Double-base cutting ring split type cohesive soil permeameter

Abstract

The utility model relates to a double-base cutting ring split type cohesive soil permeameter. The cohesive soil permeameter comprises a fixed base, a movable base, a split cutting ring, a sleeve seat, an upper cover and a permeable plate, wherein the split cutting ring wraps and clamps a sample and is embedded into the sleeve seat, the upper end and the lower end of the sleeve seat are respectively connected with the upper cover and the movable base, the movable base is arranged in the fixed base, the top surface of the upper cover is pressed downwards by utilizing a screw rod on the door type frame connected with the fixed base, and the upper cover, the sleeve seat, the movable base and the fixed base are fixed to form the permeameter. The double bases and the accessory sample plate are designed, and the sleeve base, the cutting ring and the sample are the same in height. When the sample is installed, the sample is placed on the sample plate, the movable base covers the sleeve seat in an inverted mode, the sleeve seat is clamped by the movable base and the sample plate, the cutting ring and the sample are turned over together and placed into the fixed base, it is guaranteed that the sample cannot slide in the cutting ring in the whole installation process, side wall leakage can be better prevented, and the accuracy of a test result is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical testing, in particular to a double-base ring knife split type cohesive soil permeameter. Background Art

[0002] The permeability coefficient reflects the water permeability of rock and soil and is an important geotechnical parameter that must be provided in geotechnical engineering investigation. For clay soil, it is often obtained by sampling and conducting variable head permeability tests indoors. At present, the commonly used permeameter is the Nan-55 permeameter, and its biggest disadvantage is that it is prone to side wall leakage and the accuracy of the test results is not ideal.

[0003] For example, the utility model patent with announcement number CN 2055066401 U discloses a split ring knife type clay soil permeameter to solve the side wall leakage problem. The permeameter is composed of a base, a sleeve, a split ring knife, an upper cover and a fixed frame. It adopts a split ring knife structure design, that is, the entire ring knife is assembled from two semicircular ring knives. A thin layer of vaseline is applied to the inner wall of the ring knife, and then a cylindrical sample is clamped from both sides. The sleeve is nested on the closed ring knife and then placed in the base. Its biggest feature is that by clamping the sample with a semicircular ring knife, the gap between the side wall of the sample and the ring knife is completely filled with impermeable vaseline, blocking the side wall leakage channel, thereby solving the side wall leakage problem. The permeameter has two shortcomings: 1. The side wall of the sample is wrapped with vaseline, and vaseline has strong lubricity. When the sample and the sleeve are moved into the base together, the sample is easy to slide in the ring cutter, or even slide out, affecting the filling effect of the sample side wall and the control effect of the side wall leakage; 2. When the outer wall of the ring cutter is designed as a cylindrical surface, it is difficult for the ring cutter assembly surface to reach a tight extrusion state, which affects the anti-seepage effect of the assembly surface. In order to ensure the sealing effect of the assembly surface, the outer wall of the ring cutter and the inner wall of the sleeve are designed as an inverted cone surface with a large top and a small bottom. The advantage is that as long as a certain pressure is applied to the top surface of the ring cutter, the ring cutter assembly surface will automatically reach a tight extrusion state, ensuring that the assembly surfaces are squeezed against each other and are always in a sealed and water-stopping state. However, the problem is that the ring cutter and the sleeve are tightly nested together, making it difficult to separate the ring cutter from the sleeve, reducing the efficiency of the test operation.

[0004] In view of the deficiencies of the above related patents, the utility model provides a double-base ring knife split type clay soil permeameter to solve the above technical problems. Utility Model Content

[0005] The utility model aims to solve the defects in the prior art and provides a double-base ring knife split type cohesive soil permeameter.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] A double-base split ring knife type cohesive soil permeameter, comprising a fixed base, a movable base, a split ring knife, a sleeve seat, an upper cover and a water-permeable plate;

[0008] Among them, the split ring knife clamps the sample and is embedded in the sleeve. The upper and lower ends of the sleeve are respectively connected to the upper cover and the movable base. The movable base is placed in the fixed base. The top surface of the upper cover is pressed down by the screw on the door frame connected to the fixed base, and the upper cover, sleeve, movable base and fixed base are fixed to form a permeameter.

[0009] Furthermore, a circular groove is provided on the fixed base, and door-type frames are provided on both sides of the circular groove, and the circular groove is used to place the movable base;

[0010] The portal frame is fixed on the fixed base. The portal frame is composed of columns, beams and screws, wherein the beams are connected to the columns, one end of the columns is connected to the fixed base, and the screws are installed on the beams. The portal frame is used to apply pressure to the top surface of the upper cover.

