CN108956196B - Pull-up type shearing probe and method for soil body in-situ test - Google Patents

Abstract

An upward-pulling shearing probe for soil in-situ testing, comprising a tension sensor, a central rod, a round hammer joint, two in-line shearing plates, two supporting rods, a shearing plate fixing block, a pressure bearing Block, sliding rod, tension sensor is connected with the upper end of the central rod, the lower end of the central rod is connected with the shear plate fixing block, the upper end of the sliding rod is connected with the lower end of the shearing plate fixing block, the conical joint is connected with the lower end of the sliding rod, two pieces one The font-shaped shearing plates are symmetrically arranged on both sides of the central rod, and one end of the two in-line shearing plates is rotated and arranged in the middle and lower sections of the central rod. The utility model is sleeved on the outside of the sliding rod, one end of the support rod is hinged with the bottom surface of the in-line shearing plate, and the other end is hinged with the pressure-bearing block. The invention can continuously, quickly and accurately measure the shear force of the soil body through the method of pulling force, and obtain the engineering properties of the soil layer through the shear force. The probe has low cost, simple test operation, few influencing factors and stable test results.

Description

A pull-up shear probe and method for in-situ testing of soil

technical field

The invention relates to the technical field of survey and in-situ testing of land soil layers and underwater soil layers, in particular to an up-pulling shear probe and a method for in-situ testing of soil bodies.

Background technique

At present, the in-situ testing method that can continuously, quickly and directly obtain the original state engineering properties of the soil usually adopts the static penetration method. The penetration resistance of the probe is measured, and the engineering properties of the soil layer are understood through the change of penetration resistance. It is widely used in the test of fine-grained soils such as clay soil, silty soil, sandy soil, and filling material.

However, there are many factors affecting the static penetration test. For example, the inclination of the probe will lead to the distortion of the penetration resistance measurement; the bending and inclination of the probe rod will make the penetration depth measurement inaccurate and affect the penetration force transmission. These factors will affect the static penetration test. The artificial correction has certain blindness; in addition, the reaction force of the static penetration equipment is provided by the spiral plate or the pile load. When encountering old clay and sand layers with high strength, the pressure will be reduced. It becomes very difficult to enter, and the static penetration probe is easy to be damaged. If one probe touches several holes, problems will occur, which not only affects the progress of the project, but also increases the cost of the penetration test.

When the static penetration test is used for underwater soil layer testing, it also requires a large-tonnage integrated ship as the test carrier to provide the test reaction force, which leads to high test costs, and the probe rod is easily affected by water flow, which makes the test depth shallow and the operation The risk is high, and the accuracy of the test results is not high.

SUMMARY OF THE INVENTION

In view of the deficiencies of the above-mentioned technologies, the present invention provides an up-pulling shear probe and a method for soil in-situ testing. The engineering properties of soil layers can be obtained by shearing force. The probe has low cost, simple test operation, few influencing factors, stable test results, and durable probes; changing the size of the probes can be applied to different soil layers, with a wide range of applications; and in underwater engineering When the penetration is carried out in the middle, the requirements for the test carrier are not high, the test cost is low, the water flow is less affected, and the test results are more reliable.

The present invention is achieved through the following technical solutions:

An up-pulling shear probe for soil in-situ testing, comprising a tension sensor, a center rod, and a round hammer joint, the tension sensor is connected to the upper end of the center rod, and is characterized in that it also includes two in-line shearing plates , Two support rods, shear plate fixing block, pressure-bearing block, sliding rod, the lower end of the central rod is connected with the shearing plate fixing block, the upper end of the sliding rod is connected with the lower end of the shearing plate fixing block, the conical joint is connected with the sliding rod The lower ends are connected, two in-line shearing plates are symmetrically arranged on both sides of the center rod, and one end of the two in-line shearing plates is rotated and arranged in the middle and lower section of the center rod, and the shear plate fixing block is located on the in-line shearing plate. Below, the pressure-bearing block is slidably sleeved on the outside of the sliding rod, one end of the support rod is hinged with the bottom surface of the in-line shearing plate, and the other end is hinged with the pressure-bearing block.

