A load-type foundation pit excavation support test system and method

Abstract

The present invention relates to the field of building construction technology, and discloses a load-type foundation pit excavation support test system and method. The load-type foundation pit excavation support test system includes a support frame, a foundation pit retaining structure simulation device and a load loading device. The foundation pit retaining structure simulation device is arranged on the support frame, and two load loading devices are arranged on the support frame at intervals and are located on both sides of the foundation pit retaining structure simulation device. Each load loading device includes a number of load modules, and the load modules are used to apply test simulation loads to the foundation pit retaining structure simulation device. The present invention is based on the idea of ​​"interaction between load simulation structure and soil" and a single-multi-point matrix load combination control method to simulate the initial ground stress, excavation, support and deformation control during foundation pit construction. The modular design makes the equipment easier to maintain and the test operation more convenient. It can adapt to foundation pit support control simulation under various geological conditions and depths.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to a load-type foundation pit excavation support test system and method. Background Art

[0002] Foundation pit engineering refers to a comprehensive project that involves excavating a foundation pit, taking appropriate precipitation measures, arranging surrounding structures, and conducting real-time monitoring and maintenance of buildings, structures, roads and underground pipelines around the foundation pit to ensure safe construction when constructing underground areas of buildings or structures.

[0003] Currently, research on foundation pit engineering primarily focuses on numerical analysis based on field monitoring and indoor scaled-scale model testing. However, controlling pit deformation is paramount in foundation pit engineering. Real-time field monitoring and numerical analysis methods cannot effectively reflect the dynamic process of pit deformation control. Existing indoor scaled-scale models have poor adaptability to diverse geological environments (such as silt), and experimental operations are overly complex. Summary of the Invention

[0004] Based on the above problems, the purpose of the present invention is to provide a load-type foundation pit excavation support test system and method, which can adapt to foundation pit support control simulation under various geological conditions and depths.

[0005] To achieve the above objectives, the following technical solutions are provided:

[0006] In a first aspect, the present invention provides a load-type foundation pit excavation support test system, comprising:

[0007] Support frame;

[0008] A foundation pit retaining structure simulation device is arranged on the support frame;

[0009] A load loading device, wherein the two load loading devices are spaced apart on the support frame and are located on both sides of the foundation pit retaining structure simulation device. Each of the load loading devices includes a plurality of load modules, and the load modules are used to apply test simulation loads to the foundation pit retaining structure simulation device.

[0010] As an optional solution to the load-type foundation pit excavation support test system provided by the present invention, the support frame includes a base and two support frames spaced apart on the base, and the support frames include two vertical beams spaced apart on the base and a horizontal beam connecting the two vertical beams.

[0011] As an optional solution to the load-type foundation pit excavation support test system provided by the present invention, the foundation pit retaining structure simulation device includes an elastic plate and a mounting seat, the two ends of the mounting seat are respectively connected to the two cross beams of the support frame, and the top of the elastic plate is connected to the mounting seat.

[0012] As an optional solution of the load-type foundation pit excavation support test system provided by the present invention, the load loading device also includes a fixed plate, the load module is arranged on the fixed plate, and the two sides of the fixed plate are respectively connected to the vertical beams of the two support frames.

[0013] As an optional solution of the load-type foundation pit excavation support test system provided by the present invention, the load module includes a fixed seat, an electric cylinder and a load conversion seat, the fixed seat is installed on the fixed plate, the housing of the electric cylinder is installed on the fixed seat, the output shaft of the electric cylinder is connected to the load conversion seat, the load conversion seat is used to be rigidly connected or elastically connected to the elastic plate, the output shaft of the electric cylinder is provided with a displacement sensor, and the load conversion seat is provided with a pressure sensor.

[0014] As an optional solution of the load-type foundation pit excavation support test system provided by the present invention, an elastic member is provided between the load conversion seat and the elastic plate, or a rigid rod is provided between the load conversion seat and the elastic plate.

[0015] As an optional solution of the load-type foundation pit excavation support test system provided by the present invention, the foundation pit retaining structure simulation device also includes a locking device, which is arranged on the base and is used to fix the bottom of the elastic plate.

