Testing device for simulating cascade collapse of adjacent underground structures caused by foundation pit collapse

Abstract

The utility model discloses a test device for simulating cascade collapse of adjacent underground structures caused by foundation pit collapse, which relates to the field of foundation pit indoor model tests and comprises a model box filled with sandy soil, a foundation pit model and an underground structure model arranged in the model box, and a data monitoring system arranged in the model box. According to the utility model, the foundation pit model and the underground structure model are arranged to simulate the foundation pit and the underground structure respectively, and the foundation pit model is collapsed and the adjacent underground structure model is collapsed by excavating sandy soil, so that the transient process of collapse of the foundation pit and even cascade collapse of the adjacent underground structure is really simulated; technical innovation from deformation research of a traditional model test to transient stability problem research in cascade collapse accidents is realized, hidden dangers in actual engineering can be analyzed and researched through data information obtained by a data monitoring system, and effective data support is provided for disaster prevention.

Description

Technical Field

[0001] The utility model relates to the technical field of indoor model tests for foundation pits, and particularly relates to a test device for simulating the cascading collapse of adjacent underground structures caused by the collapse of a foundation pit. Background Technique

[0002] The overburden of underground space structures is relatively thin, and the cross-section is mainly rectangular, and the cross-sectional size is similar to its length. With the development of underground space, there are more and more large underground space structures near foundation pit (groups), and they often face complex engineering geological and hydrogeological conditions, harsh surrounding environments, and extreme disaster risks such as rainstorms and floods. Once a certain foundation pit or underground structure in the system is damaged, it will cause different degrees of changes in the soil restraint conditions around the adjacent structures. In severe cases, it may cause excessive deformation, even collapse or toppling of the adjacent above-ground structures, forming a chain of damage to the engineering system.

[0003] Due to the poor integrity of the foundation pit support structure, once an accident occurs, the risk of large-scale damage or even continuous collapse caused by local damage is relatively high. Therefore, the pre-disaster system robustness is low. In addition, the foundation pit project is buried deep underground. Once local damage occurs and an accident is caused, the damage develops rapidly, and it is extremely difficult to carry out emergency rescue and control during the development of the disaster, and the intervention during the disaster is poor. In the system formed by the foundation pit (group) and the adjacent underground project, when there is a risk of continuous collapse caused by local damage in a certain foundation pit, it is necessary to clarify whether the collapse of this foundation pit will cause damage or even cascading collapse to the adjacent foundation pits or existing underground structures, and at the same time, it is necessary to consider the influence of the adjacent foundation pits and existing structures on the continuous collapse disaster mechanism of this foundation pit. However, under the existing circumstances, the mechanism of continuous collapse disaster of foundation pits or existing underground structures is not clear, and there is a lack of corresponding data information for analysis, resulting in a lack of effective means for prevention in this regard and causing relatively large economic losses. Content of the Utility Model

[0004] The purpose of the utility model is to provide a test device for simulating the cascading collapse of adjacent underground structures caused by the collapse of a foundation pit, so as to solve the technical problems put forward in the above background technique.

[0005] To solve the above technical problems, the utility model specifically provides the following technical solutions:

[0006] A test device for simulating the cascading collapse of adjacent underground structures caused by the collapse of a foundation pit, including a model box filled with sand, a foundation pit model buried in the sand in the model box for simulating a foundation pit, and an underground structure model for simulating an underground structure, and a data monitoring system for monitoring and collecting data during the process of large deformation or even collapse of the foundation pit model and the underground structure model is arranged in the model box.

[0007] As a preferred embodiment of the present utility model, the foundation pit model includes two diaphragm wall models and one foundation pit support model. Each diaphragm wall model includes side plates arranged in sequence along a straight line in the model box, and adjacent two side plates are connected by an H-shaped joint; the foundation pit support model includes a plurality of support pipes, and both ends of the plurality of support pipes are respectively connected to the two diaphragm wall models.

[0008] As a preferred embodiment of the present utility model, the underground structure model includes two side walls. Each side wall includes a plurality of wall plates arranged in sequence along a straight line, and adjacent two wall plates are connected by a joint.

[0009] As a preferred embodiment of the present utility model, a steel beam is provided at the inner top of the model box. A plurality of positioning clips are provided on the steel beam, and the plurality of positioning clips are used to respectively position the side wall and the diaphragm wall model during installation.

