physical quantity monitoring sequence, the load transfer coefficient and the constraint stiffness characteristic to construct a support-medium coupling response characteristic matrix; The envelope construction module is used for determining theoretical transfer functions at all constraint nodes according to the mechanical transfer paths and constructing an integral theoretical response envelope of the mechanical response of the support and the medium in a normal state; the deviation decomposition module is used for obtaining actual measurement response vectors corresponding to all constraint nodes in the support-medium coupling response characteristic matrix at all sampling moments and comparing the actual measurement response vectors with corresponding integral theoretical response envelope curves respectively to determine the response deviation amount of the support and the mechanical response deviation amount of the medium; And the abnormality diagnosis module is used for determining that the abnormality is caused by the support member problem, the medium change problem or the support member and medium coupling failure problem according to the support member response deviation value and the medium mechanical response deviation value.

Description

Intelligent monitoring test method and equipment for foundation pit Technical Field The invention belongs to the technical field of foundation pit engineering monitoring, and particularly relates to an intelligent foundation pit monitoring test method and equipment. Background In the process of excavating a foundation pit, the supporting piece bears lateral soil pressure, water pressure and construction disturbance load, and the stress release, displacement evolution and interface contact state of a medium can reversely influence the stress and deformation of the supporting piece, so that how to continuously monitor and accurately judge the coupling response of a foundation pit supporting system and the medium becomes an important technical problem for guaranteeing construction safety and controlling engineering risks. Currently, foundation pit safety monitoring is mainly divided into two types, namely supporting structure body monitoring and peripheral medium monitoring, in the prior art, multisource sensing units are generally arranged on supporting members such as supporting piles, anchor rods and underground continuous walls, and monitoring results are respectively compared with preset early warning thresholds so as to judge whether the foundation pit is in a safety state. However, the prior art has the following limitations that 1, the prior art generally processes the mechanical response of the supporting structure and the mechanical response of the medium separately, and the quantitative association based on the mechanical transmission path between the mechanical response and the mechanical response of the supporting structure cannot be established, so that a complete mechanical process reflecting the transmission of the load from the medium to the supporting structure and the layer-by-layer transmission inside the supporting structure is difficult to form. 2. The existing monitoring method mainly uses overrun judgment of a single measuring point or a single physical quantity as a main basis, and the transmission relation between the response of the support piece and the response of the medium is not considered sufficiently, so that although an abnormal phenomenon can be found, whether the abnormality is derived from the state change of the support piece body and the medium or the coupling relation between the support piece body and the medium is unstable is difficult to distinguish. Disclosure of Invention In order to overcome the defects in the background technology, the embodiment of the invention provides a foundation pit intelligent monitoring test method and equipment, which can effectively solve the problems related to the background technology. The invention aims at realizing the technical scheme that the foundation pit intelligent monitoring test method comprises the steps of obtaining a mechanical response parameter of a support part and a mechanical response parameter of a medium, and constructing a multi-physical-quantity monitoring sequence with aligned time sequences. Based on the space geometrical relationship between the foundation pit supporting structure and the medium, a mechanical transmission path is established, and the load transmission coefficient and the constraint stiffness characteristic of each constraint node are extracted. And (5) fusing the multi-physical-quantity monitoring sequence, the load transfer coefficient and the constraint stiffness characteristic to construct a support-medium coupling response characteristic matrix. And determining theoretical transfer functions at all constraint nodes according to the mechanical transfer paths, and constructing an integral theoretical response envelope curve of the mechanical response of the support and the medium in a normal state. And obtaining actual measurement mechanical response vectors of all constraint nodes in the support-medium coupling response characteristic matrix at all sampling moments, comparing the actual measurement mechanical response vectors with corresponding integral theoretical response envelopes respectively, and determining the support response deviation and the medium mechanical response deviation. And determining that the abnormality is caused by a support member problem, a medium change problem or a support member and medium coupling failure problem according to the support member response deviation amount and the medium mechanical response deviation amount. On the other hand, the invention provides intelligent monitoring test equipment for a foundation pit, which comprises an acquisition construction module, a path characteristic module, a matrix construction module, an envelope construction module, a deviation decomposition module and an abnormality diagnosis module. The acquisition construction module is respectively connected with the path characteristic module and the matrix construction module, the path characteristic module is connected with the matrix construction module, the matrix constr