[0011] Furthermore, two-stage circular grooves with different inner diameters are provided in the movable base, the first circular groove with a larger inner diameter is the first circular groove, and the second circular groove with a smaller inner diameter is the second circular groove. The first circular groove is used to place the sleeve, and the bottom of the second circular groove has an annular water dispersion groove for placing the water-permeable plate. The inner diameter of the second circular groove is equal to the diameter of the water-permeable plate, and the depth is equal to the thickness of the water-permeable plate. Water inlet pipes and exhaust pipes connected to the annular water dispersion groove are provided on both sides of the movable base.

[0012] Furthermore, the heights of the split ring cutter and the sleeve are the same and equal to the height of the sample.

[0013] Furthermore, the outer wall of the split ring cutter and the inner wall of the sleeve seat are both inverted conical surfaces and have the same size and shape. When the split ring cutter is embedded in the sleeve seat, the two are in close contact.

[0014] Furthermore, a puller groove is provided at the middle and lower part of the outer wall of the sleeve, and the puller groove serves as a reaction force application point of the puller hook foot.

[0015] Furthermore, an annular sealing gasket is provided between the top surface of the sleeve and the upper cover, and between the bottom surface of the sleeve and the movable base, and the ring width of the annular sealing gasket is equal to the sum of the wall thickness of the sleeve and the split ring cutter.

[0016] The beneficial effects of the utility model are as follows: 1. The application designs a double base and an accessory sample plate, and the sleeve, the ring knife and the sample are of the same height. When installing the sample, the sample is placed on the sample plate, the movable base is covered on the sleeve, and the sleeve, the ring knife and the sample are clamped by the movable base and the sample plate, turned over together, and placed in the fixed base. The entire installation process ensures that the sample cannot slide in the ring knife, which can better prevent side wall leakage and improve the accuracy of the test results;

[0017] 2. The present application provides a puller hook groove on the outer wall of the sleeve, and utilizes an accessory disc, so that the ring cutter can be easily ejected from the sleeve by a puller. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the permeameter of the embodiment of the utility model;

[0019] Figure 2 It is a cross-sectional schematic diagram of a fixed base of an infiltration instrument according to an embodiment of the utility model;

[0020] Figure 3 It is a cross-sectional schematic diagram of the movable base of the permeameter of the embodiment of the utility model;

[0021] Figure 4 It is a cross-sectional schematic diagram of a split ring knife of a permeameter according to an embodiment of the utility model;

[0022] Figure 5 This is a schematic diagram of a sleeve seat in an embodiment of the utility model;

[0023] Figure 6 This is a schematic diagram of a split ring cutter embedded in a sleeve seat according to an embodiment of the utility model;

[0024] Figure 7 It is a schematic diagram of the upper cover of an embodiment of the utility model;

[0025] Figure 8 Appendix 1: Schematic diagram of the plane and section of the sample plate;

[0026] Fig. 9 Appendix 2 Schematic diagram of the circular plate in plan and section.

[0027] Explanation of the reference numerals: 1-fixed base; 101-circular groove; 102-upright column of the fixed frame; 103-crossbeam of the fixed frame; 104-screw of the fixed frame; 2-movable base; 201-first circular groove; 202-second circular groove; 203-diffuser trough; 204-water inlet pipe; 205-exhaust pipe; 3-split ring knife; 301-semicircular ring knife; 302-combined surface sealing strip; 303-fixing pin; 4-sleeve; 5-upper cover; 501-first circular groove; 502-second circular groove; 503-diffuser trough; 504-water outlet pipe; 6-water-permeable plate; 7-annular sealing gasket. DETAILED DESCRIPTION

[0028] The present invention can be further described by the following embodiments. However, the scope of the present invention is not limited to the following embodiments.

[0029] Reference Figure 1-Figure 6A double-base split ring knife type clay soil permeameter, which includes a fixed base 1, a movable base 2, a split ring knife 3, a sleeve 4 and an upper cover 5, as well as two accessory sample plates and a circular plate. The fixed base 1 has a door-type fixed frame, and the movable base 2 is placed in the circular groove 101 of the fixed base; the top surface of the sleeve 4 is placed in the circular groove 501 of the upper cover 5, and the bottom surface is placed in the circular groove 201 of the movable base 2. The inner cavity of the sleeve 4 is a trumpet shape with a larger top and a smaller bottom; the split ring knife 3 is embedded in the sleeve 4, and is assembled by two semicircular ring knives 301, and a sealing rubber pad 302 is provided on the assembly surface. There are annular sealing gaskets 7 between the sleeve 4 and the upper cover 5, and between the sleeve 4 and the movable base 2. The downward pressing screw 104 on the door-type frame fixes the upper cover 5, the sleeve 4, the split ring knife 3, the movable base 2 and the fixed base 1 into a complete permeameter.

