Stability Analysis And Research Of Double-row Anti-slide Piles

China is a mountainous country, affected by various factors, geological disasters occur frequently, the landslides occupy a large proportion of various geological disasters.Using anti slide pile reinforcement is an effective measure in landslide treatment. For the large landslide,the former single row anti slide piles can not meet the relevant requirements. Double row and multi row anti slide piles appeared. So far, there are still many problems about the theoretical research of double row anti slide piles.Therefore, Using the finite element software and combining a specific engineering example, the safety and stability of double anti slide piles are studied in this paper.This paper introduces the calculation of slope stability analysis and various method of crustal stress balance. Establishing model is to discuss the criteria of slope instability and determine safety coefficient when the method of combining plastic zone coalescence with displacement mutation is used to estimate the slope failure. Based on the finite element strength reduction method and Mohr Kulun strength theory, analyzed the influencing facors of slope safety, which include double row spacing, pile spacing, pile position, pile length and layout method. At the same time, the bending moment, shear force distribution and displacement deformation of the piles are analyzed, and the reasonable arrangement of double row anti slide piles is put forward. Finally, a finite element analysis of a landslide in Mianxian is carried out,and a reasonable treatment scheme is established. The main results of this paper are as follows:(1) In the case of a fixed row spacing, the safety coefficient of the slope decreases with the increase of pile spacing, When the pile spacing increases from 2 times to 4 times of pile diameter, the change is obvious. However, when the pile spacing increases from 6 times to 8 times, the change is slow.(2) On the premise that the spacing of piles is the same, the safety coefficient of the slope is parabola distribution with the change of row spacing, and the safety coefficient is the maximum when the row spacing is 4 times of the pile diameter.(3) When the front row and the length of pile are fixed, the increase of the row spacing and the reduction of the pile embedment depth will change the distribution of the shear and bending moment of the back row piles. The distribution form and maximum value of the moment and shear of the front row piles are not influenced by the row spacing and the change of the pile spacing. Rock socketed piles can effectively reduce the displacement and change rate of anti slide piles. The displacement and deformation of the two rows of piles are consistent.(4) When the front row of piles are located in the middle and lower part of the slope, the safety factor of the double row piles is the biggest.When the anchorage depth is 1/2 of the pile length, the safety coefficient of the reinforcement slope is the biggest.(5) Parallel arrangement and quincunx arrangement have little influence on the safety coefficient of the slope, the bending moment of the pile body, the distribution of the shear force and the displacement of the pile.