Research and application of key technologies for rural slope safety monitoring and early warning of granite residual soil
Based on the existing slope disaster prevention and mitigation projects,the safety monitoring and early warning of typical granite residual soil slope in rural areas are studied.The results show that the monitoring profile should be selected according to the slope,slope height and slope cutting method,and the representative parts that are prone to failure can be add-ed when necessary.The content of slope safety monitoring should include rainfall,slope moisture content,slope displacement,slope foot retaining wall inclination observation and video monitoring equipment combination;The slope monitoring equipment should be arranged in different parts and elevations of the slope so as to control the stability of the slope as a whole in space.At least the displacement monitoring points should be set at the top and middle of the monitoring profile.The buried location of deformation monitoring station should be selected in the location where the performance of rock and soil mass is poor and the deformation is expected to be large.This kind of slope is small in scale and prone to instability failure,so GNSS method with low cost and flexible installation position should be adopted to carry out displacement monitoring of this kind of slope.The slope safety warning index should adopt the double index of rainfall and slope top displacement,increase the fault tolerance rate,and increase the slope water content index if necessary.In addition to the conventional SMS reminder,alarm devices such as sound and light should be set up at the scene to enhance the alarm effect.Rainfall has direct and major influence on the stability of granite residual soil slope.With the increase of rainfall,slope moisture content and slope displacement increase correspondingly and there is a certain lag phenomenon.The SIGMA/W modules and Slope/E modules in the finite element a-nalysis software Geo-studio were used to conduct seepage analysis and stability analysis of the slope.The geotechnical physi-cal parameters,soil and water characteristic curves,and permeability coefficient were derived from the measured survey data.The size of the grid unit was 1m,and the shape of the grid unit was a combination of square and triangle.Model calibration and debugging selects the maximum rainfall period during the monitoring period to fit,and the error between the displacement of the slope top of the model and the measured value is 5%,which meets the feasibility verification.The rainfall intensity of 70mm was used to define the rainfall boundary of the model,the slope stability coefficient was observed,and the early-warn-ing stability coefficient was selected as 1.1.The forewarning value of slope rainfall is 70mm/d and the displacement of slope top is 5mm/d.This study improves the effectiveness and economy of safety monitoring and early warning of dangerous slope in rural slope construction,and provides theoretical and practical guidance for solving the problem of such slope monitoring and early warning.
granite residual soilGeo-studiomonitoring for safetyforewarning
NETL
NSTL
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