Testing device and method for compression deformation modulus and strength of soil body in deep hole

Abstract

The invention relates to a testing device and method for a compression deformation modulus and strength of a soil body in a deep hole. Load plate test is the most direct and reliable way for evaluating engineering foundation state; however, no device is available for an in-hole load plate test at present. According to the testing device, a supporting ring is coated with a hydraulic rubber film; the supporting ring is assembled on a supporting plate outside a bottom center pipe; then a jack and a pressure sensor are connected with the top of the bottom center pipe and a displacement sensor is fixed on the supporting ring; a top center pipe is coated with an air pressure rubber film and upper and lower cover plates are fixed; a testing system is arranged; and an air pressure pump and a hydraulic pump are started to record measured values of the pressure sensor and the displacement sensor. According to the testing device and method, an independent in-hole load plate testing system is composed of an air pressure friction reaction-force device, a loading device and the testing device; a supporting reaction force for supporting is provided for the system by friction between the air pressure film and the hole wall; the settlement amount of the load plate is directly measured by a measuring sensor and in-hole load plate testing is realized.

Description

technical field [0001] The invention belongs to the technical field of in-situ testing of geotechnical engineering, and in particular relates to a testing device and a testing method for compressive deformation modulus and strength of soil in a deep hole. Background technique [0002] The physical and mechanical properties of soil in nature vary widely due to the influence of its genetic conditions, climate and environment. Obtaining accurate physical and mechanical parameters of soil is not only an important content of engineering investigation, but also directly related to the safety and rationality of engineering design. sex. In engineering, the test results of geotechnical laboratory are often used as the design basis, but soil is a typical three-phase granular bulk accumulation, and the disturbance during sampling, the change of boundary conditions, the transportation process, and the size effect all have certain influence on the test results, so Carrying out in-situ ...

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Problems solved by technology

However, there is currently no test system and method for the load plate in the hole. Generally, the hole is manually excavated and placed in a large-diameter load plate and then loaded at the hole. The dowel bar is used to provide the reaction force for the load plate at the bottom of the hole. Measuring the displacement of the load plate at the bottom of the hole on the surface, longer dowel rods and displacement rods have a greater impact on the micron-level test accuracy requirements, and the risk of manual digging is high, the depth is small, the cost is high, and the cycle is long. Only in important subways There are few applications in design project survey

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