Three-dimensional numerical analysis of the Changgeluo landslide-tunnel engineering disaster on Shangri-Lato Lijiang highway

Abstract

Accurately evaluating the interaction and stability of the landslide tunnel and formulating a reasonable disaster prevention plan are of great significance for ensuring the smooth completion of the Shangri-La to Lijiang highway. This paper takes the typical landslide-tunnel disaster site of Shangri-La to Lijiang highway-Changgeluo landslideas an example, uses on-site engineering geological surveys, drilling, and other methods to determine the cause mechanism and deformation characteristics of the landslide, utilizes numerical simulation to study the spatial stress-strain characteristics and stability state of the Changgeluo landslide under natural, rainfall and tunnel excavation conditions, studies the interaction between the landslide and the tunnel, and proposes corresponding disaster prevention and control plans. The results show that the Changgeluo landslide is a giant rock sliding landslide, which is in an unstable state under natural conditions. The tunnel excavation has limited influence on the overall stability of the landslide, but it will cause local deformation of the landslide.Affected by the deformation of the landslide body, the tunnel part of the landslide body will produce tensile-shear deformation failure. Rainfall seriously deteriorates the stability of the landslide, causing the landslide to lose instability and further causing the tunnel to fail and be destroyed. The original route selection plan faces huge risks, and the optimal prevention plan is to move the route eastward to avoid the tunnel so that the tunnel passes under the sliding surface. The research methods and results can provide a useful reference for similar Shangri-La to Lijiang highway disaster sites.

Keywords

• shangri-la to lijiang highway
• landslide and tunnel
• three-dimensional numerical simulation
• stability
• landslide prevention
• engineering disaster