都江堰市龙池镇李泉太沟泥石流灾害研究

Characteristics of Debris Flow Hazard of the Liquantai Gully in Longchi Town of Dujiangyan County,Sichuan Province

"5·12"汶川地震后,位于地震灾区的四川都江堰龙池镇暴发了群发性泥石流,给灾后重建工作带来很大的难度。选择其中的李泉太沟泥石流作为研究对象,通过野外调查、室内分析和泥石流静动力学参数计算,如屈服应力、流量、容重、冲出总量等计算,认为地震产生的大量崩滑体为泥石流提供了直接物源,在暴雨条件下非常容易导致泥石流的产生;另外沟道陡峭、流量大、暴发隐蔽是李泉太泥石流的主要特征;李泉太泥石流的容重较大,屈服应力较大,不仅能够摧毁公路等基础设施,还能够造成堵江等次生灾害。根据研究结果,建议重点敏感地区采取相应的工程措施,并且充分利用降雨阈值,对李泉太泥石流进行监测预警。

After the May 12th Wenchuan Earthquake ,the rainstorm caused the group debris flow hazards in Longchi Town of Dujiangyan County ,Sichuan Province ,which brought a lot of difficulty to the post-disaster reconstruction work .The Liquantai gully debris flow located in Longchi town was selected in the study ,and its characteristics were determined through the field in-vestigation ,laboratory analysis ,and calculation of static and dynamic parameters of debris flow such as the stress yield ,flow rate ,bulk density ,and total outflow .The results showed that （1） the Wenchuan Earthquake generated lots of landslides ,which were the supply for debris flow ,especially under rainstorm conditions ;（2） the Liquantai gully debris flow had the features such as steep channel ,large flow ,and concealed occurrence ;and （3） the bulk density and stress yield of the Liquantai gully debris flow were large ,which can not only cause damages to the infrastructure but also generate secondary disaster such as blocking river .The results indicated that the engineering measures need to be performed at the elevation range of 1400 to 1600 m ,and the threshold value of precipitation was used for the monitoring and early-warning of the Liquantai gully debris flow .