Bidirectional sliding type side pressure test device and test method thereof
The internal and external bidirectional sliding pressure gauge test device solves the problems of pressure loss and measurement error in existing equipment by combining bidirectional sliding fixtures and sensors, and realizes accurate measurement and efficient testing under large aperture conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGJIANG RIVER SCI RES INST CHANGJIANG WATER RESOURCES COMMISSION
- Filing Date
- 2023-04-13
- Publication Date
- 2026-07-21
AI Technical Summary
Existing pressuremeter testing equipment suffers from problems such as pressure loss during probe expansion, large measurement errors, and low test success rate. It is particularly difficult to accurately measure the critical pressure and ultimate pressure under conditions of large pore size and complex formations.
The device employs a bidirectional sliding pressure gauge, which uses bidirectional sliding fixtures to seal the inner and outer cavities. Combined with pressure and displacement sensors, it enables accurate measurement of the internal expansion pressure and radial expansion deformation of the probe, eliminating the effects of pressure loss and irrelevant volume increase.
It improves the success rate and accuracy of pressuremeter tests, with a maximum test pressuremeter expansion volume of 1500 mL, reduces human error, and ensures the continuity and accuracy of test data.
Smart Images
Figure CN116359025B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geotechnical material testing instruments, and in particular to an internal and external bidirectional sliding pressuremeter test device and its test method. Background Technology
[0002] The pressuremeter test is one of the most widely used in-situ testing methods in geotechnical engineering, especially suitable for the exploration of deep strata. The basic principle of the pressuremeter test is to use the elastic membrane in the pressuremeter device to apply lateral pressure to the borehole wall in the borehole, causing the surrounding soil to undergo radial expansion deformation. The strength deformation parameters of the foundation soil are obtained by measuring the relationship curve between pressure and deformation.
[0003] In existing pressuremeter testing equipment, the pressuremeter and the pressuremeter probe are connected by a flexible hose. Water is forced into the pressuremeter probe through the hose, causing the elastic membrane to expand and thus apply pressure to the surrounding soil. The pressure inside the pressuremeter represents the pressure inside the pressuremeter probe, and the volume of water injected represents the expansion volume of the pressuremeter probe. Existing pressuremeter testing equipment mainly suffers from the following problems:
[0004] (1) During the expansion of the probe, there is a certain pressure loss in the elastic membrane of the pressure-spot probe, and there is a certain volume increase in the pressure-spot instrument and hose that is unrelated to the expansion of the pressure-spot probe. Moreover, the longer the connecting hose is, the greater the error. It is very tedious and time-consuming to perform elastic membrane constraint force correction and instrument comprehensive deformation correction before each test.
[0005] (2) During the test, the elastic membrane of the measuring cavity of the pressure meter probe did not expand radially in a completely uniform manner. The method of converting the radial deformation of the surrounding soil by the volume of water injected has certain errors. As a result, the pressure meter curve measured by the existing pressure meter test equipment cannot accurately reflect the stress-deformation relationship of the tested soil. The measurement accuracy needs to be improved.
[0006] (3) When conducting field pressure test, the diameter of the pressure test hole obtained by drilling is generally too large. When using the existing pressure probe for field test, the test often fails because the pressure and ultimate pressure cannot be measured due to insufficient pressure expansion. Moreover, as the test depth increases, the pressure expansion required to measure the complete pressure test curve also increases, and the test success rate decreases. Summary of the Invention
[0007] In view of this, the present invention provides an internal and external bidirectional sliding pressure meter test device and its test method, which can adapt to working conditions with large pressure meter expansion, realize accurate measurement of probe pressure and expansion deformation, effectively improve the success rate and accuracy of field pressure meter tests, and thus is more suitable for practical use.
[0008] To achieve the first objective mentioned above, the technical solution of the internal and external bidirectional sliding pressure meter testing device provided by the present invention is as follows:
[0009] The bidirectional sliding pressure-suppressing test device provided by this invention includes a mandrel (1), a first central cylinder (2), a second central cylinder (3), an inner cavity elastic membrane (7), an outer cavity elastic membrane (8), an inner cavity bidirectional sliding fixing component (4), an outer cavity bidirectional sliding fixing component (5), an inner cavity pressure sensor (11), an outer cavity pressure sensor (12), a displacement sensor (13), and a pressure supply mechanism.
