Model test system for researching instability critical conditions of vegetation-covered slopes under action of rainfall

Abstract

The invention discloses a model test system for researching the instability critical condition of a vegetation-covered slope under the action of rainfall. A vegetation-covered slope model is arrangedin a centrifugal environment double-layer seepage model box; a graded rainfall feedback simulation system is used for simulating specific rainfall intensity and duration requirements and inducing thechange of a moisture field condition in the slope body of the vegetation cover slope body model; an artificial root strain analysis system simulates the physical soil fixation effect of the root system on the slope surface and the regulation and control effect of the matrix suction force; a slope surface crack high-speed camera system is used for recording the whole rainwater infiltration and slope surface scouring conditions of the test slope body and clearly capturing the whole process of slope surface crack development, extension and penetration; and a rock-soil body moisture content monitoring system is used for monitoring the response condition of the slope body moisture field in real time in the whole process under different rainfall and artificial root working conditions. The systemis used for carrying out a model test for researching the instability critical condition of the vegetation covered slope under the rainfall condition, and an effective test means is provided for evaluating the influence of vegetation on the slope stability under the rainfall condition.

Description

Technical field [0001] The invention relates to the field of geotechnical engineering and the technical field of geotechnical test models, in particular to a model test system for studying the critical conditions of instability of vegetation-covered slopes under the action of rainfall. Background technique [0002] my country is a mountainous country, with mountainous areas accounting for 69% of the land area. Geological disasters such as landslides induced by rainfall have become important issues that restrict my country's infrastructure and economic development. The main causes of existing landslide disasters include earthquakes, construction excavation disturbances, and precipitation infiltration. Landslides induced by atmospheric precipitation infiltration account for a large proportion of landslide disasters. The change of slope seepage and water field in slope under the action of rainfall is of great significance to reveal the critical conditions of slope instability. Un...

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Problems solved by technology

[0005] (1) Most rainfall model test systems did not pay attention to the influence of slope vegetation coverage on slope stability, and there was no systematic understanding of the influence of vegetation coverage on slope seepage mechanism under the action of rainfall;

[0006] (2) The rainfall model test is simulated under constant gravity conditions, which cannot reproduce the real stress field of the prototype slope;

[0007] (3) There is a lack of research on the root system soil consolidation and water regulation mechanism of different vegetation types, and the coupling mechanism of rainfall seepage and root system slope consolidation has not been clarified, and the instability conditions of the slope cannot be determined;

[0008] (4) The existing model test equipment cannot be used to simulate the soil-fixing function of the vegetation root system, and cannot monitor the bending strain change of the root system during the reinforcement and anchorage process;

[0009] (5) It is difficult to simulate the rainfall conditions in the centrifuge, and other seepage boundary conditions are often used instead, which loses the authenticity of restoring the seepage effect of rainfall on the slope;

[0010] (6) The rainfall control system is mostly based on the control of the water flow rate. When the geotechnical centrifuge is running, the hypergravity environment affects the rainfall intensity, resulting in a deviation of the rainfall intensity, and it is impossible to monitor and feedback the real-time rainfall intensity;

[0011] (7) The monitoring image records of the centrifugal model test system are relatively rough, and there is a lack of a high-speed camera system that can capture the development, extension, and deformation of slope surface cracks at high speed and stably.

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