Multifunctional intelligent tester for foundation reaction coefficient

Abstract

The invention provides a multifunctional foundation reaction coefficient intelligent tester, which comprises a rack, a confining pressure chamber, an air pressure loading system, an axial loading system and a data acquisition system, and is characterized in that the confining pressure chamber is arranged in the rack and is used for containing a test soil sample; the air pressure loading system is used for applying confining pressure and horizontal load to the test soil sample; the axial loading system is used for applying axial load to the test soil sample; and the data acquisition system is connected with the air pressure loading system and the axial loading system and is used for data acquisition and data processing. According to the method, the foundation reaction coefficient of the soil layer can be accurately obtained, the consolidation coefficient CV of the soil layer, the compression modulus Es of the soil layer and the elastic modulus E and K0d under the cyclic load condition can be approximately and continuously obtained, and related research on soil deformation and stability analysis under the cyclic load effect can be conveniently carried out; foundation settlement analysis can be carried out by utilizing the reaction coefficient and the compression modulus (Es) of the foundation.

Description

Technical Field

[0001] The invention relates to the technical field of detection equipment in civil engineering, and in particular to a multifunctional intelligent measuring instrument for foundation reaction force coefficient. Background Art

[0002] The foundation reaction coefficient is an important engineering parameter, especially in structures involving soil sample and structure interaction, which is affected by many factors. At present, the reliability of various engineering test methods is low, and the accuracy of in-situ tests is difficult to guarantee. The range of foundation reaction coefficients of each soil layer given in the standard method varies greatly, and it is difficult to determine the specific value based on the actual soil layer conditions.

[0003] Traditionally, foundation reaction coefficients are usually estimated through field experiments or back-calculated using empirical formulas, but the former is time-consuming and expensive, and the latter is overly dependent on a large amount of historical observation data. Therefore, how to effectively obtain foundation reaction coefficients has always been one of the difficult problems in the geotechnical engineering community.

[0004] The pneumatic double foundation reaction coefficient tester is a lateral load test that has little disturbance to the soil and can provide continuous soil parameters. The pneumatic double multifunctional foundation reaction coefficient tester simulates the stress state of the soil in different directions by applying air pressure, and tests the stress-strain relationship of the soil under vertical and horizontal loads. The equipment can load and unload in multiple directions, thereby more comprehensively reflecting the mechanical properties of the foundation soil, especially the foundation reaction coefficient.

[0005] The pneumatic double foundation reaction coefficient measuring instrument can not only accurately obtain the foundation reaction coefficient of the soil layer, but also approximately and continuously obtain the soil consolidation coefficient C. V , the compression modulus Es of the soil, and the elastic modulus E and K under cyclic loading conditions 0d Carrying out on-site in-situ tests based on actual projects is undoubtedly the most direct and reliable method, but on-site tests are expensive, severely affected by site conditions and construction environment, and test details are not easy to grasp and control. Therefore, developing an indoor test device to quickly determine the foundation reaction coefficient has great practical and economic value, and the loading conditions of indoor tests are easy to control, the test is efficient and fast, and the cost is lower than on-site tests.

[0006] However, there is currently no device or standard test method for measuring various soil-related parameters based on the indoor determination of foundation reaction coefficients. The foundation reaction coefficient is affected by many factors, which are closely related to the physical and mechanical properties of the soil, load characteristics, foundation form and environmental conditions. In particular, determining the foundation reaction coefficient under different loads is a difficult problem. Using indoor test equipment to simulate different loading modes of the soil and then testing the foundation reaction coefficient is an effective solution. Summary of the invention

[0007] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a multifunctional intelligent foundation reaction coefficient measuring instrument, which is used to solve the problem that there is no device and standard test method in the prior art for simultaneously measuring multiple soil-related parameters based on indoor determination of foundation reaction coefficient. By simulating different loading modes of soil through indoor test equipment, the foundation reaction coefficient is tested, thereby solving the problems of expensive testing costs at the construction site, serious influence of site conditions and construction environment, and difficulty in controlling test details.

[0008] To achieve the above-mentioned purpose and other related purposes, the present invention provides a multifunctional intelligent measuring instrument for foundation reaction coefficient, including a frame, a confining pressure chamber, a pneumatic loading system, an axial loading system, and a data acquisition system. The confining pressure chamber is arranged in the frame for containing test soil samples; the pneumatic loading system is used to apply confining pressure and horizontal load to the test soil samples; the axial loading system is used to apply axial load to the test soil samples; the data acquisition system is connected with the pneumatic loading system and the axial loading system for data acquisition and data processing.