[0016] As an optional solution of the load-type foundation pit excavation support test system provided by the present invention, the locking device includes a locking seat and a locking block arranged on the locking seat, the locking seat is arranged on the support frame, and a stop portion is provided on the locking seat. The distance between the locking block and the stop portion is adjustable, and the bottom of the elastic plate is located between the locking block and the stop portion, or the locking device includes a universal ball and a driving cylinder, and the driving cylinder is used to drive the universal ball to abut against the elastic plate.

[0017] As an optional solution of the load-type foundation pit excavation support test system provided by the present invention, the locking device also includes a locking screw, which is rotatably set on the locking seat and threadedly connected to the locking block. The locking block includes a sliding part and a nut part that are connected to each other. The sliding part is slidably set on the locking seat, and the nut part is threadedly connected to the locking screw. Screwing the locking screw can drive the sliding part to approach or move away from the stop part through the nut part.

[0018] In a second aspect, the present invention further provides a load-type foundation pit excavation support test method, which uses the above-mentioned load-type foundation pit excavation support test system and includes the following steps:

[0019] Plan the number of electric cylinders corresponding to each soil layer according to the excavation depth of the foundation pit project and the similarity scale of the model;

[0020] According to the engineering geological environment of the foundation pit, choose whether to perform bottom restraint to simulate the restraint state of the retaining structure;

[0021] Then, the load is applied through the electric cylinder according to the water and soil pressure theory.

[0022] The beneficial effects of the present invention are:

[0023] The present invention provides a load-type foundation pit excavation support test system and method. The load-type foundation pit excavation support test system includes a support frame, a foundation pit retaining structure simulation device and a load loading device. The foundation pit retaining structure simulation device is arranged on the support frame. Two load loading devices are arranged on the support frame at intervals and are located on both sides of the foundation pit retaining structure simulation device. Each load loading device includes a plurality of load modules. The load modules are used to apply test simulation loads to the foundation pit retaining structure simulation device. During the test, the number of electric cylinders corresponding to each layer of soil is planned according to the excavation depth of the foundation pit project and the similarity scale of the model. According to the geological environment of the foundation pit project, it is selected whether to perform bottom constraint to simulate the constraint state of the retaining structure. Then, according to the water and soil pressure theory, the load is calculated. , load is applied through electric cylinders, based on the idea of ​​"load simulation interaction between structure and soil" and single-multi-point matrix load combination control method, to simulate the initial ground stress, excavation, support and deformation control during foundation pit construction. On this basis, the underlying logic, robustness and control adaptability of different foundation pit deformation control theory programs are evaluated. The multi-point partitioned synchronous servo control system and 10*36 matrix layout can adapt to foundation pit excavation and support simulation in various strata and depths. Adaptive model calibration and multi-point mechanical state perception can improve the accuracy of the test model and model state visualization. The modular design makes the equipment easier to maintain and the test operation more convenient. The open algorithm extension module can adapt to foundation pit support control simulation under various geological conditions and depths. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0025] Figure 1It is a structural schematic diagram of a load-type foundation pit excavation support test system provided by a specific embodiment of the present invention;

[0026] Figure 2 It is a structural schematic diagram of a support frame provided by a specific embodiment of the present invention;

[0027] Figure 3 It is a structural schematic diagram of a foundation pit retaining structure simulation device provided by a specific embodiment of the present invention;

[0028] Figure 4 It is a structural schematic diagram of the elastic plate and the locking device provided in a specific embodiment of the present invention;

[0029] Figure 5 It is a structural schematic diagram of a locking device provided in a specific embodiment of the present invention;

[0030] Figure 6 is an exploded schematic diagram of a fixing seat and a fixing plate provided in a specific embodiment of the present invention;

[0031] Figure 7 It is a structural schematic diagram of a fixing seat, an electric cylinder, a load conversion seat and an elastic member provided in a specific embodiment of the present invention;

[0032] Figure 8 It is a structural schematic diagram of a fixing base, an electric cylinder, a load conversion base and a rigid rod provided in a specific embodiment of the present invention;

[0033] Figure 9 It is a structural schematic diagram of the elastic plate, universal ball and driving cylinder provided in a specific embodiment of the present invention.

