CN109030315B - Low stress initial one-dimensional compression-penetration test system and its working method - Google Patents

Abstract

The invention relates to a low-stress initial one-dimensional compression-penetration test system, comprising a test bench, a consolidation container is arranged on the upper part of the test bench, a pressure transmission bolt is arranged on the upper part of the consolidation container, and the pressure transmission The bolt is connected with the force transmission lever through the pressure transmission frame, the low stress loading component and the high stress loading component are arranged on the force transmission lever, and the lower part of the consolidation vessel is arranged with a water head test component; the invention also relates to a low stress loading component. Working method of the initial one-dimensional compression-penetration test system. The invention not only has simple and reasonable structure design, but also realizes the compression properties of soil samples with low stress and high stress, and can measure the permeability coefficient and pore water pressure of soil samples with different stress levels.

Description

Low stress initial one-dimensional compression-penetration test system and its working method

technical field

The invention relates to a low-stress initial one-dimensional compression-penetration test system and a working method thereof.

Background technique

In order to maintain the smoothness of the waterway and the flood discharge capacity of the river, my country inevitably carries out large-scale dredging and dredging projects for the waterway and river every year, resulting in a large amount of dredging mud. Dredged mud with high water content has high fluidity, the skeleton is in a flowing state, the strength is low, and the ability to resist deformation is poor. Due to the essential difference in fluidity and strength between natural sedimentary soil and dredged mud with high water content When one-dimensional compression test is performed, conventional test instruments often have two problems: First, the sample cap of the conventional consolidation vessel is made of metal (about 300g copper), which will cause the soil sample with high initial moisture content to overflow the sample preparation ring. The second is the metal hook of the conventional pressure loading system (the mass is about 319g). When it is applied as the first-level load and the soil sample area is 30cm ² , the load applied to the soil sample is about 12.5kPa, which is relatively high for the initial moisture content. For high soil samples, the soil samples under this pressure are very easy to overflow the sample preparation ring knife.

At present, the treatment method of large-scale dredged mud is to requisition the nearby land, build a cofferdam, and discharge the waste dredged mud into the yard for storage to form a dredged mud yard. The permeability coefficient of the dredged mud is a very critical technology in the design of the yard disposal. Due to the parameters, the traditional permeameter cannot carry out the infiltration test of the flowing dredged mud, and the traditional consolidation container used in the one-dimensional compression test cannot carry out the infiltration test of the soil after different loads because the drainage channel is not sealed at the bottom.

After searching the existing technical documents, it is found that the one-dimensional compression test device has been improved in terms of automatic compression and data acquisition in recent years, but they have not been able to overcome the above-mentioned test dilemma of fluid soil.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a low-stress initial one-dimensional compression-penetration test system and a working method thereof, which are not only reasonable in structure design, but also efficient and convenient.

In order to solve the above technical problems, the technical solution of the present invention is: a low-stress initial one-dimensional compression-penetration test system, including a test bench, the upper part of the test bench is provided with a consolidation container, and the upper part of the consolidation container is A pressure transmission bolt is provided, the pressure transmission bolt is connected with a force transmission lever through a pressure transmission frame, a low stress loading assembly and a high stress loading assembly are arranged on the force transmission lever, and the lower part of the consolidation container is provided with a water head test components.

Further, the consolidation container comprises a bottom plate, a first permeable stone, a ring knife, a second permeable stone and a sample cap arranged in sequence from bottom to top, the ring knife contains soil samples, and the first permeable stone The permeable stone is placed inside the central groove of the chassis, the outer side wall of the ring knife is sleeved with a first fixing collar, the first fixing collar is placed on the outer ring surface of the chassis, and the first fixing collar is A first O-shaped rubber ring is arranged between it and the chassis, a second fixing collar is sleeved on the outer side wall of the second permeable stone, and the second fixing collar is placed on the first fixing collar. A second O-shaped rubber ring is arranged between the second fixed collar and the first fixed collar, and a third O-shaped rubber ring is sleeved on the upper outer side wall of the ring knife. The third O-shaped rubber The ring is arranged between the ring knife and the first fixed collar.