Further, one end of the two in-line shearing plates is connected with the middle and lower sections of the center rod through the first connecting pin. Under the action of the pulling force, the in-line shearing plates can rotate around the first connecting pin. When the plate is opened and rotated 90°, the shear plate fixing block prevents the in-line shear plate from continuing to rotate.

Further, one end of the support rod is connected with the bump located on the bottom surface of the in-line shear plate 3 through the second connecting pin, and the other end is connected with the bearing block through the third connecting pin. The sliding rod moves downward, and the support rod rotates around the third connecting pin to open.

Further, the centerlines of the tension sensor, the center rod and the sliding rod are located on the same axis.

Further, the tension sensor is connected with the upper end of the centerline rod by threads, and the sliding rod is connected with the lower end of the fixing block of the shearing plate by threads.

Further, the in-line shearing plate, the support rod, the shearing plate fixing block, the pressure-bearing block, the sliding rod and the round hammer joint are all made of high-strength stainless steel.

Further, the cross-section of the in-line shearing plate is triangular, and after the in-line shearing plate is opened, the axis of the in-line shearing plate is perpendicular to the direction of tension, ensuring that the in-line shearing plate has a fixed contact with the soil. area and direction of force.

A method for soil in-situ testing, which is performed using the above-mentioned pull-up shear probe, comprising the following steps:

(1) Install the reaction force balance device at the drilling position to provide the reaction force during the pull-up shear test, the positioning sleeve of the pull-up rod is fixed at the hole of the drilling hole, the pull-up rod is vertical, and the position of the measuring point is accurate;

(2) Connect the pull-up shear probe and the pull-up rod with threads, connect the cable with the pull-up shear probe with bolts, and use a sealing gasket to do a good job of waterproofing;

(3) Put the pull-up shear probe into the maximum test depth position in the borehole. If there is a small amount of particles blocking, it can be pressed in by static pressure;

(4) The pull-up rod provides the pull-up force through the clamping tool and the traction device to ensure that the pull force, the center line of the pull-up rod, and the force direction of the probe are consistent. By applying the pull-up force to open the probe, the test can be carried out;

(5) Connect the cable of the tension sensor to the digital reading instrument, and pull the probe at a uniform rate, and carry out the pull-up shear test according to the relevant regulations. The pull-up shear probe should be calibrated in advance before the test;

(6) After the test, disassemble and clean the pull-up shear probe and pull-up rod, re-calibrate the probe, check its working status, and prepare for the next test

Further, when encountering coarse-grained soil or hard soil layer during the test, press down the pull-up shear probe, put away the in-line shear plate, and open the in-line shear plate after passing through the coarse-grained soil or hard soil layer. type shear plate, continue the test.

The present invention is an up-pulling shearing probe for soil in-situ testing. The probe can continuously, quickly and accurately measure the shearing force of the soil by means of up-pulling force, and can measure the shearing force of the soil according to the shearing force and the resistance of the cone tip. relationship to obtain soil mechanical properties. The probe has a compact and durable structure, simple and fast test operation, low test cost and few influencing factors; the probe model can be applied to different soil layers, the test results are stable and reliable, and the application range is wide; the advantages are particularly obvious in the test of soft soil layers; In addition, when conducting penetration in underwater engineering, the requirements for the test carrier that provide the reaction force are not high, the test cost is low, the influence of water flow is small, and the test results are more reliable.

Description of drawings

1 is a schematic structural diagram of an up-pulling shear probe for soil in-situ testing provided by the present invention after deployment;

2 is a schematic structural diagram of the provided up-pulling shear probe for soil in-situ testing when deployed;

Fig. 3 is the working principle diagram of the in-situ test shearing instrument with the above pull-out shearing probe as the core provided by the present invention;

Fig. 4 is the static penetration curve measured when using the in-situ test shearing instrument with the present invention as the core component and the conventional static penetration instrument to perform the same soil layer test.

