Hydrological response and deformation and failure characteristics of tension fracture slope under rainfall conditions
[Objective]In order to explore the influence of fractures on the rainfall infiltration process of slope,the response of vol-ume water content,pore water pressure and earth pressure in the deformation and failure process of fractured slope during rainfall and the evolution law of wetting front were studied.[Methods]In this paper,a combination of physical model test and numerical simulation is used to study the response of rainfall infiltration and the deformation and failure process of fractured slope.The mois-ture content,pore water pressure,soil pressure,slope displacement and deformation of risk slopes were monitored in real time dur-ing the physical model test.Rainfall was added to the numerical simulation to monitor the effective saturation and plastic strain,and increase the working condition of non fractured slopes to compare the impact of fractures on slope infiltration failure.[Results]As the dominant channel of rainfall infiltration,cracks change the seepage field of slope under rainfall conditions,and the wet peak in the pre-rainfall period is funnel-shaped.The pore water pressure sensor will fluctuate in the process of slope surface cracks,and the distribution of soil pressure inside the slope will change before large-scale slope failure.The cracks become the natural sliding surface of the slope,and the slope eventually slides along the cracks.[Conclusion]The landslide deformation failure in the rainfall process can be divided into three stages:microfracture development,local failure and large area failure.It is manifested as the slid-ing mode of early tensioning traction,mid-stage slope collapse and late push failure.There are four stages of slope front displace-ment:no displacement stage,slow creep stage,fast deformation stage,slow creep stage and short distance fast deformation stage.Compared with slopes without cracks,slopes with cracks have a faster rainfall infiltration rate.Under the same rainfall duration,the plastic deformation zone without cracks is only limited to the foot of the slope.The whole slope is inhomogeneous infiltration,Re-sulting in slow infiltration in the lower part of the slope shoulder,which makes this part become the resistance zone for sliding of the rear slope,and effectively prevents sliding of the slope along the fissure in the early rainfall period.At the front of the slope,the anti-sliding force decreases,while at the back of the slope,the sliding force increases due to the continuous rainfall and the water-holding effect of the crack,and the sliding surface of the slope extends along the crack.
fissuretrainfall infiltrationslope deformation and failurenumerical simulationmodel test
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