A pulse tube type in-situ displacement testing device and testing method for geotechnical and underground engineering model tests

Abstract

The present invention discloses a pulse tube type in-situ displacement testing device and testing method for geotechnical and underground engineering models, including: a bearing sleeve installation pipe, a flexible bearing sleeve, and auxiliary materials. The bearing sleeve installation pipe is coaxially sleeved on the outer surface of the flexible bearing sleeve and is used to temporarily fix the flexible bearing sleeve in the soil. The flexible bearing sleeve is filled with auxiliary materials, and the auxiliary materials are used to assist the support and deformation of the flexible bearing sleeve in the soil. The structure of the present invention is simple, the cost is low, and it is convenient to use. During the experiment, relevant materials can be purchased and made and used by oneself; through the two-stage deformation recording method of "flexible to rigid", the deformation on the line to be measured during the experiment is effectively recorded, and the removal of the soil after the experiment does not affect the final value of the deformation recording of the line to be measured. The present invention is an efficient means for recording in-situ displacement and provides an important reference for the in-situ displacement testing of geotechnical and underground engineering.

Description

Technical Field

[0001] The present invention relates to the field of geotechnical and underground engineering, and particularly to a pulse tube type in-situ displacement testing device and testing method for geotechnical and underground engineering model tests. Background Art

[0002] In recent years, with the comprehensive development of China's transportation infrastructure construction, more and more traffic tunnels have passed through fault-crossing areas, such as Shigangba water diversion tunnel, Duwen Highway Jiujiaoya tunnel, Duwen Expressway Longdongzi tunnel, Zipingpu tunnel, etc. In order to meet the needs of engineering construction, a large number of similar model tests have been carried out in China to study the geotechnical-structure interaction problems of underground engineering structures. The development of test and measurement technology is an important foundation for promoting the improvement of engineering construction level.

[0003] During the process of carrying out similar model tests, it has always been very difficult to accurately and comprehensively record the in-situ displacement. At present, the method of installing in-situ displacement gauges is mostly used for multi-point testing. However, the installation of too many in-situ displacement test points will not only affect the mechanical properties of the soil mass, but also be difficult to guarantee the test accuracy due to the complexity of the test environment.

[0004] Therefore, it is very necessary to improve the in-situ displacement testing method in geotechnical and underground engineering similar model tests. Summary of the Invention

[0005] The main purpose of the present invention is to overcome the deficiencies of the prior art and provide a pulse tube type in-situ displacement testing device and testing method for geotechnical and underground engineering model tests, which are simple in structure, low in cost and convenient to use.

[0006] To achieve the above object, the present invention provides a pulse tube type in-situ displacement testing device for geotechnical and underground engineering model tests, including: a material-bearing sleeve installation pipe, a flexible material-bearing sleeve and auxiliary materials. The material-bearing sleeve installation pipe is coaxially sleeved on the outer surface of the flexible material-bearing sleeve and is used to temporarily fix the flexible material-bearing sleeve in the soil mass. The flexible material-bearing sleeve is filled with auxiliary materials, and the auxiliary materials are used to assist the support and deformation of the flexible material-bearing sleeve in the soil mass.

[0007] Further, the auxiliary materials include non-cohesive support aggregates and high-permeability high-strength and rapid-setting grouting materials. The support aggregates are used to support the flexible material-bearing sleeve in the soil mass, form a linear flexible strip buried in the soil mass with the flexible material-bearing sleeve, and freely deform with the deformation of the soil mass; the high-strength and rapid-setting grouting materials are used to inject into the support aggregates to consolidate the support aggregates, so as to form a rigid strip with the flexible material-bearing sleeve. When the soil mass is removed, the flexible material-bearing sleeve forming the rigid strip will not deform.

[0008] Further, the flexible material - containing sleeve includes a linear flexible anti - seepage sleeve and an anchoring ball. One end of the linear flexible anti - seepage sleeve is open as an open end for loading auxiliary materials, and the other end is hermetically connected to the anchoring ball. The anchoring ball is used to fixedly embed the linear flexible anti - seepage sleeve in the soil body.

[0009] Further, the material - containing sleeve installation pipe includes a rigid installation pipe and a temporary fixing cap. The flexible material - containing sleeve is sleeved inside the rigid installation pipe. The temporary fixing cap is provided with an insertion hole corresponding to the rigid installation pipe. The temporary fixing cap is inserted at the top of the rigid installation pipe for the open end of the flexible material - containing sleeve to pass through and temporarily fix the open end of the flexible material - containing sleeve.

