Calculation Of The Anti-slide Piles Spacing Considering Stress Decreasing Characteristics Of Loess Soil-arch

Loess is an elastic-plastic body, there exit plastic deformation and stress deflection in soilwhen suffering landslide thrust and effect of anti-slide piles, then the stress characteristic thatthe main stress decreasing in the direction of landslide thrust force forms. Because the soilarching effect plays an important role in the function of anti-slide piles, it is of greatsignificance to study the soil arching effect between anti-slide piles in landslide governance.This paper studies the calculation of anti-slide piles spacing considering stress decreasing, themainly contributions of this research include the following aspects:（1）Through the analysis on interaction of piles and soil, mechanism, arcuation andclassification of soil arching are summarized. At the same time, combining previous researchresults, force situation, stress distribution and failure characteristics of loess soil arching areanalyzed in this paper. Especially, the stress characteristic that the main stress decreasing inthe direction of landslide thrust force is more in line with stress distribution of loess.（2）Based on characteristics of stress decreasing, reasonable arch axis, staticequilibrium conditions, relationship between internal force and stress, and Mohr-coulombstrength criterion, anti-slide pile spacing calculation formula was deduced from the angle offriction soil arching and direct soil arching. Then, the effect of landslide thrust, soil strengthparameters and anti-slide piles spacing were analyzed. The results show that: whenconsidering the friction soil arching, the pile spacing is larger; when considering the directsoil arching, pile spacing is more reasonable and safer, which should be given priority whendetermining anti-slide pile spacing. Meanwhile, the net spacing between piles has a direct proportion with soil strength parameters, and has an inverse proportion with landslide thrustforce.（3）This paper takes Hexi coal mine, Liulin, Shanxi as an example, using the formula ofanti-slide pile spacing this paper deduced, and in the premise of full analysis of the landslidegeological conditions and the mechanical properties of loess pile, we get the reasonable sizeof anti-slide pile spacing. Four years of engineering practices prove the rationality of thecalculation in this paper, and compared with the research results in some literatures, this paperanalyzes the applicability of the theoretical results.