Improved rock-soil body in-situ direct shear test device

Abstract

The utility model relates to an improved rock-soil body in-situ direct shear test device, which belongs to the technical field of soil body in-situ direct shear test devices, and comprises a shear box arranged on the bottom surface of a foundation pit, a vertical pressure load module, a vertical counter-force load module and a sliding module, the gravity center of the shear box coincides with the gravity center of the vertical pressure load module in the vertical direction, the vertical counter-force load module is arranged above the vertical pressure load module, and the gravity center of the vertical counter-force load module coincides with the gravity center of the vertical pressure load module in the vertical direction. The sliding module is arranged between the vertical pressure load module and the vertical counter-force load module, and the vertical pressure load module and the vertical counter-force load module are in sliding connection through the sliding module; the sliding module comprises a plurality of balls arranged between the vertical pressure load module and the vertical counter-force load module; and the arrangement convenience of the balls is higher.

Description

Technical Field

[0001] The utility model belongs to the technical field of soil in-situ direct shear test devices, and in particular relates to an improved rock and soil in-situ direct shear test device. Background Art

[0002] During civil engineering construction, if the rock and soil mass, which serves as the engineering foundation and foundation bearing, deforms due to sliding or local shear damage, which in turn drives the deformation of the engineering foundation, it is necessary to conduct stability evaluation of the foundation bearing capacity, soil slope and roadbed before construction. In the stability evaluation, the shear strength index of the rock and soil mass, namely the c value and the φ value, are the most important mechanical parameters. Generally, the c value and the φ value are mainly measured through in-situ direct shear tests on the rock and soil mass.

[0003] In direct shear tests, a lateral load is generally applied to the soil in the shear box to cause a lateral displacement of the soil in the shear box. The shear strength is measured by measuring the lateral load and the displacement distance. When a direct shear test is performed on loose soil, the lateral displacement of the soil and the shear box is relatively large. At this time, the vertical reaction load system located above the shear box is easily eccentric with the shear box, and the original direct shear test cannot be accurately performed. For this reason, Chinese patent CN204330502U discloses a novel in-situ direct shear test device for rock and soil. The vertical reaction load system in the in-situ direct shear test device extends to the edges of both sides of the foundation pit. Displacement balls are arranged on the lower edges of both sides of the weight platform of the vertical reaction load system. Under the adjustment action, the displacement ball contacts the piled weight bearing plate set at the two sides of the foundation pit; by setting the displacement ball, the vertical pressure load system, the vertical reaction load system and the shear box can be synchronously displaced, so that the center of gravity of the shear box, the vertical pressure load system and the vertical reaction load system are always located on the same normal line, avoiding eccentric loading caused by inertia or dislocation. However, since the vertical reaction load system is extended to the two sides of the foundation pit, the balls that provide displacement for the vertical reaction load system also need to be set on both sides of the foundation pit, and the balls are used to achieve synchronous displacement with the shear box, which makes the ball structure relatively large and the setting convenience is insufficient. Therefore, an improved in-situ direct shear test device for rock and soil with higher ball setting convenience is needed. Utility Model Content

[0004] In order to solve the above problems existing in the prior art, the utility model provides an improved in-situ direct shear test device for rock and soil, which has the characteristic of high convenience in ball setting.

[0005] The purpose of the utility model can be achieved through the following technical solutions:

[0006] An improved in-situ direct shear test device for rock and soil, comprising a shear box, a vertical pressure load module, a vertical reaction load module and a sliding module arranged on the bottom surface of a foundation pit, wherein the vertical pressure load module is arranged above the shear box, and the center of gravity of the shear box coincides with the center of gravity of the vertical pressure load module in the vertical direction, the vertical reaction load module is arranged above the vertical pressure load module, and the center of gravity of the vertical reaction load module coincides with the center of gravity of the vertical pressure load module in the vertical direction, the sliding module is arranged between the vertical pressure load module and the vertical reaction load module, and the vertical pressure load module and the vertical reaction load module are slidably connected via the sliding module;

[0007] The sliding module includes a plurality of balls arranged between the vertical pressure load module and the vertical reaction force load module.