[0030] The selected sample size is a cylinder with a height of 40.0 mm and a diameter of 61.8 mm, which is the same as the sample size of the Nan 55 type permeameter.

[0031] The split ring cutter 3 is made of copper, aluminum or stainless steel, and is a circular ring cutter assembled from two semicircular ring cutters 301, without a cutting edge, with a cylindrical inner wall and an inner diameter of 62.0 mm (considering that the surface of the sample is not smooth and regular enough, a 0.2 mm gap is reserved to avoid the ring cutter directly squeezing the sample. If the sample is a regular cylinder, the inner diameter of the ring cutter can be equal to the diameter of the sample), and an inverted conical outer wall with an upper wall thickness of 5.0 mm and an outer diameter of 72.0 mm (62+5×2=72 mm). The lower end wall thickness is 3.0mm, the outer diameter is 68.0mm (62+3×2=68mm), and the height is 40.0mm (equal to the sample height). The two semicircular ring knife assembly surfaces are both pasted with sealing gaskets 302 with a thickness of 0.1-0.2mm. One of the semicircular ring knife assembly surfaces has a fixing pin 303 with a length of about 2mm, and the other semicircular ring knife assembly surface has a corresponding pin hole. The two semicircular ring knives are combined and squeezed against each other to form a complete circular ring knife 3, and its assembly surface is sealed and has no dislocation.

[0032] The sleeve 4 is made of metal materials such as stainless steel, aluminum or copper, with a height of 40.0mm (equal to the height of the ring cutter), the inner cavity is a trumpet shape with a large upper part and a small lower part, and the inner cavity wall is an inverted conical surface, with an inner diameter of 72.0mm at the upper end and 68.0mm at the lower end, which are respectively equal to the outer wall diameters of the upper and lower ends of the split ring cutter 3. During the test, after the ring cutter is embedded in the sleeve and pressed, the two are in close contact and the top and bottom surfaces are just flush. The outer wall of the sleeve 4 is a cylindrical surface with an outer diameter of 92.0mm. There is a puller groove in the middle and lower part of the outer wall, which is used as the puller hook foot reaction point when the puller is used to disassemble the ring cutter. The groove is 5.0mm deep and 10.0mm wide.

[0033] The movable base 2 includes two levels of concentric circular grooves of different sizes, a water inlet pipe 204 and an exhaust pipe 205. The first circular groove 201 has a larger diameter, and the second circular groove 202 has a smaller diameter. The inner diameter of the first circular groove 201 is 92.0 mm, which is equal to the outer diameter of the bottom surface of the sleeve, that is, the sleeve 4 can be placed just in place, and the depth is greater than the thickness of the annular sealing gasket 7 between the sleeve and the movable base. The bottom of the second circular groove 202 has an annular water dispersion groove 203 with an inner diameter of 61.8 mm and a depth of 10.0 mm, which can just fit a circular water-permeable plate with a diameter of 61.8 mm and a thickness of 10.0 mm. The diameter of the water-permeable plate is the same as that of the sample. The water inlet pipe 204 and the exhaust pipe 205 are located on both sides of the movable base 2 and are connected to the water dispersion groove 203.

[0034] Reference Figure 7 The upper cover 5 includes two levels of concentric circular grooves of different sizes and a water outlet pipe 504. The first circular groove 501 has a larger diameter and the second circular groove 502 has a smaller diameter. The bottom surface of the second circular groove 502 is provided with an annular water dispersion groove 503, with an inner diameter of 61.8 mm and a depth of 10.0 mm, which are respectively equal to the diameter and thickness of the permeable plate, that is, the second circular groove 502 can just fit a circular permeable stone with a diameter of 61.8 mm and a thickness of 10.0 mm. The inner diameter of the first circular groove 501 is 92.0 mm, which is equal to the outer diameter of the top surface of the sleeve, that is, the top surface of the sleeve 4 can just fit into the first circular groove 501. The depth of the circular groove is greater than the thickness of the annular sealing gasket 7 between the sleeve 4 and the upper cover 5. The water outlet pipe 504 is located on the side and is connected to the annular water dispersion groove 503.

