Gravel penetration stability test device for gravel stratum construction

Abstract

The invention discloses a sand and gravel material penetration stability test device for sand and gravel stratum construction, comprising a reference rod, the lower end of the reference rod is fixedly connected to a cutting cylinder, cutting holes are arranged at intervals on the lower end surface of the cutting cylinder, a cavity is arranged on the cutting cylinder, the cutting holes are connected to the cavity, a scraper is fixedly connected to one side of each cutting hole, a test cylinder is fixedly connected inside the cutting cylinder, the bottom of the test cylinder is an open structure, a receiving groove is arranged at the bottom of the test cylinder, a plurality of cutting rods are rotatably connected in an annular array in the receiving groove, a flexible steel wire mesh is fixedly connected between the cutting rod and the side wall of the receiving groove, a water-permeable pressure plate is arranged vertically in the cutting cylinder, a downward pressure device is arranged on the upper side of the water-permeable pressure plate, and the reference rod is fixedly connected to a displacement sensor. The invention avoids cumbersome sampling links, avoids artificial compression deformation of samples, and avoids differences with actual soil properties by conducting a penetration stability test at a specific depth.

Description

Technical Field

[0001] The invention relates to the technical field of soil penetration stability testing devices, in particular to a sand and gravel material penetration stability testing device for sand and gravel stratum construction. Background Art

[0002] When shield excavation is carried out in gravel strata, the deformation of the ground is more difficult to control due to the high permeability of gravel strata, the easy collapse of sand and cobble strata, and the poor arching of the strata. Grouting treatment of gravel layers using grouting is a common method encountered during shield construction. Although grouting technology has been widely used in tunnel engineering, the research on the permeability of grouting theory is still incomplete, and it still relies heavily on construction experience, and the construction is very blind.

[0003] In order to measure the permeability of the gravel strata in the area where the tunnel passes through, engineering sampling technology is generally used to drill samples from local underground areas and fill them with water for penetration tests. The sampling process is likely to cause sample disturbance and changes in the pores in the soil, resulting in inaccurate permeability tests. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a gravel material penetration stability testing device for gravel stratum construction, thereby solving the problems existing in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A sand and gravel material penetration stability test device for sand and gravel stratum construction comprises a reference rod, the lower end of the reference rod is fixedly connected to a cutting cylinder, cutting holes are arranged at intervals on the lower end surface of the cutting cylinder, a cavity is arranged on the cutting cylinder, the cutting holes are connected to the cavity, a scraper is fixedly connected to one side of each cutting hole, a test cylinder is fixedly connected inside the cutting cylinder, the bottom of the test cylinder is an open structure, a receiving groove is arranged at the bottom of the test cylinder, a plurality of cutting rods are rotatably connected in an annular array in the receiving groove, a flexible steel mesh is fixedly connected between the cutting rod and the side wall of the receiving groove, a water-permeable pressure plate is arranged vertically and slidably in the cutting cylinder, a downward pressure device is arranged on the upper side of the water-permeable pressure plate, and the reference rod is fixedly connected to a displacement sensor;

[0007] The cutting rod is driven to rotate by a driver.

[0008] Preferably, the downward pressure device comprises a hollow tube, the lower end of the hollow tube is fixedly connected to the water-permeable pressure plate, a water outlet hole is arranged on the side of the lower end of the hollow tube, the upper end of the hollow tube is fixedly connected to the injection pipe, and the injection pipe is connected to the water pump through a hose;

[0009] An avoidance groove is arranged on the side of the reference rod, the side of the hollow tube is fixedly connected to the support rod, the side of the reference rod is fixedly connected to the electric push rod, and a pressure sensor is fixedly connected between the telescopic end of the electric push rod and the support rod.

[0010] Preferably, a guard plate is fixedly connected to the upper side of the support rod, and the guard plate is fixedly connected to the telescopic end of the electric push rod by screws.

