Risk Assessment Of Unstable Slope Around XingLong Town,ZhenBa County

As 1:50 000 nationwide geological disasters detailed investigation in full swing,for the work of geological disasters by the geological disaster information survey focus on the cause of the mechanism of geological hazards research,risk control and the construction of early warning and forecasting system,the geological disaster risk management and risk assessment has now become the 1:50 000 a vital link in the investigation of geological disasters,to establish a proper risk evaluation method is particularly important,especially in qingling-bashan mountains,the mountains complex geological conditions,geological disasters,and human settlements,narrow in the event of the consequences of any serious geological disaster areas.In xinglong town as an example,the risk evaluation on the slope,surrounding the first assume that the surrounding slope failure mode and the soil to play a strong weathering of sliding,does not involve the destruction of the rock formation,inducing factors of slope instability for rainfall,log collection town of rainfall data,through the Pearson type three curve fitting to determine a return period(10 years,50 years,in a 100)of rainfall intensity,by water infiltration of the revised Green-Ampt model in part,to be linked with the damage probability of slope,and then according to the surveying and mapping,and field survey data to determine the distribution of unstable slope position,section shape,the thickness of the overlaying soil,rock and soil physical parameters to determine the failure probability of slope under different rainfall conditions and average stability coefficient,and through the(housing)of hazardaffected bodies after one by one,the investigation,and determine the basic nature of town each house(build time,structure type,number of floors,house property value,etc.),to determine the vulnerability of the building,and finally to slope failure probabilities under different working conditions,the vulnerability of hazard-affected bodies and the value of hazard-affected body into risk evaluation formula calculation in a certain condition,in the towns surrounding slopes under the threat of value at risk of damage to property.Through the above analysis,research and investigation,some achievements and conclusions have been obtained:(1)fitting town daily rainfall data for many years,through the Green-Ampt rainfall infiltration model to calculate the slope of different positions on infiltration under different rainfall intensity,rainfall duration,the depth,and draw the town within the scope of rainfall infiltration depth map.(2)through the field investigation in slope soil layer thickness,on the whole urban soil thickness distribution fitting,slope slope DEM,rainfall infiltration depth map,a set of automatic extraction of slope is proposed to calculate section method.(3)after the extraction of slope calculation section,after considering the uncertainty of rock and soil strength parameters,calculate the failure probability of slope under different rainfall conditions,used instead of the dangers of slope.(4)on the slopes surrounding the xinglong town one by one after the calculation of damage probability,combining with the vulnerability and the value of properties of the building,in houses and slope,respectively,conducted a risk assessment under different working conditions.