[0035] There are annular sealing gaskets 7 between the top surface of the sleeve 4 and the first circular groove 501 of the upper cover 5, and between the bottom surface of the sleeve 4 and the first circular groove 301 of the movable base 3. The gasket ring width is 15.0 mm, that is, the inner diameter is 62.0 mm and the outer diameter is 92.0 mm. During the test, the permeable plate 6 and the sealing rubber gasket 7 must be installed in the movable base 2 and the upper cover 5.

[0036] The fixed base includes a circular groove 101 and a fixed frame. The circular groove 101 can just fit the movable base 2, and the inner diameter is equal to the outer diameter of the movable base 2. The fixed frame is a door-type frame, which is composed of columns 102, beams 103 and screws 104. The columns 102 on both sides are fixed on both sides of the circular groove 101 of the fixed base. The upper ends of the columns 102 are connected to the beams 103. The center of the beams 103 is connected to the screws 104 through screw holes. By rotating the screws 104, pressure is applied to the center of the top surface of the upper cover 5 to fix the entire permeameter. The net width of the frame is greater than the outer diameter of the upper cover 5 and the movable base 2, and the net height is greater than the sum of the heights of the upper cover 5, the sleeve 4 and the movable base 2.

[0037] Reference Figure 8 , Fig. 9, The sample plate in Appendix 1 is a thin metal plate with a bottom pad of about 10.0mm. The plate width is larger than the outer diameter of the top surface of the sleeve, and the plate thickness is about 3.0-5.0mm. There is a hollow ring in the center of the plate. The small circle diameter of the ring is 60.8mm (1.0mm smaller than the sample), and the large circle diameter is 67.8mm (6.0mm larger than the sample). The four directions of the solid disc in the middle are connected to the sample plate through a 1.0mm wide narrow strip. When installing the sample, the top surface of the sample is placed in the center of the sample plate ring with the top surface facing down, and the split ring knife is placed on the sample plate with the top surface facing down. The sample is clamped from both sides and closed. The excess vaseline squeezed out from the bottom of the sample will pass through the hollow ring and overflow to the bottom of the sample plate, preventing the vaseline from squeezing into the sample surface and affecting the water permeability of the sample surface.

[0038] The disc of attachment 2 is made of metal material, preferably with a thickness greater than 5.0mm, and is not easily deformed when the center is under pressure. The diameter is 66.0mm, which is 2.0mm smaller than the outer diameter of the bottom surface of the split ring knife 68.0mm. The disc is used to eject the split ring knife 3 from the sleeve 4. The ejection method is to place the disc in the center of the bottom surface of the split ring knife 3, hook the puller hook foot into the puller groove on the outer wall of the sleeve 4, align the puller push rod with the center of the disc, and rotate the push rod to eject the split ring knife 3 from the sleeve 4.

[0039] During the test, the sample installation steps are as follows: (1) Saturate the cut cylindrical sample, paste filter paper on the upper and lower surfaces, and place it with the top surface facing down in the center of the hollow ring of the sample plate in the attachment 1; (2) Evenly apply 0.1-0.2 mm thick vaseline (the thickness must be greater than the difference between the radius of the sample and the split ring cutter) on the inner wall of the two semicircular ring cutters 301, place it with the top surface (the end with the thick wall) facing down on the sample plate, clamp the sample from both sides and close it, and nest the sleeve 4 with the top surface facing down on the closed ring cutter 3 and press it down until the bottom surfaces of the two are flush, scrape off the excess vaseline squeezed out, and replace the filter paper; (3) Place the permeable stone 6 and the annular sealing gasket 7 in the movable base 2 , cover the bottom surface of the sleeve (that is, the first circular groove 201 of the movable base is connected to the bottom surface of the sleeve 4), use the movable base 2 and the sample plate of the accessory 1 to clamp the sleeve 4, the ring knife 3 and the sample together, and turn them over so that the movable base is at the bottom and the sleeve is at the top. Remove the sample plate, scrape off the extruded vaseline, replace the filter paper, and put them together into the circular groove 101 of the fixed base; (4) Place the permeable stone 6 and the annular sealing gasket 7 in the upper cover 5 and cover the top surface of the sleeve 4, rotate the screw 104 on the fixed frame, press down the top surface of the upper cover 5, and tightly fix the upper cover 5, the sleeve 4, the movable base 2 and the fixed base 1 together to form a permeameter, and the sample installation is completed. During the sample installation process, the sample needs to be moved into the circular groove 101 of the fixed base. At this time, the movable base 4 is placed on top and the sample plate is placed on the bottom. The sleeve, ring knife and sample are clamped in the middle (the three are of the same height) and turned over together, and then moved into the circular groove 101 of the fixed base together with the movable base 4. During the whole process, the sample will not slide in the ring knife, which solves the problem of the sample sliding in the ring knife 3 during the sample installation process and improves the effect of controlling side wall leakage.