In the figure: 1—tensile force sensor, 2—center rod, 3—in-line shear plate, 4—bump, 5—connecting pin, 6—connecting pin, 7—support rod, 8—shearing plate fixing block , 9—connecting pin, 10—pressure block, 11—slide rod, 12—round hammer joint, 13—pull-up shear probe, 14—drill hole, 15—cable wire, 16—pull up rod.

Detailed ways

The technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention.

As shown in Figures 1 and 2, one embodiment of the up-pulling shear probe for soil in-situ testing of the present invention includes a tension sensor 1, a central rod 2, two in-line shearing plates 3, and a support rod 7. Shearing plate fixing block 8, bearing block 10, sliding rod 11, round hammer joint 12.

The tension sensor 1 is connected with the upper end of the center rod 2, the lower end of the center rod 2 is connected with the shearing plate fixing block 8, the upper end of the sliding rod 11 is connected with the lower end of the shearing plate fixing block 8, and the conical joint 12 is connected with the lower end of the sliding rod 11. Two in-line shearing plates 3 are symmetrically arranged on both sides of the central rod 2, and one end of the two in-line shearing plates 3 is rotated and arranged in the middle and lower sections of the central rod 2. Specifically, the two in-line shearing plates 3 One end of the center rod 2 is connected with the middle and lower sections of the center rod 2 through the connecting pin 6 , and the shearing plate fixing block 8 is located under the in-line shearing plate 3 .

The pressure-bearing block 10 is slidably sleeved on the outside of the sliding rod 11 , and the pressure-bearing block 10 can slide up and down between the shearing plate fixing block 8 and the conical joint 12 . One end of the support rod 7 is connected to the convex block 4 located on the bottom surface of the in-line shearing plate 3 through the connecting pin 5 , and the other end is connected to the bearing block 10 through the connecting pin 9 .

The centerlines of the tension sensor 1, the center rod 2 and the sliding rod 11 are on the same axis, the tension sensor 1 and the upper end of the center line rod 2 can be connected by threads, and the sliding rod 11 and the lower end of the shear plate fixing block 8 can be connected by threads, which is convenient for Parts replacement and shipping.

In the initial state, the two in-line shearing plates 3 are in a closed state, that is, they are in a vertical state and are close to the center rod 2. When an upward pulling force is applied to the probe, under the action of the pulling force, the two in-line shearing plates 3 are closed. Open to both sides around the connecting pin 6 and gradually penetrate into the soil (as shown in Figure 2). 8. Prevent the in-line shearing plate 3 from continuing to rotate. During the opening process of the in-line shearing plate 3, the support rod 7 connected with the in-line shearing plate 3 drives the pressure-bearing block 10 to move down along the sliding rod 11. When the in-line shearing plate 3 is in a horizontal line At this time, the pressure-bearing block 10 is in contact with the bottom surface of the conical joint 12. At this time, the support rod 7 provides support and reinforcement to the in-line shear plate 3 through the pressure-receiving block 10 to ensure that the two in-line shear plates are in the test process. Always form a horizontal straight line.

The in-line shearing plate 3 , the support rod 7 , the shearing plate fixing block 8 , the pressure-bearing block 10 , the sliding rod 11 , and the round hammer joint 12 are all made of high-strength stainless steel.

The cross-section of the in-line shearing plate 3 is a triangle. After the shearing plate is opened, the axis of the shearing plate is perpendicular to the direction of the pulling force to ensure that the shearing plate and the soil have a fixed contact area and force direction.