[0011] Preferably, the driver includes a first motor, which is fixedly connected to the inner wall of the cutting cylinder, the main shaft of the first motor is fixedly connected to the first gear, the upper end of the test cylinder is fixedly connected to the gear ring, the first gear is meshed with the gear ring, the upper end of the rotating shaft of each cutting rod passes through the test cylinder and is fixedly connected to the second gear, and the second gear is meshed with the gear ring.

[0012] Preferably, an annular cavity is arranged in the middle of the test cylinder, and an air injection hole is arranged on the outer wall of the annular cavity. The rotating shaft of the cutting rod includes a reference shaft and a sliding shaft. The reference shaft is rotatably connected to the test cylinder, and the sliding shaft is axially slidably connected relative to the reference shaft. A sliding hole is arranged on the bottom side of the annular cavity, and an air leakage hole is arranged at the bottom of the sliding hole. A reset spring is arranged in the sliding hole. A sealing convex ring is fixedly connected to the outer side of the sliding shaft, and the sealing convex ring is slidably connected to the sliding hole.

[0013] Preferably, a sealing slip ring is slidably connected in the cavity, the air injection hole of the annular cavity is connected to the cavity, and the sealing slip ring can block the air injection hole.

[0014] Preferably, a spiral partition is fixedly connected in the cavity, an extrusion channel is formed between the spiral partitions, the extrusion channel is arranged corresponding to the cutting hole, an extrusion hole is arranged between the two cutting holes, the extrusion hole is connected to the cover plate through a torsion spring, and the space between the two spiral partitions corresponding to the extrusion hole is filled with premixed cement mortar dry material.

[0015] The advantages of the present invention are as follows: the gravel and stone material penetration stability testing device for gravel stratum construction provided by the present invention squeezes the soil at the edge of the reference hole into the cavity for storage through the rotation and descending of the cutting cylinder and the cooperation with the scraper, so that a protruding column is formed at the bottom of the reference hole, the protruding column enters the test cylinder, the water-permeable pressure plate contacts the protruding column to rise and push the displacement sensor to form a basic displacement, the first motor drives multiple cutting rods through the gear set to cut off the bottom of the column, the flexible steel wire mesh is unfolded to increase the bottom support area, and then the cutting cylinder and the test cylinder are lifted and suspended in the reference hole, and then the test cylinder is injected with a certain amount of water and pressurizes the water-permeable pressure plate, the displacement sensor forms the difference between the new displacement and the basic displacement, that is, the performance of instability and sinking caused by water absorption of the soil, and the penetration stability test is carried out at a specific depth to avoid the cumbersome sampling process, avoid the artificial compression and deformation of the sample, and avoid the difference with the actual soil properties.

[0016] The present invention injects pressurized air into the cavity above the sealing slip ring, and the sealing slip ring descends to compress the bottom space, so that the slag temporarily entering the cavity is squeezed out, and the premixed cement mortar dry material is pushed out at the same time, and the rotation movement is coordinated with the test soil after water permeation to form a mixing absorption test water, thereby avoiding local instability of the soil at that location caused by water injection during the penetration test underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a basic structural schematic diagram of the present invention;

[0018] Figure 2 It is a cross-sectional structural schematic diagram of the present invention;

[0019] Figure 3 yes Figure 2 A local enlarged view of point F in FIG.

[0020] Figure 4 It is a schematic diagram of the internal structure of the test cylinder of the present invention;

[0021] Figure 5 It is a schematic diagram of the plane projection of the cavity of the cutting cylinder of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example 1

[0023] like Figures 1 to 5 As shown, the gravel and stone material penetration stability testing device for gravel stratum construction provided by the present invention comprises a reference rod 1, the reference rod 1 can be axially connected to an existing rotating power device, the lower end of the reference rod 1 is fixedly connected to a cutting cylinder 2, the lower end surface of the cutting cylinder 2 is provided with cutting holes at intervals, the cutting cylinder 2 is provided with a cavity 22, the cavity 22 is used to collect debris, the cutting holes are connected to the cavity 22, one side of each cutting hole is fixedly connected to a scraper 23, the cutting cylinder 2 rotates and descends to cooperate with the scraper 23 to squeeze the soil into the cavity 22 for storage The cutting cylinder 2 is fixedly connected to the testing cylinder 3, the bottom of the testing cylinder 3 is an open structure, a receiving groove 31 is arranged at the bottom of the testing cylinder 3, a plurality of cutting rods 32 are rotatably connected in an annular array in the receiving groove 31, a flexible steel mesh 33 is fixedly connected between the cutting rods 32 and the side wall of the receiving groove 31, a water-permeable pressure plate 34 is vertically slidably arranged in the cutting cylinder 2, a downward pressing device 4 is arranged on the upper side of the water-permeable pressure plate 34, a reference rod 1 is fixedly connected to a displacement sensor 5, and a top rod of the displacement sensor 5 is arranged corresponding to the water-permeable pressure plate 34;