Further, a plurality of locking screws are arranged between the chassis and the second fixing collar, and the locking screws are arranged at intervals in the circumferential direction. One end of the locking screws is threadedly connected to the chassis, and the lock The other end of the tightening screw is locked with a locking nut after passing through the second fixing collar.

Further, the water head test assembly includes a water head pipe, a first water pipe and a second water pipe, the water head pipe is longitudinally arranged on one side of the consolidation container, and the first water pipe and the second water pipe are laterally arranged on the side of the consolidation container. On both sides, the upper end of the water head pipe is provided with a water head scale scale panel, and the lower end of the water head pipe is connected to one end of the first water pipe through the first flow channel opening and the second flow channel opening of the three-way valve. The three-flow channel mouth is connected to the pore water pressure gauge, the other end of the first water pipe is connected to the first permeable stone after passing through the chassis, one end of the second water pipe is connected to the first permeable stone, and the second water pipe is connected to the first permeable stone. The other end of the water pipe is provided with a two-way valve.

Further, the top of the pressure transmission bolt is provided with a displacement dial indicator, the bottom of the pressure transmission bolt is pressed on the top groove of the sample cap, and the pressure transmission frame includes an upper beam and a force transmission rod connected to each other. and the lower beam, the middle part of the pressure transmission bolt is connected with the upper beam through the thread, and the lower beam is connected with the force transmission lever through the first hinge.

Further, the low-stress loading assembly includes a low-stress weight suspension plate, the low-stress weight suspension plate is arranged directly below the force transmission rod, the high-stress loading assembly includes a high-stress weight suspension plate, and the The high stress weight hanger is set at one end of the force transmission lever.

A working method of a low-stress initial one-dimensional compression-penetration test system, comprising the low-stress initial one-dimensional compression-penetration test system described in any one of the above, comprising the following steps: loading a component, a force transmission lever through a low stress The soil sample is loaded with low stress by the consolidation container, and the soil sample is loaded with high stress through the high stress loading component, the force transmission lever, and the consolidation container. The water head test component can be used to measure the permeability coefficient and pore water of the soil samples at different stress levels. pressure.

Compared with the prior art, the present invention has the following beneficial effects: the present invention is not only simple and reasonable in structural design, but also realizes the compressive properties of low-stress and medium-high-stress soil samples, and simultaneously can measure the permeability coefficient and soil samples of different stress levels. Pore water pressure.

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Description of drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention.

FIG. 2 is a schematic front view of a consolidation vessel according to an embodiment of the present invention.

3 is a schematic top view of a consolidation container according to an embodiment of the present invention.

FIG. 4 is a schematic side view of a pressure transmission frame according to an embodiment of the present invention.

In the picture: 1-Test bench, 2-Consolidation container, 201-Chassis, 202-First permeable stone, 203-Ring knife, 204-Second permeable stone, 205-Specimen cap, 206-First fixed collar , 207- The first O-shaped rubber ring, 208- The second fixed collar, 209- The second O-shaped rubber ring, 210- The third O-shaped rubber ring, 211- Locking screw, 212- Locking nut , 3-pressure transmission bolt, 4-pressure transmission frame, 401-upper beam, 402-force transmission rod, 403-lower beam, 5-force transmission lever, 6-low stress loading assembly, 601-low stress weight hanging plate , 7-High stress loading assembly, 701-High stress weight hanging plate, 8-Head test assembly, 801-Head pipe, 802-First water pipe, 803-Second water pipe, 804-Head scale scale panel, 805-Three Through valve, 806-pore water pressure gauge, 807-two-way valve, 9-displacement dial indicator, 10-first hinge, 11-leveling assembly, 1101-adjustment box, 1102-adjustment handwheel, 1103-adjustment screw , 1104-adjusting sleeve, 1105-balance screw, 1106-balance weight, 1107-hook, 12-second hinge, 13-level, 14-third hinge, a-soil sample, b-force fulcrum.

