Study On Key Technology For Construction Of The Diaphram Wall In Granite Residual Soil Stratum

With the accelerating pace of urban development,traffic congestion and land resource problems become increasingly prominent,for which the major cities have to increase the development of underground space,and underground continuous wall as a retaining structure,with its unique advantages and the characteristics of deep foundation pit in the underground space in the construction of the popular.However,in the southern coastal provinces of China,granite residual soil distribution area is very extensive,which makes the development and construction of underground space encountered granite residual soil greatly increased the probability,or even inevitable.At the same time,the engineering properties of granite residual soil not only bring difficulties and risks to the construction of the ground-connected wall in this area,but also cause many engineering quality accidents.Obviously,in the form of high-frequency use of the wall to support the development of underground space in the form of the situation,the characteristics of granite residual soil and the formation of the wall with construction technology research,has a good engineering practice value and social and economic benefits,the main works are as follows:(1)The physical and mechanical properties of granite residual soil are analyzed and summarized.The granite residual soil is easy to soften and disintegrate in terms of origin,composition and grain size.It is characterized by strong structure and fissure.Engineering adverse effects.At the same time,the disintegration test of granite residual undisturbed soil was carried out,and the regularity of the influence of heavy mud and volume change on the disintegration was obtained.(2)The method of limit equilibrium and numerical simulation are used to solve the critical slurry severity in the trenching of the earth-connected wall,and the feasibility of the numerical simulation method is verified by comparing the solution results.(3)The wall deformation and surface subsidence caused by the construction of the granite residual soil layer are analyzed,and the factors such as mud surface height,groundwater level,ground load,soil reinforcement and mud weight are discussed.Influence of Horizontal Displacement of Channel Wall.(4)The control measures of the wall deformation of the underground continuous wall in granite residual soil layer are studied.The deformation control of the wall is analyzed from the aspects of soil reinforcement,precipitation,process improvement and excavation protection.Suggestions on Construction.