Device and method for testing horizontal reinforcement composite foundation capable of resisting strong shock ground surface fracture

Abstract

The invention belongs to the technical field of building earthquake resistance, and particularly relates to a horizontal reinforcement composite foundation test device and method for resisting strong earthquake ground surface fracture. Before the test, debugging of a bed rock dislocation loading system, debugging of a data acquisition and analysis system and a sensor, preparation of a test model material, and arrangement of a test model and the sensor are included; in the test, after-test data analysis and fracture resistance comprehensive evaluation comprise qualitative analysis of test phenomena and quantitative analysis of test data. By building the geogrid transverse reinforcement composite foundation, obvious shear fracture of a rock-soil body in a covering layer site caused by a strong shock surface fault and related hazards such as obvious uneven deformation or tensile cracks of the site surface caused by the obvious shear fracture are relieved or reduced. And the stability of the foundation can be improved, potential fracture traces can be effectively transferred out of the building foundation range, and the safety of an upper building is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of earthquake resistance of buildings, and in particular relates to a horizontal reinforced composite foundation test device and method for resisting strong earthquake surface fracture. Background Art

[0002] In the field of earthquake engineering, surface fault rupture is generally considered to be one of the main sources of earthquake damage to buildings near faults. Its destructive impact on building structures and infrastructure will not only cause serious structural damage, but may also cause casualties. The hazards associated with surface faults are mainly the obvious shear rupture of the rock and soil inside the overburden site to form a plastic zone and the resulting significant uneven deformation or tensile cracks on the site surface.

[0003] In order to deal with these hazards, the design and implementation of geosynthetic reinforced soil transverse reinforcement foundation has become an effective technical means. This foundation reinforcement method aims to improve the bearing capacity of the soil and control the uneven deformation caused by fault activity within an acceptable range. That is, by constructing a transverse reinforcement foundation, the uneven settlement of the surface can be effectively reduced and the potential rupture traces can be transferred outside the scope of the building foundation, thereby maintaining the safety of the upper building.

[0004] The present invention aims to explore and verify the effectiveness and feasibility of horizontally reinforced composite foundation in reducing earthquake damage to buildings (structures) caused by surface fault ruptures through experiments and applied research. Through this method, it is expected to provide basic technical data support for the design and construction of buildings (structures) in earthquake fault-prone areas, and provide technical support for earthquake disaster prevention and reduction planning in the area. Summary of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention aims to provide a horizontal reinforced composite foundation test device and method for resisting strong earthquake surface fractures, evaluate the ability of reinforced foundation to resist fault rupture zones, so as to reduce the harm of uneven deformation of building foundations caused by fault rupture zones in earthquakes.

[0006] In order to solve the technical problem, the technical solution of the present invention is:

[0007] A horizontal reinforced composite foundation test device for resisting strong earthquake surface fractures, characterized in that it includes a test bedrock dislocation loading system, a data acquisition and analysis system and sensors, and a building model;

[0008] The test bedrock dislocation loading system includes overall debugging of the hydraulic control system, four actuators, the dislocation box and the wire displacement meter;

[0009] The hydraulic control system includes a hydraulic control panel, a displacement signal display panel, a hydraulic output area and a displacement signal receiving area;

[0010] The box body of the dislocation box body includes high-strength resin glass test observation areas on the front and rear sides and steel plates on the left and right sides: the bottom of the box body is provided with a simulated bedrock "L"-shaped dislocation steel plate and a simulated bedrock stationary plate steel plate, and a gap is left at the junction of the two plates of the simulated bedrock "L"-shaped dislocation steel plate and the simulated bedrock stationary plate steel plate for simulating the fracture zone;

[0011] A compacted soil cover layer is provided in the dislocation box; the area above the simulated bedrock "L"-shaped dislocation steel plate is the simulated cover layer area I, the area above the simulated bedrock static plate steel plate is the simulated cover layer area II, and the junction of the two areas is the geogrid arrangement area;

[0012] A trough is provided in the geogrid arrangement area for accommodating the building foundation at the bottom of the building model; the geogrid is arranged below the building foundation;

[0013] There are four actuators, which are respectively located at the four corners of the "L"-shaped dislocation steel plate simulating the bedrock; each actuator is provided with a corresponding wire displacement meter; the wire displacement meter is fixed at the position of the support plate below the actuator, and the wire magnet head of the wire displacement meter is vertically adsorbed upward on the lower side of the "L"-shaped dislocation steel plate;

[0014] The signal receiving line of the wire displacement meter is connected to the respective displacement signal receiving area of ​​the hydraulic control system; the actuator is connected to the hydraulic output area of ​​the hydraulic control system through the Rongguang hydraulic oil pipe;

[0015] The sensors include soil pressure gauges, strain gauges, laser displacement meters and high-speed cameras; the data acquisition and analysis system is connected to each sensor respectively;

[0016] The high-speed camera is placed in front of the dislocation box;

[0017] A plurality of earth pressure gauges are arranged above the junction of the two plates of the simulated bedrock "L"-shaped dislocation steel plate and the simulated bedrock static plate steel plate to monitor the earth pressure increment change of the rupture trace during the normal fault dislocation process; the earth pressure gauges are arranged in the area where the first rupture trace and the second rupture trace develop during the normal fault bedrock dislocation process;

[0018] Geogrid strain gauges are arranged at intervals on the geogrid to analyze the fracture resistance of the horizontal reinforcement composite foundation;

[0019] On the outside of the building side columns of the building model, three-dimensional building side column strain gauges are arranged at equal distances according to the storey height to monitor the strain of the building side columns during the test and to analyze the fracture resistance of the horizontal reinforcement composite foundation;

[0020] Several laser displacement meters are arranged on the beam above the soil cover to analyze the uneven deformation of the surface.