[0010] The first central cylinder (2) is fixedly sleeved in the middle of the mandrel (1), and the second central cylinder (3) is fixedly sleeved at the upper and lower ends of the mandrel (1);
[0011] The upper and lower ends of the inner cavity elastic membrane (7) are respectively connected to the inner cavity bidirectional sliding fastener (4). The inner cavity elastic membrane (7) is set on the mandrel (1) through the inner cavity bidirectional sliding fastener (4), forming an inner cavity between the mandrel (1), the first central cylinder (2), the inner cavity elastic membrane (7), and the inner cavity bidirectional sliding fastener (4). The first central cylinder (2) is embedded inside the inner cavity. The inner cavity bidirectional sliding fastener (4) and the mandrel (1) form a sliding pair.
[0012] The upper and lower ends of the outer cavity elastic membrane (8) are respectively connected to the outer cavity bidirectional sliding fastener (5). The outer cavity elastic membrane (8) is set on the mandrel (1) through the outer cavity bidirectional sliding fastener (5). An outer cavity is formed between the mandrel (1), the second central cylinder (3), the inner cavity, the outer cavity elastic membrane (8), and the outer cavity bidirectional sliding fastener (5). The inner cavity and its components are embedded inside the outer cavity. The outer cavity bidirectional sliding fastener (5) and the mandrel (1) form a sliding pair.
[0013] The internal cavity pressure sensor (11) is disposed in the internal cavity and is used to acquire the pressure data of the internal cavity;
[0014] The external cavity pressure sensor (12) is disposed in the external cavity and is used to acquire the pressure data of the external cavity;
[0015] The displacement sensor (13) is used to acquire radial displacement data of the inner cavity elastic membrane (7);
[0016] The pressure supply mechanism is used to provide pressure to the inner cavity and the outer cavity.
[0017] The internal and external bidirectional sliding pressure meter test device provided by the present invention can be further implemented by the following technical measures.
[0018] Preferably, the pressure supply mechanism includes a pressure medium source (15), an inner cavity tube (9), and an outer cavity tube (10).
[0019] The first central cylinder (2) and the mandrel (1) are provided with an inner cavity hole (101) at corresponding positions. One end of the inner cavity tube (9) is connected to the pressure medium source, and the other end of the inner cavity tube (9) is inserted into the mandrel (1). The oil outlet of the inner cavity tube (9) extends into the inner cavity through the inner cavity hole (101), so that the pressure medium can be introduced into the inner cavity through the inner cavity tube (9).
[0020] The second central cylinder (3) and the mandrel (1) are also provided with an outer cavity hole (102) at the corresponding positions. One end of the outer cavity tube (10) is connected to the pressure medium source, and the other end of the outer cavity tube (10) is inserted into the mandrel (1). The oil outlet of the outer cavity tube (10) extends into the outer cavity through the outer cavity hole (102), so that the pressure medium can be introduced into the outer cavity through the outer cavity tube (10).
[0021] Preferably, the bidirectional sliding pressure-meter test device further includes two end limiting rings (6).
[0022] The two end limiting rings (6) are fixed on the mandrel (1) on the upper and lower sides of the outer cavity, respectively. The distance between the two end limiting rings (6) is greater than or equal to the maximum opening length of the elastic membrane (8) of the outer cavity.
[0023] Preferably, the inner cavity bidirectional sliding fixing member (4) includes an inner cavity bidirectional sliding block (201) and an inner cavity membrane retaining ring (202).
[0024] The inner cavity membrane retaining ring (202) is placed outside the inner cavity bidirectional sliding block (201) and the inner cavity elastic membrane (7), so that both ends of the inner cavity elastic membrane (7) are fixed on the inner cavity bidirectional sliding fastener (4).
[0025] Preferably, the external cavity bidirectional sliding fixing member (5) includes an external cavity bidirectional sliding block (301), an external cavity membrane retaining ring (302), and an external cavity clamping ring (303).
[0026] The outer cavity membrane retaining ring (302) is placed outside the outer cavity bidirectional sliding block (301) and the outer cavity elastic membrane (8). The outer cavity pressing ring (303) is fixed to the outer cavity bidirectional sliding block (301) by threads and is in close contact with the outer cavity membrane retaining ring (302), so that both ends of the outer cavity elastic membrane (8) are fixed on the outer cavity bidirectional sliding fastener (5).
[0027] Preferably, the internal and external bidirectional sliding pressure-suppressor test device further includes a first sealing mechanism and / or a second sealing mechanism.