Detailed ways

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following specific embodiments are given and the accompanying drawings are described in detail as follows.

As shown in Figures 1-4, a low-stress initial one-dimensional compression-penetration test system includes a test bench 1, the upper part of the test bench 1 is provided with a consolidation container 2, and the upper part of the consolidation container 2 is provided There are pressure transmission bolts 3, and the pressure transmission bolts 3 are connected to the force transmission lever 5 through the pressure transmission frame 4. The force transmission lever 5 is provided with a low-stress loading assembly 6 and a high-stress loading assembly 7. The consolidation container The lower part of 2 is provided with a water head test assembly 8 .

In the embodiment of the present invention, the consolidation container 2 includes a bottom plate 201 , a first permeable stone 202 , a ring knife 203 , a second permeable stone 204 and a sample cap 205 arranged in sequence from bottom to top, the ring knife 203 A soil sample is contained inside, the first permeable stone 202 is placed inside the central groove of the chassis 201, the outer side wall of the ring knife 203 is sleeved with a first fixing collar 206, and the first fixing collar 206 On the outer ring surface of the chassis 201, a first O-shaped rubber ring 207 is arranged between the first fixing collar 206 and the chassis 201, and a second fixing ring is sleeved on the outer side wall of the second permeable stone 204 A collar 208, the second fixing collar 208 is placed on the first fixing collar 206, a second O-shaped rubber ring 209 is arranged between the second fixing collar 208 and the first fixing collar 206, The upper outer side wall of the ring knife 203 is sleeved with a third O-shaped rubber ring 210, and the third O-shaped rubber ring 210 is arranged between the ring knife 203 and the first fixing collar 206; the sample The cap 205 is made of existing lightweight plexiglass.

In the embodiment of the present invention, a plurality of locking screws 211 pass through between the chassis 201 and the second fixing collar 208 , and the locking screws 211 are arranged at intervals in the circumferential direction. One end is threadedly connected with the chassis 201, and the other end of the locking screw 211 passes through the second fixing collar 208 and is locked by the locking nut 212; The restraining pressure of the three locking screws 211 and the locking nuts 212 realizes the sealing effect between the third O-shaped rubber ring 210 and the first fixed collar 203 and the first fixed collar 206, and realizes the first O-shaped rubber ring 210. The O-shaped rubber ring 207 is set to seal between the chassis 201 and the first fixed collar 206, and the second O-shaped rubber ring 209 is set to seal between the second fixed collar 208 and the third fixed collar Therefore, the water at the bottom of the consolidation container 2 can only reach the top of the consolidation container 2 by passing through the inside of the soil sample of the ring knife 203 .

In the embodiment of the present invention, when the initial state of the soil sample is a plastic state soil, the blade edge of the ring knife 203 is used to slowly insert the soil body vertically downward. In order to avoid cracking of the soil sample during the downward pressing process, the ring knife 203 needs to be inserted into the soil body. The excess soil on the outer wall of 203 is gradually removed, and finally the excess soil on the upper and lower parts of the ring knife 203 is flattened, and the filter paper saturated with degassed water is pasted on the upper and lower surfaces of the soil sample; The first permeable stone 202 is placed in the central groove of the chassis 201, and a first O-shaped rubber ring 207 is placed on the outer ring surface of the chassis 201; After the three O-shaped rubber rings 210, the first fixing collar 206 is put on the outside of the ring knife 203; the second fixing collar 208 is connected with the chassis 201 by three locking screws 211, and the The nut 212 is locked so that the first O-shaped rubber ring 207, the second O-shaped rubber ring 209, and the third O-shaped rubber ring 210 between the two are pressed to play a sealing role; The second permeable stone 204 and the sample cap 205; the outer ring surface of the chassis 201 is provided with a first groove for placing the first O-shaped rubber ring 207, and the lower surface of the second fixing collar 208 is provided with a useful In order to place the second groove of the second O-shaped rubber ring 209, the inner side of the first fixing collar 206 is provided with a third groove for placing the third O-shaped rubber ring 210; the first fixed The upper part of the collar 206 and the lower part of the second fixing collar 208 are provided with concave and convex parts for connection.

