CN218524505U - On-spot large-scale triaxial test device of normal position - Google Patents

Abstract

The utility model discloses a scene normal position triaxial test device, this scheme about the position that both sides lower extreme counter weight corresponds respectively set up 4 holes, thereby the dowel of being convenient for passes and plays the fixed action. And a loading steel plate is welded at the bottom of the cross beam and used for providing counter force of the jack. The balance weight bearing plate under the anchor bar connecting beam is arranged at the two ends of the cross beam, the balance weight is placed on the bearing plate, and the middle of the bearing plate is provided with the first jack, so that the maximum axial force which can be provided by the first jack is the total gravity of the balance weights at the two superposed ends of the cross beam. In addition, the sample is a cylindrical soil body formed by excavating the soil dike, is similar to the sample in a conventional triaxial apparatus, needs to be sleeved with a rubber film, and is locked by a steel hoop to realize sample sealing. After the sample is loaded, the pressure chamber is loaded, and an air compressor is used for applying pressure to the sample. And after the pressure is stable, starting the first jack to carry out a shear test on the sample, and acquiring corresponding test data by using the sensor. The scheme also has the advantages of simple structure, convenient operation and easy implementation.

Description

On-spot large-scale triaxial test device of normal position

Technical Field

The utility model relates to a field test device technical field especially relates to a large-scale triaxial test device of on-spot normal position.

Background

With the expansion of cities, traffic road facilities such as airports, high-speed rails, highways and the like gradually develop from plain areas with simple landforms to mountain areas with complex terrains, and a large amount of high fill slopes appear. The main filling material of the high-fill slope project is rockfill or soil-rock mixture. Shear strength parameters of the earth and stone mixture have a key influence on the stability of the filling side slope and the design of a supporting structure of the filling side slope. However, due to the complex material composition, irregular structure distribution and difficulty in-situ sampling of the earth-rock mixture, the shear strength index can be measured with great difficulty, and the shear strength index can be measured by in-situ large direct shear and push shear tests, indoor large direct shear and triaxial tests.

The in-situ large-scale shear test has more complex operation, relatively low precision of test results and easy dispersion, but can reflect the actual strength of a test point on a construction site; the operation of an indoor large-scale shear test is relatively simple and convenient, the boundary condition is easy to control, the precision of the test result is relatively high, but the remolded soil represents undisturbed soil, so that the test result has a great error. For the soil and stone mixture filling engineering, the soil and stone mixture is compacted in a layering way through certain compaction energy or compaction energy to form an artificial filling side slope, and the mechanical properties of the compacted soil and stone filling materials are different from those of on-site undisturbed soil materials and indoor remolded soil materials and are influenced by the compaction energy and a compaction mode, so that the shear strength index determined by adopting a natural soil and stone mixture in-situ test and the shear strength index determined by adopting a remolded soil and stone mixture indoor test cannot reasonably reflect the shear strength property of the compacted soil and stone mixture in an engineering in-situ state. At present, the research on the shear strength characteristics of the soil-rock mixture is limited by the sizes of a sample and rock blocks, and a reduced-scale indoor remolding sample test is generally adopted, so that a field large direct shear test device for the soil-rock mixture is used for testing the soil-rock mixture under an engineering state (a service state after manual compaction). However, in the field large-scale direct shear test, the consolidation and drainage processes of the sample are difficult to control, and the shear strength characteristic of the soil-rock mixture is difficult to accurately test. The triaxial test can better control the consolidation and drainage process of the sample, and the existing triaxial test devices are all indoor devices.

2016, the first ultra-large static and dynamic dual-purpose triaxial apparatus in China was successfully developed by university of major graduates, but the ultra-large triaxial apparatus is not a simple enlargement of the size of a common triaxial apparatus, and the related problems are very complicated, such as sample loading, a rubber film, a measuring method, loading equipment and the like, so that the test research reports are few so far. The device is an indoor test device, is different from a large-scale on-site triaxial test device provided by the patent, can be moved and disassembled, and can be used for directly testing on an engineering site simply and effectively.

At present, the in-situ triaxial test on site is not proposed or used, and similar devices such as an indoor ultra-large triaxial apparatus developed by university of great managerial engineering have the following problems: 1. the sample preparation is difficult, namely, a remolded sample is prepared in the device, the rockfill material cannot be fully tamped, and the sample in a field engineering in-situ state cannot be prepared; 2. the device is fine and complex, and has higher requirements on operation; 3. if the test under different conditions is required, the time consumption is long, and the efficiency is low; 4. is only suitable for indoor use and can not be used in engineering sites.