[0028] The first sealing mechanism is disposed between the mandrel (1), the bidirectional sliding fixing member (4) of the inner cavity, and the elastic membrane (7) of the inner cavity, so that the inner cavity forms a sealed cavity;
[0029] The second sealing mechanism is disposed between the mandrel (1), the bidirectional sliding fixing member (5) of the outer cavity, and the elastic membrane (8) of the outer cavity, so that the outer cavity forms a sealed cavity.
[0030] Preferably, the internal and external bidirectional sliding pressure meter test device further includes a data acquisition controller (14).
[0031] The data acquisition controller (14) is used to acquire data from the inner cavity pressure sensor (11), the outer cavity pressure sensor (12), and the displacement sensor (13). At the same time, the data acquisition controller (14) is used to control the opening and closing of the pressure medium pipeline valve of the pressure supply mechanism, and / or the output or recovery of the pressure medium by the pressure supply mechanism.
[0032] Preferably, the data acquisition controller (14) communicates with the inner cavity pressure sensor (11), the outer cavity pressure sensor (12), the displacement sensor (13), and the pressure medium pipeline valve of the pressure supply mechanism via wired or wireless communication.
[0033] Preferably, the pressure medium is a biodegradable antifreeze pressure medium.
[0034] To achieve the second objective mentioned above, the technical solution of the test method based on the internal and external bidirectional sliding pressure meter test device provided by the present invention is as follows:
[0035] The test method based on the internal and external bidirectional sliding pressure meter test device provided by the present invention includes the following steps:
[0036] Pressure medium is introduced into the inner cavity and the outer cavity respectively. The data acquisition controller (14) obtains the pressure data of the inner cavity and the outer cavity from the inner cavity pressure sensor (11) and the outer cavity pressure sensor (12) respectively in real time. After the pressure data of the inner cavity and the outer cavity reach the first stage of the test pressure setting value, the data acquisition controller (14) controls the pressure supply mechanism to stop outputting pressure medium.
[0037] The first-stage pressure test is performed, and the data acquisition controller (14) obtains the expansion displacement data of the inner cavity elastic membrane (7) from the displacement sensor (13) in real time.
[0038] After the first stage of pressurization test is completed, pressure medium is continued to be introduced into the inner cavity and the outer cavity respectively. The data acquisition controller (14) acquires the pressure data of the inner cavity and the outer cavity from the inner cavity pressure sensor (11) and the outer cavity pressure sensor (12) respectively in real time. After the pressure data of the inner cavity and the outer cavity reach the set value of the second stage of pressurization test, the data acquisition controller (14) controls the pressure supply mechanism to stop outputting pressure medium.
[0039] The second-stage pressurization test is performed, and the data acquisition controller (14) acquires the expansion displacement data of the inner cavity elastic membrane (7) from the displacement sensor (13) in real time.
[0040] Repeat the above steps until the test ends. The data acquisition controller (14) controls the pressure supply mechanism to recover the pressure medium in the inner and outer cavities.
[0041] Based on the pressure and displacement data, the soil stress-soil deformation relationship curve is obtained, and the experimental conclusions are obtained by analyzing the relationship curve.
[0042] The beneficial effects of the internal and external bidirectional sliding pressuremeter test device and its test method provided by the present invention are as follows:
[0043] 1. The probe's measuring chamber and protective chamber are sealed by bidirectional sliding fasteners. The change from a fixed type to a bidirectional sliding type ensures that the probe can work normally when the borehole diameter of the pressure test hole is too large or the formation conditions are complex, and when large radial expansion deformation occurs. The pressure medium inside the probe will not leak out due to the rupture of the elastic membrane. The maximum test volume of this bidirectional sliding pressure test device reaches more than 1500mL.
[0044] 2. By arranging pressure sensors and displacement sensors inside the probe, accurate measurement of the expansion pressure inside the probe and the radial expansion deformation of the elastic membrane in the measuring cavity is achieved. This eliminates the influence of pressure loss and irrelevant volume increase from the pressure meter, connecting hose, and elastic membrane of the pressure meter probe. Before the test, there is no need to perform elastic membrane constraint force correction and instrument comprehensive deformation correction, which effectively improves the accuracy and efficiency of the pressure meter test.