[0009] Preferably, the frame includes a frame base, a frame support rod, and a frame top plate, the bottom end of the frame support rod is fixedly connected to the frame base, and the frame top plate is fixedly connected to the top end of the frame support rod; the confining pressure chamber is arranged on the frame base, and the frame top plate is located on the upper side of the confining pressure chamber.

[0010] Preferably, the confining pressure chamber includes a confining pressure chamber base, a confining pressure chamber top cover, a confining pressure chamber connecting rod, a soil sample base, and a glass tube, the confining pressure chamber base is placed on the frame base, and the soil sample base is placed on the confining pressure chamber base; the glass tube is an open piece at both ends, the glass tube is covered on the confining pressure chamber base, and the soil sample base is located inside the glass tube; the confining pressure chamber top cover is placed on the top end surface of the glass tube, and the confining pressure chamber top cover is connected to the confining pressure chamber base through the confining pressure chamber connecting rod; the confining pressure chamber base, the confining pressure chamber top cover and the glass tube are airtightly connected; a positioning groove is also provided on the confining pressure chamber base, and the bottom end of the glass tube is placed in the positioning groove; a base air inlet cavity is provided in the confining pressure chamber base, a plurality of base air inlet holes are opened on the base air inlet cavity, and the base air inlet holes are connected with the inside of the glass tube; a glass tube air inlet hole is opened on the glass tube; the base air inlet cavity and the glass tube air inlet hole are both connected with the air pressure loading system.

[0011] Preferably, a drainage hole is provided on the base of the confining pressure chamber, and a drainage valve is provided in the drainage hole.

[0012] Preferably, the air pressure loading system includes an air source supply device, a pressure regulator, an air pressure loading controller, and several pipelines, the air source supply device is connected to a high-pressure air source, the pressure regulator is connected to several pipelines, the pressure regulator is used to adjust the pressure of the high-pressure air source; the several pipelines are respectively connected to the base air inlet cavity and the glass tube air inlet hole; the air pressure loading controller is used to control the opening and closing of several pipelines.

[0013] Preferably, the glass cylinder has two air inlet holes, either one of which is connected to a pipeline, and the other is provided with an air pressure sensor, and the air pressure sensor is communicatively connected to a data acquisition system.

[0014] Preferably, the axial loading system includes an axial loading source, an axial transmission assembly, a movable beam, a clamping seat, a loading rod, a displacement sensor, and a pressure sensor; the axial loading source is arranged on a frame base, the movable beam can be raised and lowered on a frame support rod, the clamping seat is arranged on the movable beam, and the loading rod is installed in the clamping seat; the displacement sensor and the pressure sensor are both communicatively connected to a data acquisition system for detecting the movement displacement of the loading rod and the magnitude of the reaction force exerted on the loading rod when inserted into a test soil sample; the axial loading source is transmission-connected to the movable beam via an axial transmission assembly, the movable beam moves up and down on the frame support rod, and the loading rod passes through a top cover of the confining pressure chamber and is inserted into the test soil sample in the confining pressure chamber.

[0015] Preferably, a confining pressure chamber top cover piston is detachably provided on the confining pressure chamber top cover, and airtight glue is provided in the confining pressure chamber top cover piston; when the loading rod applies axial pressure to the test soil sample, the loading rod penetrates the airtight glue in the confining pressure chamber top cover piston and enters the confining pressure chamber.

[0016] Preferably, the axial transmission assembly includes a transmission shaft, a commutator, a screw, a slider, and a guide rail, wherein the guide rail is arranged on a frame support rod, the slider is slidably arranged on the guide rail, and the slider is fixedly connected to the movable crossbeam; a threaded hole is opened on the slider, and the screw is passed through the threaded hole; the transmission shaft is connected to the screw through a commutator; and the transmission shaft is connected to an axial loading source.

[0017] Preferably, the data acquisition system includes a main control cabinet and a PC terminal, wherein the PC terminal is communicatively connected to the main control cabinet; and the main control cabinet is communicatively connected to the pneumatic loading system and the axial loading system.