[0021] The present invention also provides a method for testing a horizontally reinforced composite foundation for resisting strong earthquake surface fractures, using the above-mentioned device, the method comprising:

[0022] Debugging the experimental bedrock dislocation loading system, which includes a hydraulic control system, four actuators, a dislocation box and a wire displacement meter;

[0023] Debug the data acquisition and analysis system and sensors, including soil pressure gauges, strain gauges, laser displacement meters and high-speed cameras;

[0024] preparing test model materials, wherein the test model materials include a building model, a geogrid in a transverse reinforcement body, and a covering soil body;

[0025] Arrangement of test models and sensors, including arrangement of cover soil, arrangement of geogrid, arrangement of building model, arrangement of earth pressure gauge, arrangement of geogrid strain gauge, arrangement of building model strain gauge and arrangement of laser displacement meter;

[0026] Carry out pre-test preparation and test process, gradually load bedrock displacement, and conduct multiple working condition tests;

[0027] Finally, the data results are quantitatively and qualitatively analyzed, including the inclination angle of the building model, the soil pressure increment in the cover layer, the geogrid strain increment, the building model strain increment and the building model foundation deformation analysis.

[0028] Furthermore, the debugging method of the test bedrock dislocation loading system comprises:

[0029] Debug the wire displacement meter. Fix four wire displacement meters on the support plates below the four actuators respectively. Suspend the wire magnet head of the wire displacement meter vertically upward to the lower side of the "L"-shaped dislocation steel plate. Use a level ruler to measure and debug the verticality of the wire displacement meter until the horizontal bubble is centered.

[0030] Connect the signal receiving wires of the four wire displacement meters to the displacement signal receiving areas of the hydraulic control system respectively, then start the hydraulic control system and slowly pull out the wire of the wire displacement meter by 1 cm, and observe whether the displacement signal on the hydraulic control display panel is 1 cm, with an error of ±0.1%;

[0031] Connect the actuator to the hydraulic output area of ​​the hydraulic control system with a hydraulic oil pipe and check its sealing; then, enter the jacking rate of 1mm / s and the bedrock jacking amount of 10mm in the hydraulic control panel, and wait for the actuator to complete the jacking; then use a spirit level to measure the upper four corners of the "L"-shaped dislocated steel plate to observe whether the bubble on the spirit level is centered.

[0032] Furthermore, the debugging of the data acquisition and analysis system and sensors includes debugging of earth pressure gauges, strain gauges, laser displacement meters and high-speed cameras;

[0033] The debugging of the earth pressure gauge includes connecting the earth pressure gauge to the data acquisition and analysis system, calibrating the earth pressure gauge using the water mark method, and observing whether the collected earth pressure is consistent with the calculated value through the data display window of the data acquisition and analysis system;

[0034] Fix the earth pressure gauge at the 0cm position of the end of a 1m-long steel ruler with a scale, connect it to the data acquisition and analysis system, reset it to zero, and then place it at 10cm, 50cm, and 100cm below the horizontal surface and leave it for 10 seconds. Observe whether the earth pressure in the data acquisition and analysis system is within the range of ±5% from the actual value and adjust the earth pressure sensitivity parameter;

[0035] The debugging of the laser displacement meter includes: numbering multiple laser displacement meters and connecting them to the data acquisition and analysis system in sequence, fixing the laser displacement meters on the same side of the square steel beam with double-sided tape and the laser emission area on the same side, placing a rectangular wooden board 20 cm in front of the laser displacement meter emission area and ensuring that the distance data of the laser displacement meter in the data acquisition and analysis system is 20 cm, and translating the rectangular wooden board 10 cm away from the laser displacement meter, and observing whether the data of multiple laser displacement meters in the data acquisition and analysis system are within the range of ±5% with the actual value of 30 cm;

[0036] The debugging of the high-speed camera includes: placing the high-speed camera directly in front of the dislocation box, adjusting the camera range until the entire test dislocation box is within the field of view of the high-speed camera, analyzing the photographs of the soil containing the fracture zone, observing whether the photographs of the test dislocation box are distorted, and adjusting the exposure and angle parameters of the high-speed camera.

[0037] Furthermore, the arrangement of the test model and the sensor specifically includes:

[0038] Arrangement of the covering soil, compacting a 100cm soil covering layer in the displacement box; placing 15cm of loose soil each time, compacting with a rammer from the leftmost side of the displacement box, compacting the loose soil to 13cm with a rammer for the first time, then compacting the soil layer with a rammer for the second time, compacting the soil layer to 12cm until the third compaction reaches 10cm; compacting the soil layer to 70cm according to the above method; arranging the geogrid transverse reinforcement at the corresponding position in the soil body from 70cm to 100cm, and completing the soil compaction according to the above method;

[0039] The arrangement of geogrids includes: arranging geogrids in the most unfavorable position of fault displacement according to the building model, arranging geogrids in the geogrid arrangement area, pressing the four corners with virtual soil, laying strain gauges and connecting wires, laying virtual soil with a height of 15 cm and a thickness of 10 cm with a rammer, and measuring and correcting with a level ruler until it is level;

[0040] The layout of the building model includes: arranging the building model at the most unfavorable position of the fault dislocation, digging a square soil trench with a depth of 8 cm in the vertical direction of the ground surface, placing the building model foundation in the soil trench and filling it with 9 cm of virtual soil, tamping and scraping it flat to the same height as the surface of the covering soil;

[0041] The arrangement of earth pressure gauges includes: the earth pressure gauges are arranged in the area where the rupture trace develops during the normal fault bedrock dislocation process, and nine earth pressure gauges are arranged at intervals of 10 cm just above the junction of the two plates to monitor the rupture trace rupture during the normal fault dislocation process.

[0042] The geogrid strain gauge arrangement includes: 10 strain gauges with a spacing of 10 cm are arranged in the middle of the geogrid to analyze the fracture resistance of the horizontal reinforcement composite foundation;

[0043] The arrangement of building strain gauges includes: arranging three-dimensional strain gauges, i.e. building side column strain gauges, at equal distances according to the storey height on the outside of the building side columns of the building model to monitor the strain of the building side columns during the test, so as to analyze the fracture resistance of the horizontal reinforcement composite foundation;

[0044] The arrangement of the laser displacement meter includes: arranging multiple laser displacement meters at intervals of 40 cm starting from the inner steel plate on the right side of the dislocation box on the beam 20 cm above the covering layer to analyze the uneven deformation of the surface.

[0045] Furthermore, the stepwise loading of bedrock dislocation and multiple working condition tests include:

[0046] Start the data acquisition and analysis system to collect the test data; start the hydraulic control system, first synchronously lift 1mm, and observe whether the sensor reading is normal; carry out 10 working conditions respectively, each time the pull-wire displacement meter gives a 10mm bedrock displacement input, and clear the data collection before each test.