[0045] 3. During the pressure-side test, the data acquisition controller determines the expansion pressure inside the probe and the radial expansion deformation of the elastic membrane in real time based on the measurement results of the pressure sensor and displacement sensor to control the output and recovery of the pressure medium, so that the expansion and contraction process of the elastic membrane changes stably, avoiding errors caused by manual operation and ensuring the continuity of test data. Attached Figure Description
[0046] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0047] Appendix Figure 1 This is a typical structural schematic diagram of the internal and external bidirectional sliding pressure meter test device provided in the embodiments of the present invention;
[0048] Appendix Figure 2 For the appendix Figure 1 Cross-sectional view of position AA;
[0049] Appendix Figure 3 For the appendix Figure 1 Cross-sectional view of the BB location;
[0050] Explanation of reference numerals in the attached figures:
[0051] 1—Mandrel, 2—First central cylinder, 3—Second central cylinder, 4—Inner cavity bidirectional sliding fastener, 5—Outer cavity bidirectional sliding fastener, 6—End limiting ring, 7—Inner cavity elastic membrane, 8—Outer cavity elastic membrane, 9—Inner cavity tube, 10—Outer cavity tube, 11—Inner cavity pressure sensor, 12—Outer cavity pressure sensor, 13—Displacement sensor, 14—Data acquisition controller, 15—Pressure medium source, 101—Inner cavity hole, 102—Outer cavity hole, 201—Inner cavity bidirectional sliding block, 202—Inner cavity membrane retaining ring, 301—Outer cavity bidirectional sliding block, 302—Outer cavity membrane retaining ring, 303—Outer cavity clamping ring. Detailed Implementation
[0052] In view of this, the present invention provides an internal and external bidirectional sliding pressure meter test device and its test method, which can adapt to working conditions with large pressure meter expansion, realize accurate measurement of probe pressure and expansion deformation, effectively improve the success rate and accuracy of field pressure meter tests, and thus is more suitable for practical use.
[0053] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of an internal and external bidirectional sliding pressuremeter test device and its test method according to the present invention. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.
[0054] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships, such as A and / or B. Specifically, it can mean that A and B can be included at the same time, A can exist alone, or B can exist alone, and any of the above three situations can be met.
[0055] Internal and external bidirectional sliding pressure meter test device
[0056] See appendix Figures 1-3 The bidirectional sliding pressure-suppressing device provided in this embodiment of the invention includes a mandrel 1, a first central cylinder 2, a second central cylinder 3, an inner cavity elastic membrane 7, an outer cavity elastic membrane 8, an inner cavity bidirectional sliding fixing member 4, an outer cavity bidirectional sliding fixing member 5, an inner cavity pressure sensor 11, an outer cavity pressure sensor 12, a displacement sensor 13, and a pressure supply mechanism. The first central cylinder 2 is fixedly sleeved in the middle of the mandrel 1, and the second central cylinder 3 is fixedly sleeved at the upper and lower ends of the mandrel 1. The upper and lower ends of the inner cavity elastic membrane 7 are respectively connected to the inner cavity bidirectional sliding fixing member 4. The inner cavity elastic membrane 7 is disposed on the mandrel 1 through the inner cavity bidirectional sliding fixing member 4, forming an inner cavity between the mandrel 1, the first central cylinder 2, the inner cavity elastic membrane 7, and the inner cavity bidirectional sliding fixing member 4. The first central cylinder 2 is embedded inside the inner cavity, and the inner cavity bidirectional sliding fixing member 4 and the mandrel 1 form a sliding pair. The upper and lower ends of the outer cavity elastic diaphragm 8 are respectively connected to the outer cavity bidirectional sliding fixing member 5. The outer cavity elastic diaphragm 8 is set on the mandrel 1 through the outer cavity bidirectional sliding fixing member 5, forming an outer cavity between the mandrel 1, the second central cylinder 3, the inner cavity, the outer cavity elastic diaphragm 8, and the outer cavity bidirectional sliding fixing member 5. The inner cavity and its components are embedded inside the outer cavity. The outer cavity bidirectional sliding fixing member 5 and the mandrel 1 form a sliding pair. The inner cavity pressure sensor 11 is set in the inner cavity to acquire the pressure data of the inner cavity. The outer cavity pressure sensor 12 is set in the outer cavity to acquire the pressure data of the outer cavity. The displacement sensor 13 is used to acquire the radial displacement data of the inner cavity elastic diaphragm 7. The pressure supply mechanism is used to provide pressure to the inner cavity and the outer cavity.