[0018] As described above, the multifunctional intelligent measuring instrument for foundation reaction coefficient according to the present invention has the following beneficial effects:

[0019] The multifunctional intelligent measuring instrument for foundation reaction coefficient of the present invention can obtain the foundation reaction coefficient of the soil layer more accurately, and then can approximately and continuously obtain the consolidation coefficient C of the soil layer.V , the compression modulus Es of the soil layer, and the elastic modulus E and K under cyclic loading conditions 0d , which is convenient for conducting relevant research on soil deformation and stability analysis under cyclic loads; using the foundation reaction coefficient and compression modulus (Es), foundation settlement analysis can be carried out, especially to evaluate the settlement amount and settlement speed of buildings or structures under load. In addition, by controlling the gas pressure and feedback monitoring of other sensors, the initial conditions of the soil in multiple groups of tests can be controlled to adapt to different test needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the spatial structure of the multifunctional intelligent measuring instrument for foundation reaction force coefficient of the present invention;

[0021] Figure 2 The graph is a graph of the pressure and deformation in the test soil sample measured by the multifunctional intelligent measuring instrument for foundation reaction force coefficient of the present invention.

[0022] Description of reference numerals:

[0023] 1. Rack base; 2. Rack support rod; 3. Rack top plate; 4. Confining pressure chamber base; 401. Drain hole; 5. Soil sample base; 6. Glass cylinder; 601. Air pressure sensor; 602. Air inlet hole of glass cylinder; 7. Confining pressure chamber top cover; 8. Confining pressure chamber connecting rod; 9. Confining pressure chamber top cover piston; 10. Moving crossbeam; 1001. Displacement sensor; 11. Clamping seat; 1101. Pressure sensor; 12. Loading rod; 13. Slider; 14. Guide rail; 15. Screw; 16. Commutator; 17. Drive shaft; 18. Axial loading source; 19. Air pressure loading system; 20. Main control cabinet; 21. PC terminal. DETAILED DESCRIPTION

[0024] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0025] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0026] like Figure 1 As shown, the present invention provides a multifunctional intelligent measuring instrument for foundation reaction coefficient, including a frame, a confining pressure chamber, a pneumatic loading system 19, an axial loading system, and a data acquisition system. The confining pressure chamber is arranged in the frame for containing test soil samples; the pneumatic loading system 19 is used for applying confining pressure and horizontal load to the test soil samples; the axial loading system is used for applying axial load to the test soil samples; the data acquisition system is connected with the pneumatic loading system 19 and the axial loading system for data acquisition and data processing.

[0027] The multifunctional intelligent measuring instrument for foundation reaction coefficient involved in the present invention is provided with a confining pressure chamber and an air pressure loading system 19. The air pressure loading system 19 can apply confining pressure to the test soil sample, so that the test soil sample exhibits mechanical behavior similar to that of the actual foundation under different confining pressure conditions, that is, the test soil sample is consolidated under a certain confining pressure. Then, a horizontal load is applied through the air pressure loading system 19, and the reaction of the actual foundation when it is subjected to the horizontal load is judged by the reaction of the test soil sample when it is subjected to the horizontal load. An axial loading system is provided, and an axial load can be applied. The reaction of the actual foundation when it is subjected to the axial load is judged by the reaction of the test soil sample when it is subjected to the axial load. The detection of the foundation reaction coefficient can be completed indoors, which solves the problems in the prior art that the on-site test is expensive, seriously affected by the site conditions and the construction environment, and the test details are difficult to control.

[0028] Preferably, Figure 1As shown, the rack includes a rack base 1, a rack support rod 2, and a rack top plate 3, the bottom end of the rack support rod 2 is fixedly connected to the rack base 1, and the rack top plate 3 is fixedly connected to the top of the rack support rod 2; the confining pressure chamber is arranged on the rack base 1, and the rack top plate 3 is located on the upper side of the confining pressure chamber. In this embodiment, the number of racks is two groups, the number of confining pressure chambers is two, the number of rack support rods 2 in each group of racks is two, the number of rack top plate 3 is one, and the two rack support rods 2 and one rack top plate 3 form a "door" shape. The purpose of the rack top plate 3 is to ensure the stability of the rack support rod 2.

