为了实现暴雨型山体滑坡的动态预警,基于已有的滑坡成果,在线性时不变理论的框架内探讨一种预警方法——电抗阈值法。基于地质体地电特性TD阻容模型,在外电场作用下将“滑带层”动态含水量△WS变换为反映大地系统传输函数的“滑带层”复阻抗特性△Zs,实现对滑坡隐患体(以“滑带层”为主)动态含水量的间接监测;基于“莫尔-库伦”破坏准则,通过对“滑带层”平均倾斜角口和现场静摩擦因数μ阈值的求证获得μ的动态阈值边界;基于模拟实验和理论分析,在时域系统中通过频谱变换将△WS、△ZS和μ归一为因果系统函数,获得反映暴雨型山体滑坡的理论阈值区。模拟实验结果表明:在外电场激发下,“滑带层”动态含水量△瞅与“滑带层”复阻抗△Zs以及现场静摩擦因数P具有鲜明的拟合性,且它们在时间域上均具有阈值特性。使用该方法能将不变系统内的多参数有效拟合,可以为暴雨型山体滑坡阈值报警技术的研究提供一种可探讨的新途径。
In order to realize the dynamic warning for the heavy rainfall landslide, based on the existing landslide theory and within linear time-invariant systems theory framework, a warning way named reactance threshold value method was discussed. The dynamic water content of sliding layer AWs is transformed to complex impedance △Zs which reflects the transmission function of geodetic system based on TD resistance-capacity model under the action of external electric field. Based on Mohr-Coulomb failure criterion, the dynamic threshold boundary of the static friction factor μ is obtained through analyzing the average slope angle and static friction factor μ threshold of the sliding layer. △Ws, △Zs and μ are normalized to causal system function through spectrum transformation in timing-domain system, and theory threshold area of heavy rainfall landslides is obtained based on theory analysis. The simulation experimental results show the dynamic water content of sliding layer △Ws, complex impedance △Zs and static friction factor μ have distinct fitting feature under the action of external electric field, and the three parameters all have threshold characteristics in time domain. This method can effectively fit multiple parameters in the time invariant system, and it can provide a new negotiated way to dynamic threshold warning technology research of heavy rainfall landslide warning.