[0047] Furthermore, the quantitative and qualitative analysis of the test results include: the inclination angle of the building model, the analysis of the soil pressure increment in the covering layer, the strain increment analysis of each layer of the geogrid, that is, whether the strain of the geogrid adjacent to the building model changes significantly, the strain increment analysis of the building model, whether the foundation of the building model passes through the fracture zone, and whether the foundation of the building model produces obvious uneven deformation, that is, whether a stepped steep slope is produced.

[0048] Compared with the prior art, the advantages of the present invention are:

[0049] (a) The present invention provides a test scheme and method for a horizontally reinforced composite foundation for resisting strong earthquake surface fault zones, which is a mature test scheme for a horizontally reinforced composite foundation for resisting strong earthquake surface fault zones.

[0050] (b) The present invention provides a test scheme and method for a horizontally reinforced composite foundation for resisting strong earthquake surface fault zones, which can change the number of geogrid layers added in the covering layer and study the ability of geogrids with different numbers of layers to resist the development of strong earthquake surface fault zones.

[0051] (c) The present invention provides a test scheme and method for a horizontally reinforced composite foundation for resisting strong earthquake surface fracture zones, which can change the type of covering layer and study the ability of the lateral reinforcement under different covering layers to resist strong earthquake surface fractures.

[0052] (d) The present invention provides a test scheme and method for a horizontally reinforced composite foundation that can resist strong earthquake surface fault zones. The soil pressure arranged on the center line of the junction between the "L"-shaped dislocation steel plate simulating the bedrock and the stationary plate steel plate simulating the bedrock in the covering layer can monitor the changes in the soil pressure of the covering layer during the test to analyze the anti-fracture capacity of the horizontally reinforced composite foundation; strain gauges are arranged on the geogrid to monitor the strain of the geogrid during the test to analyze the anti-fracture capacity of the horizontally reinforced composite foundation; three-dimensional strain gauges are arranged on the outside of the side columns of the building at equal distances according to the floor height to monitor the strain of the side columns of the building during the test to analyze the anti-fracture capacity of the horizontally reinforced composite foundation.

[0053] (e) Compared with other test methods, this test adds a comprehensive evaluation table for the fracture resistance of horizontal reinforcements. After the test, the quantitative and qualitative analysis indicators are filled into the evaluation table based on the data from the data acquisition and analysis system. This provides a quantitative comparison of the ability of horizontal reinforcements to resist the development of surface fault zones due to strong earthquakes, and improves the credibility of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of the device arrangement provided by an embodiment of the present invention;

[0055] Figure 2 A schematic diagram of a building model on a covering layer provided by an embodiment of the present invention;

[0056] Figure 3 A schematic diagram of a geogrid provided in an embodiment of the present invention;

[0057] Figure 4 A schematic diagram of the test model material provided by an embodiment of the present invention;

[0058] Figure 5 A schematic diagram of the arrangement positions of sensors provided in an embodiment of the present invention;

[0059] Figure 6 A flow chart of the test method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The specific implementation mode of the present invention is described below in conjunction with embodiments:

[0061] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0062] At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0063] Embodiment 1:

[0064] This embodiment provides a method for testing a horizontally reinforced composite foundation for resisting strong earthquake surface rupture, including debugging of a bedrock dislocation loading system, debugging of a data acquisition and analysis system 8 and sensors, preparation of test model materials, arrangement of test models and sensors, and quantitative and qualitative comprehensive analysis of data results.

[0065] (1) Debugging of the experimental bedrock dislocation loading system, including overall debugging of the hydraulic control system 1, four actuators 2, the dislocation box 7, and the wire displacement meter 3.

[0066] like Figure 1 As shown, the experimental bedrock dislocation loading system includes overall debugging of the hydraulic control system 1, four actuators 2, the dislocation box 7 and the wire displacement meter 3;

[0067] The hydraulic control system 1 includes a hydraulic control panel, a displacement signal display panel, a hydraulic output area and a displacement signal receiving area;

[0068] The box body of the dislocation box body 7 includes high-strength resin glass test observation areas on the front and rear sides and steel plates on the left and right sides: the bottom of the box body is provided with a simulated bedrock "L"-shaped dislocation steel plate 4 and a simulated bedrock stationary plate steel plate 9, and a gap is left at the junction of the two plates of the simulated bedrock "L"-shaped dislocation steel plate 4 and the simulated bedrock stationary plate steel plate 9 to simulate the fracture zone;

[0069] A compacted soil covering layer is provided in the dislocation box 7; the upper part of the simulated bedrock "L"-shaped dislocation steel plate 4 is the simulated covering layer zone I 14, the upper part of the simulated bedrock stationary plate steel plate 9 is the simulated covering layer zone II 15, and the junction of the two zones is the geogrid arrangement zone 16;

[0070] The first step is to debug the wire displacement meter 3, and fix four wire displacement meters 3 at the support plate position below the actuator 2. The wire magnet head of the wire displacement meter 3 is vertically adsorbed on the lower side of the "L"-shaped dislocation steel plate 4, and the wire of the wire displacement meter 3 is measured with a level until the horizontal bubble is centered.

[0071] Furthermore, the signal receiving wires of the four wire displacement meters 3 are respectively connected to the respective displacement signal receiving areas of the hydraulic control system 1, and then the hydraulic control system 1 is started and the wire of the wire displacement meter 3 is slowly pulled out by 1 cm to observe whether the displacement signal of the hydraulic control display panel is 1 cm, with an error of ±0.1%.

[0072] Furthermore, the actuator 2 is connected to the hydraulic output area of ​​the hydraulic control system 1 with a hydraulic oil pipe and its sealing is checked; then, the jacking rate of 1mm / s and the bedrock jacking amount of 10mm are input into the hydraulic control panel, and the jacking of the actuator 2 is completed; then, the upper four corners of the "L"-shaped dislocated steel plate 4 are measured with a spirit level to observe whether the bubble of the spirit level is centered.

[0073] (2) The debugging of the data acquisition and analysis system 8 and sensors includes debugging of the soil pressure gauge 21, strain gauge, laser displacement meter 5, and high-speed camera 10 used.