Therefore, further improvements and improvements are needed in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art not enough, provide a large-scale triaxial test device of on-the-spot normal position.

The purpose of the utility model is realized through the following technical scheme:

the large-scale triaxial test device of on-spot normal position mainly includes the embankment, to the confining pressure module of sample circumference application pressure and can follow the vertical load module of embankment longitudinal movement. And the confining pressure module is arranged in the soil dike and is internally provided with a sample. The vertical load module is arranged on the earth embankment, and the loading end of the load of the vertical load module presses the sample after penetrating through the confining pressure module.

Specifically, the confining pressure module comprises a pressure chamber, a first bottom plate, an air compressor, a rubber membrane, a first top plate, a second bottom plate, a steel ferrule and a sensor group. The first bottom plate is arranged in the soil embankment. The pressure chamber is arranged on the first bottom plate and is connected with the first bottom plate in a sealing mode. The output end of the air compressor is communicated with the pressure chamber through a hose. The second bottom plate is arranged at the bottom of the sample, and the first top plate is arranged at the top of the sample. The rubber membrane wraps the side face of the sample, and the top and the bottom of the rubber membrane are respectively connected with the first top plate and the bottom plate in a sealing mode through steel collars. The sensor groups are respectively arranged in the pressure chamber, the sample, the first top plate and the first bottom plate and are used for measuring the pressure of the pressure chamber, the pore pressure of the sample and the compression deformation of the sample.

As a preferred embodiment of the present invention, the sensor group mainly includes a first pressure sensor, a second pressure sensor, a first displacement sensor, and a second displacement sensor. The first pressure sensor is arranged in the pressure chamber and used for measuring the air pressure in the pressure chamber. The second pressure sensor is disposed within the sample for measuring a pore pressure of the sample. The first displacement sensor is arranged on the first top plate and used for measuring the displacement of the first top plate in the vertical direction. The second displacement sensor is arranged on the first bottom plate and used for measuring the displacement of the first bottom plate in the vertical direction.

As an optimal scheme, in order to fix a position the position of sample and restore the job site better, first bottom plate and second bottom plate are pre-buried in the embankment.

Specifically, the vertical load module mainly comprises a cross beam, a balancing weight, an anchor bar, a balancing weight plate, a roller, a first jack, a third pressure sensor for measuring vertical load, and a sliding unit for reducing the resistance of the cross beam and the first jack to move relative to each other.

Specifically, the first jack is arranged on the top of the first top plate, and the driving end of the first jack is connected with the bottom of the sliding unit. The middle part of the cross beam is arranged on the sliding unit. The balancing weights are respectively located at two ends of the cross beam. The counterweight plate is arranged at the bottom of the counterweight block, and the counterweight block is placed on the counterweight plate. The roller is installed at the bottom of the counterweight plate, and the rolling direction of the roller is perpendicular to the length direction of the cross beam. The roller is pressed on the soil embankment and can roll on the soil embankment longitudinally. The anchor bars are vertically arranged, the upper ends of the anchor bars are connected with the cross beam, the lower ends of the anchor bars are connected with the counterweight plate, and the counterweight plate and the counterweight block are balanced on the cross beam. The third pressure sensor is arranged on the jack and is positioned between the jack and the sample.

Further, the cross beam mainly comprises a second top plate, a third bottom plate, a partition plate, a first reinforcing plate and a second reinforcing plate. The second top plate and the third bottom plate are arranged horizontally and in parallel. The partition plate is vertically arranged between the second top plate and the third bottom plate. The partition plates are uniformly distributed between the second top plate and the third bottom plate at intervals. The first reinforcing plate and the second reinforcing plate are arranged between adjacent partition plates. The first reinforcing plate and the second reinforcing plate are obliquely arranged to be connected into an X-shaped structure. The first reinforcing plate and the second reinforcing plate are respectively connected with the joint of the second top plate and the partition plate and the joint of the third bottom plate and the partition plate.

As the utility model discloses a preferred scheme, in the actual test, the top that needs the crossbeam because of the difference of the implementation condition in place highly adjusts, vertical load device still includes fastening nut. And the upper end and the lower end of each anchor bar are provided with threads. And the fastening nuts are respectively arranged at the connecting parts of the anchor bars and the top of the second top plate and the bottom of the weight plate. During adjustment, the maximum height of the cross beam can be adjusted only by adjusting the fastening nuts at the upper end and the lower end of the anchor bar.