[0057] The beneficial effects of the internal and external bidirectional sliding pressuremeter testing device provided in this embodiment of the invention are as follows:
[0058] 1. The probe's measuring chamber and protective chamber are sealed by bidirectional sliding fasteners. The change from a fixed type to a bidirectional sliding type ensures that the probe can work normally when the borehole diameter of the pressure test hole is too large or the formation conditions are complex, and when large radial expansion deformation occurs. The pressure medium inside the probe will not leak out due to the rupture of the elastic membrane. The maximum test volume of this bidirectional sliding pressure test device reaches more than 1500mL.
[0059] 2. By arranging pressure sensors and displacement sensors inside the probe, accurate measurement of the expansion pressure inside the probe and the radial expansion deformation of the elastic membrane in the measuring cavity is achieved. This eliminates the influence of pressure loss and irrelevant volume increase from the pressure meter, connecting hose, and elastic membrane of the pressure meter probe. Before the test, there is no need to perform elastic membrane constraint force correction and instrument comprehensive deformation correction, which effectively improves the accuracy and efficiency of the pressure meter test.
[0060] 3. During the pressure-side test, the data acquisition controller determines the expansion pressure inside the probe and the radial expansion deformation of the elastic membrane in real time based on the measurement results of the pressure sensor and displacement sensor to control the output and recovery of the pressure medium, so that the expansion and contraction process of the elastic membrane changes stably, avoiding errors caused by manual operation and ensuring the continuity of test data.
[0061] The pressure supply mechanism includes a pressure medium source 15, an inner cavity tube 9, and an outer cavity tube 10. An inner cavity hole 101 is provided at a corresponding position on the first central cylinder 2 and the mandrel 1. One end of the inner cavity tube 9 is connected to the pressure medium source, and the other end of the inner cavity tube 9 extends into the mandrel 1. The oil outlet of the inner cavity tube 9 extends into the inner cavity through the inner cavity hole 101, allowing the pressure medium to flow into the inner cavity through the inner cavity tube 9. An outer cavity hole 102 is also provided at a corresponding position on the second central cylinder 3 and the mandrel 1. One end of the outer cavity tube 10 is connected to the pressure medium source, and the other end of the outer cavity tube 10 extends into the mandrel 1. The oil outlet of the outer cavity tube 10 extends into the outer cavity through the outer cavity hole 102, allowing the pressure medium to flow into the outer cavity through the outer cavity tube 10. In this configuration, the pressure supply mechanism can more easily inject pressure medium into the inner and outer cavities, changing the pressure in the inner and outer cavities.
[0062] The bidirectional sliding pressuremeter device further includes two end limiting rings 6. The two end limiting rings 6 are fixed to the mandrel 1 on the upper and lower sides of the outer cavity, respectively, and the distance between the two end limiting rings 6 is greater than or equal to the maximum expansion length of the elastic membrane 8 in the outer cavity. In this configuration, the two end limiting rings 6 prevent the bidirectional sliding fixing member 5 from sliding out of the mandrel 1, thus avoiding the bidirectional sliding pressuremeter device provided in this embodiment from malfunctioning.
[0063] The internal cavity bidirectional sliding fastener 4 includes an internal cavity bidirectional sliding block 201 and an internal cavity membrane retaining ring 202. The internal cavity membrane retaining ring 202 is positioned outside the internal cavity bidirectional sliding block 201 and the internal cavity elastic membrane 7, so that both ends of the internal cavity elastic membrane 7 are fixed to the internal cavity bidirectional sliding fastener 4. In this case, the internal cavity elastic membrane 7 can avoid excessive local deformation leading to rupture under conditions of large lateral expansion.
[0064] The external cavity bidirectional sliding fastener 5 includes an external cavity bidirectional sliding block 301, an external cavity membrane retaining ring 302, and an external cavity clamping ring 303. The external cavity membrane retaining ring 302 is engaged with the external cavity bidirectional sliding block 301 and the external cavity elastic membrane 8. The external cavity clamping ring 303 is threaded onto the external cavity bidirectional sliding block 301 and in close contact with the external cavity membrane retaining ring 302, thus fixing both ends of the external cavity elastic membrane 8 to the external cavity bidirectional sliding fastener 5. In this configuration, the external cavity elastic membrane 8 can be prevented from rupturing due to excessive local deformation under conditions of large lateral expansion.