[0074] The debugging of the earth pressure gauge 21 includes connecting the earth pressure gauge 21 to the data acquisition and analysis system 8, calibrating the earth pressure gauge 21 using the water mark method, and observing whether the collected earth pressure is consistent with the calculated value through the data display window of the data acquisition and analysis system 8.

[0075] Furthermore, the soil pressure gauge 21 is fixed at the "0 cm" position at the end of a steel ruler with a scale of 1 m in length, connected to the data acquisition and analysis system 8 and reset to zero, and then placed at 10 cm, 50 cm, and 100 cm below the horizontal plane respectively and left to stand for 10 seconds, and the soil pressure in the data acquisition and analysis system 8 is observed to see whether the difference between the soil pressure and the actual value (0.98 kPa, 4.9 kPa, and 9.8 kPa respectively according to the calculation method of water pressure) is within the range of ±5%, and the soil pressure sensitivity parameters are adjusted.

[0076] The debugging of the laser displacement meter 5 includes, preferably, numbering the nine laser displacement meters 5 (No. 1 to No. 9) and connecting them to the data acquisition and analysis system 8 in sequence, fixing the laser displacement meter 5 on the same side of the square steel beam with double-sided tape and the laser emission area is located on the same side, placing a rectangular wooden board 20 cm in front of the emission area of ​​the laser displacement meter 5 and ensuring that the distance data of the nine laser displacement meters 5 in the data acquisition and analysis system 8 is 20 cm, and further translating the rectangular wooden board 10 cm away from the laser displacement meter 5. Observe whether the data of the nine laser displacement meters 5 in the data acquisition and analysis system 8 are within the range of ±5% with the actual value of 30 cm.

[0077] The debugging of the high-speed camera 10 includes placing the high-speed camera 10 directly in front of the shift box 7, adjusting the camera range until the entire test shift box 7 is within the field of view of the high-speed camera 10, analyzing the photographs of the soil containing the fracture zone, observing whether the photographs of the test shift box 7 are distorted, and adjusting the exposure and angle parameters of the high-speed camera 10.

[0078] (3) Test model materials and processing include the preparation of the building model 6, the preparation of the geogrid 22 in the lateral reinforcement, and the preparation of the covering layer soil.

[0079] Preparation of building model 6, such as Figure 2 As shown, the manufacturing of the building side column 11, the building floor 12, and the building foundation 13, preferably, the steel structure building model 6 in the present invention adopts a square six-layer 65Mn steel structure with a similarity ratio of 1:20, a floor height of 15cm, and a floor side length of 30cm, and the side column is a rectangular steel plate with a length of 81cm and a width of 1.5cm. The manufacturing of the building foundation 13 adopts, preferably, the present invention adopts a reinforced concrete structure with a similarity ratio of 1:20, and the length, width and height of the foundation are 20cm, 20cm, and 3cm respectively. Preferably, the ratio of materials in the present invention is cement: gypsum: sand: water = 3:12:30:12, the compressive strength is 3.75Mpa, and the steel bar used in the independent foundation structure is a Φ2.4@25 steel wire mesh, and the size of the mesh is 19cm×19cm.

[0080] like Figure 3The preparation of the geogrid 22 in the transverse reinforcement includes: preferably, the geogrid 22 in the present invention adopts polyester bidirectional welded geogrid with a tensile strength of 40KN / m 2 , the length is 1730mm, the width is 1000mm, the spacing between the transverse ribs and the longitudinal ribs is 5cm, and the thickness is 1mm.

[0081] The preparation of the covering soil includes: preferably, the natural clay foundation is used in the present invention and its moisture content is 10%.

[0082] In the first step, the size of the test model (4.6m×1.8m×1m) in the present invention is used to about 15m 3 The clay was initially screened using a mesh sieve with a pore size of 5 mm.

[0083] Furthermore, 5 soil samples were randomly taken from the screened soil pile for moisture content determination test, and the mean moisture content was calculated.

[0084] Furthermore, soil with high water content is placed on a waterproof tarpaulin to dry and its water content is measured in due course; soil with low water content is measured according to its current water content and its water requirement is sprayed with a sprinkler in layers on the soil pile. After stirring evenly with a shovel, its water content is measured until it meets the requirements.

[0085] Furthermore, the soil that meets the requirements is packed into 10kg waterproof woven bags and then stacked on double-sided waterproof canvas. After stacking, a water-containing sponge net is laid on top of the soil pile and the double-sided waterproof canvas is covered on the woven bag soil pile and finally the soil pile is compacted and sealed around.

[0086] (4) The arrangement of the test model materials and sensors includes the arrangement of the covering soil, the arrangement of the geogrid 22, the arrangement of the building model 6, the arrangement of the earth pressure gauge 21, the arrangement of the geogrid strain gauge 17, the arrangement of the building model 6 strain gauge, and the arrangement of the laser displacement meter 5.

[0087] Arrangement of the covering soil layer: 100 cm of soil covering layer is completed by compaction in the displacement box 7.

[0088] Further, 15 cm of loose soil is placed each time, and compacted with a rammer starting from the leftmost side of the shift box 7. The loose soil is compacted with the rammer for the first time to 13 cm, and then the soil layer is compacted with the rammer for the second time to 12 cm until the third compaction reaches 10 cm.

[0089] Furthermore, after the soil layer is compacted to 70 cm according to the above method, after the geogrid 22 transverse reinforcement bodies are arranged at corresponding positions in the soil body of 70 cm to 100 cm, the soil layer is compacted according to the above method.

[0090] The arrangement of the geogrid 22 includes, in the present invention, arranging the geogrid 22 centered on the most unfavorable position of the fault displacement according to the building model 6 .

[0091] like Figure 4 A compacted soil covering layer is provided in the dislocation box 7; above the simulated bedrock "L"-shaped dislocation steel plate 4 is a simulated covering layer zone I 14, above the simulated bedrock stationary plate steel plate 9 is a simulated covering layer zone II 15, and the junction of the two zones is a geogrid arrangement zone 16.

[0092] Furthermore, geogrid 22 is arranged in geogrid arrangement area 16, and after the geogrid strain gauge 17 and connecting wires are laid out with soft soil at its four corners, soft soil with a height of 15 cm and a thickness is laid and compacted to 10 cm with a rammer, and measured and corrected with a spirit level until it is level.