[0029] Preferably, Figure 1 As shown, the confining pressure chamber includes a confining pressure chamber base 4, a confining pressure chamber top cover 7, a confining pressure chamber connecting rod 8, a soil sample base 5, and a glass tube 6. The confining pressure chamber base 4 is placed on the frame base 1, and the soil sample base 5 is placed on the confining pressure chamber base 4; the glass tube 6 is an opening at both ends, the glass tube 6 is covered on the confining pressure chamber base 4, and the soil sample base 5 is located inside the glass tube 6; the confining pressure chamber top cover 7 is placed on the top end surface of the glass tube 6, and the confining pressure chamber top cover 7 is connected to the confining pressure chamber base 4 through the confining pressure chamber connecting rod 8. Connection; the confining pressure chamber base 4, the confining pressure chamber top cover 7 and the glass tube 6 are airtightly connected; a positioning groove is also provided on the confining pressure chamber base 4, and the bottom end of the glass tube 6 is placed in the positioning groove; a base air inlet cavity is provided in the confining pressure chamber base 4, and a plurality of base air inlet holes are opened on the base air inlet cavity, and the base air inlet hole is connected with the interior of the glass tube 6; a glass tube air inlet hole 602 is opened on the glass tube 6; the base air inlet cavity and the glass tube air inlet hole 602 are both connected with the air pressure loading system 19.

[0030] In this embodiment, a plurality of threaded holes of the confining pressure chamber base 4 are provided, a plurality of confining pressure chamber top cover connecting holes are provided on the confining pressure chamber top cover 7, and the confining pressure chamber connecting rod 8 is a stud, so the bottom end of the confining pressure chamber connecting rod 8 is screwed into the threaded hole of the confining pressure chamber base to fix the confining pressure chamber connecting rod 8, and then the confining pressure chamber top cover connecting hole is sleeved on the outer periphery of the confining pressure chamber connecting rod 8, and then a nut is screwed into the confining pressure chamber connecting rod 8, so that the confining pressure chamber top cover 7 is pressed on the top end of the glass tube 6. The glass tube 6 is made of organic glass.

[0031] Further, such as Figure 1 As shown, the soil sample base 5, the confining pressure chamber top cover 7, and the confining pressure chamber base 4 are all cylindrical, the diameter of the confining pressure chamber base 4 is larger than the diameter of the soil sample base 5, the diameter of the glass tube 6 is larger than the diameter of the soil sample base 5 and smaller than the diameter of the confining pressure chamber base 4, and a plurality of base air inlet holes are opened on the confining pressure chamber base 4 between the glass tube 6 and the soil sample base 5.

[0032] Preferably, Figure 1As shown, a drainage hole 401 is also provided on the outer peripheral surface of the confining pressure chamber base 4, and a drainage valve is provided in the drainage hole 401. The drainage hole 401 is connected to the inside of the glass cylinder 6, and is used to discharge the pore water of the soil sample when the test soil sample is consolidated. The drainage valve is used to control the opening and closing of the drainage hole 401.

[0033] Preferably, in this embodiment, the air pressure loading system 19 includes an air source supply device, a pressure regulator, an air pressure loading controller, and a plurality of pipelines. The air source supply device is connected to the high-pressure air source, and the pressure regulator is connected to the plurality of pipelines. The pressure regulator is used to adjust the pressure of the high-pressure air source; the plurality of pipelines are respectively connected to the air inlet cavity of the base and the air inlet hole 602 of the glass tube; and the air pressure loading controller is used to control the opening and closing of the plurality of pipelines. The pressure regulator and the air pressure loading controller are both communicatively connected to the main control cabinet 20. The air pressure loading system 19 is used to uniformly load the test soil sample so that the test soil sample exhibits mechanical behavior similar to that of the actual foundation under different stress conditions.

[0034] Preferably, Figure 1 As shown, there are two glass cylinder air inlet holes 602, one of which is connected to a pipeline, and the other is provided with an air pressure sensor 601, which is connected to a data acquisition system. In this embodiment, the air pressure sensor 601 is used to detect the size of the confining pressure on the test soil sample in the glass cylinder 6; the pipeline connected to the other glass cylinder air inlet hole 602 is used to pass a high-pressure gas source into the glass cylinder 6 to apply confining pressure and horizontal load.

[0035] Preferably, Figure 1 As shown, the axial loading system includes an axial loading source 18, an axial transmission assembly, a movable beam 10, a clamping seat 11, a loading rod 12, a displacement sensor 1001, and a pressure sensor 1101. The axial loading source 18 is arranged in the frame base 1, the movable beam 10 is arranged on the frame support rod 2 in a liftable manner, the clamping seat 11 is arranged on the movable beam 10, and the loading rod 12 is installed in the clamping seat 11; the displacement sensor 1001 and the pressure sensor 1101 are both communicatively connected with the data acquisition system, and are used to detect the movement displacement of the loading rod 12 and the magnitude of the reaction force received by the loading rod 12 when inserted into the test soil sample; the axial loading source 18 is transmission-connected to the movable beam 10 through the axial transmission assembly, the movable beam 10 moves up and down on the frame support rod 2, and the loading rod 12 passes through the top cover 7 of the confining pressure chamber and is inserted into the test soil sample in the confining pressure chamber.

