The Research Of Deep Cutting Stability In 74 South Provincial Highway Engineering Of Zhejiang Province

Withing Engineering construction of the traffic,such as highway and railway,in the mountain area and hills area etc,a large number of deep buried and high excavated engineerings will be inevitably encountered.So more and more artificial slope,especially rock mass slope will be formed.The slope stability is an important issue affecting the engineering construction and post-operational safty.In general,slope stability involves two stages,that is,the one during excavation and the long-term one after excavation.Therefore,it is of great significance to analysis the slope stability after excavation and study the process of excavation and support.Objects of study are the high slope projects located in 74 provincial highway south extension project K68+580?K69+080 and K70+960?K71+500 sections.According to geological survey and mapping,laboratory testand analysis,this paper studies their stability with systematic approach from the perspectives of geological conditions and controlled structural plane.On this basis,Reinforcement Measures aimed at slope are proposed.The main work is as follows:(1)According to topography and stratigraphy of high excavated slope,weathering degree of rock mass and development of structural plane,Unfavorable combination of structural plane which control the stability of rockmass slope and potential instability mode are analysised;(2)With the stereographic projection,the Qualitative analysis and evaluation of typical wedge is carried out.The finite element analys is verifies;(3)Mohr-Coulomb yielding criterionis is used in order to analyse high excavated slope on finite element strength reduction method;(4)According to the conclusion of the seanalysis above,the supporting treatment scheme about K68+580?K69+080 and K70+960?K71+500 sections is appositely proposed and provide guidance for the similar projects.According to the conclusion of the seanalysis above,the main research achievements are as follows:(1)Unfavorable combination of structural plane which control the stability of rockmass slope is structural plane of rock mass.The Qualitative analysis and evaluation of typical wedge is usful in the high slope projects;(2)Elastic modulus and poisson ratio have little effect on safety coefficient of high excavated slope.Dilation angle has large effect and it must be considered in calculation.Safety coefficient of hight excavated slope decreases significantly with the height of excavation slope increasing.The correlation between safety and hight excavated slope is hyperbola.Safety coefficient of hight excavated slope decreases significantly with slope angle of excavation slope increasing.(3)According to the case of 74 provincial highway south extension project in Zhejiang,the supporting treatment scheme about K68+580?K69+080 and K70+960?K71+500 sections is appositely proposed and provide guidance for the similar projects.