[0008] As a preferred technical solution of the utility model, vertical limiters are arranged on both sides of the sliding module, and the vertical limiters are slidably connected to the upper surface and the lower surface of the sliding module respectively, and the vertical limiters are used to limit the displacement of the sliding module in the vertical direction.

[0009] As a preferred technical solution of the utility model, the sliding module also includes a transverse limiter, which is arranged at both ends of the sliding module along its own sliding direction, and is used to limit the travel of the sliding module along its own sliding direction.

[0010] As a preferred technical solution of the utility model, the sliding module also includes two parallel bearing plates, the two bearing plates are arranged parallel to the bottom surface of the foundation pit, a plurality of the balls are arranged between the two bearing plates and are respectively in rolling contact with the two bearing plates, and the two bearing plates are respectively connected to the vertical pressure load module and the vertical reaction load module.

[0011] As a preferred technical solution of the utility model, a lateral load module is arranged on the side of the shear box, and the center of gravity of the lateral load module is in the same horizontal plane as the center of the shear box.

[0012] As a preferred technical solution of the utility model, a plurality of balls are arranged between the lateral load module and the bottom surface of the foundation pit.

[0013] The beneficial effects of the utility model are:

[0014] (1) By setting a sliding module composed of balls between the vertical pressure load module and the vertical reaction load module, it is ensured that the vertical pressure load module moves synchronously with the shear box when the shear box moves, and the center of gravity of the two is always aligned in the vertical direction to avoid eccentricity. It can also reduce the number of balls to be set, ensuring the convenience of setting the balls;

[0015] (2) By arranging vertical limiters on both sides of the sliding module, when the vertical pressure load module deviates from the horizontal plane in its movement direction, the load-bearing plate connected to the vertical pressure load module is limited in the vertical direction to complete the vertical limitation. At the same time, by arranging the vertical limiter around the sliding module, when the vertical pressure load module drives the load-bearing plate to tilt, when the load-bearing plate acts on the vertical limiter, the force arm is smaller, thereby improving the service life of the vertical limiter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is a side view structural diagram of the sliding module of the utility model;

[0019] Figure 3 This is a front view structural diagram of the sliding module of the utility model;

[0020] Figure 4 It is a structural schematic diagram of the vertical limiter of the utility model.

[0021] Description of main component symbols:

[0022] In the figure: 1. shear box; 2. vertical pressure load module; 3. vertical reaction load module; 4. lateral load module; 5. sliding module; 51. load-bearing plate; 52. ball; 53. vertical limiter; 531. roller; 54. lateral limiter; 6. foundation pit. DETAILED DESCRIPTION

[0023] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0024] See also Figure 1-4 , an improved in-situ direct shear test device for rock and soil, comprising a shear box 1, a vertical pressure load module 2, a vertical reaction load module 3 and a sliding module 5 arranged on the bottom surface of a foundation pit 6, the vertical pressure load module 2 being arranged above the shear box 1, and the center of gravity of the shear box 1 coincides with the center of gravity of the vertical pressure load module 2 in the vertical direction, the vertical reaction load module 3 being arranged above the vertical pressure load module 2, and the center of gravity of the vertical reaction load module 3 coincides with the center of gravity of the vertical pressure load module 2 in the vertical direction;

