山西典型黄土崩塌破坏模式及其早期辨识

Failure Modes and Early Identification of Typical Loess Collapse in Shanxi

针对黄土崩塌隐蔽性、突发性的特点,旨在实现黄土崩塌的早期辨识及预判,并提出相应的应急防治措施。通过对山西典型黄土崩塌破坏模式进行分类总结,归纳了黄土崩塌不稳定界面及相应的诱发因素,提取了黄土崩塌早期辨识特征因子;通过综合指数法对崩塌危险性进行了半定量分析;按照量化评价标准,对黄土崩塌危险性进行分级;根据不同的危险性级别,采取相应的应急防治措施;突出变形迹象对黄土崩塌的贡献,实现优先判别。研究表明:①黄土崩塌的变形破坏主要集中于4种岩土体结构组合、5个典型破坏接触面;②黄土崩塌危险性可划分为高、中、较低、低4个级别,对应应急避让、临灾监测、应急调查、勘查、治理等防治措施;③变形迹象评分结果达到判定级别“危险性高”时,可直接介入地质灾害预警预报措施。

In view of the concealment and abruptness of loess collapse,the early identification and prediction of loess collapse were investigated,and corresponding emergency prevention measures were proposed.The characteristic factors for early identification of loess collapse were first of all extracted based upon summary on the inducing factors of loess instability via classifying the failure modes of loess in Shanxi Province.Subsequently,the risk of loess collapse was analyzed semi-quantitatively by using comprehensive index method,and on the basis of the quantitative result,the criterion for rating the risk of loess collapse was proposed,and emergency prevention measures were presented corresponding to different risk levels.Research result showed that:(1)the deformation and destruction of loess collapse mainly happened in four kinds of rock and soil structure combination and five typical damage contact surfaces;(2)the risk of loess collapse can be divided into four levels,namely,high level,medium level,relatively low level,and low level,each should be followed with corresponding emergency response measures such as emergency avoidance,disaster monitoring,emergency investigation,exploration and treatment;(3)early warning and forecasting measures for geological hazards can be directly taken when the deformation indication score reaches“high risk”of the judgment level.