CN-121980644-A - Foundation pit rigidity analysis method based on performance design and related equipment

CN121980644ACN 121980644 ACN121980644 ACN 121980644ACN-121980644-A

Abstract

The embodiment of the application provides a foundation pit rigidity analysis method based on performance design and related equipment, belonging to the technical field of building design. The method comprises the steps of constructing a nonlinear soil pressure displacement function model corresponding to foundation pit support according to a nonlinear relation between support structure displacement and soil pressure, deriving the nonlinear soil pressure displacement function model to obtain a nonlinear stiffness model of foundation soil, dispersing a foundation pit support structure into beam units, simplifying surrounding foundation soil into a distributed spring system coupled with beam unit nodes to construct a spring generalized finite element model, calculating updated soil pressure distribution according to the node displacement and the nonlinear soil pressure displacement function model, and outputting final support structure internal force, deformation and soil pressure distribution results. The embodiment of the application can realize more accurate and more reliable foundation pit supporting performance design and provides a key technical support for safety evaluation of foundation pit supporting performance.

Inventors

WU YANG
CHEN XIANZHEN
HUANG JIE
YANG ZEPING
WU LIANG
LI SHUBIN
CAO ZHIPENG
ZHENG LIANXIAO
WANG CHENCHAO
Shao Zhenxin

Assignees

广州大学
中铁十四局集团有限公司
厦门路桥工程投资发展有限公司

Dates

Publication Date: 20260505
Application Date: 20251226

Claims (10)

1. The foundation pit rigidity analysis method based on the performance design is characterized by comprising the following steps of: constructing a nonlinear soil pressure displacement function model corresponding to foundation pit support according to the nonlinear relation between the displacement of the support structure and the soil pressure, wherein the nonlinear soil pressure displacement function model is used for describing a continuously-conductive analytical function model of the soil pressure changing along with the displacement in a non-limiting state; deriving the nonlinear earth pressure displacement function model to obtain a nonlinear stiffness model of foundation soil; dispersing the foundation pit supporting structure into beam units, simplifying surrounding foundation soil mass into a distributed spring system coupled with beam unit nodes to construct a spring generalized finite element model, wherein the stiffness of the spring system is defined by the nonlinear stiffness model; Taking static soil pressure as an initial load, and solving by combining the spring generalized finite element model to obtain node displacement of the support structure; And calculating updated soil pressure distribution according to the node displacement and the nonlinear soil pressure displacement function model, updating initial load and rigidity in the spring generalized finite element model according to the updated and corrected soil pressure and the corresponding nonlinear rigidity model if the updated soil pressure exceeds the limit soil pressure, carrying out next iteration solution, and outputting final support structure internal force, deformation and soil pressure distribution results for performance design and safety evaluation of foundation pit support.
2. The method of claim 1, wherein the nonlinear earth pressure displacement function model is a piecewise function constructed based on a Sigmoid function, and wherein the nonlinear earth pressure displacement function model has a formula: wherein the displacement is greater than or equal to zero, which is the passive non-limiting soil pressure Displacement less than zero is the active non-limiting earth pressure , In order to support the displacement of the structure, And The extreme displacements of the passive and active regions respectively, And The non-linear parameters of the passive and active regions respectively, And The passive and active soil pressure coefficients respectively, Is the weight of the soil body, To calculate depth.
3. The method of claim 2, wherein prior to constructing the non-linear earth pressure displacement function model for the foundation pit support based on the non-linear relationship between support structure displacement and earth pressure, the method further comprises: Acquiring p-y curve discrete data points representing soil body mechanical behaviors, and carrying out parameter inversion analysis on the analytical function model by utilizing a global optimization algorithm so as to fit the p-y curve data, thereby determining nonlinear parameters And Is a value of (2).
4. The method of claim 1, wherein the overall balance equation of the spring generalized finite element model is expressed as: Wherein, the To support the stiffness matrix of the structural beam unit, For the foundation spring stiffness matrix assembled by the nonlinear stiffness model of the foundation soil, As the displacement vector of the node, Is a node load vector.
5. The method of claim 4, wherein the solving, with the static soil pressure as an initial load, in combination with the spring generalized finite element model, results in the node displacement of the support structure, comprising: And converting the static soil pressure distribution into equivalent node load acting on the beam unit nodes, taking the equivalent node load as initial load of first iteration, and solving by combining the spring generalized finite element model to obtain the node displacement of the support structure.
6. The method of claim 1, wherein updating the initial load and stiffness in the spring generalized finite element model based on the updated and corrected soil pressure and the corresponding nonlinear stiffness model if it is determined that the updated soil pressure exceeds a limit soil pressure comprises: Judging whether the target soil pressure calculated by the current support structure displacement exceeds the corresponding limit soil pressure according to the limit displacement of the passive region and the active region in the nonlinear soil pressure displacement function model and the limit soil pressure; and if the target soil pressure calculated by the current support structure displacement exceeds the corresponding limit soil pressure, correcting the target soil pressure to the corresponding limit soil pressure according to the target.
7. The method according to any one of claims 1 to 6, further comprising: Responding to design parameters corresponding to foundation pit supporting engineering input by a user, wherein the design parameters comprise supporting structure parameters, soil layer distribution parameters, soil body mechanical parameters, excavation working conditions and supporting setting information, the supporting structure parameters comprise elastic modulus and section moment of inertia, and the soil body mechanical parameters comprise soil body weight, cohesive force, internal friction angle, static soil pressure coefficient, active and passive soil pressure coefficient and limit displacement And Nonlinear parameters of active region And non-linear parameters of the passive region 。 And constructing a nonlinear relation between the displacement of the supporting structure and the soil pressure according to the design parameters corresponding to the foundation pit supporting engineering.
8. A performance design-based foundation pit stiffness analysis device, the device comprising: The model construction module is used for constructing a nonlinear soil pressure displacement function model corresponding to the foundation pit support according to the nonlinear relation between the displacement of the support structure and the soil pressure, wherein the nonlinear soil pressure displacement function model is used for describing a continuously-conductive analytical function model of the soil pressure changing along with the displacement in a non-limiting state; the model derivation module is used for deriving the nonlinear soil pressure displacement function model to obtain a nonlinear stiffness model of foundation soil; The spring construction module is used for dispersing the foundation pit supporting structure into beam units and simplifying surrounding foundation soil into a distributed spring system coupled with beam unit nodes so as to construct a spring generalized finite element model, wherein the rigidity of the spring system is defined by the nonlinear rigidity model; The model solving module is used for solving by taking the static soil pressure as an initial load and combining the spring generalized finite element model to obtain the node displacement of the supporting structure; And the parameter updating module is used for calculating updated soil pressure distribution according to the node displacement and the nonlinear soil pressure displacement function model, updating initial load and rigidity in the spring generalized finite element model according to the updated and corrected soil pressure and the corresponding nonlinear rigidity model if the updated soil pressure exceeds the limit soil pressure, carrying out next iteration solution, and outputting final support structure internal force, deformation and soil pressure distribution results for performance design and safety evaluation of foundation pit support.
9. A computer device, characterized in that it comprises a memory storing a computer program and a processor implementing the method according to any one of claims 1 to 7 when executing the computer program.
10. A computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the method of any one of claims 1 to 7.

