考虑桩间水平土拱效应的边坡桩间墙组合结构受力计算方法

Load calculation method for retaining wall between piles considering horizontal soil arching effects

抗滑桩桩间水平土拱效应目前主要用于确定桩间距,在桩间组合结构的受力计算中应用较少。如桩间墙,设计者多按设桩处的剩余下滑力计算桩上荷载,采取将土压力或剩余下滑力折减,或将土体参数提高的方法估算墙上荷载,未充分考虑桩间水平土拱的影响。首先理论分析了桩间水平土拱对桩间墙组合结构受力的影响,认为在桩间水平土拱影响下,抗滑桩的受力应为土拱拱顶处的剩余下滑力;挡土墙的受力应为拱前土体产生的主动土压力或剩余下滑力。在此基础上,推导了考虑土拱效应时该组合结构中抗滑桩和挡土墙的受力计算方法。以某实际铁路堑坡为例,通过计算考虑桩间水平土拱效应的桩间墙受力分配,说明了桩间水平土拱效应对桩间墙组合结构受力的影响。

The horizontal soil arching effects between stabilizing piles are mainly used for determining the spacing of the piles, while they are rarely employed to calculate the load on the retaining wall between piles. In the current calculation methods, the load applying on the retaining wall is usually roughly evaluated by reducing the driving force acting on its nearby piles or increasing the value of shearing strength indices. These methods do not sufficiently consider the horizontal soil arching effects. To improve the calculation, the effects of horizontal soil arching on the loads acting on the retaining wall between piles are theoretically analyzed. The results show that the driving force at the apex of the soil arch should be taken as the load on the piles, and the load on the retaining wall is the active earth pressure induced by the soil in front of the arch. Based on the results, a new method for calculating the load is deduced by considering the horizontal soil arching effects. A railway cut slope stabilized by the retaining wall between piles is taken as an example to show the effects of the soil arching by calculating the load on the structures using the proposed method.