[0034] In the picture:

[0035] 1. Support frame; 2. Foundation pit retaining structure simulation device; 3. Load loading device;

[0036] 11. Base; 12. Support frame;

[0037] 121, vertical beam; 122, horizontal beam; 1221, long hole;

[0038] 21. Elastic plate; 22. Mounting seat; 23. Locking device;

[0039] 221, seat body; 222, fixed angle plate; 223, mounting plate;

[0040] 231, locking seat; 2311, stopper; 2312, limiting groove; 2313, connecting part; 232, locking block; 233, locking screw; 2331, handle rod; 234, universal ball; 235, driving cylinder;

[0041] 2321, sliding portion; 2322, nut portion;

[0042] 31. Load module; 32. Fixing plate; 321. Limiting hole;

[0043] 311. Fixed seat; 312. Electric cylinder; 313. Load conversion seat; 314. Elastic member; 315. Rigid rod. DETAILED DESCRIPTION

[0044] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention more clearly understood, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It is apparent that the described embodiments are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that the terms "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0046] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0047] like Figures 1 to 9As shown, this embodiment provides a load-type foundation pit excavation support test system, which includes a support frame 1, a foundation pit retaining structure simulation device 2 and a load loading device 3. The foundation pit retaining structure simulation device 2 is arranged on the support frame 1, and two load loading devices 3 are arranged on the support frame 1 at intervals and are located on both sides of the foundation pit retaining structure simulation device 2. Each load loading device 3 includes a number of load modules 31, and the load module 31 is used to apply a test simulation load to the foundation pit retaining structure simulation device 2. Based on the water and soil pressure theory, the ground stress state is simulated by the two load loading devices 3 on both sides of the foundation pit retaining structure simulation device 2, and the retaining structure is simulated by the foundation pit retaining structure simulation device 2. The excavation state simulation is achieved by unloading on one side, and the support state simulation is achieved by replacing the rigid load module with the unloaded electric cylinder 312 and then loading.

[0048] To ensure the support reliability of the support frame 1, the support frame 1 optionally includes a base 11 and two support frames 12 spaced apart on the base 11. The support frames 12 include two vertical beams 121 spaced apart on the base 11 and a horizontal beam 122 connecting the two vertical beams 121. This structure is simple and reliable, with low manufacturing costs and convenient mass production. To facilitate leveling of the base 11, the base 11 optionally includes a plurality of retractable leveling feet.

[0049] Optionally, the foundation pit retaining structure simulation device 2 includes an elastic plate 21 and a mounting base 22. The two ends of the mounting base 22 are respectively connected to the crossbeams 122 of the two support frames 12, and the top of the elastic plate 21 is connected to the mounting base 22. The retaining structure is simulated by the elastic plate 21. The elastic plate 21 acts as an elastically deformable thin plate. The force applied to the elastic plate 21 is a plane strain problem. Depending on the model scale, it can be combined horizontally and vertically to achieve the required load application. The left and right sides are single-multi-point matrix load combination devices. Based on the water and soil pressure theory, the ground stress state at this time is simulated, and the elastic plate 21 simulates the retaining structure. The excavation state simulation is achieved by unloading on one side, and the support state simulation is achieved by replacing the rigid load module with the unloaded electric cylinder 312 and then loading it. The initial state simulates the static soil pressure, the excavation state simulates the active soil pressure, and the support process simulates the passive soil pressure. To achieve diversified load characteristics, the simulation can be based on linear elastic springs and nonlinear springs. Based on a random control system, the simulation of "time effect" can be achieved.

[0050] Optionally, the mounting base 22 includes a base body 221, a fixed angle plate 222, and a mounting plate 223. The two fixed angle plates 222 are disposed at either end of the base body 221 and are connected to the two crossbeams 122, respectively. The mounting plate 223 is disposed at the bottom of the base body 221, and the top of the elastic plate 21 is connected to the mounting plate 223. The connection between the crossbeams 122 and the base body 221 via the fixed angle plates 222 provides a simple and reliable installation method. The top of the elastic plate 21 can be fixed to the mounting plate 223 using multiple bolts and nuts, and the removable mounting plate 223 facilitates replacement of the elastic plate 21. In some embodiments, the top of the elastic plate 21 can also be welded to the mounting plate 223, which facilitates construction and provides a strong structure.