The probe assembly process is as follows:

The first step, the central bar 2 is connected with the shearing plate fixing block 8, the lower section of the in-line shearing plate 3 and the central bar 2 are hinged by the connecting pin 6, and the in-line shearing plate 3 can be rotated around the connecting pin 6 , after rotating 90 degrees, the pressure-bearing block 8 prevents the in-line shearing plate 3 from continuing to rotate.

The second step is to connect the sliding rod 11 to the lower end of the shearing plate fixing block 8, cover the bearing block 10 to the outside of the sliding rod 11, and then connect one end of the support rod 7 to the bottom surface of the in-line shearing plate 3. 4 is connected through the connecting pin 5, and the other end is connected with the bearing block 10 through the connecting pin 9.

The present invention also provides a process of using the pull-up shear probe to perform an in-situ test. Different from previous tests, the main steps are as follows (as shown in Figure 3):

(1) Install the reaction force balance device at the position of drill hole 14 to provide the reaction force during the pull-up shear test. The positioning sleeve of the pull-up rod 16 is fixed at the hole of the hole of hole 14. The pull-up rod is vertical 16 and the measuring point is accurate location;

(2) Connect the pull-up shearing probe 13 and the pull-up rod 14 with threads, connect the cable 15 with the pull-up shear probe 13 with bolts, and use a sealing gasket to do waterproof work;

(3) Put the pull-up shear probe 13 into the maximum test depth position in the borehole; if there is a small amount of particles blocking it, it can be pressed in by static pressure;

(4) The pull-up rod 16 provides the pull-up force through the clamping tool and the traction device to ensure that the pull force, the center line of the pull-up rod, and the force direction of the probe are consistent. By applying the pull-up force to open the probe, the test can be performed;

(5) Connect the cable of the tension sensor 1 to the digital reading instrument, pull the probe at a uniform rate, and carry out the pull-up shear test according to the relevant regulations. The pull-up shear probe should be calibrated in advance before the test;

(6) After the test, disassemble the pull-up shear probe 13 and pull-up rod 16, clean them, calibrate the probe again, check its working state, and prepare for the next test.

When encountering a coarse-grained soil or a hard soil layer during the test, the probe can be pressed down, the shearing plate can be retracted, and the shearing plate can be opened after passing through the coarse-grained soil or hard soil layer, and the test can be continued.

In order to prove the effect of the present invention, a confirmatory test was carried out on site, and the in-situ test shearing instrument with the core components of the cordless static penetrator and the pull-up type in-situ test up-pull type shear probe newly developed by the present invention was used as the core component. Tests were carried out on the same soil layer respectively, and the test results are shown in Figure 4.

The test results show that the curve of the up-pull in-situ shear test and the conventional static penetration curve have the same variation law, indicating that the in-situ shear test fully meets the test requirements of the static penetration test of the fine-grained soil layer. It solves the problems that the existing static penetration probe is easy to be damaged, there are many factors affecting the test results and the cost of static penetration in underwater engineering is high, and it can more accurately measure the soil resistance on the shear plate, which is more realistic. Therefore, the test results can be widely used in various engineering in-situ tests, and have great promotion and application prospects.

The invention breaks through the problems of insufficient reaction force or low test accuracy in soft soil when the cone tip resistance is measured by pressing down in the conventional in-situ test, and overcomes the limitation that the underwater in-situ test must use a large ship as a test carrier , the shear force of the soil body can be obtained by uplifting, so as to obtain the soil parameters. According to the mechanical characteristics of different soil layers, different types of probes can be used, which expands the application range of the in-situ shear tester; in the underwater test, the use of the pull-up shear probe can eliminate the need for a large integrated ship as a carrier, which greatly reduces the test cost. , and the contact area between the pull-up shear probe and the soil is large, the measured shear resistance can be converted into cone tip resistance, and the test results are more accurate. The probe can be widely used in various types of fine-grained rock soil and underwater. It has good promotion and application prospects in the in-situ test of soil.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (7)

