抗滑桩加固边坡中桩要素设计的三维有限元分析

Three-dimension FEM Analysis of Pile Design Factors on Slopes Reinforced with Anti-slide Piles

抗滑桩加固边坡是工程中常用的方法，其中桩位、桩间距、桩径、桩长等桩要素是抗滑桩设计的重要问题，它直接关系到边坡工程的造价与安全．通过典型的边坡实例，利用考虑桩一土相互作用的有限元折减程序，探讨计算模型尺寸、桩要素对边坡安全系数的影响．分析可知，计算模型尺寸对边坡安全系数影响很小，模型尺寸为O．5s时计算效率最高；边坡安全系数随桩位近似呈二次抛物线分布，抗滑桩布置于边坡中部既能获得最大的安全系数又能充分发挥材料的抗滑作用，为最佳桩位布置点．边坡的安全系数随桩间距的增大而减小，随桩径、桩长增大近似呈线性增加，桩间距增大桩间土拱作用逐渐减弱，最后趋近于无桩状态．桩长设计中，桩的锚固深度宜为桩长的1／3—1，2．

Slope reinforced with piles is commonly method in engineering pile design factors such as pile location, pile spacing, pile diameter, pile length are very important problems in slopes reinforced with anti-slide piles, which affect the engineering cost and safety. Taking a typical slope for example,based on a finite element program,we discusse the model size and pile factors influence on slope safety factor. It is considered that the model size has no effect on slope factor, and the model size has the highest computational efficiency at the 0.5S. The middle of the slope is the best position which can make the largest safety factor of the slope and can make the material give full play to the role of anti-slide. The safety factor of slope decreases with the increase of pile spacing, while approxi- mate linearly increases with the increase of pile length and pile diameter. Soil arching fades out with the increases of pile spacing, finally approaching stakeless state. In the design of pile length, pile anchorage depth of pile length appropriates for 1/3 to 1/2.