[0051] Optionally, the fixed angle plate 222 is connected to the crossbeam 122 via a fastener. The crossbeam 122 is provided with an elongated hole 1221, and the fastener is adjustable through the elongated hole 1221. Due to the adjustable position of the fastener, the installation position of the fixed angle plate 222 relative to the crossbeam 122 is adjustable, thereby achieving adjustable installation position of the entire mounting base 22 relative to the crossbeam 122, thereby achieving adjustable position of the elastic plate 21, and expanding the scope of application of the simulation test.

[0052] To facilitate the fixed installation of the load module 31, optionally, the load loading device 3 also includes a fixed plate 32, and the load module 31 is arranged on the fixed plate 32. The two sides of the fixed plate 32 are respectively connected to the vertical beams 121 of the two support frames 12, thereby leaving enough space in the middle of the fixed plate 32 to install the load module 31.

[0053] Optionally, the load module 31 includes a fixed seat 311, an electric cylinder 312 and a load conversion seat 313. The fixed seat 311 is installed on the fixed plate 32, the shell of the electric cylinder 312 is installed on the fixed seat 311, the output shaft of the electric cylinder 312 is connected to the load conversion seat 313, the load conversion seat 313 is used to be rigidly connected or elastically connected to the elastic plate 21, the output shaft of the electric cylinder 312 is provided with a displacement sensor, and the load conversion seat 313 is provided with a pressure sensor. The fixing plate 32 is arranged on the supporting frame 1 to ensure the stability and reliability of the fixing plate 32. Since the fixing seat 311 is installed on the fixing plate 32, the shell of the electric cylinder 312 is installed on the fixing seat 311, which provides a stable and reliable working environment for the electric cylinder 312. The output shaft of the electric cylinder 312 is connected to the load conversion seat 313, and the load conversion seat 313 is rigidly or elastically connected to the elastic plate 21, so that the electric cylinder 312 can perform rigid or flexible loading on the elastic plate 21. It has a wide range of applications, strong versatility, and low test cost. Since the output shaft of the electric cylinder 312 is provided with a displacement sensor, it is convenient to provide the displacement data of the output shaft of the electric cylinder 312 during the test, thereby monitoring the displacement deformation of the foundation pit soil. Since the load conversion seat 313 is provided with a pressure sensor, it is convenient to provide the pressure data of the load conversion seat 313 during the test, thereby monitoring the deformation pressure of the foundation pit soil. It has rich test functions and is conducive to carrying out various tests in the foundation pit excavation and support process.

[0054] To ensure loading accuracy, a limiting hole 321 is optionally provided on the fixing plate 32, and the output shaft of the electric cylinder 312 passes through the limiting hole 321. The limiting hole 321 can prevent the uneven load of the electric cylinder 312 and the overturning moment generated by its own gravity, and can refine the mechanical state of the soil layer. The limiting hole 321 and the output shaft of the electric cylinder 312 are arranged coaxially to ensure the centering of the loading. Since the electric cylinder 312 array is arranged in multiple columns and rows, a corresponding plurality of limiting holes 321 are also arranged in an array on the fixing plate 32. The number of electric cylinders 312 corresponding to each layer of soil is planned based on the excavation depth of the foundation pit project and the similarity scale of the model.

[0055] Two fixing plates 32 can be provided, and the two fixing plates 32 are respectively mounted on the two support frames 12. Each fixing plate 32 is provided with a plurality of loading modules, so as to facilitate the loading test on both sides of the elastic plate 21 between the two support frames 12. Optionally, the two sides of the fixing plate 32 are respectively connected to the two vertical beams 121. The fixing plate 32 and the vertical beams 121 can be fixedly connected by bolts or by welding, which is not limited here. The two sides of the fixing plate 32 are respectively connected to the vertical beams 121 of the two support frames 12, so as to leave enough space in the middle of the fixing plate 32 to install the load module 31.