Further, the sliding module mainly comprises a first steel plate, a bearing seat, a rotating shaft and a bearing. And two ends of the rotating shaft are arranged on the first steel plate through bearing seats. The bearings are arranged on the rotating shaft side by side, and the rolling direction of the bearings is consistent with the length direction of the cross beam. The bottom of the steel plate is fixedly connected with the driving end of the first jack.

Preferably, for the convenience of adjusting the crossbeam height, make the crossbeam better with the wholeness of counter weight simultaneously, vertical load device still includes the second jack. The second jack is arranged on the balance weight, and the top of the second jack is abutted to the cross beam. The number of the second jacks is at least two, and the second jacks are arranged side by side.

Further, in order to make the jacking force that the second jack was applyed to the crossbeam transmit the crossbeam more evenly on, vertical load device still includes the fourth steel sheet. The fourth steel plate is arranged between the second jack and the cross beam.

As the utility model discloses a preferred scheme, when experimental, in order to avoid counter weight and crossbeam to rock or remove, vertical load device is still including latch segment, first spring, second spring and the latch segment that is used for locking the gyro wheel. The locking blocks are arranged in pairs at the front and rear positions of the roller, the top ends of the locking blocks are connected with the bottom of the counterweight plate through the first springs, and the locking blocks can rotate around the connection positions. The locking piece sets up at the back of latch segment, and the one end of lock piece is passed through the second spring and is connected with the latch segment, and the other end of lock piece can rotate around the junction and push up the locking that realizes the latch segment on the counterweight plate bottom. When the locking device is used, if the roller is required to be locked, the locking block can be downwards rotated and contacted with the roller, meanwhile, the locking block is upwards turned, the locking block is enabled to be propped against the bottom of the counterweight plate, a relatively stable supporting structure is formed, the roller is firmly pressed by the locking block, and when the front locking block and the rear locking block are simultaneously acted on the roller, the roller is encircled to form an encircling posture, so that the roller is further locked. If when will release the gyro wheel, can promote the locking piece and overturn back, locking piece and locking piece reset simultaneously under the effect of second spring and first spring respectively this moment, and the gyro wheel unblock can promote whole vertical load device and roll forward this moment, until reaching on the next sample.

As the utility model discloses an optimal scheme, for furthest reduction job site true situation, the cross section of native dyke is trapezoidal, and its grade ratio is 1: 1, adopts the pile material of building the high fill side slope to roll layer upon layer, lays according to the thickness of layer height 300mm and rolls. And a test groove is also dug in the middle of the soil dike. And a plurality of cylindrical samples are dug in the test groove. The samples are arranged side by side in the test cell.

Furthermore, a rail convenient for the vertical load module to move is further arranged on the soil embankment. The track is laid at the top of the earth dike.

As the preferred scheme of the utility model, in order to improve the bulk rigidity of confined pressure module, pressure chamber, first bottom plate, first roof, second bottom plate all adopt the steel sheet structure.

The utility model also discloses a construction method based on large-scale triaxial test device of on-spot normal position, this construction method mainly includes following step:

step S1: building a soil dike with the height of 2m, the width of 18m, the length of about 40m and the gradient ratio of 1: 1 on a construction site, rolling the soil dike layer by adopting rockfill materials for building a high fill side slope, simultaneously embedding a series of members, laying and rolling the members according to the thickness of one layer of 300 mm;

step S2: embedding a rectangular steel plate (a first bottom plate) capable of being embedded with a pressure chamber in the earth dike, arranging a round steel plate (a second bottom plate) with the same area as the bottom of the sample at the center of the rectangular steel plate, wherein the two steel plates are arranged at the bottom of the sample to be excavated;

and step S3: digging 4 cylindrical samples with certain sizes in the built soil dike, wherein the samples are arranged at intervals;

and step S4: arranging a track at the top of the built test soil embankment, and arranging a vertical load module;

step S5: sleeving a rubber film on a first sample subjected to a triaxial test, fixing the rubber film at positions above and below the sample (namely a first top plate and a second bottom plate, wherein the first top plate is placed after excavation, and the second bottom plate is pre-embedded), sleeving a steel sleeve ring, locking, then covering a pressure chamber, embedding the pressure chamber with a rectangular steel plate (the first bottom plate) pre-embedded at the bottom, installing a second displacement sensor on the pre-embedded steel plate, and installing a vertical load module right above the sample;

