砂土中楔形桩竖向承载特性试验研究  

Experiments on Vertical Bearing Performance of a Tapered Pile in Sandy Soil

作　　者：杨晓峰 李乐乐 姚兆明[1] 于锋 YANG Xiaofeng;LI Lele;YAO Zhaoming;YU Feng(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan Anhui,232001,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《安徽理工大学学报（自然科学版）》2023年第3期82-89,共8页Journal of Anhui University of Science and Technology:Natural Science

基　　金：安徽省自然科学基金资助项目(1908085QE214);安徽理工大学研究生创新基金(2022CX2040);安徽理工大学高层次人才引进基金(12367)。

摘　　要：相同竖向承载力条件下,楔形桩比等直径桩更能节省材料,具有良好的工程应用前景,但其桩身截面尺寸渐变、桩侧表面倾斜、竖向承载机理比常规等直径桩更加复杂。为了揭示砂土密实度和楔角对楔形桩竖向承载特性的影响,在松砂、中密砂和密砂地基中开展系列模型试验,分析荷载-沉降曲线、桩侧平均阻力-沉降曲线、轴力-深度曲线、桩侧阻力和端阻随荷载变化曲线等试验结果。结果表明,桩顶直径和入土桩长不变时,楔形桩竖向承载力随楔角的增大而降低,但单位侧表面积下的桩侧阻力却随楔角的增大而增加,约为等直径桩的2倍;楔角约为1.5°时,楔形桩单位体积承载力最大;随着桩顶竖向荷载增大,楔形桩对桩周土挤压效果增强,使桩土界面法向压力和桩侧摩擦力增大,是一种桩侧阻力增加型的优良桩型。试验结果对竖向受荷楔形桩的工程实践具有一定的借鉴意义。Compared with the traditional equal-diameter piles,it costs less pile construction materials for tapered piles under the same vertical bearing capacity conditions,and there is a good engineering application prospect for tapered piles.However,due to the gradual change in the cross-sectional size of the tapered pile shaft and the inclination of the pile side surface,the vertical bearing mechanism of the tapered pile is more complex than that of the conventional equal-diameter pile.In order to reveal the influence of sand density and tapering angle on bearing performance of tapered piles subjected to vertical loads on pile top,series of model tests were carried out in loose sand,medium dense sand and dense sand,and the load-settlement curves,average vertical resistance unit side surface area of pile shaft-settlement curves,axial force-depth curves,side resistance and end resistance curves varying with loads were analyzed.The results showed that when the diameter of the pile top and the length of the pile embedded in the soil were constant,the vertical bearing capacity of the tapered pile decreased with the increase of the tapering angle,but the pile side resistance per unit surface area increased with the increase of the tapering angle,about twice as large as that of the equal-diameter pile.The bearing capacity per unit volume of the pile was the largest when the tapering angle was about 1.5°.As the vertical load on the top of the pile increases,the compression effect of the tapered pile on the soil around the pile was enhanced,making an increase in normal pressure and friction at the pile soil interface,so that it was an excellent pile type.The test results have certain guiding significance for the engineering practice of vertically loaded tapered pile foundations.

关 键 词：楔形桩 楔角 竖向荷载 承载特性 砂土 

分 类 号：TU473[建筑科学—结构工程]