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

Abstract

An up-pull type shear probe used for soil body in-situ testing is disclosed. The probe includes a tension sensor, a central bar, a taper joint, two straight shearing plates, two supporting bars, a shearing plate fixing block, a bearing block and a slide bar. The tension sensor is connected to the upper end of the central bar, and the lower end of the central bar is connected to the shearing platefixing block. The upper end of the slide bar is connected to the lower end of the shearing plate fixing block, and the lower end of the slide bar is connected to the taper joint. The two straight shearing plates are at two sides of the central bar symmetrically, and one end of each straight shearing plate is rotatably disposed on the middle lower section of the central bar. The shearing plate fixing block is under the straight shearing plates. The bearing block sleeves the slide bar. One end of each supporting bar is hinged to the bottom surface of the corresponding straight shearing plate, and the other end is hinged with the bearing block. The shearing force of a soil body is continuously, rapidly and accurately measured through an up-pulling force manner, and engineering properties of the soil are obtained through the shearing force. The probe has characteristics of a low cost, simple test operation, few influence factors and stable test results.

Description

technical field [0001] The invention relates to the technical field of surveying and in-situ testing of land soil layers and underwater soil layers, in particular to a pull-up shear probe and a method for in-situ testing of soil bodies. Background technique [0002] At present, the in-situ test method that can continuously, quickly and directly obtain the engineering properties of the original state of the soil usually adopts the static penetration method. This method is to press the probe into the soil at a certain rate by static pressure, and use the sensor The penetration resistance of the probe is measured, and the engineering properties of the soil layer can be understood through the change of the penetration resistance. It is widely used in the test of fine-grained soils such as cohesive soil, silty soil, sandy soil, and filling materials. [0003] However, there are many factors affecting the static penetration test. For example, the inclination of the probe will lead...

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Problems solved by technology

[0003] 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 measurement of the penetration depth inaccurate and affect the transmission of penetration force. The artificial correction has a certain blindness; in addition, the reaction force of the static penetration testing equipment is provided by the spiral plate or the pile load. When encountering the old clay and sand layers with high strength, the pressure It becomes very difficult to enter, and the static penetrating probe is easily damaged, and a probe will touch several holes to cause problems, which not only affects the progress of the project but also increases the cost of the penetrating test

[0004] When the static penetrating test is used for the underwater soil test, it also requires a large-tonnage integrated ship as the test carrier to provide the test reaction force, resulting in expensive test costs, and the probe rod is easily affected by the water flow, making the test depth shallow and difficult to operate. The risk is high, and the accuracy of the test results is not high

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