[0056] The number of electric cylinders 312 corresponding to each soil layer is planned based on the excavation depth of the foundation pit and the similarity scale of the model. Based on the geological environment of the foundation pit, the need for bottom constraints is determined to simulate the restrained state of the retaining structure. Loads are then applied via the electric cylinders 312 according to theoretical calculations of water and soil pressure. Load units can be divided into flexible and rigid loads using different load conversion modules. Directional guides and load conversion modules are used to prevent overturning moments caused by uneven loads and self-gravity, allowing for a more refined understanding of the soil's mechanical state.

[0057] To facilitate the elastic connection between the load conversion base 313 and the elastic plate 21, an elastic member 314 is optionally provided between the load conversion base 313 and the elastic plate 21, or a rigid rod 315 is optionally provided between the load conversion base 313 and the elastic plate 21. The elastic member 314 may be a spring, and the number of elastic members 314 may be one, two, or more, depending on the loading requirements, which is not limited here. The rigid rod 315 may be one, two, or more, depending on the loading requirements, which is not limited here. The modular design allows for easy removal and replacement. To ensure the connection strength between the output shaft of the electric cylinder 312 and the load conversion base 313, the output shaft of the electric cylinder 312 is optionally threadedly connected to the load conversion base 313. In other embodiments, the output shaft of the electric cylinder 312 and the load conversion base 313 may also be fixed by welding, clamping, or other methods. Optionally, the output shaft of the electric cylinder 312 is provided with a threaded section, and the load conversion base 313 is provided with a central threaded hole that threadably mates with the threaded section. The central threaded hole is set at the center position of the load conversion base 313 to ensure that the load conversion base 313 is evenly stressed. The deformation of the "elastic thin plate - enclosure structure" is monitored in real time, and the deformation is sensed by a pressure sensor. The overall height and lateral adjustment of the support frame 1, the lateral modular adjustment of the fixing base 311 of the electric cylinder 312, the load application method, and the elastic plate 21 can be replaced according to the address conditions and load conditions to improve the observability of the deformation of the maintenance structure. Deformation monitoring can be carried out through both contact and non-contact monitoring solutions, such as pointer displacement sensors, laser displacement sensors, and visual monitoring.

[0058] To facilitate the simulation of the restrained state of the retaining structure, the foundation pit retaining structure simulation device 2 optionally further includes a locking device 23, which is disposed on the base 11 and is used to fix the bottom of the elastic plate 21. To facilitate the locking device 23 in fixing the bottom of the elastic plate 21, the locking device 23 optionally includes a locking seat 231 and a locking block 232 disposed on the locking seat 231, the locking seat 231 being disposed on the support frame 1, the locking seat 231 being provided with a stop portion 2311, the spacing between the locking block 232 and the stop portion 2311 being adjustable, and the bottom of the elastic plate 21 being located between the locking block 232 and the stop portion 2311, or the locking device 23 includes a universal ball 234 and a driving cylinder 235, the driving cylinder 235 being used to drive the universal ball 234 to abut against the elastic plate 21. The universal ball 234 allows the position and posture of the elastic plate 21 to be adjusted, thereby facilitating the simulation of the restraint strength of the enclosure structure in sand and gravel formations. Multiple universal balls 234 and drive cylinders 235 can be provided, with multiple universal balls 234 distributed on both sides of the elastic plate 21.

[0059] Depending on the engineering geological environment of the foundation pit, the user can choose whether to constrain the bottom of the elastic plate 21. The locking device 23 can be a fixed constraint method consisting of a locking seat 231 and a locking block 232, thereby simulating the strong constraint state of the retaining structure in hard rock formations. The locking device 23 can also be a fixed constraint method consisting of a universal ball 234, thereby simulating the constraint strength of the retaining structure in sandy soil or gravel formations, thereby improving the authenticity of the soil simulation and the accuracy of the test results. Because the spacing between the locking block 232 and the stop portion 2311 of the locking device 23 is adjustable, it can be applied to elastic plates 21 of different thicknesses and the bottom constraint strength of the elastic plate 21 can be adjusted. The force transmission direction and strength of the universal ball 234 are adjustable, which has a wide range of applications and low test costs.

