Experimental Study Of Cement Mixing Anchor Pipes Bracing Structure Of Foundation Pit

There are many large and more than 5 meters deep soft soil foundation pits in the soft area of Hangzhou and Shaoxing which cannot be supported by costly and complex approaches, such as row of piles with bracing system or mid-island and the traditional method of soil nailing is defected by difficult pore-forming and weak uplift resistance. As a new type of soil sailing, Cement mixing anchor pipe is an efficient approach to support soft soil foundation pit of 6 or 8 meters deep combined with the application of soil stabilization in passive area。The application of Cement mixing anchor pipe and soil stabilization in passive area of soft soil foundation pit goes as follows:cement columns are first installed as curtain walls and in foundation pits of passive area cement columns are installed to reinforce soil. During excavation, cement mixing anchor pipes are installed with layered excavation and edge grouting edge drilling method while concrete is sprayed to reinforce the surface.Based upon the previous study of Composite soil nailing support,Passive area soil consolidation and Cement mixing anchor pipes as well as the features of construction in practice, study the principles, calculation, design and construction about the application of cement mixing anchor pipe and soil stabilization in passive area of soft soil foundation pits with researches of traditional theories, on-site experiments and finite-element methods.Now are the main studies:by experiments, probe in the working mechanism and loading features of cement mixing anchor pipes, conclude the relevant application conditions and methods, illustrate its difference from traditional soil nailing and anchor pipes; by finite-element methods, indicate the efficiency in soil stabilization of passive area and propose suggestions on stabilization.