[0025] Specifically, the foundation pit 6 is a rectangular parallelepiped pit dug on the ground, the bottom surface of the foundation pit 6 is parallel to the ground, the shear box 1 is arranged on the bottom surface of the foundation pit 6, and a vertical pressure load module 2 is arranged directly above the shear box 1. The vertical pressure load module 2 includes at least one jack, and the center of gravity of the jack is parallel to the center of gravity of the shear box 1 in the vertical direction. In this embodiment, the jack is cylindrical as a whole, and the axis of the columnar jack is perpendicular to the ground and passes through the center of gravity of the shear box 1. At the same time, the vertical reaction load module 3 includes a steel beam spanning the top edge of the foundation pit 6, and a counterweight is arranged on the upper part of the steel beam. The center of gravity of the steel beam coincides with the axis of the jack in the vertical direction;

[0026] At the same time, a lateral load module 4 is arranged on the side of the shear box 1, and the center of gravity of the lateral load module 4 is in the same horizontal plane as the center of the shear box 1. Specifically, the lateral load module 4 also includes a columnar jack, one end of the columnar jack of the lateral load module 4 is connected to the side of the foundation pit 6, and the other end is detachably connected to the side of the shear box 1. The axis of the jack passes through the center of gravity of the shear box 1, and the jack itself extends and retracts to drive the end of the jack close to the shear box 1 to abut or separate from the shear box 1;

[0027] At the same time, a plurality of balls 52 are arranged between the lateral load module 4 and the bottom surface of the foundation pit 6, and the plurality of balls 52 are used to prevent the lateral load module 4 from bending under the action of its own weight, thereby deviating from the center of gravity position of the shear box 1;

[0028] During use, the operator sets up the sample and shear box 1 according to the experimental requirements. The jack in the vertical pressure load module 2 directly above the shear box 1 extends outward to apply a pressure perpendicular to the shear box 1 to the shear box 1 below. At this time, the shear box 1 applies a reaction force to the jack, which makes the jack tend to move upward. The vertical reaction load module 3 located above the vertical pressure load module 2 uses its own weight to prevent the movement of the jack, thereby allowing the vertical pressure load module 2 to stay in place and provide a stable downward pressure for the shear box 1 below. At the same time, the lateral load module 4 extends toward the shear box 1 to apply a lateral force to the shear box 1. The operator counts the force and displacement received by the sample, and then counts the c value and φ value of the sample to complete the in-situ direct shear test of the rock and soil.

[0029] In the above process, some sample soils are relatively loose. When the direct shear test is performed on the relatively loose soil, the lateral displacement degree of the soil and the shear box 1 is relatively large. At this time, there is a probability that the center of gravity of the shear box 1 moves out of the position directly below the center of gravity of the vertical pressure load module 2, so that the center of gravity of the shear box 1 no longer coincides with the vertical pressure load module 2, resulting in eccentricity. The eccentricity will affect the measurement result. For this reason, a sliding module 5 is also included. The sliding module 5 is arranged between the vertical pressure load module 2 and the vertical reaction load module 3. The vertical pressure load module 2 and the vertical reaction load module 3 are slidably connected through the sliding module 5;

[0030] Specifically, the sliding module 5 includes a plurality of balls 52 disposed between the vertical pressure load module 2 and the vertical reaction load module 3. In this embodiment, the top surface of the jack of the vertical pressure load module 2 and the bottom surface of the steel beam are both horizontal planes parallel to the ground, and a plurality of balls 52 are disposed between the top surface of the jack of the vertical pressure load module and the bottom surface of the steel beam;

[0031] When the shear box 1 has a large degree of horizontal displacement, the vertical pressure load module 2 connected to the shear box 1 also has a tendency to move horizontally under the drive of the shear box 1. At this time, since the vertical pressure load module 2 and the vertical reaction load module 3 are in contact through the ball 52, the resistance between the two to relative horizontal movement is small. At this time, the displacement of the shear box 1 can smoothly drive the vertical pressure load module 2 to move horizontally synchronously, and since a number of balls 52 are arranged between two planes parallel to the ground, the movement direction of the vertical pressure load module 2 is limited to the horizontal direction. At this time, the length of the jack applied to the shear box 1 in the vertical direction remains unchanged, and the force acting on the shear box 1 remains unchanged during the displacement process. The eccentricity effect is eliminated while the pressure remains unchanged. At the same time, the force transmission between the vertical pressure load module 2 and the vertical reaction load module 3 is transmitted through a number of balls 52.

