Underground in-situ soil body loading device

Abstract

The invention discloses an underground in-situ soil body loading device. The underground in-situ soil body loading device comprises a supporting shoe, an actuator and a loading unit which are contained in a drilling casing pipe and coaxially arranged. The supporting shoe comprises a rigid supporting shoe box, a supporting shoe oil cylinder contained in the rigid supporting shoe box and a plurality of supporting shoe bodies evenly distributed between the rigid supporting shoe box and the drilling casing pipe, and the supporting shoe oil cylinder is connected with the supporting shoe bodies through telescopic connecting rods respectively. The telescopic connecting rods are driven by the supporting shoe oil cylinders to synchronously move in the radial direction of the drilling casing pipe, so that the corresponding supporting shoe bodies and the inner side wall of the drilling casing pipe are in a tensioned or separated state; and the loading unit comprises a soil sample protection cylinder, and a loading rod, a loading head, a loading cap and a sleeve film which are positioned in the soil sample protection cylinder and are connected in sequence, and the loading unit is controlled by an actuator to load. According to the device, the supporting shoe located in the drilling casing pipe is used as a loading reaction frame, and it can be guaranteed that loading force is applied to an in-situ soil sample in a centered mode in the loading and sample preparation process of the rock-soil underground in-situ soil body.

Description

technical field [0001] The invention belongs to the field of downhole in-situ triaxial test, in particular to an in-situ soil loading device for downhole. Background technique [0002] The stress level and particle-pore microstructure of soil are the main influencing factors of soil strength parameters. However, the load borne by the soil in the indoor test is quite different from the real situation. At the same time, sampling often causes soil sample disturbance, pore structure and water content changes, stress unloading, etc., resulting in a large difference between the soil parameters measured in the laboratory test and the in-situ soil. However, for soil layers containing pebbles, gravel layers, loose sand layers, and weathered rock layers where it is difficult to obtain high-quality soil samples, the sampling method is not applicable, and in-situ testing is required to determine its mechanical parameters to reflect a larger range (compared to In terms of small-plot te...

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Problems solved by technology

[0005] In view of the deficiencies in the above-mentioned background technology, the present invention proposes an in-situ soil loading device for downhole, which is introduced into the shoe device in the shield machine, and applied to the in-situ triaxial loading test in the downhole through design improvement to solve the problem of completing the mantle. How to load the test piece underground and how to ensure the technical problem of loading

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