[0036] In this embodiment, the axial loading source 18 adopts an AC servo motor. The servo motor can apply a maximum pressure of 150KN and can achieve stepless speed regulation at 0.01-500mm / min, which can ensure axial constant speed loading (strain control) or constant pressure loading (stress control) during the test. The clamping seat 11 is used to clamp the loading rod 12. The pressure sensor 1101 is arranged in the clamping seat 11, and the top of the loading rod 12 is in contact with the pressure sensor 1101. In this way, when the loading rod 12 penetrates into the test soil sample, the pressure sensor 1101 can detect the reaction force applied by the test soil sample to the loading rod 12. The displacement sensor 1001 is arranged on the moving beam 10 to judge the displacement change of the moving beam 10 (the frame top plate 3 can be used as the reference plane, and the confining pressure chamber top cover 7 can also be used as the reference plane), and then the lifting displacement of the loading rod 12 is obtained.

[0037] Preferably, Figure 1 As shown, a confining pressure chamber top cover piston 9 is detachably provided on the confining pressure chamber top cover 7, and an airtight glue is provided in the confining pressure chamber top cover piston 9; when the loading rod 12 applies axial pressure to the test soil sample, the loading rod 12 penetrates the airtight glue in the confining pressure chamber top cover piston 9 and enters the confining pressure chamber.

[0038] In this embodiment, the piston 9 of the confining pressure chamber top cover is in the shape of a three-way valve, and has three openings on the piston 9, namely, a first opening, a second opening, and a third opening, wherein the first opening and the second opening are on the same straight line, and the loading rod 12 sequentially passes through the first opening and the second opening to enter the glass cylinder 6. The third opening is used to inject airtight glue into the confining pressure chamber top cover 7, and the airtight glue adopts a sealing material that is easy to clean.

[0039] Preferably, Figure 1 As shown, the axial transmission assembly includes a transmission shaft 17, a commutator 16, a screw 15, a slider 13, and a guide rail 14. The guide rail 14 is arranged on the frame support rod 2, and the slider 13 is slidably arranged on the guide rail 14. The slider 13 is fixedly connected to the moving beam 10; a threaded hole is opened on the slider 13, and the screw 15 is passed through the threaded hole; the transmission shaft 17 is transmission-connected to the screw 15 through the commutator 16; the transmission shaft 17 is connected to the axial loading source 18.

[0040] In this embodiment, the top end of the screw rod 15 is rotatably disposed on the frame top plate 3, and the frame top plate 3 also provides a limit for the movement of the slider 13 on the screw rod 15. The axial transmission assembly is a prior art and will not be repeated here.

[0041] Preferably, Figure 1 As shown, the data acquisition system includes a main control cabinet 20 and a PC terminal 21, wherein the PC terminal 21 is connected to the main control cabinet 20 for communication; the main control cabinet 20 is connected to the air pressure loading system 19 and the axial loading system for communication.

[0042] In this embodiment, the main control cabinet 20 is respectively connected to the pressure regulator, the air pressure loading controller, the air pressure sensor 601, the axial loading source 18, the displacement sensor 1001, and the pressure sensor 1101 for collecting the detection parameters of the above-mentioned components and analyzing the detection parameters. The PC terminal 21 is connected to the main control cabinet 20 for the convenience of the operator to control and monitor the test process in real time. The foundation reaction force coefficient can also be exported and saved through the PC terminal 21.