[0060] To facilitate adjustment of the spacing between the locking block 232 and the stop portion 2311, the locking device 23 optionally further comprises a locking screw 233, which is rotatably disposed on the locking seat 231 and threadedly connected to the locking block 232. The locking block 232 comprises a sliding portion 2321 and a nut portion 2322 connected thereto. The sliding portion 2321 is slidably disposed on the locking seat 231, and the nut portion 2322 is threadedly connected to the locking screw 233. Twisting the locking screw 233 can drive the sliding portion 2321 toward or away from the stop portion 2311 via the nut portion 2322. The spacing between the locking block 232 and the stop portion 2311 can be adjusted by twisting the screw, which is quick and easy to operate. The locking screw 233 and the nut portion 2322 form a screw-nut pair, which realizes motion transmission between the locking screw 233 and the nut portion 2322, and has stable transmission and high precision.

[0061] Optionally, a limiting groove 2312 is provided on the locking seat 231, and the nut portion 2322 is located in the limiting groove 2312. The limiting groove 2312 limits the nut portion 2322 so that the nut portion 2322 can only slide in the limiting groove 2312 and cannot rotate, thereby ensuring the motion transmission between the locking screw 233 and the nut portion 2322.

[0062] To facilitate manual operation by the operator, optionally, a handle rod 2331 is provided on the locking screw 233. The handle rod 2331 is passed through the end of the locking screw 233 and is perpendicular to the locking screw 233.

[0063] To facilitate the fixing of the locking seat 231, a connecting portion 2313 is optionally provided on the locking seat 231, and the connecting portion 2313 is fixedly connected to the support frame 1. The connecting portion 2313 can be in the shape of an ear plate, and two connecting portions 2313 are respectively provided on both sides of the locking seat 231, so that the two sides of the locking seat 231 are evenly stressed.

[0064] The load-type foundation pit excavation and support test system provided in this embodiment is based on the concept of "load simulation structure and soil interaction" and a single-multi-point matrix load combination control method to simulate the initial ground stress, excavation, support and deformation control during foundation pit construction. On this basis, the underlying logic, robustness and control adaptability of different foundation pit deformation control theory programs are evaluated. The multi-point partitioned synchronous servo control system and 10*36 matrix layout can adapt to foundation pit excavation and support simulation in various strata and depths. Adaptive model calibration and multi-point mechanical state perception can improve the accuracy of the test model and the visualization of the model state. The modular design makes the equipment easier to maintain and the test operation more convenient. The open algorithm extension module can adapt to foundation pit support control simulation under various geological conditions and depths.

[0065] This embodiment also provides a load-type foundation pit excavation support test method, which uses the above-mentioned load-type foundation pit excavation support test system and includes the following steps: planning the number of electric cylinders 312 corresponding to each layer of soil according to the excavation depth of the foundation pit project and the similarity scale of the model; selecting whether to perform bottom constraint according to the geological environment of the foundation pit project to simulate the constraint state of the retaining structure; and then applying the load through the electric cylinder 312 according to the water and soil pressure theory.

[0066] The load-type foundation pit excavation and support test method provided in this embodiment is based on the concept of "load simulation structure and soil interaction" and a single-multi-point matrix load combination control method to simulate the initial ground stress, excavation, support and deformation control during foundation pit construction. On this basis, the underlying logic, robustness and control adaptability of different foundation pit deformation control theory programs are evaluated. The multi-point partitioned synchronous servo control system and 10*36 matrix layout can adapt to foundation pit excavation and support simulation in various strata and depths. Adaptive model calibration and multi-point mechanical state perception can improve the accuracy of the test model and the visualization of the model state. The modular design makes the equipment easier to maintain and the test operation more convenient. The open algorithm extension module can adapt to foundation pit support control simulation under various geological conditions and depths.