[0024] The cutting rod 32 is arc-shaped, so that the rotation of two adjacent cutting rods 32 is not interfered, and the end of the cutting rod 32 away from the rotating shaft is higher than the other end. After the multiple cutting rods 32 rotate, the other ends gather on the central axis of the test cylinder 3 to form an upwardly protruding support arch, which cooperates with the expansion of the flexible steel wire mesh 33 to intercept the soil entering the test cylinder 3 and form a stable support when the pressing device 4 performs a compression test.

[0025] The cutting rod 32 is driven to rotate by the driver 6, and the driver 6 includes a first motor 61, the first motor 61 is fixedly connected to the inner wall of the cutting cylinder 2, the main shaft of the first motor 61 is fixedly connected to the first gear 62, the upper end of the test cylinder 3 is fixedly connected to the gear ring 63, the first gear 62 is meshed with the gear ring 63, the upper end of the rotating shaft of each cutting rod 32 passes through the test cylinder 3 and is fixedly connected to the second gear 64, the second gear 64 is meshed with the gear ring 63, and the first motor 61 can drive all the cutting rods 32 to rotate through the gear and gear ring structure.

[0026] The present invention uses the existing technology to drill a reference hole in the stratum to be tested, and the cutting cylinder 2 rotates and descends to cooperate with the scraper 23 to squeeze the soil at the edge of the reference hole into the cavity 22 for storage, so that a protruding column is formed at the bottom of the reference hole, and the protruding column enters the test cylinder 3. The permeable pressure plate 34 contacts the protruding column and rises and pushes the displacement sensor 5 to form a basic displacement. The first motor 61 drives multiple cutting rods 32 through a gear set to cut off the bottom of the column, and the flexible wire mesh 33 is unfolded to increase the bottom support area. Then the cutting cylinder 2 and the test cylinder 3 are lifted and suspended in the reference hole. Then the test cylinder 3 is injected with a certain amount of water and pressurized on the permeable pressure plate 34. The displacement sensor 5 forms the difference between the new displacement and the basic displacement, that is, the performance of instability and sinking caused by water absorption of the soil. The penetration stability test is carried out at a specific depth to avoid the cumbersome sampling process, avoid the artificial compression deformation of the sample, and avoid differences with the actual soil properties. Example 2

[0027] like Figures 1 to 5 As shown, the downward pressure device 4 includes a hollow tube 41, the lower end of the hollow tube 41 is fixedly connected to the water-permeable pressure plate 34, a water outlet hole 42 is arranged on the side of the lower end of the hollow tube 41, and an injection pipe 43 is fixedly connected to the side of the upper end of the hollow tube 41, and the injection pipe 43 is connected to the water pump through a hose;

[0028] An avoidance slot is provided on the side of the reference rod 1, a support rod 45 is fixedly connected to the side of the hollow tube 41, and the support rod 45 extends from the avoidance slot to the outside of the reference rod 1. An electric push rod 46 is fixedly connected to the side of the reference rod 1, and a pressure sensor 47 is fixedly connected between the telescopic end of the electric push rod 46 and the support rod 45, and the pressure sensor 47 measures the pressure applied to the water-permeable pressure plate 34. A guard plate 48 is fixedly connected to the upper side of the support rod 45, and the guard plate 48 is fixedly connected to the telescopic end of the electric push rod 46 by screws.

