暴雨型山体滑坡预警技术——电抗阈值法

唐冬梅^{1, 2}，陈一平^{1, 2}，柳建新^{1, 2}，杨 振³

(1. 中南大学 地球科学与信息物理学院，长沙 410083；
2. 中南大学有色资源与地质灾害探查湖南省重点实验室，长沙410083；
3. 湖南继善高科技有限公司，长沙 410208)

摘 要：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？W_s变换为反映大地系统传输函数的“滑带层”复阻抗特性？Z_s，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α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？W_s、？Z_s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？W_s与“滑带层”复阻抗？Z_s以及现场静摩擦因数μ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。

关键词：暴雨型滑坡；复阻抗；动态含水量；静摩擦因数；阈值报警

Reactance threshold value method for heavy rainfall landslide warning

TANG Dong-mei^{1, 2}, CHEN Yi-ping^{1, 2}, LIU Jian-xin^{1, 2}, YANG Zhen³

(1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. Hunan Key Laboratory of Non-ferrous Resources and Geological Hazard Detection,
Central South University, Changsha 410083, China;
3. Hunan Geo-sun High Technology Limited Company, Changsha 410208, China)

Abstract: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 ？W_s is transformed to complex impedance ？Z_s 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. ？W_s, ？Z_s 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 ？W_s, complex impedance ？Z_s 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.

Key words:heavy rainfall landslide; complex impedance; dynamic water content; static friction factor; threshold warning