[0010] As a preferred embodiment of the present utility model, a plurality of bolt holes are evenly distributed on the steel beam and the top of the model box, and the steel beam is connected to the bolt holes on the model box by bolts.

[0011] As a preferred embodiment of the present utility model, the data monitoring system includes a plurality of strain gauges, a plurality of earth pressure cells, a plurality of displacement gauges, a plurality of laser displacement sensors and a PIV industrial camera. The plurality of strain gauges are respectively arranged on the opposite side walls of the two diaphragm wall models, at both ends of the plurality of support pipes and on the two side walls. A metal rectangular bar is provided at the top of each wall plate. Among them, the plurality of displacement gauges are arranged vertically on the metal rectangular bar to calculate the inclination angle of the side wall of the underground structure, and the remaining plurality of displacement gauges are respectively arranged on the tops of the plurality of side plates and the tops of the plurality of wall plates. The plurality of earth pressure cells are respectively arranged on the opposite side walls of the two diaphragm wall models and the opposite side walls of the two side walls. The plurality of laser displacement sensors are all arranged on the steel beam. An observation window is provided on one side of the model box, and the PIV industrial camera is arranged outside the model box and in front of the observation window.

[0012] The present utility model has the following beneficial effects compared with the prior art:

[0013] The present utility model respectively simulates the foundation pit and the underground structure by setting the foundation pit model and the underground structure model, and causes the collapse of the foundation pit model and the subsequent collapse of the adjacent underground structure model by excavating sand, truly simulating the transient process of the foundation pit collapse and even the cascading collapse of the adjacent underground structure, realizing the technological innovation from the deformation research of traditional model tests to the research on transient stability problems in cascading collapse accidents. Moreover, the data information obtained by the data monitoring system can analyze and study the hidden dangers in actual projects, providing effective data support for disaster prevention. Brief Description of the Drawings

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0015] Figure 1 It is a schematic structural diagram of a test device for simulating the cascading collapse of adjacent underground structures caused by the collapse of a foundation pit in the present invention;

[0016] Figure 2 It is a schematic structural diagram of the foundation pit model of the present invention;

[0017] Figure 3 It is a schematic structural diagram of the underground structure model of the present invention;

[0018] Figure 4 It is a front structural diagram of a test device for simulating the cascading collapse of adjacent underground structures caused by the collapse of a foundation pit in the present invention.

[0019] The labels in the figure are respectively represented as follows:

[0020] 1, side plate; 2, support pipe; 3, wall panel; 4, joint; 5, metal rectangular bar; 6, H-shaped joint; 7, strain gauge; 8, earth pressure cell; 9, displacement meter; 10, model box; 11, laser displacement sensor; 12, PIV industrial camera. Specific embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] The following will first explain the concepts involved in this application with reference to the drawings. It should be noted here that the explanations of the following concepts are only for making the content of this application easier to understand, and do not represent a limitation on the protection scope of this application; at the same time, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0023] Such as Figures 1 to 4As shown in the figure, the utility model provides a test device for simulating the cascading collapse of adjacent underground structures caused by the collapse of a foundation pit, which includes a model box 10 filled with sand. Inside the model box 10, there is a foundation pit model buried in the sand for simulating the foundation pit and an underground structure model for simulating the underground structure. Inside the model box 10, there is a data monitoring system for monitoring and collecting data during the process of large deformation or even collapse of the foundation pit model and the underground structure model.

[0024] When conducting the test of the utility model, the model box 10 is placed at a predetermined position, and the relevant structural parameters of the foundation pit model and the underground structure model are determined according to the actual engineering situation. Then, the foundation pit model and the underground structure model are buried in the sand inside the model box 10. Subsequently, the sand inside the model box 10 is excavated until over-excavation of the sand causes the collapse of the foundation pit model, and the data monitoring system is used to monitor and collect the data information of the cascading collapse of the adjacent underground structure caused by the collapse of the foundation pit model. It not only truly simulates the transient process of the foundation pit collapse and even the cascading collapse of the adjacent underground structure, realizes the technological innovation from the deformation research of traditional model tests to the research on transient stability problems in cascading collapse accidents, but also the data information obtained through the data monitoring system can be used to analyze and study the potential hazards in actual engineering, providing effective data support for disaster prevention.