[0029] The cutting cylinder 2 and the test cylinder 3 descend so that the protruding column passively enters the test cylinder 3, the electric push rod 46 contracts, and the water-permeable pressure plate 34 moves from the bottom to the top in the test cylinder 3 along the upper end of the protruding column. In this process, the guard plate 48 protects the pressure sensor 47. During the test, the guard plate 48 and the telescopic end of the electric push rod 46 are loosened, and the electric push rod 46 applies a test pressure to the intercepted protruding column entering the test cylinder 3 through the water-permeable pressure plate 34, and records the basic displacement of the displacement sensor 5. Subsequently, the soil in the test cylinder 3 is injected with water through the hollow tube 41-water outlet 42. The displacement sensor 5 records the displacement of the soil after collapse and sinking after absorbing water, thereby testing the permeability stability of the soil. The permeability stability test is carried out at a specific depth to avoid cumbersome sampling links, avoid artificial compression and deformation of samples, and avoid differences with actual soil properties. Example 3

[0030] like Figures 1 to 5 As shown, an annular cavity 7 is arranged in the middle of the test cylinder 3, and an air injection hole 71 is arranged on the outer wall of the annular cavity 7. The rotating shaft of the cutting rod 32 includes a reference shaft 321 and a sliding shaft 322. The reference shaft 321 is rotatably connected to the test cylinder 3, and the sliding shaft 322 is axially slidably connected relative to the reference shaft 321. A sliding hole is arranged on the bottom side of the annular cavity 7, and an air leakage hole 323 is arranged at the bottom of the sliding hole. A reset spring 324 is arranged in the sliding hole. A sealing convex ring 325 is fixedly connected to the outer side of the sliding shaft 322, and the sealing convex ring 325 is slidably connected to the sliding hole.

[0031] The sealing slip ring 8 is slidably connected in the cavity 22 , and the gas injection hole 71 of the annular cavity 7 is communicated with the cavity 22 , and the sealing slip ring 8 can block the gas injection hole 71 .

[0032] After completing the soil permeability instability performance test, pressurized air is injected into the cavity 22 above the sealing slip ring 8, the sealing slip ring 8 descends and causes the air injection hole 71 to leak, the pressurized air enters the annular cavity 7 and pushes the multiple sealing convex rings 325, so that the sliding shaft 322 has a tendency to move downward, and at this time the cutting rod 32 is controlled to rotate, the cutting rod 32 first descends to form an inclined slope between the flexible steel wire mesh 33 and the inner wall of the receiving groove 31, so that the intercepted soil is convenient to fall again, reducing the cleaning workload after taking out the equipment. Example 4

[0033] like Figures 1 to 5 As shown, a spiral partition 81 is fixedly connected in the cavity 22, and an extrusion channel is formed between the spiral partitions 81. The extrusion channel is arranged corresponding to the cutting hole, so as to facilitate the introduction of the soil at the edge of the reference hole into the cavity 22 in a strip shape for storage. An extrusion hole is arranged between the two cutting holes, and the extrusion hole is connected to the cover plate 82 by rotation of a torsion spring. The space between the two spiral partitions 81 corresponding to the extrusion hole is filled with premixed cement mortar dry material 83.

