The Research On Stability Of Grillage Flexible Supporting Structure With Prestressed Anchors Considering The Influence Of Rainfall

Along with our country western development strategy in depth, problem of slope in loess area is more and more outstanding. The problems of rainfall is easy to cause the loess slope instability are discussed by many scholars. As to slope supported by grillage flexible supporting structure with prestressed anchors, rarely seen on its stability linked to rainfall infiltration.Therefore, research on influence of rainfall infiltration on stability of grillage flexible supporting structure with prestressed anchors, enriching its stability in loess areas to promote this kind of flexible retaining structure has an important value.The previous research production is summarized such as unsaturated soil under rainfall infiltration, unsaturated soil strength theory, law of rainfall infiltration in unsaturated soil and its relationship with soil slope stability, the grillage flexible supporting structure with prestressed anchors of the overall stability research methods is combined, and the dynamic stability of grillage flexible supporting structure with prestressed anchors under the condition of rainfall infiltration is analyzed. The works and achievements are completed as follows:(1) According to the calculation method of friction type grouting anchor pullout capacity, experiment on water uplift bearing capacity influence on friction type grouting anchor is combined. A method to calculate the ultimate extraction bearing capacity of the friction type grouting anchor with different soil water content is raised.(2) According to a loess slope in Lanzhou city supported with grillage flexible supporting structure with prestressed anchors, the unsaturated loess slope seepage field under the condition of rainfall is simulated and unsaturated loess water characteristic curve and coefficient of permeability characteristic curve are fitted with the Van Genuchten model. A method to calculate the ultimate extraction bearing capacity of the friction type grouting anchor with different soil water content is raised, and the dynamic stability of grillage flexible supporting structure with prestressed anchors under the condition of rainfall infiltration is analyzed.(3) Analysis the influence law of rainfall condition, soil parameters, structure parameters on the grillage flexible supporting structure with prestressed anchors flexible supporting the overall stability. (4) The guidance of the design and construction of grillage flexible supporting structure with prestressed anchors considering the influence of rainfall in unsaturated loess area is raised:when it designed as the saturated soils theory we should be set aside enough safety storage, especially the effects of moisture content on anchors ultimate extraction bearing capacity. The slope top should be solidification treatmented if conditions are satisfied. Drainage slope and drainage ditch should be set up. Slope top should not set up other drainage trench, if drainage trench must be set, measures should be taken to prevent the leakage of pipe ditch. When setting panel, drainage hole should be set according to the requirements.