摘要
在调查重庆南川甑子岩-二垭岩段88处近水平层状大型危岩形成的地质环境背景基础上,分析了危岩发育特征、影响因素以及稳定情况,查明了危岩体结构与失稳模式的相关性,分坠落式、倾倒式、滑移式三种失稳模式进行稳定性分析。研究表明该危岩带是金佛山向斜核部经长期地质演化形成的近水平层状厚层灰岩陡崖,受降雨、岩溶、底部软弱层及大面积地下采空影响形成的,属特大型危岩带。其中,危岩带内的塔状岩体是西南缓倾层状灰岩山区典型的危岩类型,破坏机理复杂,易形成崩塌碎屑流。通过稳定性计算并综合考虑现场调查结果,认为带内危岩体在天然工况下整体稳定性较高,但暴雨工况和地震工况下稳定性骤降,尤其是危岩分布集中的甑子岩、和尚帽以及二垭岩区段,具有较高的成灾可能性,亟需开展监测预警工作。
Zengziyan - Eryayan including 88 large flat bedded unstable rocks is an outsize unstable rocks belt.Based on the detailed geological survey about this belt,the development characteristic,influence factors and stability were analyzed. The correlation between the structure of unstable rocks and failure mode was found out. There are three types of failure mode,falling,toppling and slippage. Researches show that the unstable rocks belt was formed from flat-thick stratum limestone cliff affected by the geological evolution,precipitation,karst,weak layers and large areas gob. Among this belt, the tower-type rocks are representative in southwestern mountainous area with flat-thick limestone stratum. Their failure mechanism is complicated,and easy to forming collapse and debris flow. According the calculation of stability and the result of field survey,we believe the overall stability of unstable rock belt under natural conditions was relatively high. While in the rainy conditions or seismic conditions,the stability plunged. Especially zones of Zengziyan,Heshangmao and Eryayan,unstable rocks there are apt to collapse. As a result,monitoring and early warning should be carried out as soon as possible.
出处
《中国地质灾害与防治学报》
CSCD
2015年第1期16-22,共7页
The Chinese Journal of Geological Hazard and Control
基金
国家自然科学基金(41302246)
中国地质调查局地质调查工作项目(1212012220140
121201140079101)
十二五国家科技支撑课题(2012BAK10B01)
关键词
危岩带
缓倾厚层
陡崖
崩塌
稳定性
unstable rocks belt
flat-thick stratum
cliff
collapse
stability