step S6: the steel plate above the pressure chamber and the test sample is provided with a plurality of prefabricated holes, and a series of sensors and components for monitoring are arranged in the prefabricated holes in an inserting mode, wherein the sensors comprise a pressure sensor and a displacement sensor, and the components comprise a first jack, a hose of an air compressor and the like;

step S7: starting an air compressor to provide a certain pressure for the sample, then starting the operation of the first jack until the sample is damaged, and recording all data (including the data of the sensor group) during the operation;

step S8: and (4) moving the whole vertical load module to be right above the second test sample to be tested through the pulleys below the counterweight bearing plate and the track at the top of the soil dike, repeating the operations in the steps 5-7, recording all data while operating, and repeating the operations for the third and fourth test samples.

The utility model discloses a working process and principle are: the crossbeam of this scheme adopts the H shaped steel of taking floor and lacing plate, and the position that the lower extreme counter weight of both sides corresponds about, the upper and lower of crossbeam respectively sets up 4 holes, thereby the anchor bar (can be the reinforcing bar of car silk mouth) of being convenient for passes and plays fixed effect. The bottom welding loading steel sheet is used for providing the jack counter force in the middle of the crossbeam, and whole crossbeam framework shape is similar to the shoulder pole form, and the counter weight bearing board under the anchor bar tie-beam is passed through at the both ends of crossbeam, places counter weight (large-scale cuboid steel) on the bearing board, and the centre is used for providing the counter force of the first jack of sample loading, and consequently the biggest axial force that first jack can provide to the sample is about the total gravity of crossbeam plus roof beam both ends counter weight. In addition, the sample is a cylindrical soil body formed by excavating a soil dike, is similar to the sample in a conventional triaxial apparatus, needs to be sleeved with a rubber film, and is locked by a steel ferrule to realize sample sealing. After the sample is loaded, the pressure chamber is installed, and the second pressure sensor is used for applying pressure to the sample. And after the pressure is stable, starting the first jack to carry out a shear test on the sample, and acquiring corresponding test data by using the sensor.

Compared with the prior art, the utility model discloses still have following advantage:

(1) The utility model provides a large-scale triaxial test device of on-spot normal position can reduce the rockfill material and receive the influence of reduced scale effect at indoor conventional triaxial, makes the soil body characteristic that triaxial test obtained often can be more accurate.

(2) The utility model provides a system appearance mode that large-scale triaxial test device in scene normal position adopted can guarantee the degree of ramming of sample, ensures that the test result is more close actual conditions.

(3) The utility model provides a large-scale triaxial test device of on-spot normal position can carry out the normal position at the engineering scene experimental, and the portable flexibility of test device is strong, and for indoor triaxial apparatus, the size effect that has reducible building stones influences, and system appearance is easy, and advantages such as easy operation and high test efficiency can effectual solution meet among the traditional test scale effect, system appearance difficulty and the inefficiency scheduling problem.

Drawings

Fig. 1 is a front view of the large-scale triaxial test apparatus in situ provided by the present invention.

Fig. 2 is a top view of the large-scale triaxial test device in situ in the field provided by the present invention.

Fig. 3 is a side view of the large-scale triaxial test device in situ in the field provided by the present invention.

Fig. 4 is a partially enlarged schematic view of a dotted circle in fig. 3.

Fig. 5 is a schematic structural diagram of a vertical load module provided by the present invention.

Fig. 6 is a side view of a counterweight structure provided by the present invention.

Fig. 7 is a partially enlarged schematic view of the roller provided by the present invention.

The reference numbers in the above figures illustrate:

1-beam, 2-counterweight block, 3-anchor bar, 4-counterweight plate, 5-roller, 6-first jack, 7-second top plate, 8-third bottom plate, 9-clapboard, 10-first reinforcing plate, 11-second reinforcing plate, 12-fastening nut, 13-first steel plate, 14-bearing, 15-earth dike, 16-second jack, 17-fourth steel plate, 18-locking block, 19-locking block, 20-rubber film, 21-pressure chamber, 22-sample, 23-second bottom plate, 24-first bottom plate, 25-steel ferrule, 26-second pressure sensor, 27-first displacement sensor, 28-first pressure sensor, 29-air compressor, 30-hose, 31-first top plate, 32-second displacement sensor.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention will be further described with reference to the accompanying drawings and examples.

