Study On The Characteristics Of Highway Geological Hazards And The Countermeasures In The Intertidal Zone Of Lingling, Western

In terms of complex landforms and varied topography in western Yunnan, steep mountains, deep valleys, and basin-range caused the limited traffic conditions since ancient times. In recent years, the significant increase in highway geologic hazard had restricted the efficiency and security oftransportation seriously. As a result, it is essential to pay much attention about highway and geological conditions in the west of Yunnan.According to "the reconstruction project of G320 national highway inBaoshan (from Baoshan to Pupiao)", this study regards the basin-range Interlacing zone in the west of Yunnan Province as research object.Located in thesoutheast edge of contact zone between the Eurasian Plate and the India Plate, Basin-range Interlacing Zone in the west of Yunnan Province show the interlacingterrain phenomenon between the high mountains and basins, which is higher at the north. GaoligongMountain, Biluo Snow Mountain, Nu Mountain and Yunling Mountain extend from north to south. Nujiang River, Lancangjiang River and Jinshajiang River are parallel flowing hundreds between these high mountains, which is cut deeply. At this area, there is a special physicalgeographicalphenomenon that a mountain is between two rivers or a mountain is between two rivers, so that is Basin-range Interlacing. The paper mainly talks Basin-range Interlacing Zone in the west of Yunnan Province thought the study of Baoshan Basin and Pupiao Basin.Based on the characteristics of local landform, research area is divided into four geomorphic units to basin area, foothill area, slope area and mountaintop area.After the completely study of the local geography, structure, Formation lithology, condition of engineering geology, condition of hydrogeology, neotectonics and human project activity at the research area, the paper drew conclusion of the distribution and development of geological disasters at the different geomorphic units of the study area. (1) The basin area is mainly composed of gravel, clay, sand crumbs mixture, forming the relativelyold alluvial fan. The characteristics are loose soil structure, poor mechanical property.The type of disaster is the settlement of the foundation. It may lead less geologic hazard which account for approximate 3.8% of the total numbers of disasters in the research area. (2) The foothills belt is mainly composed of alluvial fan and slope sediments composition.The types of geologic hazard are small-scale soil landslide and unstable slope occupied 17.3% of the total; (3) It is obvious that geological disasterin the research area are distributed regionally and mainly located in the slope zone. Due to complexgeological environment, the intensivefault distribution, joint fissure development, rock weathering intensity,human activities are limited strongly.Moreover, rainfall, river erosion, earthquakes and other natural factors may lead a large number of geological disasters. It includes varioustypes of geological hazards which are landslide, collapse, unstable slope and debris flows, contributed approximately 75% of the total disasters in the research area. (4) The Peak District rock weathering, vertical karst geological disaster mainly lead the rock collapse, accounting for 3.8% of the total number of samples.According to the characteristics of highway engineering, the paper also analyses the geological hazard effect.It may intensify the number of the geographical disasters such as the landslide, collapse, debris flow, unstable slope and foundation settlement, to name but a few.Particularly, unstable slope with the engineering disturbances seem to be easier to lead collapse or landslide. In different geomorphic units, landslide, collapse, debrismay be induced bydigging deep to fill high, cutting and filling, the new bridge and tunnel construction. Furthermore, slope is regarded as the key ingredient of causes of geological disasters. This study also summarized the type of geological disaster types happened on highway zone based on different geomorphic units.At last, due to geological hazard development situation and distribution characteristics, control and mitigation are proposed for geological hazard at different geomorphic units of the study area.