[0032] In order to ensure that the forces between the vertical pressure load module 2 and the vertical reaction load module 3 can be evenly transmitted to each other, the sliding module 5 also includes two parallel bearing plates 51, the two bearing plates 51 are arranged parallel to the bottom surface of the foundation pit 6, and a plurality of balls 52 are arranged between the two bearing plates 51 and respectively in rolling contact with the two bearing plates 51. The two bearing plates 51 are respectively connected to the vertical pressure load module 2 and the vertical reaction load module 3. When the vertical pressure load module 2 moves horizontally under the drive of the shear box 1, the bearing plate 51 below is also driven to move horizontally. The bearing plate 51 completes the horizontal movement under the action of the balls 52. At the same time, the pressure of the upper vertical reaction load module 3 on the vertical pressure load module 2 is first transmitted to the upper bearing plate 51, then to the plurality of balls 52, and finally to the bearing plate 51 below, and then to the vertical pressure load module 2.

[0033] In a general solution, the setting position of the ball 52 is usually between the vertical reaction load module 3 and the foundation pit 6, or between the vertical pressure load module 2 and the shear box 1. For the former, although the synchronous displacement between the vertical pressure load module 2 and the shear box 1 can be achieved, this solution requires that the ball 52 be set on the surface of the vertical reaction load module 3 on both sides of the foundation pit 6 and between the foundation pit 6. The number of the ball 52 is large, and the convenience of setting the ball 52 is insufficient. For the latter solution, it can only achieve the pressure of the vertical pressure load module 2 on the shear box 1, and the lateral displacement of the shear box 1 itself, but cannot achieve the synchronous displacement of the vertical pressure load module 2 and the shear box 1, and thus cannot ensure that the center of gravity of the shear box 1 and the vertical pressure load module 2 are aligned, which is prone to eccentricity.

[0034] By setting a sliding module 5 composed of balls 52 between the vertical pressure load module 2 and the vertical reaction load module 3, it is ensured that the vertical pressure load module 2 is synchronously displaced with the shear box 1 when the shear box 1 is displaced, and the center of gravity of the two is always aligned in the vertical direction to avoid eccentricity. In addition, the number of balls 52 to be set can be reduced to ensure the convenience of setting the balls 52.

[0035] In the above process, due to various random errors, the movement direction of the vertical pressure load module 2 is no longer horizontal. At this time, the vertical pressure load module 2 will drive the load-bearing plate 51 to no longer be parallel to another load-bearing plate 51. For this reason, vertical limiters 53 are provided on both sides of the sliding module 5. The vertical limiters 53 are respectively slidably connected to the upper surface and the lower surface of the sliding module 5. The vertical limiters 53 are used to limit the displacement of the sliding module 5 in the vertical direction;

[0036] Specifically, there are several vertical limiters 53, each of which includes a vertical plate and two parallel horizontal plates. The two horizontal plates are arranged at both ends of the vertical plate and are perpendicular to the vertical plates. Two rollers 531 are respectively arranged on the surface of the two horizontal plates facing each other. The vertical distance between the upper and lower rollers 531 of the vertical limiter 53 is equal to the vertical distance between the upper and lower surfaces of the two load-bearing plates 51. At this time, the vertical limiter 53 can be clamped on the side of the sliding module 5. When the sliding module 5 deviates from the sliding direction parallel to the ground, it will inevitably move in the vertical direction. At this time, the load-bearing plate 51 moving in the vertical direction abuts against at least one of the wheels, and the wheels hinder the movement of the load-bearing plate 51 in the vertical direction, thereby preventing the sliding module 5 from deviating from the sliding direction and completing the vertical limit.