Example 1:

as shown in fig. 1 to 4, the present embodiment discloses an in-situ large triaxial test apparatus, which mainly includes an earth dike 15, a confining pressure module for applying pressure to the circumferential direction of a test sample 22, and a vertical load module capable of moving longitudinally along the earth dike 15. The confining pressure module is arranged in the soil embankment 15, and a sample 22 is arranged in the confining pressure module. The vertical load module is arranged on the earth embankment 15, and the loading end of the load presses the test sample 22 after penetrating through the confining pressure module.

Specifically, the confining pressure module comprises a pressure chamber 21, a first bottom plate 24, an air compressor 29, a rubber membrane 20, a first top plate 31, a second bottom plate 23, a steel ferrule 25 and a sensor group. The first bottom plate 24 is disposed within the earth embankment 15. The pressure chamber 21 is mounted on the first bottom plate 24 and is connected with the first bottom plate 24 in a sealing manner. The output of the air compressor 29 communicates with the pressure chamber 21 through a hose 30. The second bottom plate 23 is placed on the bottom of the test specimen 22 and the first top plate 31 is placed on top of the test specimen 22. The rubber membrane 20 wraps the side face of the sample 22, and the top and the bottom of the rubber membrane 20 are respectively connected with the first top plate 31 and the bottom plate in a sealing mode through the steel sleeve 25. The sensor groups are respectively arranged in the pressure chamber 21, in the sample 22, on the first top plate 31 and on the first bottom plate 24, and are used for measuring the pressure of the pressure chamber 21, the pore pressure of the sample 22 and the compression deformation of the sample 22.

As a preferred embodiment of the present invention, the sensor group mainly includes a first pressure sensor 28, a second pressure sensor 26, a first displacement sensor 27, and a second displacement sensor 32. The first pressure sensor 28 is arranged in the pressure chamber 21 for measuring the air pressure in the pressure chamber 21. The second pressure sensor 26 is disposed within the test specimen 22 for measuring the pore pressure of the test specimen 22. The first displacement sensor 27 is provided on the first top plate 31 for measuring the amount of displacement of the first top plate 31 in the vertical direction. The second displacement sensor 32 is provided on the first base plate 24 for measuring the amount of displacement of the first base plate 24 in the vertical direction.

As the preferred scheme of the utility model, in order to fix a position the position of sample 22 and restore the job site better, first bottom plate 24 and second bottom plate 23 are pre-buried in embankment 15.

Specifically, as shown in fig. 5 to 7, the vertical load module mainly includes a cross beam 1, a counterweight 2, an anchor bar 3, a counterweight plate 4, a roller 5, a first jack 6, a third pressure sensor for measuring vertical load, and a sliding unit for reducing resistance to mutual movement between the cross beam 1 and the first jack 6.

Specifically, the first jack 6 is placed on the top of the first top plate 31, and the driving end of the first jack is connected with the bottom of the sliding unit. The middle of the beam 1 is arranged on the sliding unit. The balancing weights 2 are respectively positioned at two ends of the cross beam 1. The counterweight plate 4 is arranged at the bottom of the counterweight block 2, and the counterweight block 2 is placed on the counterweight plate 4. The roller 5 is arranged at the bottom of the counterweight plate 4, and the rolling direction of the roller is vertical to the length direction of the beam 1. The roller 5 is pressed on the soil embankment 15 and can roll on the soil embankment 15 longitudinally. The anchor bars 3 are vertically arranged, the upper ends of the anchor bars are connected with the cross beam 1, the lower ends of the anchor bars are connected with the weight plate 4, and the weight plate 4 and the weight block 2 are balanced on the cross beam 1. The third pressure sensor is arranged on the jack between the jack and the test piece 22.

Further, the cross member 1 mainly includes a second top plate 7, a third bottom plate 8, a partition plate 9, a first reinforcing plate 10, and a second reinforcing plate 11. The second top plate 7 and the third bottom plate 8 are arranged horizontally and parallel to each other. The partition 9 is vertically arranged between the second top plate 7 and the third bottom plate 8. The partition plates 9 are uniformly distributed between the second top plate 7 and the third bottom plate 8 at intervals. The first reinforcing plate 10 and the second reinforcing plate 11 are each disposed between adjacent separators 9. The first reinforcing plate 10 and the second reinforcing plate 11 are obliquely arranged and connected to form an X-shaped structure. The first reinforcing plate 10 and the second reinforcing plate 11 are respectively connected with the joint of the second top plate 7 and the partition plate 9 and the joint of the third bottom plate 8 and the partition plate 9.