[0010] Further, the temporary fixing cap includes a cap body, a buckle, and a spring. The cap body is also provided with a protruding hole corresponding to the insertion hole for the open end of the linear flexible anti - seepage sleeve to protrude. The buckle and the spring form a tightening structure arranged above the cap body and corresponding to the protruding hole on the cap body. After the linear flexible anti - seepage sleeve is filled with materials, the open end of the linear flexible anti - seepage sleeve is tightened by squeezing the buckle to prevent the support aggregate from overflowing.

[0011] Further, the support aggregate is sand grains with no cohesion and good permeability, having a particle size between 80 mesh and 100 mesh, and the high - strength and rapid - setting grouting material is an epoxy - based grouting material with high permeability.

[0012] Further, the anchoring ball is provided with a hollow cylinder for restricting the sliding of the rigid installation pipe. The diameter of the rigid strip formed after grouting of the linear flexible anti - seepage sleeve is controlled within 5 mm.

[0013] Further, the cap body is provided with a clamping block protruding to both sides and a fixing block with a through - hole. The buckle includes a clamping rod and a U - shaped clamping groove provided at the end of the clamping rod. The U - shaped clamping groove is clamped into the clamping block protruding to both sides, and at the same time, the clamping rod passes through the fixing block with a through - hole. The spring is sleeved on the clamping rod and clamped between the U - shaped clamping groove and the fixing block. The clamping and loosening of the linear flexible anti - seepage sleeve are realized by the restoring force of the spring.

[0014] Further, the test method includes the following steps;

[0015] S1. Fill the flexible material - containing sleeve with non - cohesive support aggregate;

[0016] S2. Sleeve the flexible material - containing sleeve into the material - containing sleeve installation pipe, and then bury the material - containing sleeve installation pipe in the test soil body;

[0017] S3. Take out the material - containing sleeve installation pipe, and the flexible material - containing sleeve filled with support aggregate is left alone in the test soil body;

[0018] S4. After the model test is completed, before the flexible material-bearing sleeve is taken out, high-strength and rapid-setting grouting material is injected into the flexible material-bearing sleeve until the linear flexible anti-seepage sleeve forms a rigid strip.

[0019] S5. The linear flexible anti-seepage sleeve buried in the soil mass is dug out, and the displacement change of the soil mass is tested through the deformation analysis of the linear flexible anti-seepage sleeve.

[0020] The beneficial effects of the present invention are as follows: The structure of the present invention is simple, the cost is low, and it is convenient to use. During the experiment, relevant materials can be purchased and made by oneself; through the two-stage deformation recording method of "flexible to rigid", it is ensured that the deformation on the line position to be measured during the experiment is effectively recorded, and the removal of the soil mass after the experiment does not affect the final value of the deformation record of the line position to be measured. The present invention is an efficient method for recording in-situ displacement, providing an important reference for the in-situ displacement test of geotechnical and underground engineering.

[0021] When it is necessary to test the in-situ displacement of geotechnical materials in the similarity model test of geotechnical and underground engineering, this device (including the material-bearing sleeve installation pipe) is buried in advance when filling the soil mass; after the soil mass filling is completed and before the experiment starts, the material-bearing sleeve installation pipe is pulled out so that the linear flexible anti-seepage sleeve is in a straight state before the experiment; during the experiment, the flexible strip formed by the linear flexible anti-seepage sleeve filled with supporting aggregate deforms with the soil mass; after the experiment is completed, the supporting aggregate is consolidated into a rigid strip by injecting high-strength and rapid-setting grouting material, avoiding the deformation of the supporting aggregate and the linear flexible anti-seepage sleeve that represents the soil displacement during the experiment from being disturbed, and finally the in-situ displacement of the soil mass is tested by measuring the shape of the rigid strip after the supporting aggregate is consolidated. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the test device of the present invention;

[0023] Figure 2 It is a schematic connection diagram of the temporary fixing cap and the rigid installation pipe of the present invention;

[0024] Figure 3 It is a schematic structural diagram of the anchoring ball of the present invention;

[0025] Figure 4 It is a schematic structural diagram of the buckle of the present invention;

[0026] Figure 5 It is a schematic connection structure diagram of the buckle and the cap body of the present invention;

[0027] Figure 6 It is a schematic structural diagram of the flexible material-bearing sleeve before and after deformation of the present invention;

[0028] Description of reference numerals: 1, material receiving sleeve installation pipe; 2, flexible material receiving sleeve; 3, auxiliary materials; 11, rigid installation pipe; 12, temporary fixing cap; 21, linear flexible anti-seepage sleeve; 22, anchoring ball; 31, supporting aggregate; 32, high-strength and rapid-setting grouting material; 221, hollow cylinder; 121, cap body; 122, buckle; 123, spring; 1221, clamping rod; 1222, U-shaped card slot; 1211, clamping block; 1212, fixing block; 2211, column body. Specific embodiments