[0037] By arranging vertical limiters 53 on both sides of the sliding module 5, when the vertical pressure load module 2 deviates from the horizontal plane in the movement direction, the load-bearing plate 51 connected to the vertical pressure load module 2 is limited in the vertical direction to complete the vertical limitation. At the same time, by arranging the vertical limiter 53 around the sliding module 5, when the vertical pressure load module 2 drives the load-bearing plate 51 to tilt, when the load-bearing plate 51 acts on the vertical limiter 53, the force arm is smaller, thereby improving the service life of the vertical limiter 53.

[0038] Similarly, it also includes a transverse limiter 54, which is arranged at the two side ends of the lower load-bearing plate 51 along the sliding direction of the sliding module, and the upper surface of the transverse limiter 54 is parallel to the upper load-bearing plate 51. The transverse limiter 54 is used to prevent the sliding module 5 from having too large a travel in the sliding direction, causing the ball 52 to fall out.

[0039] The working principle and use process of this utility model:

[0040] During use, the operator sets up the sample and shear box 1 according to the experimental requirements. The jack in the vertical pressure load module 2 directly above the shear box 1 extends outward to apply a pressure perpendicular to the shear box 1 to the shear box 1 below. At this time, the shear box 1 applies a reaction force to the jack, which makes the jack tend to move upward. The vertical reaction load module 3 located above the vertical pressure load module 2 uses its own weight to prevent the movement of the jack, thereby allowing the vertical pressure load module 2 to stay in place and provide a stable downward pressure for the shear box 1 below. At the same time, the lateral load module 4 extends toward the shear box 1 to apply a lateral force to the shear box 1. The operator counts the force and displacement received by the sample, and then counts the c value and φ value of the sample to complete the in-situ direct shear test of the rock and soil.

[0041] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An improved in-situ direct shear test device for rock and soil, characterized in that: It comprises a shear box, a vertical pressure load module, a vertical reaction load module and a sliding module arranged on the bottom surface of the foundation pit, wherein the vertical pressure load module is arranged above the shear box, and the center of gravity of the shear box coincides with the center of gravity of the vertical pressure load module in the vertical direction, the vertical reaction load module is arranged above the vertical pressure load module, and the center of gravity of the vertical reaction load module coincides with the center of gravity of the vertical pressure load module in the vertical direction, the sliding module is arranged between the vertical pressure load module and the vertical reaction load module, and the vertical pressure load module and the vertical reaction load module are slidably connected via the sliding module; The sliding module includes a plurality of balls arranged between the vertical pressure load module and the vertical reaction force load module.

2. The improved in-situ direct shear test device for rock and soil according to claim 1 is characterized in that: Vertical limiters are arranged on both sides of the sliding module. The vertical limiters are respectively slidably connected to the upper surface and the lower surface of the sliding module. The vertical limiters are used to limit the displacement of the sliding module in the vertical direction.

3. The improved in-situ direct shear test device for rock and soil according to claim 2, characterized in that: The sliding module further comprises a transverse limiter, which is arranged at both ends of the sliding module along its own sliding direction, and is used to limit the travel of the sliding module along its own sliding direction.

4. The improved in-situ direct shear test device for rock and soil according to claim 3 is characterized by: The sliding module also includes two parallel bearing plates, which are arranged parallel to the bottom surface of the foundation pit. Several balls are arranged between the two bearing plates and are in rolling contact with the two bearing plates respectively. The two bearing plates are respectively connected to the vertical pressure load module and the vertical reaction load module.

5. The improved in-situ direct shear test device for rock and soil according to claim 1 is characterized by: A lateral load module is arranged on the side of the shear box, and the center of gravity of the lateral load module is in the same horizontal plane as the center of the shear box.

6. The improved in-situ direct shear test device for rock and soil according to claim 5, characterized in that: A plurality of balls are arranged between the lateral load module and the bottom surface of the foundation pit.

Images