基于表面位移的公路滑坡监测预警研究

Study of highway landslide monitoring and early warning based on surface displacements

公路滑坡是常见的地质灾害,但对运营期公路边坡进行长期监测并成功预警的实例却很少。主要原因是公路边坡点多、线长、规模小、缺乏详细的地质勘探资料、监测费用高、预警难度大。利用拉索触发式位移计对滑坡表面位移进行监测,精度可达1mm,通过电信的GPRS公网实时传送到远程监控中心,全程自动化,且费用低。同时,利用有限元商用软件PLAXIS的强度折减模块和塑性分析模块对不同参数组合进行计算,在缺乏滑坡岩土体强度参数、渗透系数、土-水特征曲线等资料的情况下,建立滑坡安全系数与表面监测位移的关系,从而通过表面位移量的变化进行阶段式预警,并制定相应的预防措施。提出的方法已在湘西某高速公路滑坡获得应用。

The successfully monitoring and early warning for highway slope in operation period are not common though the highway landslide is the common disaster.The main reason is that the highway slope has the characteristics including spot distribution along road,long interval,small scale,large quantity and lack of statistics,which cause the high monitoring costs and difficult early warning.In this paper,the wire pulling displacement meter with the precise of 1 mm is used to monitor the surface displacements of landslide,and the GPRS net of China Telecom is applied to transform the monitoring data;the whole system has high automation and low cost.Meantime,the FEM software PLAXIS is used to conduct the strength reduction analysis and plastic analysis.Based on the calculation results with different parameters,the relationship between the slope safety factor and surface displacement is established in lack of the strength parameters,permeability and soil water characteristic curve;and the corresponding early warning measures are proposed according to the change of surface displacement.This method has been applied to a highway landslide in Hunan province.