[0025] In this embodiment, the foundation pit model and the underground structure model are equivalently designed according to the strength and stiffness of the actual project to ensure the effectiveness of the simulation test results.

[0026] The foundation pit model includes two diaphragm wall models and one foundation pit support model. Each diaphragm wall model includes side plates 1 arranged in sequence along a straight line inside the model box 10, and adjacent two side plates 1 are connected by H-shaped joints 6; the foundation pit support model includes a plurality of support pipes 2, and both ends of the plurality of support pipes 2 are respectively connected to the two diaphragm wall models.

[0027] The foundation pit model is composed of two diaphragm wall models and one foundation pit support model. Both ends of the plurality of support pipes 2 of the foundation pit support model respectively support two opposite side plates 1 to ensure the stability of the foundation pit model.

[0028] In this embodiment, the side plates 1 are aluminum plates, and the support pipes 2 are PVC pipes. The cross-sectional dimensions of the aluminum plates and PVC pipes are equivalently designed according to the flexural stiffness and compressive stiffness of the actual project to reflect the physical characteristics in the actual project, so that when simulating working conditions such as over-excavation, it can cause the overturning failure of the diaphragm wall, thereby triggering the collapse of the foundation pit.

[0029] The underground structure model includes two side walls, and each side wall includes a plurality of wall panels 3 arranged in sequence along a straight line, and adjacent two wall panels 3 are connected by joints 4.

[0030] The underground structure model is formed by two side walls, and each side wall is formed by connecting multiple wall panels 3 through joints 4. In this embodiment, the wall panel 3 is a PVC panel and the joint 4 is a PVC joint. The cross-sectional dimensions of the PVC panel are designed in accordance with the principles of equivalent flexural stiffness and equivalent compressive stiffness to reflect the physical characteristics in actual engineering.

[0031] Steel beams are provided on the inner top of the model box 10, and multiple positioning clips are provided on the steel beams, and the multiple positioning clips are used to respectively position the side wall and the diaphragm wall model during installation.

[0032] By setting the positioning clips to position the side wall and the diaphragm wall model during installation, the accuracy of the placement of the foundation pit model and the underground structure model during installation can be ensured after the steel beam is fixed on the model box 10. The positioning clip can be a carpenter's clamp and can be removed after installation.

[0033] Multiple bolt holes are evenly distributed on the steel beam and the top of the model box 10, and the steel beam is connected to the bolt holes on the model box 10 through bolts.

[0034] By setting multiple bolt holes, the position of the steel beam on the model box 10 can be adjusted, realizing the precise adjustment of the positions of the foundation pit model and the underground structure model, thereby adjusting the spacing between the foundation pit model and the underground structure model. Different spacing foundation pit models and underground structure models can be tested and simulated to obtain more test data, so as to provide data for reference for the risk assessment and prevention and control of related projects.

[0035] The data monitoring system includes multiple strain gauges 7, multiple earth pressure cells 8, multiple displacement gauges 9, multiple laser displacement sensors 11 and a PIV industrial camera 12. The multiple strain gauges 7 are respectively arranged at both ends of the two diaphragm wall models, multiple support pipes 2 and the two side walls. A metal rectangular strip 5 is arranged at the top of each wall panel 3. Among them, the multiple displacement gauges 9 are arranged vertically on the metal rectangular strip 5 to calculate the inclination angle of the side wall of the underground structure. The remaining multiple displacement gauges 9 are respectively arranged at the tops of multiple side plates 1 and the tops of multiple wall panels 3. The multiple earth pressure cells 8 are respectively arranged on the opposite side walls of the two diaphragm wall models and the opposite side walls of the two side walls. The multiple laser displacement sensors 11 are all arranged on the steel beam. An observation window is arranged on one side of the model box 10, and the PIV industrial camera 12 is arranged outside the model box 10 and in front of the observation window.

