Evolvement Process Of The Qinyu Landslide And The Optimization Of Route Plan

The national highway 212 (G212) is a vital channel connecting northwest and southwest area of China and it is greatly influenced by landslide and mud-rock flow. The degree of research to the Qinyu landslide where landslide are developing seriously straightly relate to the selection of the Lanzhou-Hainan highway and the improvement of G212 in the Qinyu landslide section. Landslide is a system and the evolvement of it is a process. It should be started from the dynamic evolvement of the whole system process since the evolvement of landslide is a system evolvement. Based on field investigation and various tests, calculation and analysis, The Qinyu landslide are studied from the viewpoint of geo-system science. The evolvement regulation of the deformation and failure of the Qinyu landslide should be mastered from the whole process and inner functional mechanism, and it can give reasonable comment and forecast of the stability of landslide at present and in the future.The thesis is supported by western traffic science & technology item which is construction technique research of 212(Lanzhou—Chongqing) in the Longnan Area (the southern Gansu province): Mechanism and Design Parameters of Landslides along the Highway. The Qinyu landslide and the distribution and development of every landslide are found out through regional investigation of geological environment in the area on the basis of previous researches. The Qinyu landslide are studied in detailed through scaled engineering mapping, reconnaissance and geophysical testing analyzing in the room including drilling, pitting, grooving, geophysical testing and the like.The great background of the development of landslide in researching area is caused by special structure section, complicated and frail geological surroundings, special geography as well as the intense interlacement and transformation of lithosphere' s inner and outer power. To be exactly, the inner reason for the growth of landslide are mountainous landform, fault zone of Congdi—Qinyu—Tiejia Mount, the development of counter-slope stratum of the Gudaoling Formation of Middle Devonian, Lower Permian and Triassic;outer influencing factors are decline of Mingjiang, earthquake activities and humans' projects.The geophysical process of the Qinyu landslide are analyzed through systematic engineering geological analysis based on formation conditions, trigger factors and current characteristics of the Qinyu landslide. From qualitative perspective, The Qinyu landslide experienced four stages of development and evolvement which were A area formation, B area formation, ancient landslide revival (C area formation) and the landslidedisassembling. These four stages formed the basic landform of the existing the Qinyu landslide. Based on geological investigation and geophysical process analysis using FLAC3D, The Qinyu landslide are simulated by numerical method from qualitative perspective. The result of the stimulation showed that the front of the III2 landslide acted intensively and it was continuously adjusting through the falling and a small scope of landslides, the ITJ2 landslide was being in the slipping period and for the adjustment of the stress it would regularly concentrate around the central slippery belt. With the decline of the intensity of central slippery belt, the revival of is an inevitable. Besides, FLAC3D stimulation and limiting equilibrium calculation method indicates that the opening of express highway, tough would reduce the active intensity of III2 ,would promote the revival of II1.Finally, based on the principle of the selection of express highway, the scheme of the selection of express highway of the Qinyu landslide is optimized and proposed the scheme of right bank tunnel is the best from the engineering and geological perspective.