[0065] The internal and external bidirectional sliding pressure-suppressing test device further includes a first sealing mechanism and / or a second sealing mechanism. The first sealing mechanism is disposed between the mandrel 1, the internal bidirectional sliding fixing member 4, and the internal elastic membrane 7, thus forming a sealed cavity within the internal cavity. In this configuration, leakage of the pressure medium within the internal cavity from between the mandrel 1, the internal bidirectional sliding fixing member 4, and the internal elastic membrane 7 can be prevented. The second sealing mechanism is disposed between the mandrel 1, the external bidirectional sliding fixing member 5, and the external elastic membrane 8, thus forming a sealed cavity within the external cavity. In this configuration, leakage of the pressure medium within the external cavity from between the mandrel 1, the external bidirectional sliding fixing member 5, and the external elastic membrane 8 can be prevented.
[0066] The internal and external bidirectional sliding pressure-side test device also includes a data acquisition controller 14. The data acquisition controller 14 is used to acquire data from the internal cavity pressure sensor 11, the external cavity pressure sensor 12, and the displacement sensor 13. Simultaneously, the data acquisition controller 14 is used to control the opening and closing of the pressure medium pipeline valves of the pressure supply mechanism, and / or the output or withdrawal of the pressure medium by the pressure supply mechanism. In this case, data acquisition and the opening and closing of the pressure medium pipeline valves of the pressure supply mechanism can be completed solely through the data acquisition controller 14, ensuring real-time and accurate data acquisition, reducing errors caused by manual operation, and guaranteeing the continuity of test data. In this embodiment, the pressure medium source 15 has both output and withdrawal functions. That is, the pressure medium source has an integrated oil pump. In this case, after the pressure-side test, the pressure medium can be recovered through the integrated oil pump of the pressure medium source 15. Furthermore, if the pressure medium is water or nitrogen, the oil pump can be replaced with a water pump or a gas pump to recover water or pressurized gas, enabling the internal and external bidirectional sliding pressure-side test device provided in this embodiment to have the ability to be reused repeatedly.
[0067] The data acquisition controller 14 communicates with the internal cavity pressure sensor 11, the external cavity pressure sensor 12, the displacement sensor 13, and the pressure medium pipeline valve of the pressure supply mechanism via wired or wireless communication. Wireless communication is more convenient.
[0068] Test method based on internal and external bidirectional sliding pressure meter test device
[0069] The test method based on the internal and external bidirectional sliding pressure meter test device provided in this embodiment of the invention includes the following steps:
[0070] Step S1: Pressure medium is introduced into the inner cavity and the outer cavity respectively. The data acquisition controller 14 obtains the pressure data of the inner cavity and the outer cavity from the inner cavity pressure sensor 11 and the outer cavity pressure sensor 12 in real time. After the pressure data of the inner cavity and the outer cavity reach the first stage of pressurization setting value of the test, the data acquisition controller 14 controls the pressure supply mechanism to stop outputting pressure medium.
[0071] Step S2: Perform the first-stage pressure test. The data acquisition controller 14 acquires the expansion displacement data of the inner cavity elastic membrane 7 from the displacement sensor 13 in real time.
[0072] Step S3: After the first stage of pressurization test is completed, pressure medium is continued to be introduced into the inner cavity and the outer cavity respectively. The data acquisition controller 14 obtains the pressure data of the inner cavity and the outer cavity from the inner cavity pressure sensor 11 and the outer cavity pressure sensor 12 in real time. After the pressure data of the inner cavity and the outer cavity reach the set value of the second stage of pressurization test, the data acquisition controller 14 controls the pressure supply mechanism to stop outputting pressure medium.
[0073] Step S4: Perform the second-stage pressure test. The data acquisition controller 14 acquires the expansion displacement data of the inner cavity elastic membrane 7 from the displacement sensor 13 in real time.
[0074] Step S5: Repeat the above steps until the test ends. The data acquisition controller 13 controls the pressure supply mechanism to recover the pressure medium in the inner and outer cavities.
[0075] Step S6: Based on the pressure data and displacement data, obtain the soil stress-soil deformation relationship curve, and analyze the relationship curve to obtain the test conclusion.
[0076] The beneficial effects of the test method based on the internal and external bidirectional sliding pressuremeter test device provided in the embodiments of the present invention are as follows:
[0077] 1. The probe's measuring chamber and protective chamber are sealed by bidirectional sliding fasteners. The change from a fixed type to a bidirectional sliding type ensures that the probe can work normally when the borehole diameter of the pressure test hole is too large or the formation conditions are complex, and when large radial expansion deformation occurs. The pressure medium inside the probe will not leak out due to the rupture of the elastic membrane. The maximum test volume of this bidirectional sliding pressure test device reaches more than 1500mL.