[0093] The arrangement of the building model 6 includes arranging the building model 6 at the most unfavorable position of the fault displacement in the present invention. Preferably, the center of the base bottom surface of the building model 6 in the present invention is located at a position half of the boundary line between the two plates.

[0094] Furthermore, a square soil trench with a depth of 8 cm is dug vertically on the ground surface, the building foundation 13 is placed in the soil trench and filled with 9 cm of virtual soil, which is compacted and scraped flat to the same height as the surface of the covering soil layer;

[0095] like Figure 5 , the arrangement of the earth pressure gauge 21 includes: the earth pressure gauge 21 is arranged in the area where the rupture trace develops during the normal fault bedrock dislocation process, and nine earth pressure gauges 21 are arranged at intervals of 10 cm just above the junction of the two plates, in order to monitor the earth pressure increment change of the rupture of the first rupture trace 19 and the second rupture trace 20 during the normal fault dislocation process;

[0096] The arrangement of the geogrid strain gauge 17 includes arranging 10 strain gauges with a spacing of 10 cm in the middle of the geogrid 22 to analyze the fracture resistance of the horizontal reinforced composite foundation.

[0097] The arrangement of the strain gauges 18 of the building side column includes arranging three-dimensional strain gauges at equal distances at the outer side of the building side column 11 according to the storey height, monitoring the strain of the building side column 11 during the test, so as to analyze the fracture resistance of the horizontal reinforcement composite foundation;

[0098] The arrangement of the laser displacement meter 5 includes arranging nine laser displacement meters 5 at intervals of 40 cm starting from the inner steel plate on the right side of the displacement box 7 on the beam 20 cm above the covering layer, so as to analyze the uneven deformation of the ground surface.

[0099] (5) Complete the preparatory work before the test according to the above steps and conduct the test.

[0100] The first step is to start the data acquisition and analysis system 8 to collect test data.

[0101] Further, the hydraulic control system 1 is started, and the hydraulic system is lifted synchronously by 1 mm to observe whether the sensor reading is normal.

[0102] Furthermore, 10 working conditions were respectively carried out, and each time the wire displacement meter 3 gave an input of 10 mm bedrock displacement, and the data collection was cleared before each test.

[0103] (6) Quantitative and qualitative analysis of the test results include the building inclination angle, soil pressure increment analysis in the covering layer, strain increment analysis of each geogrid layer (whether the strain of the geogrid adjacent to the building changes significantly), building strain increment analysis, whether the building foundation passes through the rupture zone, and whether the building foundation undergoes obvious uneven deformation (whether a step-like steep slope is produced).

[0104] The present invention also provides a comprehensive evaluation table of the fracture resistance of horizontal reinforcements (Table 1). Combined with the above test scheme, a test method for horizontal reinforcement composite foundations to resist strong earthquake surface fracture zones is provided, such as Figure 6 .

[0105] Table 1 Comprehensive evaluation table of the fracture resistance of horizontal reinforcement

[0106] project Result (yes or no) Is there any obvious uneven deformation of the building foundation? Is the building tilted? Is the foundation of the building's lateral reinforcement body penetrated by the crack trace? Is the strain change of the building side column greater than 50με? Is the strain change on the far right side of the geogrid at the top of the foundation greater than 100με? Is the soil pressure change at the height of 50cm in the cover layer greater than 5kPa?

[0107] Note: In the comprehensive evaluation table of fracture resistance of horizontal reinforcements;

[0108] If the number of "No" in the cumulative results of the evaluation table is greater than or equal to 5, the fracture resistance of the horizontal reinforcement is "excellent";

[0109] If the number of "No" in the cumulative results of the evaluation table is greater than or equal to 4 and less than 5, the fracture resistance of the horizontal reinforcement is "good";

[0110] If the number of "No" in the cumulative results of the evaluation table is less than 4, the fracture resistance of the horizontal reinforcement is "poor".

[0111] Embodiment 2:

[0112] This embodiment provides a method for testing a horizontally reinforced composite foundation that resists strong earthquake surface fractures. Figure 1-Figure 6 and Table 1.

[0113] In the actual test, the cover layer is arranged completely, the building model 6, the geogrid 22, and the test instruments are arranged in the correct position. The hydraulic output device is controlled to lift 10 mm each time until the lift reaches 100 mm, and the test is completed. After the test, the test results are quantitatively and qualitatively analyzed, which specifically includes the following steps:

[0114] Step 1: Debug the loading system used in the test, place four wire displacement meters 3 on the lower side of the active disk of the dislocation box 7, and connect them to the respective displacement signal receiving areas of the hydraulic control system 1 of the loading system; operate the hydraulic control system 1 to vertically lift 1mm for a preliminary experiment; use a steel ruler to measure and verify whether the simulated bedrock "L"-shaped dislocation steel plate 4 is lifted by 1mm, and observe whether the lifting distance of the simulated bedrock "L"-shaped dislocation steel plate 4 is consistent with the observed value. If the two are inconsistent, it is necessary to adjust the calibration parameters of the hydraulic control system 1. If they are consistent, proceed to the next step.

[0115] Step 2: Debugging of the data acquisition and analysis system 8 and sensors, including debugging of the soil pressure gauge 21, strain gauge, laser displacement meter 5, and high-speed camera 10 used;

[0116] Debug the earth pressure gauge 21, connect the earth pressure gauge 21 to the data acquisition and analysis system 8, calibrate the earth pressure gauge 21 using the water mark method, and observe whether the collected earth pressure measurement value and the calculated value are consistent through the data display window of the data acquisition and analysis system 8. If the two are inconsistent, it is necessary to adjust the calibration parameters of the earth pressure gauge 21. If they are consistent, proceed to the next step;

[0117] Debug the laser displacement meter 5, connect the laser displacement meter 5 to the data acquisition and analysis system 8, fix the laser displacement meter 5 on the bracket and then move a fixed distance to observe whether the collected distance and the actual distance are consistent through the data display window of the data acquisition and analysis system 8. If the two are inconsistent, it is necessary to adjust the calibration parameters of the laser displacement meter 5. If they are consistent, proceed to the next step;

[0118] Debug the high-speed camera 10. After the high-speed camera 10 is connected to the data acquisition and analysis system 8, place the high-speed camera 10 directly in front of the shift box 7, adjust the camera range until the entire test shift box 7 is within the field of view of the high-speed camera 10, load the test shift box 7, perform high-speed photography, and analyze the captured data. If the data results do not meet the test requirements, adjust the parameters of the high-speed camera 10. Repeat the above steps after adjustment until the captured data results meet the test requirements. If they meet the test requirements, proceed to the next step.

