Testing device and method of foundation pit excavation rock soil centrifuge

Abstract

The invention relates to a testing device and method of a foundation pit excavation rock soil centrifuge. The device comprises a mold box (16), an enclosure wall body (1), a positioning unit, supporting units and a testing unit, wherein the inner space of the mold box (16) is divided into an experiment region and a water level control box through a baffle (13); a counterforce bracket (7) is arranged at the upper end of the mold box (16); the enclosure wall body (1) is internally provided with a separation wall body (2) according to the requirements, and the inner space of the enclosure wall body (1) is separated into a plurality of excavation regions; the positioning unit is used for hanging the enclosure wall body (1) on the counterforce bracket (7); the supporting units are detachably mounted in the excavation regions layer by layer and abut against inner walls of the excavation regions; the testing unit comprises a pore pressure meter, a soil pressure meter, a strain gauge and a laser displacement meter. Compared with the prior art, the testing device is applicable to more complicated foundation pit centrifugal model tests; meanwhile, the testing device is convenient to mount and detach, and can be repeatedly and circularly utilized; the utilization rate of materials is improved, and components and parts are convenient to replace.

Description

technical field [0001] The invention relates to the technical field of centrifuge model testing in geotechnical engineering, in particular to a test device and a test method for a centrifuge for foundation pit excavation. Background technique [0002] The geotechnical centrifuge adopts different accelerations, and can generate the stress-strain state of the prototype foundation pit with a smaller model. By observing the deformation state and failure process of the model foundation pit enclosure structure and the surrounding soil, the foundation pit under complex conditions can be prepared. The in-depth study of engineering properties provides an effective means. However, there are two main problems in the centrifuge test for foundation pit excavation carried out at present. First, the foundation pit model and support form are simple, and most of the tests can only simulate the partial foundation pit, and the internal support form is limited to one-way straight rod support. ...

AI Technical Summary

Problems solved by technology

First, the foundation pit model and support form are simple, and most of the tests can only simulate the part of the foundation pit, and the internal support form is limited to one-way straight rod support. The impact of boundary effects leads to large deviations between test results and engineering measured data

Second, some full-scale foundation pit model tests cannot well control the subsidence of the foundation pit enclosure structure in the soil. Since the foundation pit enclosure structure must be placed in the soil before the soil is completely consolidated, This leads to the subsidence of the foundation pit enclosure structure placed in the incompletely consolidated soil sample due to the high density of the soil during the consolidation process, which leads to the failure of the test

Images