[0078] 2. By arranging pressure sensors and displacement sensors inside the probe, accurate measurement of the expansion pressure inside the probe and the radial expansion deformation of the elastic membrane in the measuring cavity is achieved. This eliminates the influence of pressure loss and irrelevant volume increase from the pressure meter, connecting hose, and elastic membrane of the pressure meter probe. Before the test, there is no need to perform elastic membrane constraint force correction and instrument comprehensive deformation correction, which effectively improves the accuracy and efficiency of the pressure meter test.
[0079] 3. During the pressure-side test, the data acquisition controller determines the expansion pressure inside the probe and the radial expansion deformation of the elastic membrane in real time based on the measurement results of the pressure sensor and displacement sensor to control the output and recovery of the pressure medium, so that the expansion and contraction process of the elastic membrane changes stably, avoiding errors caused by manual operation and ensuring the continuity of test data.
[0080] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.
[0081] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A bidirectional sliding pressuremeter test device, characterized in that, The components include a mandrel (1), a first central cylinder (2), a second central cylinder (3), an inner cavity elastic diaphragm (7), an outer cavity elastic diaphragm (8), an inner cavity bidirectional sliding fastener (4), an outer cavity bidirectional sliding fastener (5), an inner cavity pressure sensor (11), an outer cavity pressure sensor (12), a displacement sensor (13), and a pressure supply mechanism. The first central cylinder (2) is fixedly sleeved in the middle of the mandrel (1), and the second central cylinder (3) is fixedly sleeved at the upper and lower ends of the mandrel (1); The upper and lower ends of the inner cavity elastic membrane (7) are respectively connected to the inner cavity bidirectional sliding fastener (4). The inner cavity elastic membrane (7) is disposed on the mandrel (1) through the inner cavity bidirectional sliding fastener (4), forming an inner cavity between the mandrel (1), the first central cylinder (2), the inner cavity elastic membrane (7), and the inner cavity bidirectional sliding fastener (4). The first central cylinder (2) is embedded inside the inner cavity. The inner cavity bidirectional sliding fastener (4) and the mandrel (1) form a sliding pair. The upper and lower ends of the outer cavity elastic membrane (8) are respectively connected to the outer cavity bidirectional sliding fastener (5). The outer cavity elastic membrane (8) is set on the mandrel (1) through the outer cavity bidirectional sliding fastener (5). An outer cavity is formed between the mandrel (1), the second central cylinder (3), the inner cavity, the outer cavity elastic membrane (8), and the outer cavity bidirectional sliding fastener (5). The inner cavity and its components are embedded inside the outer cavity. The outer cavity bidirectional sliding fastener (5) and the mandrel (1) form a sliding pair. The internal cavity pressure sensor (11) is disposed in the internal cavity and is used to acquire the pressure data of the internal cavity; The external cavity pressure sensor (12) is disposed in the external cavity and is used to acquire the pressure data of the external cavity; The displacement sensor (13) is used to acquire radial displacement data of the inner cavity elastic membrane (7); The pressure supply mechanism is used to provide pressure to the inner cavity and the outer cavity; The pressure supply mechanism includes a pressure medium source (15), an inner cavity tube (9) and an outer cavity tube (10). The first central cylinder (2) and the mandrel (1) are provided with inner cavity holes (101) at corresponding positions. One end of the inner cavity tube (9) is connected to the pressure medium source, and the other end of the inner cavity tube (9) is inserted into the mandrel (1). The oil outlet of the inner cavity tube (9) extends into the inner cavity through the inner cavity hole (101), so that the pressure medium can be introduced into the inner cavity through the inner cavity tube (9). The second central cylinder (3) and the mandrel (1) are also provided with an outer cavity hole (102) at the corresponding positions. One end of the outer cavity tube (10) is connected to the pressure medium source, and the other end of the outer cavity tube (10) is inserted into the mandrel (1). The oil outlet of the outer cavity tube (10) extends into the outer cavity through the outer cavity hole (102), so that the pressure medium can be introduced into the outer cavity through the outer cavity tube (10). The inner cavity bidirectional sliding fastener (4) includes an inner cavity bidirectional sliding block (201) and an inner cavity membrane retaining ring (202). The inner cavity membrane retaining ring (202) is placed outside the inner cavity bidirectional sliding block (201) and the inner cavity elastic membrane (7), so that both ends of the inner cavity elastic membrane (7) are fixed on the inner cavity bidirectional sliding fastener (4).