In the embodiment of the present invention, when the initial state of the soil sample is fluid plastic state soil, the first permeable stone 202 saturated with degassed water is first put into the central groove of the bottom plate 201, and placed in the bottom plate 201 The first O-shaped rubber ring 207 is placed on the outer ring surface of the ring knife 203; after the third O-shaped rubber ring 210 is hooped on the upper part of the ring knife 203, the first fixing collar 206 is put on the outside of the ring knife 203 ; Stir the fluid reshaped soil sample evenly and slowly pour it into the ring knife 203. During the pouring process, the mud can be lifted up and down with iron wire to remove air bubbles in the mud. After filling, the upper surface of the soil sample is scraped; The second fixing collar 208 is connected to the chassis 201, and is locked by the locking nut 212, so that the first O-shaped rubber ring 207, the second O-shaped rubber ring 209, the third O-shaped rubber ring 207 and the third O-shaped rubber ring 207 between the two parts are locked The letter-shaped rubber ring 210 is pressurized to play a sealing role; it is left for 24 hours to ensure that the excess static pore water pressure in the fluid-reshaped soil sample is dissipated.

In the embodiment of the present invention, the water head test assembly 8 includes a water head pipe 801, a first water pipe 802 and a second water pipe. Two water pipes are laterally arranged on both sides of the consolidation container, the upper end of the water head pipe 801 is provided with a water head scale scale panel 804 , and the lower end of the water head pipe 801 is connected to the first flow channel port and the second flow channel port of the three-way valve 805 One end of the first water pipe 802, the third flow port of the three-way valve 805 is connected to the pore water pressure gauge 806, and the other end of the first water pipe 802 is connected to the first permeable stone 202 after passing through the chassis 201, One end of the second water pipe is connected with the first permeable stone 202, and the other end of the second water pipe is provided with a two-way valve 807; Connect to lift.

In the embodiment of the present invention, the top of the pressure transmission bolt 3 is provided with a displacement dial indicator 9, the bottom of the pressure transmission bolt 3 is pressed against the top groove of the sample cap 205, and the pressure transmission frame 4 includes The upper beam 401, the force transmission rod 402 and the lower beam 403 are connected to each other, the middle part of the pressure transmission bolt 3 is connected with the upper beam 401 through the thread, and the lower beam 403 is connected with the force transmission lever 5 through the first hinge 10. The soil sample height change is determined by the reading of the displacement dial indicator 9; Placed between two power transmission rods 402, the upper cross beam 401, the two power transmission rods 402 and the lower cross beam 403 form a mouth-shaped pressure transmission frame 4; the displacement dial indicator 9 passes through the vertical frame and the test bench 1 phase connection.

In the embodiment of the present invention, the low-stress loading assembly 6 includes a low-stress weight suspension plate 601 , the low-stress weight suspension plate 601 and the force transmission rod 402 are located on the same vertical plane, and the high-stress loading assembly 7 It includes a high-stress weight hanging plate 701, and the high-stress weight hanging plate 701 is arranged at one end of the force transmission lever 5; the weight load on the low-stress weight hanging plate 601 is transmitted according to 1:1 The load of the sample cap 205 acting on the soil sample is 0.5~12.5kPa; the weight load on the high stress weight hanging plate 701 is transmitted to the sample in a 12:1 transmission method The cap 205, the load of the sample cap 205 acting on the soil sample is 25~1600kPa.

