Formation Mechanism of Passive Soil Archin Front of Embedded Section of Anti-slide Piles

Anti-slide pile is one of the main means of landslide control. The effect of passive soil arch in front of embedded section of piles has an important influence on the bearing capacity of anti-slide pile. In order to further study the geometry of passive soil arching effect in front of piles and the influence rule of pile spacing, the plane strain finite element models were used to simulate and analyze the interaction between anti-slide piles and soil in front of piles with different pile spacing. A method to determine the width of soil arch with obvious physical significance was proposed. The describing equation of soil arch axis was fitted by searching for the σ_xm (maximum σ_x value at the central section of soil between piles) of the soil in front of piles. The influence regularity of pile spacing on the arch height and width of passive soil arch and the soil force in front of piles were studied and discussed. Based on the comparison with the calculation results of single pile, a method for determining the influence range of pile effect of adjacent pile groups is proposed, which further confirms the existence of soil arch in front of pile. The results show that the direction of internal principal stress of soil in front of pile is deflected. The passive soil arch in front of pile is formed gradually, with the increase of pile displacement. The soil arch in front of the pile is formed when the pile spacing is 2.5 ~ 4.5 times of the pile width, and the soil arch effect is most obvious at 3 ~ 4 times. The width and height of soil arch increase linearly with pile spacing in the range of pile spacing of soil arch existing. The passive soil arch in front of pile increases the interaction range between adjacent anti-slide piles. The research results provide a new method for researching the bearing capacity of the soil in front of anti-slide pile, and have certain reference value for the engineering practice.