[0119] Step 3: Test model materials and processing include the preparation of building models, the preparation of building models 6, the preparation of geogrids 22 in the transverse reinforcement, and the preparation of the covering soil; preferably, the steel structure building model 6 in the present invention adopts a six-layer steel structure with a similarity ratio of 1:20 and a layer height of 15 cm; preferably, the reinforcement length of the geogrid 22 is the length of the projection of the main rupture trace on the surface of the covering layer. In the present invention, the length of the geogrid 22 is 1000mm and the width is 1730mm. When preparing the geogrid 22, 10 soil pressure gauges 21 are arranged at the position with the greatest impact on the development of rupture; preferably, clay with a moisture content of 10% is used in the present invention.

[0120] Step 4: When making a foundation with a height of 70 cm or less, place 15 cm of loose soil in the shift box 7, and use a rammer to tamp it from the leftmost side of the shift box 7. Use the rammer to perform the first tamping and tamp the loose soil to 13 cm.

[0121] Furthermore, the soil layer is compacted twice more with a tamping hammer in the same way until the soil layer is compacted to 10 cm. Figure 5 An earth pressure gauge 21 is arranged at the junction of the two plates.

[0122] Furthermore, the soil layer is compacted to 70 cm according to the above method and an earth pressure gauge 21 is arranged.

[0123] Step 5: When making a 70cm to 100cm foundation, spread 15cm high virtual soil on the top of the simulated covering layer I zone 14, scrape the virtual soil flat with a square wooden stick, and scrape the top against the black standard line of the glass plate in the observation area of ​​the test dislocation box 7 (black standard lines are pasted at intervals of 5cm in height in the test observation area of ​​the test dislocation box 7) following the principle of "more shoveling and less filling".

[0124] Furthermore, the loose soil is lightly tamped for the first time with a rammer with a small drop distance, tamping the loose soil vertically downward by 3 cm, and then the compacted soil is further compacted with a large drop distance, tamping the soil vertically downward by 2 cm.

[0125] Furthermore, the compacted soil of the simulated cover layer I zone 14 is measured with a level ruler and the compacted soil is observed outside the shift box 7 to see whether there are convex or concave parts in the compacted soil, and the uneven soil is trimmed until it is flat.

[0126] Furthermore, the zone II 15 of the simulated covering layer is compacted, and the compaction method is consistent with the compaction method of the zone I 14 of the simulated covering layer.

[0127] Furthermore, the geogrid 22 is arranged in the geogrid arrangement area 16. Preferably, the longitudinal length of the bidirectional geogrid 22 is 1730 mm, the latitudinal length is 1000 mm, the small square of the geogrid 22 is 50 mm×50 mm, and before placing the geogrid 22, strain gauges are attached at intervals of 100 mm along the latitudinal direction at half of the surface of the geogrid 22 in the longitudinal direction and connected to the data monitoring and analysis system.

[0128] Furthermore, if Figure 4 As shown, the geogrid 22 with strain gauges attached is placed in the geogrid arrangement area 16, and both sides of the geogrid 22 are 35 mm away from the glass plate of the observation area.

[0129] Furthermore, when the geogrid 22 is placed in the correct position, 15 cm high false soil is laid on the outside of the geogrid 22 to prevent the geogrid 22 from moving when false soil is placed in other areas of the geogrid 22. Then, 15 cm high false soil is placed in other areas of the geogrid 22. After the false soil is laid, observe along the standard line in the observation area of ​​the displacement box 7 to see if there are any uneven areas of the laid false soil, and repair the uneven areas. After the false soil is leveled, measure the false soil with a level ruler until it is level.

[0130] Furthermore, when the soft soil surface is horizontal, the soil is compacted in the same manner as that of the simulated cover layer I zone 14. After the soil is compacted, an earth pressure gauge 21 is arranged at the junction of the two plates.

[0131] Furthermore, the geogrids 22 and the earth pressure gauges 21 are laid out at the heights of 80 cm and 90 cm, and the laying method is the same as that at the height of 70 cm.

[0132] Step 6: After the covering layer is completed, a square soil trench with a depth of 8 cm and a side length of 50 cm is dug just above the junction of the upper and lower plates. The building model 6 is placed in the soil trench, and the soil is filled in layers and compacted. After the building model 6 is placed, the strain gauge on the building model 6 is connected to the data acquisition and analysis system 8.

[0133] Step 7: Arrange nine laser displacement meters 5 at intervals of 40 cm on the crossbar above the covering layer and connect them to the data acquisition and analysis system 8. Arrange four wire displacement meters 3 under the active plate of the shifting box 7 and connect them to the displacement signal receiving area of ​​the hydraulic control system 1. Start the data acquisition and analysis system 8, the high-speed camera 10, and the hydraulic control system 1.

[0134] Step 8: Operate the hydraulic control system 1 to lift up vertically by 1 mm, observe whether the data acquisition and analysis system 8 and the high-speed camera 10 are working normally, and complete the preliminary experiment.

[0135] Step 9: Control the hydraulic control system 1 to lift vertically upward by 10 mm, the data acquisition and analysis system 8 to collect data during the test, and the high-speed camera 10 to take pictures and record the test process, thus completing one test condition.

[0136] Step 10: Follow step 9 until the vertical lifting test of 100 mm is completed. It can be understood that before each test starts, the data acquisition and analysis system 8 performs a monitoring data clearing operation.

[0137] Step 11: Analyze the results of the data acquisition and analysis system 8 and the photos taken by the high-speed camera 10. Preferably, record whether the building foundation has obvious uneven deformation, whether the building is tilted, whether the foundation of the building's lateral reinforcement is passed through by the rupture trace, whether the strain change of the building's side column is greater than 50με, whether the strain change of the rightmost geogrid at the top of the foundation is greater than 100με, and whether the change in soil pressure at a height of 50cm in the covering layer is greater than 5kPa, and fill the results into Table 1, a comprehensive evaluation table for the anti-fracture capacity of horizontal reinforcements, for statistical analysis.