In the embodiment of the present invention, the other end of the force transmission lever 5 is provided with a leveling assembly 11 , and the leveling assembly 11 includes an adjustment box 1101 arranged at the lower part of the test bench 1 . A bevel gear pair is arranged inside, the first bevel gear composing the bevel gear pair is connected with the adjusting hand wheel 1102 arranged laterally, and the second bevel gear composing the bevel gear pair is connected with the adjusting screw 1103 arranged longitudinally, An adjusting rod 1104 is connected with the external thread of the adjusting bolt. The adjusting rod 1104 is connected with the force fulcrum of the force transmission lever 5 through the second hinge 12 . The balance screw 1105 is connected, and the left end of the balance screw 1105 is threadedly connected with a counterweight 1106; the right end of the balance screw 1105 is connected to the center position of the lower beam 403 of the pressure transmission frame 4 through a hook 1107, and the second hinge 12 adopts diamond-shaped knife-edge pin; the third hinge 14 adopts a rotating pin; when the adjusting handwheel 1102 is rotated, the first bevel gear mobilizes the second bevel gear to rotate, thereby driving the adjusting bolt to rotate, because the force transmission lever 5 and the second hinge 12 to limit the rotation of the adjusting rod 1104, so that the relative distance between the adjusting bolt and the adjusting rod 1104 can be adjusted, and the position of the counterweight 1106 can be adjusted at the same time, so that the force transmission lever 5 can be wound around The second hinge 12 rotates, so that the balance of the force transmission lever 5 can be adjusted under no-load conditions; of course, the leveling component 11 can directly use the leveling component in the existing single-lever consolidation instrument .

In the embodiment of the present invention, a level 13 is provided at one end of the force transmission lever 5 , and the level 13 assists in adjusting the balance of the force transmission lever 5 under no-load condition.

In an embodiment of the present invention, a working method of a low-stress initial one-dimensional compression-penetration test system, including the low-stress initial one-dimensional compression-penetration test system described in any one of the above, includes the following steps: The stress loading component 6, the force transmission lever 5, and the consolidation container are used to load the soil sample with low stress. The high stress loading component 7, the force transmission lever 5, and the consolidation container are used to load the soil sample with high stress. The water head test component 8 can be used. The permeability coefficient and pore water pressure of soil samples with different stress levels were measured.

In the embodiment of the present invention, a second permeable stone 204 and a sample cap 205 are sequentially placed on top of the soil sample, a displacement dial indicator 9 is fixed on the top of the sample cap 205, and the leveling assembly 11 is adjusted so that the level The air bubble of 13 is in the middle position, and the balance of the force transmission lever 5 under no-load condition is adjusted by the leveling assembly 11;

Low-stress system loading process: when the required load is less than 12.5kPa and greater than 0.5kPa, place a weight on the low-stress weight hanging plate 601, and the weight of the weight will transfer the load to the sample in a 1:1 manner Cap 205; at this time, the soil sample is subjected to the vertical consolidation pressure of 0.5kPa~12.5kPa of the sample cap 205, and the deformation data during the consolidation process of the soil sample is read through the displacement dial table 9;

High-stress system loading process: when the required load is greater than 12.5kPa, by placing a weight on the high-stress weight hanging plate 701, the weight of the weight will transfer the load to the sample cap in a 12:1 transmission mode. When the soil sample is subjected to the vertical consolidation pressure of 25~1600kPa of the sample cap 205, the deformation data during the consolidation process of the soil sample is read through the displacement dial gauge 9.

In the embodiment of the present invention, the pore pressure test process measures the pore water pressure: open the two-way valve 807, and then connect the three-way valve 805 to the head pipe 801, at this time the three-way valve 805 is connected to the pore water The pressure gauge 806 is isolated from each other, and the two-way valve 807 discharges water and forms a continuous flow of water, indicating that the residual air at the bottom of the sample is exhausted; then the three-way valve 805 is connected to the pore water pressure gauge 806, and the three-way The valve 805 is isolated from the water head pipe 801, the two-way valve 807 is closed, and the pore water pressure value is read during the loading process.

In the embodiment of the present invention, the permeability coefficient is measured during the penetration test: when the soil compression deformation is stable under each level of load and the pore water pressure drops to zero, the three-way valve 805 is connected to the water head pipe 801. The three-way valve 805 is isolated from the pore water pressure gauge 806, the two-way valve 807 is closed, the head pressure of the water head pipe 801 cannot be greater than the vertical load applied to the top of the soil sample, and the initial water head height is selected according to the permeability of the soil sample, The initial water head height requirement is met by raising and lowering the water head scale scale panel 804, and then the change of the water head height with time is read to obtain the permeability coefficient in the current soil state.