[0043] The multifunctional intelligent measuring instrument for foundation reaction force coefficient according to the present invention has the following working steps:

[0044] S1: The operator shall follow the attached Figure 1 and descriptions of the above-mentioned parts, produce and assemble the above-mentioned parts;

[0045] S2: The operator selects the test soil sample and places it on the soil sample base 5, then places the bottom end of the glass tube 6 in the positioning groove on the confining pressure chamber base 4, then sets the confining pressure chamber top cover 7 on the confining pressure chamber connecting rod 8, and uses a nut to press the confining pressure chamber top cover 7 onto the top of the glass tube 6;

[0046] S3: injecting airtight glue into the piston 9 of the top cover of the confining pressure chamber, and at the same time testing the airtightness of the glass cylinder 6 in step S2 to ensure good airtightness;

[0047] S4: Open the air pressure loading system 19 through the main control cabinet 20, the air source supply device provides high-pressure air (or high-pressure nitrogen), and then adjust the pressure of the air source through the pressure regulator, and then open each pipeline through the air pressure loading controller, and the gas enters the glass tube 6 through the base air inlet cavity, the base air inlet hole, and the glass tube air inlet hole 602, ensuring that the pressure in all directions inside the glass tube 6 is the same;

[0048] S5: Observe the size of the confining pressure in the glass cylinder 6 through the air pressure sensor 601 on the air inlet 602 of the glass cylinder, and adjust the size of the confining pressure according to the deadweight stress of the test soil sample in the actual project or the expected confining pressure conditions. Generally speaking, the confining pressure should be increased gradually to avoid sudden damage to the test soil sample. When the confining pressure gradually increases, open the drain valve on the outer peripheral surface of the confining pressure chamber base 4 to drain the pore water in the test soil sample so that the soil sample reaches a consolidated state;

[0049] S6: Real-time monitoring of the volume change or the change in the drainage volume of the test soil sample by means of the glass cylinder 6 to determine whether the test soil sample has completed consolidation;

[0050] S7: After the test soil sample is consolidated in step S6, the operator may apply an axial load and a horizontal load to the test soil sample;

[0051] S7.1: When the axial load is applied, the axial loading source 18 is started. The axial loading source 18 drives the screw 15 to rotate through the transmission shaft 17 and the commutator 16, and then the slider 13 drives the moving beam 10 to descend on the guide rail 14. The moving beam 10 drives the loading rod 12 to move downward. The loading rod 12 pierces the airtight glue in the piston 9 of the top cover of the confining pressure chamber and enters the glass tube 6, and then continues to descend and penetrates into the test soil sample. At this time, the test soil sample will exert a reaction force on the loading rod 12, and the pressure sensor 1101 collects the reaction force and feeds it back to the main control cabinet 20. The displacement sensor 1001 is used to detect the displacement of the loading rod 12 when it descends, so as to determine the magnitude of the reaction force exerted on the loading rod 12 by the test soil samples of different depths. The displacement sensor 1001 also feeds back the displacement of the loading rod 12 when it descends to the main control cabinet 20; this is used to determine the reaction of the test soil sample when it is subjected to the axial load;

[0052] S7.2: When applying a horizontal load, the air pressure loading system 19 is started, the air source supply device provides high-pressure air (or high-pressure nitrogen), and then the pressure of the air source is adjusted by the pressure regulator, and then the pipeline of the glass cylinder air inlet hole 602 is opened by the air pressure loading controller, and the gas enters the glass cylinder air inlet hole 602 through the pipeline, and the air applies a horizontal load to the test soil sample, so as to judge the reaction of the test soil sample when subjected to the horizontal load;

[0053] S7.3: When the axial load and the horizontal load are applied simultaneously, the axial loading source 18 and the air pressure loading system 19 are started simultaneously, so as to determine the reaction of the test soil sample when the axial load and the horizontal load are applied simultaneously; the specific operation is the same as step S7.1 and step S7.2, and will not be repeated here;

[0054] S8: After the load application in step S7 is completed, the main control cabinet 20 sorts and processes the parameters, and then displays and draws a parameter diagram of the test soil sample through the PC terminal 21 (such as Figure 2 Then archive;

[0055] S9: After the test is completed, the above-mentioned components are disassembled, the test soil sample is taken out from the glass cylinder 6, and the glass cylinder 6 is cleaned; the airtight glue in the piston 9 of the top cover of the confining pressure chamber is cleaned.

[0056] Preferably, in step S2, the test soil sample is usually cylindrical or cubic, and the shape should meet the measurement requirements, and the test soil sample should be uniform and free of gaps. In order to prevent water loss or air pressure leakage during the test, the upper and side parts of the test soil sample should be wrapped with a film or sealed with other materials to maintain the initial moisture content and state of the test soil sample.

[0057] Preferably, in step S4, the key step of consolidating the test soil sample is that the air pressure in all directions must be equal. Once the gas enters the glass tube 6, the gas will fill the internal space of the glass tube 6 and be evenly applied to the top, bottom and sides of the test soil sample, thereby achieving isotropic consolidation.