[0067] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A load-type foundation pit excavation support test system, characterized in that: include: Support frame (1); A foundation pit retaining structure simulation device (2) is arranged on the support frame (1); A load loading device (3), wherein two load loading devices (3) are spaced apart on the support frame (1) and located on both sides of the foundation pit retaining structure simulation device (2), each of the load loading devices (3) comprises a plurality of load modules (31), and the load modules (31) are used to apply a test simulation load to the foundation pit retaining structure simulation device (2); the support frame (1) comprises a base (11) and two support frames (12) spaced apart on the base (11), and the support frames (12) comprise a plurality of support frames (31) spaced apart on the base ( 11) and a crossbeam (122) connecting the two vertical beams (121); the foundation pit retaining structure simulation device (2) includes an elastic plate (21) and a mounting seat (22), the two ends of the mounting seat (22) are respectively connected to the crossbeams (122) of the two support frames (12), and the top of the elastic plate (21) is connected to the mounting seat (22); the load loading device (3) also includes a fixed plate (32), the load module (31) is arranged on the fixed plate (32), and both sides of the fixed plate (32) are connected to the crossbeams (122) of the two support frames (12). The load module (31) is respectively connected to the vertical beams (121) of the two support frames (12); the load module (31) includes a fixed seat (311), an electric cylinder (312) and a load conversion seat (313); the fixed seat (311) is installed on the fixed plate (32); the housing of the electric cylinder (312) is installed on the fixed seat (311); the output shaft of the electric cylinder (312) is connected to the load conversion seat (313); the load conversion seat (313) is rigidly connected or elastically connected to the elastic plate (21); the output shaft of the electric cylinder (312) is arranged A displacement sensor is provided, and a pressure sensor is provided on the load conversion seat (313); during the test, the number of electric cylinders corresponding to each soil layer is planned according to the excavation depth of the foundation pit project and the similarity scale of the model, and whether to perform bottom constraint is selected according to the geological environment of the foundation pit project to simulate the constraint state of the enclosure structure; the excavation state simulation is achieved by unloading on one side, and the support state simulation is achieved by replacing the rigid load module with the unloaded electric cylinder (312) and then loading; the initial state simulates the static soil pressure, the excavation state simulates the active soil pressure, and the support process simulates the passive soil pressure.

2. The load-type foundation pit excavation support test system according to claim 1 is characterized in that: An elastic member (314) is provided between the load conversion seat (313) and the elastic plate (21), or a rigid rod (315) is provided between the load conversion seat (313) and the elastic plate (21).

3. The load-type foundation pit excavation support test system according to claim 1 is characterized in that: The foundation pit retaining structure simulation device (2) further comprises a locking device (23), wherein the locking device (23) is arranged on the base (11), and the locking device (23) is used to fix the bottom of the elastic plate (21).

4. The load-type foundation pit excavation support test system according to claim 3 is characterized in that: The locking device (23) comprises a locking seat (231) and a locking block (232) arranged on the locking seat (231); the locking seat (231) is arranged on the supporting frame (1); a stop portion (2311) is provided on the locking seat (231); the spacing between the locking block (232) and the stop portion (2311) is adjustable; the bottom of the elastic plate (21) is located between the locking block (232) and the stop portion (2311); or the locking device (23) comprises a universal ball (234) and a driving cylinder (235); the driving cylinder (235) is used to drive the universal ball (234) to abut against the elastic plate (21).

5. The load-type foundation pit excavation support test system according to claim 4 is characterized in that: The locking device (23) also includes a locking screw (233), which is rotatably arranged on the locking seat (231) and threadedly connected to the locking block (232). The locking block (232) includes a sliding portion (2321) and a nut portion (2322) connected to each other. The sliding portion (2321) is slidably arranged on the locking seat (231), and the nut portion (2322) is threadedly connected to the locking screw (233). Screwing the locking screw (233) can drive the sliding portion (2321) to approach or move away from the stop portion (2311) through the nut portion (2322).

6. A load-type foundation pit excavation support test method, characterized in that: The load-type foundation pit excavation support test system according to any one of claims 1 to 5 comprises the following steps: The number of electric cylinders (312) corresponding to each soil layer is planned according to the excavation depth of the foundation pit project and the similarity scale of the model; According to the engineering geological environment of the foundation pit, choose whether to perform bottom restraint to simulate the restraint state of the retaining structure; Then, the load is applied by the electric cylinder (312) according to the water and soil pressure theory.

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