[0138] It can be understood that the test device and method for a horizontal reinforced composite foundation resistant to strong earthquake surface fractures provided in this example are simple to operate; the number of layers of geogrids added in the covering layer can be changed, and the ability of geogrids with different numbers of layers to resist the development of strong earthquake surface fracture zones can be studied; the type of reinforcement in the covering layer can be changed, and the ability of horizontal reinforcements made of different reinforcement materials to resist the development of strong earthquake surface fracture zones can be studied; the type of covering layer can be changed, and the ability of lateral reinforcements under different covering layers to resist strong earthquake surface fractures can be studied; compared with other test methods, this test adds buildings on the covering layer and arranges strain gauges on the side columns of the buildings. In the test, the influence of the reinforced composite foundation on the buildings on the covering layer can be observed; compared with other test methods, this test adds a comprehensive evaluation table for the fracture resistance of horizontal reinforcements. After the test, the quantitative and qualitative analysis indicators are filled in the evaluation table based on the data of the data acquisition and analysis system and the photos taken by the high-speed camera, so that there is a quantitative comparison of the ability of horizontal reinforcements to resist the development of strong earthquake surface fracture zones, which improves the accuracy of the test results.

[0139] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

[0140] Many other changes and modifications may be made without departing from the concept and scope of the present invention.It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A horizontal reinforced composite foundation test device for resisting strong earthquake surface fractures, characterized in that: It includes a test bedrock dislocation loading system, a data acquisition and analysis system (8) and sensors, and a building model (6); The experimental bedrock dislocation loading system comprises overall debugging of a hydraulic control system (1), four actuators (2), a dislocation box (7) and a wire displacement meter (3); The hydraulic control system (1) comprises a hydraulic control panel, a displacement signal display panel, a hydraulic output area and a displacement signal receiving area; The dislocation box (7) comprises high-strength resin glass test observation areas on the front and rear sides and steel plates on the left and right sides: a simulated bedrock "L"-shaped dislocation steel plate (4) and a simulated bedrock stationary plate steel plate (9) are provided at the bottom of the box, and a gap is left at the junction of the simulated bedrock "L"-shaped dislocation steel plate (4) and the simulated bedrock stationary plate steel plate (9) for simulating a fracture zone; A compacted soil covering layer is provided in the dislocation box (7); the upper portion of the simulated bedrock "L"-shaped dislocation steel plate (4) is a simulated covering layer zone I (14); the upper portion of the simulated bedrock stationary plate steel plate (9) is a simulated covering layer zone II (15); and the junction of the two zones is a geogrid arrangement zone (16); A groove is provided in the geogrid arrangement area (16) for arranging the building foundation (13) at the bottom of the building model (6); a geogrid (22) is arranged below the building foundation (13); There are four actuators (2), which are respectively located at the four corners of the "L"-shaped dislocation steel plate (4) simulating the bedrock; each actuator (2) is correspondingly provided with a wire displacement meter (3); the wire displacement meter (3) is fixed at the position of the support plate below the actuator (2), and the wire magnet head of the wire displacement meter (3) is vertically adsorbed upward on the lower side of the "L"-shaped dislocation steel plate (4); The signal receiving line of the wire displacement meter (3) is connected to the respective displacement signal receiving area of ​​the hydraulic control system (1); the actuator (2) is connected to the hydraulic output area of ​​the hydraulic control system (1) through a hydraulic oil pipe; The sensors include an earth pressure gauge (21), a strain gauge, a laser displacement meter (5) and a high-speed camera (10); the data acquisition and analysis system (8) is connected to each sensor respectively; A high-speed camera (10) is placed directly in front of the shifting box (7); A plurality of soil pressure gauges (21) are arranged above the junction of the two plates of the simulated bedrock "L"-shaped dislocation steel plate (4) and the simulated bedrock stationary plate steel plate (9) to monitor the soil pressure increment change of the rupture trace during the normal fault dislocation process; the soil pressure gauges (21) are arranged in the area where the first rupture trace (19) and the second rupture trace (20) are developed during the normal fault bedrock dislocation process; The geogrid strain gauges (17) are arranged at intervals on the geogrid (22) to analyze the fracture resistance of the horizontal reinforcement composite foundation; Arranging three-dimensional building side column strain gauges (18) at equal distances according to the floor height on the outside of the building side columns (11) of the building model (6) to monitor the strain of the building side columns (11) during the test and to analyze the fracture resistance of the horizontal reinforcement composite foundation; A plurality of laser displacement meters (5) are arranged on a beam above the soil cover layer to analyze the uneven deformation of the ground surface.

2. A test method for horizontally reinforced composite foundations resistant to strong earthquake surface fractures, characterized in that: The horizontal reinforcement composite foundation test device for resisting strong earthquake surface fracture according to claim 1 comprises the following steps: Debug the test bedrock dislocation loading system; Debugging the data acquisition and analysis system (8) and sensors; Prepare test model materials; Arrangement of test models and sensors; Carry out pre-test preparation and test process, gradually load bedrock displacement, and conduct multiple working condition tests; Finally, the data results are quantitatively and qualitatively analyzed, including the building inclination angle, soil pressure increment in the cover layer, geogrid strain increment, building strain increment and building foundation deformation analysis.

3. The horizontal reinforcement composite foundation test method for resisting strong earthquake surface fracture according to claim 2 is characterized in that: The test bedrock dislocation loading system debugging includes overall debugging of the hydraulic control system (1), four actuators (2), a dislocation box (7) and a wire displacement meter (3); Debugging methods, including: The wire displacement meter (3) is debugged. The first, second, third and fourth wire displacement meters (3) are fixed to the support plate below the actuator (2) respectively. The wire magnet head of the wire displacement meter (3) is vertically adsorbed upward on the lower side of the "L"-shaped dislocation steel plate (4). The verticality of the wire of the wire displacement meter (3) is measured and debugged with a level until the horizontal bubble is centered. The signal receiving wires of the wire displacement meter (3) are respectively connected to the respective displacement signal receiving areas of the hydraulic control system (1), and then the hydraulic control system (1) is started and the wire of the wire displacement meter (3) is slowly pulled out by 1 cm, and the displacement signal on the hydraulic control display panel is observed to be 1 cm, with an error of ±0.1%; The actuator (2) is connected to the hydraulic output area of ​​the hydraulic control system (1) with a hydraulic oil pipe and its sealing is checked; then, a lifting rate of 1 mm / s and a bedrock lifting amount of 10 mm are input into the hydraulic control panel, and the lifting of the actuator (2) is completed; then, a level ruler is used to measure the upper four corners of the "L"-shaped dislocated steel plate (4) to observe whether the bubble of the level ruler is centered.

