透明土中连续球体型锚杆拔出机理研究  

Pull-out mechanism of continuous ball shape anchors in transparent soil

作　　者：夏元友[1] 陈晨[1] NI Qing 

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]School of Engineering,University of Warwick

出　　处：《岩土工程学报》2017年第5期804-812,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金面上项目(51374163)

摘　　要：采用透明土材料和粒子图像测速法(PIV)技术,通过物理模型试验研究锚杆拔出机理。在模型试验中采用A、B两种不同尺寸的连续球体锚杆锚固段,试验获得各锚杆锚固段上移对周围土体的扰动规律、锚杆位移与锚固力变化曲线以及拔出破坏时破裂面的位置及形状。通过分析连续球体锚杆锚固段的极限承载力和锚固段破坏机理,推导出连续球体锚杆抗拔力的计算公式。试验结果分析表明:本文试验条件下,锚杆拔出时竖向位移最大影响范围与连续球体的半径和间距有直接关系;A、B型连续球体锚杆的极限承载力,分别比普通圆柱型锚杆提高52%和117%;连续球体锚杆锚固段在上拔破坏过程中抗拔力的贡献可分为3个部分:直杆与土层的黏结、肩部端承力和黏土黏聚力。A physical modelling system is developed to study the pull-out mechanism of embedded soil anchors using transparent soil and particle image velocimetry （PIV）. In the system, two different continuous ball shape anchors are set in the experiment to observe displacement impact areas, soil displacement, load-displacement curve and shape and location of pull-out failure interface. After analyzing the ultimate bearing capacity and the failure mechanism of the soil anchors, a suggested method is given. From the results, based on the circumstances of this model, the maximum vertical displacement impact areas have direct relationship with the radius of the ball and the distance between the balls during pull-out of the soil anchors. The continuous ball shape soil anchors （type A and B） can effectively provide 52% and 117% more force than the normal cylinder anchors. The pull-out force of the continuous ball shape soil anchors can be divided into three different parts： adhesion on shaft, end bearing in clay and cohesive through clay.

关 键 词：土层锚杆 模型试验 透明土 土体位移 锚固机理 

分 类 号：TU433[建筑科学—岩土工程]