[0040] After the test, the method to eject the split ring cutter from the socket is to place the circular plate of accessory 2 on the bottom surface of the split ring cutter (the end with the smaller outer diameter), with the diameter of the circular plate larger than the inner diameter of the split ring cutter and smaller than its outer diameter. Fix the puller hook foot in the puller groove of the socket, align the push rod with the center of the circular plate, rotate the push rod to squeeze the circular plate, and the circular plate squeezes the ring cutter. Once the ring cutter is loose, it will fall out of the ring.

[0041] In summary, the present application designs a double base and an accessory sample plate, and the sleeve, knife ring and sample are of the same height. When installing the sample, the sample is placed on the sample plate, the movable base is placed upside down on the sleeve, and the sleeve, knife ring and sample are clamped by the movable base and the sample plate, turned over together, and placed in the fixed base. The entire installation process ensures that the sample cannot slide in the knife ring, which can better prevent side wall leakage and improve the accuracy of the test results.

[0042] The above shows and describes the basic principles, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A double-base ring knife split type cohesive soil permeameter, It is characterized in that It comprises a fixed base (1), a movable base (2), a split ring knife (3), a sleeve (4), an upper cover (5) and a water-permeable plate (6); The split ring cutter (3) clamps the sample and is embedded in the sleeve (4); the upper and lower ends of the sleeve (4) are respectively connected to the upper cover (5) and the movable base (2); the movable base (2) is placed in the fixed base (1); the top surface of the upper cover (5) is pressed down by a screw (104) on a door frame connected to the fixed base (1), so that the upper cover (5), the sleeve (4), the movable base (2) and the fixed base (1) are fixed to form the permeameter.

2. A double-base ring knife split type cohesive soil permeameter according to claim 1, It is characterized in that The fixed base (1) is provided with a circular groove (101), and door-type frames are provided on both sides of the circular groove (101). The circular groove (101) is used to place the movable base (2); The portal frame is fixed on the fixed base (1), and the portal frame is composed of a column (102), a crossbeam (103), and a screw (104), wherein the crossbeam (103) is connected to the column (102), one end of the column (102) is connected to the fixed base (1), and the screw (104) is installed on the crossbeam (103). The portal frame is used to apply pressure to the top surface of the upper cover (5).

3. A double-base ring knife split type cohesive soil permeameter according to claim 1 or 2, It is characterized in that The movable base (2) is provided with two-stage circular grooves with different inner diameters, the first circular groove (201) having a larger inner diameter, and the second circular groove (202) having a smaller inner diameter. The first circular groove (201) is used to place the sleeve (4). The bottom of the second circular groove (202) is provided with an annular water dispersion groove (203) for placing a water permeable plate (6). The inner diameter of the second circular groove (202) is equal to the diameter of the sample and the diameter of the water permeable plate, and the depth is equal to the thickness of the water permeable plate (6). A water inlet pipe (204) and an exhaust pipe (205) connected to the annular water dispersion groove (203) are provided on both sides of the movable base (2).

4. A double-base ring knife split type cohesive soil permeameter according to claim 3, It is characterized in that The heights of the split ring cutter (3) and the sleeve (4) are the same and equal to the height of the sample.

5. A double-base ring knife split type cohesive soil permeameter according to claim 1, It is characterized in that The outer wall of the split ring knife (3) and the inner wall of the sleeve (4) are both inverted conical surfaces and have the same size and shape. When the split ring knife (3) is embedded in the sleeve (4), the two are in close contact and the top and bottom surfaces of the two are flush.

6. A double-base ring knife split type cohesive soil permeameter according to claim 1, It is characterized in that A puller groove is provided at the middle and lower part of the outer wall of the sleeve (4), and the puller groove serves as a reaction force application point of the puller hook foot.

7. A double-base ring knife split type cohesive soil permeameter according to claim 1, It is characterized in that There are annular sealing gaskets between the top surface of the sleeve (4) and the upper cover (5), and between the bottom surface of the sleeve and the movable base (2), and the ring width of the annular sealing gasket is equal to the sum of the wall thickness of the sleeve (4) and the split ring knife (3).

Images