Unless otherwise stated, the terms used in any of the technical solutions disclosed in the present disclosure and used to represent the positional relationship or shape include a state or shape that is similar to, similar to, or close to.

Any component provided by the present invention may be assembled from a plurality of individual components, or may be a single component manufactured by an integral molding process.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the specific embodiments of the present invention can still be carried out. Modification or equivalent replacement of some technical features; without departing from the spirit of the technical solution of the present invention, all of them should be included in the scope of the technical solution claimed in the present invention.

Claims (3)

1. A low stress initiation one-dimensional compression-infiltration testing system, comprising: the test bed comprises a test bed, wherein a consolidation container is arranged on the upper portion of the test bed, a pressure transfer bolt is arranged on the upper portion of the consolidation container and is connected with a force transfer lever through a pressure transfer frame, a low-stress loading assembly and a high-stress loading assembly are arranged on the force transfer lever, a water head testing assembly is arranged on the lower portion of the consolidation container, the consolidation container comprises a chassis, a first permeable stone, a cutting ring, a second permeable stone and a sample cap which are sequentially arranged from bottom to top, a soil sample is contained in the cutting ring, the first permeable stone is arranged in a central groove of the chassis, a first fixing lantern ring is sleeved on the outer side wall of the cutting ring and is arranged on the outer annular surface of the chassis, a first O-shaped rubber ring is arranged between the first fixing lantern ring and the chassis, a second fixing lantern ring is sleeved on the outer side wall of the second permeable stone, and is arranged on the first fixing lantern ring, be provided with second O style of calligraphy rubber circle between the fixed lantern ring of second and the first fixed lantern ring, the upper portion lateral wall cover of cutting ring is equipped with third O style of calligraphy rubber circle, third O style of calligraphy rubber circle sets up between cutting ring and the first fixed lantern ring, wear to be equipped with a plurality of locking screw between the fixed lantern ring of chassis and second, a plurality of locking screw hoop interval sets up, locking screw's one end and chassis threaded connection, locking screw's the other end utilizes lock nut to lock after passing the fixed lantern ring of second, head test component contains water head pipe, first water pipe and second water pipe, water head pipe vertically sets up in one side of consolidation container, first water pipe and second water pipe transversely set up in the both sides of consolidation container, the upper end of water head pipe is provided with the scale panel, the lower extreme of water head pipe is through the first runner mouth of three-way valve, The one end of first water pipe is inserted to the second flow way mouth, the third flow way mouth of three-way valve is connected with the pore water pressure gauge, the other end of first water pipe is connected with first permeable stone after passing the chassis, the one end of second water pipe is connected with first permeable stone, the other end of second water pipe is provided with the two-way valve, pass the top of pressure bolt and be provided with the displacement percentage table, pass the bottom pressure of pressure bolt on the top recess of sample cap, pass the pressure frame and contain interconnect's upper portion crossbeam, biography power pull rod and lower part crossbeam, pass the middle part of pressure bolt and be connected with the upper portion crossbeam through the screw thread, the lower part crossbeam is connected with biography power lever through first hinge.

2. The low stress initiation one-dimensional compression-infiltration testing system of claim 1, wherein: the low stress loading subassembly contains the low stress weight platform sling, the low stress weight platform sling sets up under biography power pull rod, the high stress loading subassembly contains the high stress weight platform sling, the high stress weight platform sling sets up at one side end of biography power lever.

3. A method of operating a low stress initiation one-dimensional compression-infiltration testing system, using a low stress initiation one-dimensional compression-infiltration testing system according to any of claims 1-2, comprising the steps of: the soil sample is subjected to low stress loading through the low stress loading assembly, the force transmission lever and the consolidation container, the soil sample is subjected to high stress loading through the high stress loading assembly, the force transmission lever and the consolidation container, and the water head testing assembly is used for measuring the permeability coefficient and the pore water pressure of the soil sample at different stress levels.

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