应用微芯桩传感器的拉裂型边坡危岩体临崩倾斜变形特征现场实测研究

Field measurement study on the pre-collapse inclination deformation characteristics of tension-cracking slope rock mass using micro-core-pile sensor

边坡危岩体崩塌的监测预报一直是地质灾害防灾研究的重点和薄弱环节。基于微电子机械系统(micro-electromechanical system,简称MEMS)技术构建了危岩体微小倾斜角度与强振加速度的“采集-计算-传输”机制,研制了微芯桩传感器,实现了危岩体的低功耗长期监测。通过拉裂型危岩体崩塌现场实测分析,发现了拉裂型危岩体具有倾斜变形加速并伴随强振动频次、幅值增加的崩塌前兆。探明了临崩加速倾斜阶段累计倾斜变形量与倾斜变形速率之间具有显著指数关系,且倾斜速率倒数与距离崩塌时长具有线性相关性,进而建立了“倾斜速率倒数法”崩塌时间预测模型,形成了基于MEMS倾斜角度传感数据特征的预测模型实时应用算法流程。研究成果可对崩塌灾害的监测预警产生积极的促进作用。

The monitoring and forecasting of slope dangerous rock mass collapses have always been a critical yet underdeveloped area in geological disaster prevention research.An automatic sensing mechanism was devised for capturing,computing,and transmitting minor tilt angles and strong vibration accelerations of tension-cracking dangerous rock masses.A micro-core-pile geological disasters monitoring sensor has been devised,enabling low-power long-term monitoring.Through on-site monitoring and analysis of tension-cracking rock mass collapses,it was found that these rock masses exhibit a precursor of collapse characterized by accelerated tilt deformation accompanied by an increase in the frequency and amplitude of strong vibrations.It was revealed that there is a significant exponential relationship between the cumulative tilt deformation and the tilt deformation rate during the accelerated tilt phase immediately preceding collapse,and a linear correlation exists between the reciprocal of the tilt rate and the remaining time before collapse.Subsequently,a‘reciprocal tilt rate method’was established for predicting the time to collapse,and an algorithm for real-time application of the prediction model based on MEMS tilt angle sensor data characteristics was developed.These research findings can have a positive promoting effect on the monitoring and early warning of collapse disasters.