As the utility model discloses a preferred scheme, in the actual test, the top that pushes away because of the different needs in the implementation condition in place crossbeam 1 highly adjusts, vertical load device still includes fastening nut 12. And the upper end and the lower end of the anchor bar 3 are both provided with threads. And the fastening nuts 12 are respectively arranged at the connecting parts of the anchor bars 3 and the top of the second top plate 7 and the bottom of the anchor bars 3 and the counterweight plate 4. During adjustment, the maximum height of the cross beam 1 can be adjusted only by adjusting the fastening nuts 12 at the upper end and the lower end of the anchor bar 3.

Further, the sliding module mainly includes a first steel plate 13, a bearing housing, a rotating shaft, and a bearing 14. Both ends of the rotating shaft are mounted on the first steel plate 13 through bearing seats. The bearings 14 are arranged side by side on the rotating shaft, and the rolling direction of the bearings is consistent with the length direction of the cross beam 1. The bottom of the steel plate is fixedly connected with the driving end of the first jack 6.

Preferably, for the convenience of adjusting the height of crossbeam 1, make crossbeam 1 better with the integrative nature of counter weight simultaneously, vertical load device still includes second jack 16. The second jack 16 is provided on the counterweight, and the top thereof abuts against the cross member 1. The number of the second jacks 16 is at least two, and the second jacks are arranged side by side.

Further, in order to make the jacking force that second jack 16 applyed to crossbeam 1 transmit crossbeam 1 more evenly on, vertical load device still includes fourth steel sheet 17. The fourth steel plate 17 is arranged between the second jack 16 and the cross beam 1.

As the preferred scheme of the utility model, when experimental, in order to avoid counter weight and crossbeam 1 to rock or remove, vertical load device is still including latch segment 18, first spring, second spring and the lock piece 19 that is used for locking gyro wheel 5. The locking blocks 18 are arranged in pairs at the front and rear positions of the roller 5, and the top ends of the locking blocks are connected with the bottom of the counterweight plate 4 through first springs, so that the locking blocks 18 can rotate around the connection positions. The locking piece 19 sets up the back at latch segment 18, and the one end of latch segment 19 is connected with latch segment 18 through the second spring, and the other end of latch segment 19 can rotate around the junction and push up the locking that realizes latch segment 18 on the weight plate 4 bottom. When the locking device is used, if the roller 5 needs to be locked, the locking blocks 18 can be rotated downwards and contacted with the roller 5, meanwhile, the locking blocks 19 are turned upwards, the locking blocks 19 are enabled to be propped against the bottom of the counterweight plate 4, a relatively stable supporting structure is formed, the locking blocks 18 are enabled to firmly press the roller 5, and when the front locking block 18 and the rear locking block 18 act on the roller 5 simultaneously, an encircling gesture is formed on the roller 5, and the roller 5 is further locked. When the roller 5 is released, the locking block 19 can be pushed to turn back, at this moment, the locking block 19 and the locking block 18 are reset simultaneously under the action of the second spring and the first spring respectively, the roller 5 is unlocked, and at this moment, the whole vertical loading device can be pushed to roll forwards until the next sample 22 is reached.

As the utility model discloses an optimal scheme, for furthest reduction job site true situation, soil embankment 15's cross section is trapezoidal, and its grade ratio is 1: 1, adopts the rockfill material of building the high fill side slope to roll layer upon layer, lays according to the thickness of layer height 300mm and rolls. And a test groove is also dug in the middle of the soil dike 15. A plurality of cylindrical test samples 22 are dug in the test groove. The test specimens 22 are arranged side by side in the test cell.

Further, a rail convenient for the vertical load module to move is further arranged on the soil embankment 15. The track is laid at the top of the earth embankment 15.

As the preferred scheme of the utility model, in order to improve the bulk rigidity of confined pressure module, pressure chamber 21, first bottom plate 24, first roof 31, second bottom plate 23 all adopt the steel sheet structure.

