Study On Groundwater To The Mechanical Function Of Landslide

In recent centuries in the worldwide scale occurs the calamity collapses the slippery geological disaster, about 80% disasters to which locate the extreme climate conditions or the climate variation factors directly or indirectly, about 55% and is directly related to heavy rainstorm, which induce to the long-term sustainability or unexpected heavy rainfall. This paper aims to study different types of landslide occurrence of groundwater and hydrogeologic conditions of the structure, analysis of the impact of landslide dynamic changes of the groundwater seepage field, summed up landslide buried underground water supply, changes in migration and seepage fielde. Studies from the following several aspects:(1) through collects domestic and foreign landslide literature comprehensively, carries on the system to these material to reorganize, summarizes in the landslide in vivo ground water classification and the characteristic, the landside mass ground water hydrology geology structure; The elaboration landside mass inside and outside water supply supplies condition as well as the influence function which as well as between the landslide in vivo ground water and the gneiss interaction produces to the landslide.(2) rests on the landslide the underground hydrodynamic force characteristic and infiltrates the flow field function way, divides the landside mass ground water function effect type into the hydrostatic pressure effect, the uplift pressure effect, the osmotic pressure (or hydrodynamic pressure) the effect, the slippery body is filled with water increases the heavy effect and the slippery belt earth full water softening effect, and succinctly summarizes under each kind of effect ground water function geological model. (3) infers the landslide ground water transfusion elementary theory, infers the ground water transfusion fundamental equation using the Darcy law, and assigns its initial condition and the boundary condition; Introduced infiltrates the flow field numerical simulation the finite element elementary theory, the implementation step and the unit division.(4) acts according to the landside mass ground water supplies, the migration condition, divides into the diving water-bearing stratum pattern, the bearing pressure water-bearing stratum pattern, the diving and the bearing pressure water-bearing stratum mix pattern three kinds mechanics function pattern, and carries on mechanics function effect analysis to each kind of pattern; Meanwhile carries on the landslide stability analyses to each kind of pattern selection corresponding landslide vertical and horizontal relationships, compared with its stable coefficient value size.(5) chooses Sichuan Province Xuanhan Tiantai large landslide which belongs the "diving and confined aquifer mixed mode" as an example to analyse groundwater mechanical function; simulate and analyse landslide groundwater seepage field with Visual MODFLOW software. Through model analysis, we can know that the landslide areas of groundwater discharge run-off the main flow of landslide and slope leading edge of the valley on the formation of landslide displacement of water Tong (Landslide la subsidence trough), but eventually the flow of leading-edge features of the valley. Decline of groundwater seepage field changes with the terrain slope, the more the lower the water table near the river valley, the more steep terrain, the greater the groundwater hydraulic gradient.(6) through analying Sichuan Province Xuanhan Tiantai examples of large landslides in numerical simulation of seepage field, studys in a one-time maximum rainfall for the 50mm, 80mm, 100mm, 120mm, 150mm, 200mm case, with increasing rainfall recharge, landslide body, the water table or pressure head to increase in varying degrees.(7) as the largest one-time 80mm rainfall for example, from 7 to 365 days, the increase over time, the body water table slope between 440 ~ 500m of the dramatic changes in the groundwater seepage field, and the landslide slip surface elevation changes in the scope of broadly consistent with that of rainfall infiltration recharge of ground water on the sliding surface significantly affect groundwater, landslides value of groundwater in the landslide head strong slip larger changes in the region.