Shuiwen dizhi gongcheng dizhi (Sep 2021)
Characteristics of Kazila mountain landslide and its mitigation measures on the Sichuan-Tibet Railway
Abstract
In order to examine the characteristics of geological hazards in the entrance planning area of the Kazila mountain tunnel on the Sichuan-Tibet Railway, and to evaluate the geological hazard risks that may be endangered during the planning, construction and operation of the Sichuan-Tibet Railway, the “air-space-ground” integrated technologies such as high-precision remote sensing, airborne Lidar and engineering geological survey are used in the study area, and two landslides and a potential unstable slope of Eluodui in the entrance area of the Kazila mountain tunnel are identified. The Eluodui unstable slope is located in the middle of the two landslides, the volume of 1# landslide and 2# landslide are about 32.48×106 m3 and 10.15×106 m3, respectively, and both of the landslides are large-scale rock ones that have occurred. The volume of the Eluodui unstable slope is about 35.80×104 m3, the lower part is strongly weathered rock mass, and the upper part is gravelly soil structure. It is a medium-sized composite structure slope. The evaluation results show that the route selection at the entrance of the Kazila mountain tunnel of the Sichuan-Tibet Railway passes through the middle ridge of two landslide masses, and the two landslides do not pose a geological safety risk to the railway route selection, but there are potential geological safety hazards on the unstable slope of Eluodui at the entrance of the tunnel, and the slided mass is stable under the natural conditions. The unstable slope of Eluodui is stable under the natural and seismic conditions, and is unstable under the rainstorm conditions. In order to avoid potential geological hazards caused by engineering construction disturbance, it is suggested to shift the route selection entrance of the Kazila mountain tunnel to the southeast, and prevent and control the potential landslide risk from the source through reasonable design of slope excavation and real-time monitoring during construction and engineering control during operation. The study may provide a scientific geological basis for scientific route selection of the Sichuan-Tibet Railway.
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