Unloading method of seepage-stress coupling field test

Abstract

The invention relates to a method of determining the seepage and stress coupling characteristic of rock and soil mass by the unloading effect of stage excavation. It is aiming at the characteristic of stage excavation in practical underground excavation engineering, after excavation unloading in each step, by water-pressure test in hole and stress monitor or deformation monitor to rock and soil mass in the disturbed zone, the seepage characteristic and the change rule of deformation to rock and soil mass in excavation process are obtained; then by figures of deformation monitor or stress monitor, through the numerical back-analysis method, the force characteristic and stress distributing rule of rock and soil mass near the test point are determined after blasting damage and unloading disturbance; and furthermore the coupling model of the seepage and stress coupling characteristic of rock and soil mass is built. The invention can make use of the prior rule of water-pressure test in hole directly3with simple operation can reflect the stress changeable path and the seepage and stress coupling characteristic of rock and soil mass in scene in all aspects and can eliminate the representation of indoor sample and the dimension effect thoroughly.

Description

technical field [0001] The invention relates to a geotechnical engineering, especially an unloading method for field tests of seepage-stress coupling in underground cavern engineering. Background technique [0002] Under engineering disturbance conditions such as excavation and loading, the rock and soil mass is deformed, the stress field is adjusted accordingly, and the structural properties and geometric characteristics of the rock and soil mass are changed accordingly, resulting in the occurrence of seepage characteristics and seepage movement laws of the rock and soil mass. On the other hand, changes in the seepage characteristics and seepage movement laws of rock and soil further change its mechanical behavior and stress state. This interaction and mutual influence is called seepage-stress coupling. At present, the research on the seepage-stress coupling mechanism of rock and soil mass is mostly carried out in indoor laboratories by means of loading, that is, to test t...

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Problems solved by technology

The reason is that the advantage and convenience of using the unloading method for seepage-stress coupling field test has not yet been recognized by the majority of engineering and technical personnel; SL31-2003), only made relevant provisions on the work content, test methods and technical requirements of the borehole pressure water test, but did not involve the test method of the seepage characteristics of rock and soil mass under the condition of seepage-stress coupling

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