4. The horizontal reinforcement composite foundation test method for resisting strong earthquake surface fracture according to claim 1 is characterized in that: The debugging of the data acquisition and analysis system (8) and sensors includes debugging of the soil pressure gauge (21), strain gauge, laser displacement meter (5) and high-speed camera (10); The debugging of the earth pressure gauge (21) includes connecting the earth pressure gauge (21) to the data acquisition and analysis system (8), calibrating the earth pressure gauge (21) using a water mark method, and observing whether the collected earth pressure is consistent with the calculated value through the data display window of the data acquisition and analysis system (8); The soil pressure gauge (21) is fixed at the 0 cm position of the end of a steel ruler with a scale of 1 m in length, connected to the data acquisition and analysis system (8) and reset to zero, and then placed at 10 cm, 50 cm, and 100 cm below the horizontal surface respectively and left to stand for 10 seconds, and the soil pressure in the data acquisition and analysis system (8) is observed to see whether the difference between the soil pressure and the actual value is within the range of ±5%, and the soil pressure sensitivity parameter is adjusted; The debugging of the laser displacement meter (5) includes: numbering a plurality of laser displacement meters (5) and connecting them to the data acquisition and analysis system (8) in sequence, fixing the laser displacement meters (5) on the same side of the square steel beam with double-sided tape and with the laser emission area on the same side, placing a rectangular wooden board 20 cm in front of the emission area of ​​the laser displacement meter (5) and ensuring that the distance data of the laser displacement meter (5) in the data acquisition and analysis system (8) is 20 cm, translating the rectangular wooden board 10 cm in a direction away from the laser displacement meter (5), and observing whether the data of the plurality of laser displacement meters (5) in the data acquisition and analysis system (8) are within the range of ±5% of the actual value of 30 cm; The debugging of the high-speed camera (10) includes: placing the high-speed camera (10) directly in front of the displacement box (7), adjusting the camera range until the entire test displacement box (7) is located within the field of view of the high-speed camera (10), analyzing the photographs of the soil body containing the fracture zone, observing whether the photographs of the test displacement box (7) are distorted, and adjusting the exposure and angle parameters of the high-speed camera (10).

5. The horizontal reinforcement composite foundation test method for resisting strong earthquake surface fracture according to claim 1 is characterized in that: The arrangement of the test model and the sensor specifically includes: Arrangement of the covering soil layer, compacting a 100 cm soil covering layer in the shift box (7); placing 15 cm of loose soil each time, using a rammer to compact from the leftmost side of the shift box (7), using a rammer to compact the loose soil to 13 cm for the first time, then using a rammer to compact the soil layer for the second time, compacting the soil layer to 12 cm until the third time compaction reaches 10 cm; compacting the soil layer to 70 cm according to the above method; arranging the geogrid (22) transverse reinforcement body at the corresponding position in the soil body from 70 cm to 100 cm, and then completing the soil compaction according to the above method; The arrangement of the geogrid (22) includes: arranging the geogrid (22) at the most unfavorable position of the fault displacement according to the building model (6), arranging the geogrid (22) in the geogrid arrangement area (16), pressing the four corners with virtual soil to lay strain gauges and connecting wires, laying virtual soil with a height of 15 cm and a thickness of 10 cm with a rammer, and measuring and correcting with a level ruler until it is level; The arrangement of the building model (6) includes: arranging the building model (6) at the most unfavorable position of the fault displacement, digging a square soil trench with a depth of 8 cm in the vertical direction of the ground surface, placing the building model (6) and the building foundation (13) in the soil trench and filling 9 cm of virtual soil, tamping and scraping it flat to the same height as the surface of the covering soil body; The arrangement of the earth pressure gauge (21) includes: the earth pressure gauge (21) is arranged in the area where the fracture trace develops during the normal fault bedrock dislocation process, and nine earth pressure gauges (21) are arranged at intervals of 10 cm just above the junction of the two plates to monitor the earth pressure increment change of the fracture trace during the normal fault dislocation process; The arrangement of the geogrid strain gauge (17) includes: arranging 10 strain gauges with a spacing of 10 cm in the middle of the geogrid (22) to analyze the fracture resistance of the horizontal reinforcement composite foundation; The arrangement of the strain gauges (18) of the building side columns includes: arranging three-dimensional strain gauges at equal distances according to the storey height on the outside of the building side columns (11) to monitor the strain of the building side columns (11) during the test process, so as to analyze the fracture resistance of the horizontal reinforcement composite foundation; The arrangement of the laser displacement meter (5) includes: arranging a plurality of laser displacement meters (5) at intervals of 40 cm starting from the right inner steel plate of the displacement box (7) on a beam 20 cm above the covering layer, so as to analyze the uneven deformation of the ground surface.

6. The horizontal reinforcement composite foundation test method for resisting strong earthquake surface fracture according to claim 1 is characterized in that: The stepwise loading of bedrock dislocation and multiple working condition tests are performed, including: Start the data acquisition and analysis system (8) to collect test data; start the hydraulic control system (1), first synchronously lift 1 mm, and observe whether the sensor reading is normal; perform 10 working conditions respectively, each time the wire displacement meter (3) inputs 10 mm bedrock displacement, and clears the data acquisition before each test.

7. The horizontal reinforcement composite foundation test method for resisting strong earthquake surface fracture according to claim 1 is characterized in that: The quantitative and qualitative analysis of the test results include: the inclination angle of the building, the analysis of the soil pressure increment in the covering layer, the strain increment analysis of each layer of the geogrid, that is, whether the strain of the geogrid adjacent to the building changes significantly, the strain increment analysis of the building, whether the building foundation passes through the fracture zone, and whether the building foundation produces obvious uneven deformation, that is, whether a stepped steep slope is produced.

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