2. The internal and external bidirectional sliding pressure-meter test device according to claim 1, characterized in that, It also includes two end limiting rings (6). The two end limiting rings (6) are fixed on the mandrel (1) on the upper and lower sides of the outer cavity respectively, and the distance between the two end limiting rings (6) is greater than or equal to the maximum opening length of the elastic membrane (8) of the outer cavity.
3. The internal and external bidirectional sliding pressure-meter test device according to claim 1, characterized in that, The external cavity bidirectional sliding fastener (5) includes an external cavity bidirectional sliding block (301), an external cavity membrane retaining ring (302), and an external cavity clamping ring (303). The outer cavity membrane retaining ring (302) is placed outside the outer cavity bidirectional sliding block (301) and the outer cavity elastic membrane (8). The outer cavity pressing ring (303) is fixed to the outer cavity bidirectional sliding block (301) by threads and is in close contact with the outer cavity membrane retaining ring (302), so that both ends of the outer cavity elastic membrane (8) are fixed on the outer cavity bidirectional sliding fastener (5).
4. The internal and external bidirectional sliding pressure meter test device according to claim 1, characterized in that, It also includes a first sealing mechanism, and / or a second sealing mechanism. The first sealing mechanism is disposed between the mandrel (1), the inner cavity bidirectional sliding fixing member (4), and the inner cavity elastic membrane (7), so that the inner cavity forms a sealed cavity; The second sealing mechanism is disposed between the mandrel (1), the bidirectional sliding fixing member (5) of the outer cavity, and the elastic membrane (8) of the outer cavity, so that the outer cavity forms a sealed cavity.
5. The internal and external bidirectional sliding pressure-meter test device according to claim 1, characterized in that, It also includes a data acquisition controller (14). The data acquisition controller (14) is used to acquire data from the inner cavity pressure sensor (11), the outer cavity pressure sensor (12), and the displacement sensor (13). At the same time, the data acquisition controller (14) is used to control the opening and closing of the pressure medium pipeline valve of the pressure supply mechanism, and / or the output or recovery of the pressure medium by the pressure supply mechanism.
6. The internal and external bidirectional sliding pressuremeter test device according to claim 1, characterized in that, The data acquisition controller (14) communicates with the inner cavity pressure sensor (11), the outer cavity pressure sensor (12), the displacement sensor (13), and the pressure medium pipeline valve of the pressure supply mechanism via wired or wireless communication.
7. A test method based on the internal and external bidirectional sliding pressuremeter test apparatus according to any one of claims 1-6, characterized in that, Includes the following steps: Pressure medium is introduced into the inner cavity and the outer cavity respectively. The data acquisition controller (14) obtains the pressure data of the inner cavity and the outer cavity from the inner cavity pressure sensor (11) and the outer cavity pressure sensor (12) respectively in real time. After the pressure data of the inner cavity and the outer cavity reach the first stage of the test pressure setting value, the data acquisition controller (14) controls the pressure supply mechanism to stop outputting pressure medium. The first-stage pressure test is performed, and the data acquisition controller (14) obtains the expansion displacement data of the inner cavity elastic membrane (7) from the displacement sensor (13) in real time. After the first stage of pressurization test is completed, pressure medium is continued to be introduced into the inner cavity and the outer cavity respectively. The data acquisition controller (14) obtains the pressure data of the inner cavity and the outer cavity from the inner cavity pressure sensor (11) and the outer cavity pressure sensor (12) respectively in real time. After the pressure data of the inner cavity and the outer cavity reach the second stage of pressurization setting value, the data acquisition controller (14) controls the pressure supply mechanism to stop outputting pressure medium. The second-stage pressurization test is performed, and the data acquisition controller (14) acquires the expansion displacement data of the inner cavity elastic membrane (7) from the displacement sensor (13) in real time. Repeat the above steps until the test ends. The data acquisition controller (14) controls the pressure supply mechanism to recover the pressure medium in the inner and outer cavities. Based on the pressure and displacement data, the soil stress-soil deformation relationship curve is obtained, and the experimental conclusions are obtained by analyzing the relationship curve.