[0029] The following will clearly and completely describe the technical solutions in the present invention with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] See Figures 1 to 6 。

[0031] The present invention includes a material receiving sleeve installation pipe 1, a flexible material receiving sleeve 2 and auxiliary materials 3. The material receiving sleeve installation pipe 1 is coaxially sleeved on the outer surface of the flexible material receiving sleeve 2 and is used to temporarily fix the flexible material receiving sleeve 2 in the soil body. The flexible material receiving sleeve 2 is filled with auxiliary materials 3, and the auxiliary materials 3 are used to assist the flexible material receiving sleeve 2 in supporting and deforming in the soil body. With such a design, the device can realize the test of continuous point positions of in-situ displacement through the linear characteristics of the flexible material receiving sleeve 2 itself.

[0032] In an embodiment, the auxiliary materials 3 include a non-cohesive supporting aggregate 31 and a high-permeability high-strength and rapid-setting grouting material 32. The supporting aggregate 31 is used to support the flexible material receiving sleeve 2 in the soil body, form a linear flexible strip buried in the soil body with the flexible material receiving sleeve 2, and freely deform with the deformation of the soil body; the high-strength and rapid-setting grouting material 32 is used to inject into the supporting aggregate to consolidate the supporting aggregate, so as to form a rigid strip with the flexible material receiving sleeve. When the soil body is removed, the flexible material receiving sleeve forming the rigid strip will not deform. With such a design, after the test is completed and the deformation of the soil body stops, the high-strength and rapid-setting grouting material 32 is injected into the supporting aggregate 31 wrapped by the flexible material receiving sleeve 2. Since the supporting aggregate 31 is consolidated, the deformed flexible material receiving sleeve 2 is formed into a rigid strip, avoiding the disturbance of the deformation representing the soil body displacement generated by the supporting aggregate 31 and the flexible material receiving sleeve 2 in the test due to changes in the external environment. Finally, the in-situ displacement test of the soil body is realized by testing the shape of the consolidated rigid strip.

[0033] In one embodiment, the flexible material - holding sleeve 2 includes a linear flexible anti - seepage sleeve 21 and an anchoring ball 22. One end of the linear flexible anti - seepage sleeve 21 is open as an open end for loading auxiliary materials 3, and the other end is hermetically connected to a cylinder 2211 on the anchoring ball 22. The cylinder 2211 on the anchoring ball 22 can be inserted into the opening at the other end of the linear flexible anti - seepage sleeve 21. At the same time, strong glue can be selected to bond the cylinder 2211 and the opening at the other end of the linear flexible anti - seepage sleeve 21 together to strengthen the sealed connection between the linear flexible anti - seepage sleeve 21 and the anchoring ball 22. The anchoring ball 22 has a certain weight. When the material - holding sleeve installation pipe 1 is taken out, the anchoring ball 22 prevents the linear flexible anti - seepage sleeve 21 from being pulled out together with the material - holding sleeve installation pipe 1. With such a design, it is ensured that the linear flexible anti - seepage sleeve 21 will not move under the influence of external forces in the soil body, ensuring the accuracy of test data.

[0034] In one embodiment, the material - holding sleeve installation pipe 1 includes a rigid installation pipe 11 and a temporary fixing cap 12. The flexible material - holding sleeve 2 is sleeved inside the rigid installation pipe 11. The temporary fixing cap 12 is provided with an insertion hole corresponding to the rigid installation pipe 11. The temporary fixing cap 12 is inserted at the top of the rigid installation pipe 11 for the open end of the flexible material - holding sleeve 2 to pass through and temporarily fix the open end of the flexible material - holding sleeve 2. With such a design, the flexible material - holding sleeve 2 can be buried in the soil through the rigid installation pipe 11, and then the rigid installation pipe 11 and the temporary fixing cap 12 are taken out together when the soil filling is completed and the test is about to start, ensuring that the flexible material - holding sleeve 2 is in a non - deformed state before the test starts. Moreover, this installation pipe has a simple structure and can be reused, with strong economic practicality.

[0035] In one embodiment, the temporary fixing cap 12 includes a cap body 121, a buckle 122 and a spring 123. The cap body 121 is also provided with a protruding hole corresponding to the insertion hole for the open end of the linear flexible anti - seepage sleeve 21 to protrude. The buckle 122 and the spring 123 form a tightening structure arranged above the cap body 121 and corresponding to the protruding hole on the cap body 121. When the linear flexible anti - seepage sleeve 21 is filled with materials, the open end of the linear flexible anti - seepage sleeve 21 is tightened by squeezing the buckle 122 to prevent the support aggregate 31 from overflowing. With such a design, it is ensured that the support aggregate 31 inside the linear flexible anti - seepage sleeve 21 will not leak out after installation and before grouting, thus affecting the test effect.

