Research On Classification And Typical Disaster Mechanism Of Cut Slopes In Highway Projects Based On Their Dynamic Deformation And Failure Characteristics During The 5.12 Wenchuan Earthquake

Under the dynamic action of the 5.12 earthquake, the deformations and failures of cut slopes in highway projects have many styles during the Wenchuan earthquake, considere the classifications under the dynamic action are important theoretical and practical significance.Based on field survey of typical damage the cut slopes of the earthquake during the 5.12 wen chuan earthquake, through analysis different geological conditions, structure typical, geometric conditions and position relationship of the slope trend and causative fault and deformations and failures typical, create a dynamic response characteristics system of cut slope in highway projects during the aerthquake action, and analysis typical damage mechanism of cut slope in highway projects.The mostly content and study result in this thesis can sum as 3 parts blow.1) According to the spot investigation material, get conclusion that the deformations characteristics of cut slopes in highway projects during the Wenchuan earthquake:The deformations characteristic of the debris slope are surface slipping collapse, shallow layer collapse, partial slide, whole slide and posterior border partial slide cracking and deformation.The deformations characteristic of bedding rock slope are surface collapse slide, partial slide, posterior border tension cracking, dumping, buckling, upper part consequent landslide or shear layers collapse and shallow layer consequent landslide sliding cracking and deformation.The deformations characteristic of fragmentation rock slope are shallow layer collapse, partial rock along transfixion fracture surface showed zigzag broken type whole slide, shallow layer loosening deformation and surface rock along joint fracture spalling deformation.2) Analysis geological conditions, structure typical, geometric conditions and position relationship of the slope trend and causative fault and deformations and failures typical influence on dynamic response characteristic of the slope.On that basis, the slope can be firstly divided into debris slope and rock slope, the rock slope is subdivided into entier slope, massive slope, layered slope structure, fragmentation slope and loose slope; Second, consider the slope height and slope rate characteristics of the slope, the slope can be divided into high-steep slope, high slow slope and low slope; Final, consider the slope trend and causative fault with different angle, the slope can be divided into three types:trend parallel fault, trend vertical fault and trend skew fault. In this way, based dynamic response characteristics, the cut slopes in highway projects can be divided into 6 types,18 sub-types and 54 small classes.3) Professional numerical analysis software-PLAXIS is used to simulate and analysis deformation and disaster of slope in the earthquake level dynamic continuing action, and the results obtained with the spot investigation result after the Wenchuan earthquake, the analyaed results show that disaster mechanism mainly is slope body posterior border tension crack, slope body medium anterior shear slipping damage for the cut debris slope; that disaster mechanism mainly is along some level shear slipping damage, medium anterior pulling damage for the layered rock cut slope structure; that disaster mechanism mainly is superficial zone showed zigzag shear slipping damage for the fragmentation cut rock slope.The results of research on classification and typical damage mechanism of cut slopes in highway projects with earthquake dynamic action characteristics has certain significance for the solution of practical engineering problems.