The Study Of Dafanglijia Landslide Stability And Stress Of Double Row Anti-slide Pile

Dafang-Lijia landslide, which is located in Zhuanglang County of Gansu Province, is a mixed deep-level giant thrust load caused debris landslide, the road to be constructed will pass in the front of the landslide, for ensuring traffic safety, it is necessary to study the influence of Dafang-Lijia landslide.This paper regards Dafang-Lijia landslide as study subject, the basic engineering geological characteristics has been identified by methods of field investigation, engineering drilling and laboratory test and analysis. The paper analyzes its cause of the formation, and finishes the work of stability calculation and treatment design. In the process of landslide control design, the double row anti slide piles have been adopted as a two stage retaining due to the special profiles of the landslide and the large residual sliding force.Determining the value of landslide thrust bore by each row of pile is an important task for designing double row anti slide piles, but the pile bearing thrust calculation is controversial at present. Based on the analysis of the previous for the pile bearing thrust calculation method and the previous research, the paper analyzes the force on each block under the action of double row anti slide piles, proposes that the thrust on bottom row anti slide pile generated by the self weight of soil between two piles, reaction force of soil resistance in front of the upper row piles, reaction force of deformation resistance of upper row piles.The deformation resistance calculation on each pile is inconclusive, the paper derive the calculation of deformation resistance with cantilever beam method according to Winkler model, analyzes the influencing factors of deformation resistance, it is found that the deformation resistance is affected by a landslide thrust, slippery slope thrust position, pile calculating width, sliding body and foundation proportional coefficient of sliding bed.Finally, according to the stress analysis and the transfer coefficient method, the landslide thrust calculation formula of each row piles is derived in this paper. And the treatment design of Dafang-Lijia landslide was given according to calculation formula of landslide thrust force.