1. a pull-up type shearing probe for soil in-situ testing, comprising a tension sensor, a center rod, a conical joint, and the tension sensor is connected with the upper end of the center rod, it is characterized in that: also comprise two in-line shears Plate, two support rods, shearing plate fixing block, pressure-bearing block, sliding rod, the lower end of the center rod is connected with the shearing board fixing block, the upper end of the sliding rod is connected with the lower end of the shearing board fixing block, the conical joint is connected with the sliding The lower ends of the rods are connected, and two in-line shearing plates are symmetrically arranged on both sides of the center rod, and one end of the two in-line shearing plates is rotated and arranged in the middle and lower sections of the center rod, and the shearing plate fixing block is located in the in-line shearing plate. Below the plate, the pressure-bearing block is slidingly sleeved on the outside of the sliding rod, one end of the support rod is hinged with the bottom surface of the in-line shear plate, and the other end is hinged with the pressure-bearing block; one end of the two in-line shear plates is connected to the center The middle and lower sections of the rod are connected by the first connecting pin. Under the action of tension, the in-line shearing plate can rotate around the first connecting pin. When the in-line shearing plate is opened and rotated 90°, the shearing plate fixing block prevents the in-line shearing plate The in-line shear plate continues to rotate; the cross-section of the in-line shear plate is triangular, and after the in-line shear plate is opened, the axis of the in-line shear plate is perpendicular to the direction of tension, ensuring that the in-line shear plate and the soil It has a fixed contact area and force direction. 2. The pull-up shear probe for soil in-situ testing according to claim 1, wherein one end of the support rod is connected to a convex block located on the bottom surface of the in-line shear plate through the second connecting pin The other end is connected with the pressure-bearing block through the third connecting pin. Under the action of the pulling force, the pressure-bearing block moves down along the sliding rod, and the support rod rotates and opens around the third connecting pin. 3 . The pull-up shear probe for soil in-situ testing according to claim 1 , wherein the center lines of the tension sensor, the center rod and the sliding rod are located on the same axis. 4 . 4. The pull-up shear probe for soil in-situ testing as claimed in claim 1, characterized in that: the tension sensor is connected with the upper end of the center rod by a thread, and the sliding rod and the lower end of the shear plate fixing block are connected by a thread connect. 5. The pull-up shearing probe for soil in-situ testing as claimed in claim 1, wherein the in-line shearing plate, the support rod, the shearing plate fixing block, the bearing block, Sliding rods and conical joints are made of high-strength stainless steel. 6. A method for soil in-situ testing, characterized in that it is carried out using the pull-up shear probe described in any one of claims 1-5, comprising the steps of: (1) Install the reaction force balance device at the drilling position to provide the reaction force during the pull-up shear test. The positioning sleeve of the pull-up rod is fixed at the hole of the drilling hole, the pull-up rod is vertical, and the position of the measuring point is accurate; (2) Connect the pull-up shear probe to the pull-up rod with threads, connect the cable to the pull-up shear probe with bolts, and use a sealing gasket for waterproofing; (3) Put the pull-up shear probe into the maximum test depth position in the borehole. If there is a small amount of particles blocking it, use the method of static pressure to press in; (4) The pull-up rod provides the pull-up force through the clamping tool and the traction device to ensure that the pull force, the center line of the pull-up rod, and the force direction of the probe are consistent, and the probe is opened by applying the pull-up force to conduct the test; (5) Connect the cable of the tension sensor to the digital reading instrument, and pull the probe at a uniform rate, and carry out the pull-up shear test according to the relevant regulations. Before the test, the pull-up shear probe should be calibrated in advance; (6) After the test, disassemble and clean the pull-up shear probe and pull-up rod, calibrate the probe again, check its working status, and prepare for the next test. 7. The method for soil in-situ testing as claimed in claim 6, characterized in that: when encountering coarse-grained soil or hard soil layer during the test, press down the pull-up shear probe, and put it away. After passing through the coarse-grained soil or hard soil layer, open the in-line shearing board and continue the test.

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