The utility model also discloses a construction method based on large-scale triaxial test device of on-spot normal position, this construction method mainly includes following step:

step S1: building a soil dike 15 with the height of 2m, the width of 18m, the length of about 40m and the gradient ratio of 1: 1 on a construction site, rolling the soil dike 15 layer by adopting rockfill materials for building a high fill side slope, simultaneously embedding a series of members, laying and rolling according to the thickness of about one layer of 300 mm;

step S2: a rectangular steel plate (a first bottom plate 24) capable of being embedded with the pressure chamber 21 is pre-buried in the earth embankment 15, a round steel plate (a second bottom plate 23) with the same area as the bottom of the sample 22 is arranged at the center of the rectangular steel plate, and the two steel plates are arranged at the bottom of the sample 22 to be excavated;

and step S3: digging 4 cylindrical samples 22 with certain sizes in the built soil dike 15, wherein the samples 22 are arranged at intervals;

and step S4: arranging a track on the top of the built test soil embankment 15, and arranging a vertical load module;

step S5: sleeving a rubber film 20 on a first sample 22 subjected to a triaxial test, fixing the rubber film 20 at positions above and below the sample 22 (namely a first top plate 31 and a second bottom plate 23, wherein the first top plate 31 is placed after excavation, and the second bottom plate 23 is pre-embedded), sleeving a steel sleeve 25, locking, covering a pressure chamber 21, enabling the pressure chamber 21 to be embedded with a rectangular steel plate (a first bottom plate 24) pre-embedded at the bottom, installing a second displacement sensor 32 on the pre-embedded steel plate, and installing a vertical load module right above the sample 22;

step S6: the steel plate above the pressure chamber 21 and the test sample 22 has a plurality of prefabricated holes through which a series of sensors for monitoring, including pressure sensors and displacement sensors, and parts including the first jack 6 and the hose 30 of the air compressor 29, etc., are inserted;

step S7: starting the air compressor 29 to provide a certain pressure for the sample 22, and then starting the operation of the first jack 6 until the sample 22 is damaged, and recording all data (including the data of the sensor group) at the same time;

step S8: the whole vertical load module is moved to the position right above the second test sample 22 to be tested through the pulleys below the counterweight bearing plate and the rail at the top of the earth dike 15, the operation of the steps 5-7 is repeated, all data are recorded simultaneously, and the operation is also repeated for the third test sample 22 and the fourth test sample 22.

The utility model discloses a working process and principle are: the crossbeam 1 of this scheme adopts the H shaped steel of taking floor and lacing plate, and the position that both sides lower extreme counter weight corresponds about, the upper and lower of crossbeam 1 respectively sets up 4 holes, thereby the anchor bar 3 of being convenient for (can be the reinforcing bar of car screw mouth) passes and plays fixed effect. Bottom welding loading steel sheet is used for providing the jack counter force in the middle of crossbeam 1, and the similar carrying pole form of whole crossbeam 1 framework shape, and the counter weight bearing board under 3 tie-beams of anchor bar is passed through at the both ends of crossbeam 1, places counter weight (large-scale cuboid steel) on the bearing board, and the centre is used for providing the counter force of the first jack 6 of sample 22 loading, and consequently the biggest axial force that 6 first jacks 6 can provide to sample 22 is about the total gravity of crossbeam 1 plus roof beam both ends counter weight. In addition, the sample 22 is a cylindrical soil body formed by excavating the soil embankment 15, and similar to the sample 22 in a conventional triaxial apparatus, a rubber film 20 needs to be sleeved on the sample 22, and the sample 22 is sealed through locking of a steel hoop. After the sample 22 is loaded, the pressure chamber 21 is loaded, and the second pressure sensor 26 applies pressure to the sample 22. After the pressure is stabilized, the first jack 6 is started to perform a shear test on the sample 22, and corresponding test data is acquired by using the sensor.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be equivalent replacement modes, and all are included in the scope of the present invention.

Claims (10)

1. A large-scale triaxial test device of on-spot normal position, characterized by, including the earth embankment, apply the confining pressure module of the pressure to the sample circumference, and can be along the vertical load module of the longitudinal movement of the earth embankment; the confining pressure module is arranged in the soil dike and is internally provided with a sample; the vertical load module is arranged on the earth dike, and the loading end of the load presses the sample after penetrating through the confining pressure module;

the confining pressure module comprises a pressure chamber, a first bottom plate, an air compressor, a rubber film, a first top plate, a second bottom plate, a steel ferrule and a sensor group; the first bottom plate is arranged in the soil dike; the pressure chamber is arranged on the first bottom plate and is connected with the first bottom plate in a sealing way; the output end of the air compressor is communicated with the pressure chamber through a hose; the second bottom plate is arranged at the bottom of the sample, and the first top plate is arranged at the top of the sample; the side surface of the sample is wrapped by the rubber film, and the top and the bottom of the rubber film are respectively connected with the first top plate and the bottom plate in a sealing manner through steel sleeves; the sensor groups are respectively arranged in the pressure chamber, the sample, the first top plate and the first bottom plate and are used for measuring the pressure of the pressure chamber, the pore pressure of the sample and the compression deformation of the sample.

