The Study On Model Experiment And Design Method Of The Anti-sliding Micro-pile With Composite

Abstract:This paper which is supported by transportation science and technology development and innovation project of Hunan province, has completed a large collection of anti-sliding micro-pile research information at home and abroad, and design a large-scale physical model experiment about the anti-sliding micro-pile to study the anti-sliding characteristics in Different composite structure. Then the article proposes a new method of the anti-sliding micro-pile about internal force calculation and design with the experiment results. Finally, the applicable environment of the anti-sliding micro-pile composite structure is discussed. The paper mainly obtains the cognition from the research as follows:(1) The anti-sliding characteristics of single piles and composite piles among double-row anti-slide micro-piles are studied through three model experiments. The monitoring results of slope displacement indicate that miniature piles can provide relatively bigger sliding resistance and decrease deformation rates and it has obvious slope reinforcement effect. There are three failure models of the pile body, namely the disengaging between pile and soil, the tension fracture and the shear fracture failure of piles. The soil pressure acting on the free section of single pile body is "S" shaped distribution. The backward pile bears bigger soil pressure owing to directly contacting loads. Meanwhile the ratio of the maximum of soil pressure between the forward piles and backward piles is (0.53-0.50):1.The ratio of maximum negative bending moments between the backward piles and the forward piles is(0.67-0.80):1.(2)A new method of the anti-sliding micro-pile about internal force calculation combine is proposed considering the anti-sliding characteristics and failure mechanism from model test results. The compare between the calculated results and the experiment results shows that the method is correct and superior. (3)The design principle and content of anti-sliding micro-pile composite structure are summarized and perfected as well as the design steps of anti-sliding micro-pile with composite structure and the design method has used in reinforcement design of K38+560-K38+680slope in Tong-ping highway.(4) Based on the hole creating technology, construction progress and the moment bearing capacity of micro-pile, the applicable environment of the anti-sliding micro-pile with composite structure is discussed.