Method for determining the position of landslide slip surface based on B-type inclinometer curve
In the actual deep hole displacement monitoring,the mutation character of the inclinometer curve is the key basis for the identification of slip surface.For the B-type inclinometer curve,the bulge convex point of the curve is usually taken as the position of sliding surface.However,this method is easily affected by the arrangement interval of detection points and the coordinate-scale,which makes the position of the sliding surface unclear and the value uncertain.In order to overcome these shortcomings effectively and improve the accuracy on identification of sliding surface with inclinometer curve,the landslide in this study is simplified into a generalized model composed of sliding body,sliding interval and immovable body based on the variation characteristics of B-type inclinometer curve.And we also analyzed the characteristics of soil displacement rate and acceleration at different depths in the process of landslide movement.The results show that the soil displacement rate will form multiple curve clusters along the depth direction,and different curve clusters correspond to the sliding section of sliding surface and non-sliding section respectively.In addition,if the displacement rate is converted into acceleration,the soil acceleration curve has more obvious clustering characteristics which can provide an important basis for accurately distinguishing the interval range of sliding bodies and immovable bodies.Furthermore,this study extracts the soil acceleration of the day with significant clustering characteristics of acceleration curve during the monitoring period and draws a scatter plot,which can quickly and accurately determine the depth range of different sections of the slope.Based on the acceleration data in the sliding section of each sliding surface on that day,we use cubic spline interpolation to calculate the maximum acceleration in the section.Since the soil acceleration at sliding surface is the largest,the soil depth corresponding to this value can be used as the calculated depth of the sliding surface.The method proposed in this paper can determine the position of the sliding surface more accurately and make the determination of the sliding surface position computable.It effectively improves the utilization and reliability of monitoring data on deep displacement of borehole,and has great practical value.
inclinometer curvesliding surface positionrelative displacementinflection point calculationcubic spline interpolation