2. The in-situ large triaxial test apparatus according to claim 1, wherein the sensor group comprises a first pressure sensor, a second pressure sensor, a first displacement sensor, and a second displacement sensor; the first pressure sensor is arranged in the pressure chamber and used for measuring the air pressure in the pressure chamber; the second pressure sensor is arranged in the sample and used for measuring the pore pressure of the sample; the first displacement sensor is arranged on the first top plate and used for measuring the displacement of the first top plate in the vertical direction; the second displacement sensor is arranged on the first bottom plate and used for measuring the displacement of the first bottom plate in the vertical direction.

3. The in-situ large triaxial test device according to claim 1, wherein the first and second bottom plates are embedded in the earth embankment.

4. The in-situ large triaxial test device according to claim 1, wherein the vertical load module includes a crossbeam, a counterweight, an anchor bar, a counterweight plate, a roller, a first jack, a third pressure sensor for measuring vertical load, and a sliding unit for reducing resistance of the crossbeam and the first jack to move relative to each other;

the first jack is arranged at the top of the first top plate, and the driving end of the first jack is connected with the bottom of the sliding unit; the middle part of the cross beam is arranged on the sliding unit; the balancing weights are respectively positioned at two ends of the cross beam; the counterweight plate is arranged at the bottom of the counterweight block, and the counterweight block is placed on the counterweight plate; the roller is arranged at the bottom of the counterweight plate, and the rolling direction of the roller is vertical to the length direction of the cross beam; the roller is pressed on the soil embankment and can longitudinally roll on the soil embankment; the anchor bars are vertically arranged, the upper ends of the anchor bars are connected with the cross beam, the lower ends of the anchor bars are connected with the counterweight plate, the counterweight plate and the counterweight block are balanced on the cross beam, and the third pressure sensor is arranged on the jack and located between the jack and the sample.

5. The in-situ large triaxial test apparatus according to claim 4, wherein the cross beam comprises a second top plate, a third bottom plate, a partition plate, a first reinforcement plate, and a second reinforcement plate; the second top plate and the third bottom plate are arranged horizontally and in parallel; the partition plate is vertically arranged between the second top plate and the third bottom plate; the partition plates are uniformly distributed between the second top plate and the third bottom plate at intervals; the first reinforcing plate and the second reinforcing plate are arranged between the adjacent partition plates; the first reinforcing plate and the second reinforcing plate are obliquely arranged and connected to form an X-shaped structure; the first reinforcing plate and the second reinforcing plate are respectively connected with the joint of the second top plate and the partition plate and the joint of the third bottom plate and the partition plate.

6. The in-situ large triaxial test apparatus according to claim 4, wherein the sliding unit comprises a first steel plate, a bearing seat, a rotating shaft, and a bearing; two ends of the rotating shaft are arranged on the first steel plate through bearing seats; the bearings are arranged on the rotating shaft side by side, and the rolling direction of the bearings is consistent with the length direction of the cross beam; the bottom of the steel plate is fixedly connected with the driving end of the first jack.

7. The in-situ large triaxial test device according to claim 4, wherein the vertical load module further comprises a locking block for locking the roller, a first spring, a second spring and a locking block; the locking blocks are arranged in pairs at the front and rear positions of the roller, and the top ends of the locking blocks are connected with the bottom of the counterweight plate through first springs, so that the locking blocks can rotate around the connection positions; the locking piece sets up at the back of latch segment, and the one end of lock piece is passed through the second spring and is connected with the latch segment, and the other end of lock piece can rotate around the junction and push up the locking that realizes the latch segment on the counterweight plate bottom.

8. The in-situ large triaxial test device according to claim 1, wherein the cross section of the earth dike is trapezoidal, the gradient ratio of the earth dike is 1: 1, rockfill materials for constructing a high fill side slope are adopted for carrying out layer-by-layer rolling, and the rockfill materials are laid and rolled according to the thickness of 300mm of the layer height; a test groove is also dug in the middle of the soil dike; digging a plurality of cylindrical samples in the test groove; the samples are arranged side by side in the test cell.

9. The in-situ large triaxial test device according to claim 1, wherein a rail for facilitating movement of the vertical load module is further provided on the earth embankment; the track is laid at the top of the earth dike.

10. The in-situ large triaxial test apparatus according to claim 1, wherein the pressure chamber, the first bottom plate, the first top plate and the second bottom plate are all made of steel plate.

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