[0034] The present invention injects pressurized air into the cavity 22 above the sealing slip ring 8, and the sealing slip ring 8 descends to compress the bottom space, so that the debris temporarily entering the cavity 22 is squeezed out, and the premixed cement mortar dry material 83 is pushed out at the same time, and the rotational motion is coordinated with the test soil after water permeation to form a mixing absorption test water, thereby avoiding local instability of the soil at that location caused by water injection during the penetration test underground.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A sand and gravel material penetration stability testing device for sand and gravel stratum construction, comprising a reference rod (1), the lower end of the reference rod (1) is fixedly connected to a cutting cylinder (2), the lower end surface of the cutting cylinder (2) is provided with cutting holes at intervals, the cutting cylinder (2) is provided with a cavity (22), the cutting holes are connected to the cavity (22), one side of each cutting hole is fixedly connected to a scraper (23), and the interior of the cutting cylinder (2) is fixedly connected to a testing cylinder (3), characterized in that: The bottom of the test cylinder (3) is an open structure, a receiving groove (31) is arranged at the bottom of the test cylinder (3), a plurality of cutting rods (32) are rotatably connected in an annular array in the receiving groove (31), a flexible steel wire mesh (33) is fixedly connected between the cutting rods (32) and the side wall of the receiving groove (31), a water-permeable pressure plate (34) is vertically slidably arranged in the cutting cylinder (2), a downward pressing device (4) is arranged on the upper side of the water-permeable pressure plate (34), and the reference rod (1) is fixedly connected to a displacement sensor (5); The cutting rod (32) is driven to rotate by a driver (6); The downward pressure device (4) comprises a hollow tube (41), the lower end of the hollow tube (41) is fixedly connected to the water-permeable pressure plate (34), a water outlet hole (42) is provided on the side surface of the lower end of the hollow tube (41), and the upper end of the hollow tube (41) is fixedly connected to the injection tube (43), and the injection tube (43) is connected to the water pump via a hose; The reference rod (1) is provided with an avoidance groove on the side, the hollow tube (41) is fixedly connected to a support rod (45) on the side, the support rod (45) extends from the avoidance groove to the outside of the reference rod (1), the reference rod (1) is fixedly connected to an electric push rod (46) on the side, and a pressure sensor (47) is fixedly connected between the telescopic end of the electric push rod (46) and the support rod (45); The gravel material penetration stability testing device for gravel stratum construction is used to perform a soil penetration stability test at a specific depth.

2. The gravel material penetration stability testing device for gravel stratum construction according to claim 1 is characterized by: The upper side of the support rod (45) is fixedly connected to a guard plate (48), and the guard plate (48) is fixedly connected to the telescopic end of the electric push rod (46) via screws.

3. The gravel material penetration stability testing device for gravel stratum construction according to claim 1 is characterized by: The driver (6) comprises a first motor (61), the first motor (61) is fixedly connected to the inner wall of the cutting cylinder (2), the main shaft of the first motor (61) is fixedly connected to the first gear (62), the upper end of the test cylinder (3) is fixedly connected to the gear ring (63), the first gear (62) and the gear ring (63) are meshed, the upper end of the rotating shaft of each cutting rod (32) passes through the test cylinder (3) and is fixedly connected to the second gear (64), and the second gear (64) is meshed with the gear ring (63).

4. The gravel material penetration stability testing device for gravel stratum construction according to claim 3 is characterized by: An annular cavity (7) is arranged in the middle of the test cylinder (3), and an air injection hole (71) is arranged on the outer wall of the annular cavity (7). The rotating shaft of the cutting rod (32) comprises a reference shaft (321) and a sliding shaft (322). The reference shaft (321) is rotationally connected to the test cylinder (3), and the sliding shaft (322) is axially slidably connected relative to the reference shaft (321). A sliding hole is arranged on the bottom side of the annular cavity (7), and an air leakage hole (323) is arranged at the bottom of the sliding hole. A reset spring (324) is arranged in the sliding hole. A sealing convex ring (325) is fixedly connected to the outer side of the sliding shaft (322), and the sealing convex ring (325) is slidably connected to the sliding hole.

5. The gravel material penetration stability testing device for gravel stratum construction according to claim 1 is characterized by: The cavity (22) is slidably connected with a sealing slip ring (8); the air injection hole (71) of the annular cavity (7) is in communication with the cavity (22); and the sealing slip ring (8) can block the air injection hole (71).

6. The gravel material penetration stability testing device for gravel stratum construction according to claim 1 is characterized by: The cavity (22) is fixedly connected with a spiral partition (81), an extrusion channel is formed between the spiral partitions (81), the extrusion channel is arranged corresponding to the cutting hole, an extrusion hole is arranged between the two cutting holes, the extrusion hole is rotatably connected to the cover plate (82) through a torsion spring, and the space between the two spiral partitions (81) corresponding to the extrusion hole is filled with premixed cement mortar dry material (83).

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