Description

Foundation pit rigidity analysis method based on performance design and related equipment Technical Field The application relates to the technical field of building design, in particular to a foundation pit rigidity analysis method based on performance design and related equipment. Background In the related technology, along with the shortage of land resources and the deterioration of traffic environment caused by the rapid expansion of cities, sustainable development and utilization of underground space have become key ways for coping with urban diseases, wherein deep and large foundation pit engineering is taken as a necessary trend of urban construction, the safety control core is a key scientific problem of complex interaction mechanism of supporting structures and surrounding soil bodies, particularly the characteristic that soil pressure is nonlinear adjusted along with structural deformation, and accurate analysis and performance control must be realized by a solid numerical simulation method. Disclosure of Invention The main purpose of the embodiment of the application is to provide a foundation pit rigidity analysis method and related equipment based on performance design, which can realize more accurate and more reliable foundation pit support performance design and provide a key technical support for safety evaluation of foundation pit support performance. In order to achieve the above objective, an aspect of the embodiments of the present application provides a method for analyzing rigidity of a foundation pit based on performance design, where the method includes: constructing a nonlinear soil pressure displacement function model corresponding to foundation pit support according to the nonlinear relation between the displacement of the support structure and the soil pressure, wherein the nonlinear soil pressure displacement function model is used for describing a continuously-conductive analytical function model of the soil pressure changing along with the displacement in a non-limiting state; deriving the nonlinear earth pressure displacement function model to obtain a nonlinear stiffness model of foundation soil; dispersing the foundation pit supporting structure into beam units, simplifying surrounding foundation soil mass into a distributed spring system coupled with beam unit nodes to construct a spring generalized finite element model, wherein the stiffness of the spring system is defined by the nonlinear stiffness model; Taking static soil pressure as an initial load, and solving by combining the spring generalized finite element model to obtain node displacement of the support structure; And calculating updated soil pressure distribution according to the node displacement and the nonlinear soil pressure displacement function model, updating initial load and rigidity in the spring generalized finite element model according to the updated and corrected soil pressure and the corresponding nonlinear rigidity model if the updated soil pressure exceeds the limit soil pressure, carrying out next iteration solution, and outputting final support structure internal force, deformation and soil pressure distribution results for performance design and safety evaluation of foundation pit support. In some embodiments, the nonlinear earth pressure displacement function model is a piecewise function constructed based on a Sigmoid function, and the nonlinear earth pressure displacement function model is formulated as: wherein the displacement is greater than or equal to zero, which is the passive non-limiting soil pressure Displacement less than zero is the active non-limiting earth pressure,In order to support the displacement of the structure,AndThe extreme displacements of the passive and active regions respectively,AndThe non-linear parameters of the passive and active regions respectively,AndThe passive and active soil pressure coefficients respectively,Is the weight of the soil body,To calculate depth. In some embodiments, before the constructing a nonlinear earth pressure displacement function model corresponding to the foundation pit support according to the nonlinear relation between the displacement of the support structure and the earth pressure, the method further includes: Acquiring p-y curve discrete data points representing soil body mechanical behaviors, and carrying out parameter inversion analysis on the analytical function model by utilizing a global optimization algorithm so as to fit the p-y curve data, thereby determining nonlinear parameters AndIs a value of (2). In some embodiments, the overall balance equation of the spring generalized finite element model is expressed as: Wherein, the To support the stiffness matrix of the structural beam unit,For the foundation spring stiffness matrix assembled by the nonlinear stiffness model of the foundation soil,As the displacement vector of the node,Is a node load vector. In some embodiments, the solving, with the static soil pressure as