[0058] Preferably, in step S5, the confining pressure should be gradually increased, and the typical confining pressure can range from tens to hundreds of KPa, and the specific value depends on the test requirements. The purpose of opening the drain valve is to simulate the consolidation of the soil under drainage conditions. While applying the confining pressure, the test soil sample is allowed to drain. When the pore water in the test soil sample is under pressure, it will be gradually discharged, and the test soil sample reaches a consolidated state. However, for the test soil sample that does not meet the drainage conditions, the drain valve is closed. Under this condition, after applying the confining pressure, the pore water pressure inside the test soil sample will rise, and the test soil sample will consolidate under the action of the pore water pressure. Control of the consolidation time of the test soil sample: It usually takes a certain amount of time for the test soil sample to reach the consolidated state, which depends on the permeability of the test soil sample and the test requirements. For highly permeable sand, the consolidation time is shorter; for low permeability clay, the consolidation time is longer. The operator can determine whether the test soil sample has completed consolidation by detecting the volume change and drainage change of the test soil sample. The stress and strain data during the consolidation process will gradually tend to be stable. Of course, the displacement and volume change rates can also be monitored at all times through the PC terminal 21, the main control cabinet 20, and other instruments that monitor volume changes and displacement changes. When these change rates are reduced to a certain extent, it can be considered that the test soil sample has completed consolidation. In addition, in some cases, the consolidation of the test soil sample can be carried out in stages as needed, such as gradually increasing the confining pressure, and then maintaining each confining pressure for a period of time until the test soil sample reaches a stable state under a higher pressure. This staged and gradual pressurization method can better simulate the consolidation behavior of the soil under gradual pressure, especially for deeply buried soil layers. After consolidation is completed, the end pressure is maintained for a period of time to ensure that the test soil sample reaches a completely consolidated state. The end pressure is usually the initial stress state required for actual testing.

[0059] Preferably, when applying the axial load in step S7.1, the axial load source 18 can be controlled by the PC terminal 21 and the main control cabinet 20 to apply the axial pressure in two ways: constant speed loading or constant pressure loading.

[0060] Preferably, in step S8, the operator sets the relevant dimensions of the test soil sample, the frequency of collecting various data during the test, and various control parameters of the test loading (such as loading rate, limited maximum displacement) through the PC terminal 21, and then draws the variable tracking curve of the test soil sample during the test in real time according to the data collected by each sensor, with the horizontal axis set to the test time or axial displacement, and the vertical axis set to variables such as load or confining pressure.

[0061] The multifunctional intelligent measuring instrument for foundation reaction coefficients of the present invention is a device designed to measure test soil samples indoors, which is easy to control, has efficient and fast measurement, and has a lower cost than field tests. It solves the problems that field tests are expensive, are seriously affected by site conditions and construction environment, and are difficult to control test details. The present invention can not only obtain the reaction coefficient of the foundation more accurately, but also obtain the consolidation coefficient C of the test soil sample approximately and continuously. V , the compression modulus Es of the soil, and the elastic modulus E and K under cyclic loading conditions 0d . It is convenient to carry out relevant research on soil deformation and stability analysis under cyclic loading.

[0062] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0063] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A multifunctional intelligent measuring instrument for foundation reaction coefficient, characterized in that: The invention comprises a frame, a confining pressure chamber, a pneumatic loading system (19), an axial loading system, and a data acquisition system. The confining pressure chamber is arranged in the frame and is used to contain test soil samples. The pneumatic loading system (19) is used to apply confining pressure and horizontal load to the test soil samples. The axial loading system is used to apply axial load to the test soil samples. The data acquisition system is connected to the pneumatic loading system (19) and the axial loading system and is used for data acquisition and data processing.

2. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 1 is characterized in that: The frame comprises a frame base (1), a frame support rod (2), and a frame top plate (3); the bottom end of the frame support rod (2) is fixedly connected to the frame base (1), and the frame top plate (3) is fixedly connected to the top end of the frame support rod (2); the confining pressure chamber is arranged on the frame base (1), and the frame top plate (3) is located on the upper side of the confining pressure chamber.

3. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 2 is characterized in that: The confining pressure chamber comprises a confining pressure chamber base (4), a confining pressure chamber top cover (7), a confining pressure chamber connecting rod (8), a soil sample base (5), and a glass cylinder (6); the confining pressure chamber base (4) is placed on the frame base (1), and the soil sample base (5) is placed on the confining pressure chamber base (4); the glass cylinder (6) is a member with openings at both ends, the glass cylinder (6) covers the confining pressure chamber base (4), and the soil sample base (5) is located inside the glass cylinder (6); the confining pressure chamber top cover (7) is placed on the top end surface of the glass cylinder (6), and the confining pressure chamber top cover (7) is connected to the confining pressure chamber base (4) through the confining pressure chamber connecting rod (8); the confining pressure chamber base (4), the confining pressure chamber top cover (7), and the glass cylinder (6) are hermetically connected; The confining pressure chamber base (4) is also provided with a positioning groove, and the bottom end of the glass cylinder (6) is placed in the positioning groove; The base (4) of the confining pressure chamber is provided with a base air inlet cavity, and a plurality of base air inlet holes are opened on the base air inlet cavity, and the base air inlet holes are connected with the interior of the glass cylinder (6); the glass cylinder (6) is provided with a glass cylinder air inlet hole (602); the base air inlet cavity and the glass cylinder air inlet hole (602) are both connected with the air pressure loading system (19).

4. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 3 is characterized in that: The confining pressure chamber base (4) is also provided with a drainage hole (401), and a drainage valve is arranged in the drainage hole (401).

5. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 3 is characterized in that: The air pressure loading system (19) includes an air source supply device, a pressure regulator, an air pressure loading controller, and a plurality of pipelines. The air source supply device is connected to a high-pressure air source, the pressure regulator is connected to a plurality of pipelines, and the pressure regulator is used to adjust the pressure of the high-pressure air source; the plurality of pipelines are respectively connected to the base air inlet cavity and the glass tube air inlet hole (602); the air pressure loading controller is used to control the opening and closing of the plurality of pipelines.

6. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 5 is characterized in that: The glass cylinder has two air inlet holes (602), one of which is connected to a pipeline, and the other is provided with an air pressure sensor (601), and the air pressure sensor (601) is communicatively connected to a data acquisition system.

7. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 3 is characterized in that: The axial loading system comprises an axial loading source (18), an axial transmission assembly, a movable crossbeam (10), a clamping seat (11), a loading rod (12), a displacement sensor (1001), and a pressure sensor (1101); the axial loading source (18) is arranged in a frame base (1); the movable crossbeam (10) is arranged on a frame support rod (2) in a manner that it can be raised or lowered; the clamping seat (11) is arranged on the movable crossbeam (10); and the loading rod (12) is installed in the clamping seat (11); the displacement sensor (1001) and the pressure sensor (1101) are both connected to a data acquisition system for communication, and are used to detect the movement displacement of the loading rod (12) and the magnitude of the reaction force applied to the loading rod (12) when the loading rod (12) is inserted into a test soil sample; The axial loading source (18) is connected to the movable crossbeam (10) through an axial transmission assembly. The movable crossbeam (10) moves up and down on the frame support rod (2). The loading rod (12) penetrates the top cover (7) of the confining pressure chamber and is inserted into the test soil sample in the confining pressure chamber.

8. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 7 is characterized in that: The confining pressure chamber top cover (7) is detachably provided with a confining pressure chamber top cover piston (9), and the confining pressure chamber top cover piston (9) is provided with airtight glue; when the loading rod (12) applies axial pressure to the test soil sample, the loading rod (12) penetrates the airtight glue in the confining pressure chamber top cover piston (9) and enters the confining pressure chamber.

9. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 8 is characterized in that: The axial transmission assembly comprises a transmission shaft (17), a commutator (16), a screw rod (15), a slider (13), and a guide rail (14); the guide rail (14) is arranged on a frame support rod (2); the slider (13) is slidably arranged on the guide rail (14); the slider (13) is fixedly connected to a movable crossbeam (10); a threaded hole is provided on the slider (13); the screw rod (15) is passed through the threaded hole; the transmission shaft (17) is transmission-connected to the screw rod (15) through the commutator (16); and the transmission shaft (17) is connected to an axial load source (18).

10. The multifunctional intelligent measuring instrument for foundation reaction coefficient according to claim 1 is characterized in that: The data acquisition system comprises a main control cabinet (20) and a PC terminal (21), wherein the PC terminal (21) is communicatively connected to the main control cabinet (20); and the main control cabinet (20) is communicatively connected to a pneumatic loading system (19) and an axial loading system.

Images