[0036] In one embodiment, the support aggregate 31 is sand grains with no cohesive force and good permeability, and the particle size is between 80 mesh and 100 mesh. The high - strength and rapid - setting grouting material 32 is an epoxy resin - based grouting material with good penetration performance. Preferably, the high - strength and rapid - setting grouting material 32 can adopt commercially available cement - based low - viscosity potting glue, and the support aggregate 31 can select non - cohesive quartz sand with a particle size between 80 mesh and 100 mesh. With such a design, it is ensured that the grouting material can penetrate into all parts of the linear flexible anti - seepage sleeve 21 before the support aggregate 31 solidifies.

[0037] In one embodiment, a hollow cylinder 221 for restricting the sliding of the rigid installation pipe 11 is provided at the upper end of the anchoring ball 22. With this design, the rigid installation pipe 11 will not shake, improving the integrity of the rigid installation pipe 11 and the linear flexible anti-seepage sleeve 21 during the soil filling process, and the test effect is better. The diameter of the rigid strip formed after the linear flexible anti-seepage sleeve 21 is grouted is controlled within 5 mm. Because the linear flexible anti-seepage sleeve 21 filled with the supporting aggregate 31 starts to solidify after injecting the high-strength quick-setting grouting material 32, and the linear flexible anti-seepage sleeve 21 will produce an expansion effect during the solidification process. The diameter of the rigid strip formed after the expansion is preferably controlled within 5 mm for the best test effect.

[0038] In one embodiment, the cap body 121 is provided with a clamping block 1211 protruding to both sides and a fixing block 1212 with a through hole. The buckle 122 includes a clamping rod 1221 and a U-shaped clamping groove 1222 provided at the end of the clamping rod 1221. The U-shaped clamping groove 1222 is clamped into the clamping block 1211 protruding to both sides. At the same time, the clamping rod 1221 passes through the fixing block 1212 with a through hole. The spring 123 is sleeved on the clamping rod 1221 and clamped between the U-shaped clamping groove 1222 and the fixing block 1212. Through the restoring force of the spring 123, the U-shaped clamping groove 1222 and the clamping block 1211 clamp and loosen the linear flexible anti-seepage sleeve 21. With this design, the tightening effect on the open end of the linear flexible anti-seepage sleeve 21 is achieved, and the mechanism is simple, economical and practical.

[0039] In one embodiment, a method for testing the in-situ displacement of a pulse tube in a geotechnical and underground engineering model test, the test method includes the following steps;

[0040] S1. Fill the flexible material-bearing sleeve 2 with the non-cohesive supporting aggregate 31;

[0041] S2. Put the flexible material-bearing sleeve 2 on the material-bearing sleeve installation pipe 1, tighten the open end of the flexible material-bearing sleeve 2 through the temporary fixing cap 12, and then bury the material-bearing sleeve installation pipe 1 in the test soil;

[0042] S3. Take out the material-bearing sleeve installation pipe 1, and the flexible material-bearing sleeve 2 filled with the supporting aggregate 31 is left alone in the test soil;

[0043] S4. When the model test is completed, before taking out the flexible material-bearing sleeve 2, inject the high-strength quick-setting grouting material 32 into the flexible material-bearing sleeve 2 until the linear flexible anti-seepage sleeve 21 forms a rigid strip;

[0044] S5. Dig out the linear flexible anti-seepage sleeve 21 buried in the soil, and analyze the displacement change of the test soil through the deformation of the linear flexible anti-seepage sleeve 21.

