新疆维吾尔自治区乌恰县康苏红层崩塌运动学特征研究  

KINEMATICAL CHARACTERISTICS OF COLLAPSE IN RED BEDS IN KANGSU TOWN,WUQIA COUNTY,XINJIANG

作　　者：杨龙伟[1,2] 魏云杰 彭令[2] 王文沛[2] 朱赛楠[2] 王俊豪 YANG Longwei;WEI Yunjie;PENG Ling;WANG Wenpei;ZHU Sainan;WANG Junhao(College of Geological Engineering and Geomatics,Chang an University,Xi'an 710054,China;China Institute of Geological Environment Monitoring,Beijing 100081,China)

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]中国地质环境监测院,北京100081

出　　处：《工程地质学报》2020年第3期520-529,共10页Journal of Engineering Geology

基　　金：国家重点研发计划(资助号:2018YFC1505404);中国地质调查局地质调查项目(资助号:DD20190647,DD20179609,DD20190637);国家自然科学青年基金项目(资助号:41602362).

摘　　要：以新疆维吾尔自治区乌恰县康苏红层崩塌为例,基于DAN-W运动学模型进行了红层崩塌碎屑流空间预测评价,同时根据无人机航拍图和野外地质现场调查,结合崩塌研究区的工程地质要素,分析该崩塌的形成特征和失稳模式。结果表明:该崩塌为拉裂式崩塌,主要受危岩体岩性组合和坡体结构面组合控制,其孕灾模式为差异风化阶段→岩体结构变形破坏阶段→悬挑危岩阶段→崩塌失稳落下阶段,具有典型的碎屑流运动特征。同时利用动力学模型软件DAN-W对该崩塌碎屑流的运动过程进行计算,得到崩塌碎屑流的运动时长约为50 s,堆积体平均厚度达到2 m,最大速度为11.5 m·s^-1,冲击最远距离达到315 m,与实际情况相符。表明DAN-W模型可以用来分析红层崩塌碎屑流的动力学灾害效应,为红层地区类似的潜在崩塌碎屑流灾害的形成特征和运动效应分析提供借鉴。This paper examines the kinematical characteristics of the collapse-debris flow in red beds. It presents an evaluation method about spatial prediction of the collapse-debris flow in red beds. It takes the Kangsu collapse in red beds as an example. It uses the aerial photography of the unmanned aerial vehicle and the field geological survey, and combines them with the engineering geological elements of the collapse study area. It analyses the formation mechanism and the failure types of the collapse. The research shows that the collapse is the crack-type collapse. The collapse is mainly controlled by the combination of lithology of dangerous rock mass and structural plane of slope body. The hazard mode is given as follows: Firstly, rocks have the different weathering resistance under the conditions of wind and other external forces. Secondly, under the action of freezing and thawing, the rock mass structure is destroyed. Thirdly, when the unloading fracture zone is expanded further, the bottom of dangerous rock mass can be in an empty state. At last, under the action of gravity, the collapse occurs unsteadily and impacts to the slope surface to form debris flow. And the DAN-W model is used to simulate the motion process of the collapse-debris flow. The calculation results show that the duration of the collapse-debris flow movement is about 50 s, the average thickness about accumulation body reaches 2 m and the maximum speed is 11.5m·s ^-1 . And the longest impact distance is 315 m. The calculated results are in good agreement with the actual situation. It proves that DAN-W model can be used to analyze the dynamic hazard effects of the collapse-debris flow in red beds area. The paper provides a reference for the analysis of the formation characteristics and movement effects of similar potential collapse-debris flow hazards in red beds.

关 键 词：红层 崩塌-碎屑流 失稳模式 运动学 数值模拟 

分 类 号：P642.23[天文地球—工程地质学]