[0036] The strain gauge 7 is used to monitor the bending moment of the diaphragm wall model and the side wall bending moment of the underground structure during the excavation and collapse of the foundation pit, and to monitor the change in the axial force of the support pipe 2. The earth pressure cell 8 is used to monitor the change in earth pressure in the active and passive zones and the change in earth pressure on the side wall and on the side away from the foundation pit model during the excavation and collapse of the foundation pit. The displacement gauge 9 is used to monitor the horizontal displacement at the top of the diaphragm wall model and the change in the inclination angle of the side wall, as well as the uneven settlement of the underground structure model after the collapse of the adjacent foundation pit model. The displacement gauge 9 is arranged along the length direction of the model box 10. The laser displacement sensor 11 is used to monitor the settlement of the surface soil during the cascading collapse of the adjacent underground structure caused by the collapse of the foundation pit. The PIV industrial camera 12 is used to observe the formation process of the slip surface of the deep soil during the cascading collapse of the adjacent underground structure caused by the collapse of the foundation pit.

[0037] Since it is a two-dimensional plane strain problem along the length direction of the foundation pit in the test model, the strain gauge 7 used to measure the bending moment of the side wall of the diaphragm wall model and the underground structure model can be arranged only in the middle of the foundation pit model.

[0038] The above-described embodiments and / or implementation manners are only used to illustrate the preferred embodiments and / or implementation manners for realizing the technology of the present invention, and do not impose any form of limitation on the implementation manners of the technology of the present invention. Any person skilled in the art, without departing from the scope of the technical means disclosed in the content of the present invention, may make some modifications or changes to other equivalent embodiments, but should still be regarded as the same technology or embodiment as the present invention in essence.

[0039] In this article, specific examples are used to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. The above is only the preferred implementation manner of the present application. It should be noted that due to the limitation of literal expression and the objectively existing infinite specific structures, for those of ordinary skill in the art, without departing from the principle of the present application, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the concept and technical solution of the utility model to other occasions without improvement, should all be regarded as the protection scope of the present application.

Claims

1. A test device for simulating the cascading collapse of adjacent underground structures caused by foundation pit collapse, characterized in that: The model box (10) comprises a model box (10), the model box (10) being filled with sand, the model box (10) being provided with a foundation pit model buried in the sand for simulating a foundation pit and an underground structure model for simulating an underground structure, and the model box (10) being provided with a data monitoring system for monitoring and collecting large deformation or even collapse processes of the foundation pit model and the underground structure model; The underground structure model comprises two side walls, each of the side walls comprises a plurality of wall panels (3) arranged in sequence along a straight line, and two adjacent wall panels (3) are connected via a joint (4); The data monitoring system comprises a plurality of strain gauges (7), a plurality of earth pressure boxes (8), a plurality of displacement meters (9), a plurality of laser displacement sensors (11) and a PIV industrial camera (12). The plurality of strain gauges (7) are respectively arranged on the opposite side walls of two ground-connected wall models, at both ends of a plurality of support tubes (2) and on two side walls. A metal rectangular bar (5) is arranged on the top of each wall panel (3). The plurality of displacement meters (9) are arranged on the metal rectangular bar (5) in a vertical direction to calculate the inclination angle of the side wall of the underground structure. The remaining plurality of displacement meters (9) are respectively arranged on the top of a plurality of side panels (1) and the top of a plurality of wall panels (3). The plurality of earth pressure boxes (8) are respectively arranged on the opposite side walls of the two ground-connected wall models and on the opposite side walls of the two side walls. The plurality of laser displacement sensors (11) are all arranged on steel beams. An observation window is arranged on one side of the model box (10). The PIV industrial camera (12) is arranged outside the model box (10) and in front of the observation window.

2. The test device for simulating cascading collapse of adjacent underground structures caused by foundation pit collapse according to claim 1, characterized in that: The foundation pit model comprises two ground-connected wall models and a foundation pit support model, each of the ground-connected wall models comprises side panels (1) arranged in sequence along a straight line and arranged in a model box (10), and two adjacent side panels (1) are connected via an H-shaped joint (6); the foundation pit support model comprises a plurality of support pipes (2), and both ends of the plurality of support pipes (2) are respectively connected to the two ground-connected wall models.

3. The test device for simulating foundation pit collapse causing cascading collapse of adjacent underground structures according to claim 1, characterized in that: A steel beam is provided on the inner top of the model box (10), and a plurality of positioning clips are provided on the steel beam. The plurality of positioning clips are used to respectively position the side wall and the ground-connected wall models during installation.

4. The test device for simulating cascading collapse of adjacent underground structures caused by foundation pit collapse according to claim 3, characterized in that: A plurality of bolt holes are evenly distributed on the steel beam and on the top of the model box (10), and the steel beam is connected to the bolt holes on the model box (10) via bolts.

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