[0045] It should be understood that the examples and embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. Those skilled in the art can make various modifications and changes based on it. Any modifications made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A pulse tube type in-situ displacement testing device for geotechnical and underground engineering model tests, characterized in that, The test device includes a material receiving sleeve installation pipe (1), a flexible material receiving sleeve (2), and auxiliary materials (3). The material receiving sleeve installation pipe (1) is coaxially sleeved on the outer surface of the flexible material receiving sleeve (2) and is used to temporarily fix the flexible material receiving sleeve (2) in the soil. The flexible material receiving sleeve (2) is filled with auxiliary materials (3), and the auxiliary materials (3) are used to assist the flexible material receiving sleeve (2) in supporting and deforming in the soil; The auxiliary materials (3) include supporting aggregates (31) and high-strength and rapid-setting grouting materials (32). The supporting aggregates (31) are used to support the flexible material receiving sleeve (2) in the soil, form a linear flexible strip buried in the soil, and freely deform with the deformation of the soil; The high-strength and rapid-setting grouting materials (32) are used to inject into the supporting aggregates (31) to solidify the supporting aggregates (31), so as to form a rigid strip from the flexible material receiving sleeve (2). When the soil is removed, the flexible material receiving sleeve (2) formed into a rigid strip will not deform; The flexible material receiving sleeve (2) includes a linear flexible anti-seepage sleeve (21) and an anchoring ball (22). One end of the linear flexible anti-seepage sleeve (21) is open as an open end for loading auxiliary materials (3), and the other end is hermetically connected to the anchoring ball (22). The anchoring ball (22) is used to fix the linear flexible anti-seepage sleeve (21) buried in the soil; The supporting aggregates (31) are sand grains with a particle size between 80 mesh and 100 mesh, and the high-strength and rapid-setting grouting materials (32) are epoxy resin-based grouting materials.

2. The pulse tube type in-situ displacement testing device for geotechnical and underground engineering model tests according to claim 1, characterized in that, The material receiving sleeve installation pipe (1) includes a rigid installation pipe (11) and a temporary fixing cap (12). The flexible material receiving sleeve (2) is sleeved inside the rigid installation pipe (11). The temporary fixing cap (12) is provided with a jack corresponding to the rigid installation pipe (11). The temporary fixing cap (12) is inserted at the top of the rigid installation pipe (11) for the open end of the flexible material receiving sleeve (2) to pass through and temporarily fix the open end of the flexible material receiving sleeve (2).

3. The pulse tube type in-situ displacement testing device for geotechnical and underground engineering model tests according to claim 2, characterized in that, The temporary fixing cap (12) includes a cap body (121), a buckle (122), and a spring (123). The cap body (121) is also provided with a protruding hole corresponding to the jack for the open end of the linear flexible anti-seepage sleeve (21) to protrude. The buckle (122) and the spring (123) form a tightening structure arranged above the cap body (121) and corresponding to the protruding hole on the cap body (121). After the linear flexible anti-seepage sleeve (21) is filled with materials, the open end of the linear flexible anti-seepage sleeve (21) is tightened by squeezing the buckle (122) to prevent the supporting aggregates (31) from overflowing.

4. The pulse tube type in-situ displacement testing device for geotechnical and underground engineering model tests according to claim 1 or 2, characterized in that, The anchoring ball (22) is provided with a hollow cylinder (221) for restricting the sliding of the rigid installation pipe (11). The diameter of the rigid strip formed by the linear flexible anti-seepage sleeve (21) after grouting is controlled within 5 mm.

5. The pulse tube type in-situ displacement testing device for geotechnical and underground engineering model tests according to claim 3, characterized in that, The cap body (121) is provided with clamping blocks (1211) protruding towards both sides and fixing blocks (1212) with through holes. The buckle (122) includes a clamping rod (1221) and a U-shaped clamping groove (1222) arranged at the end of the clamping rod (1221). The U-shaped clamping groove (1222) is clamped into the clamping blocks (1211) protruding towards both sides. At the same time, the clamping rod (1221) passes through the fixing block (1212) with a through hole. The spring (123) is sleeved on the clamping rod (1221) and clamped between the U-shaped clamping groove (1222) and the fixing block (1212). The clamping and loosening of the U-shaped clamping groove (1222) and the clamping block (1211) on the linear flexible anti-seepage sleeve (21) are realized through the restoring force of the spring (123).

6. A pulse tube type in-situ displacement testing method for geotechnical and underground engineering model tests, characterized in that, Including the testing device according to claim 1, the testing method includes the following steps; S1. Fill the flexible material-bearing sleeve (2) with supporting aggregate (31); S2. Sleeve the flexible material-bearing sleeve (2) in the material-bearing sleeve installation pipe (1), and then bury the material-bearing sleeve installation pipe (1) in the tested soil mass; S3. Take out the material-bearing sleeve installation pipe (1), and the flexible material-bearing sleeve (2) filled with supporting aggregate (31) is left alone in the tested soil mass; S4. When the model test is completed, before taking out the flexible material-bearing sleeve (2), inject high-strength and rapid-setting grouting material (32) into the flexible material-bearing sleeve (2) until the linear flexible anti-seepage sleeve (21) forms a rigid strip; S5. Dig out the linear flexible anti-seepage sleeve (21) buried in the soil mass, and analyze the displacement change of the tested soil mass through the deformation of the linear flexible anti-seepage sleeve (21).

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