粉土地区楔形群桩的水平承载特性分析

The horizontal bearing characteristics of wedge-shaped pile group in silt area

近年来异形桩逐渐引起国内外学者的广泛关注,但鲜有针对楔形群桩受水平力的研究。本文以开封周边的粉土为研究对象,进行楔形单桩的模型试验和数值模拟,在验证单桩模型的可行性后建立楔形群桩数值模型,并对楔形群桩水平承载特性进行数值分析,以桩体弹性模量和楔形角为变量,研究不同荷载下桩身水平位移、桩身弯矩等的变化特征。结果表明:在水平荷载作用下,群桩的水平位移整体变化趋势一致,排桩之间的弯矩差别较大;桩体弹性模量的变化对群桩水平位移的影响并不明显,群桩位移效应系数约为25%~30%;在小角度范围内,群桩水平承载力随楔形角的增加而逐渐增大。本文研究成果对楔形群桩水平承载特性的认识具有重要意义。

In recent years,special-shaped piles have gradually attracted extensive attention of scholars at home and abroad,but there are few studies on the horizontal force of wedge piles.This paper takes the silt around Kaifeng as the research object,conducts the model test and the numerical simulation of the wedge single pile,after verifying the feasibility of the single pile model,the wedge group pile numerical model is established.The horizontal bearing characteristics of wedge-shaped pile group were numerically analyzed,and the elastic modulus and wedge angle of the pile were used as variables to study the variation characteristics of the horizontal displacement and the bending moment of the pile under different loads.The results show that under the action of horizontal load,the overall change trend of the horizontal displacement of the pile group is the same,the bending moment between row piles is quite different.The change of the pile elastic modulus has no obvious influence on the horizontal displacement of the pile group and the displacement effect coefficient of pile group is about 25%~30%.In the small angle range,the horizontal bearing capacity of pile group increases with the enlargement of wedge angle.The results are of great significance to the understanding of the horizontal bearing characteristics of wedge-shaped pile group.