摘要
为提高黄土地区钻孔灌注桩承载力和沉降计算分析水平,采用大型直剪仪开展了无泥皮及夹不同厚度泥皮条件下黄土与混凝土接触面剪切试验。试验结果表明,无泥皮条件下接触面剪应力随剪切位移的增加而增大,且法向应力较小时,接触面剪应力剪切位移曲线前半段呈双曲线型,后半段为斜直线,法向应力较大时呈双曲线型。夹不同厚度泥皮条件下接触面剪应力剪切位移曲线均呈软化型,且随着泥皮厚度的增加,软化程度逐渐减弱,剪应力逐渐减小。法向应力相同时,不同泥皮条件下接触面剪应力剪切位移曲线在剪切的初始阶段基本重合。泥皮的存在使黄土与混凝土接触面粘聚力和内摩擦角均显著减小。随着泥皮厚度的增加,接触面粘聚力逐渐减小,其变化速率也逐渐减小,而接触面内摩擦角变化不大。
In order to improve the level of calculation and analysis of bearing capacity and settlement of the castin-situ bored pile in loess region,shear tests on the loess-concrete interface,under conditions of no slurry and various slurry thicknesses,were performed using a large direct shear apparatus.Test results indicate that under conditions of no slurry,shear stress of interface increases with the increase of shear displacement.When the normal stress is comparatively small,the first half of the shear stress-shear displacement curve of the interface is a hyperbola,while the second half is an inclined line.When the normal stress is comparatively great,the shear stress-shear displacement curve of the interface is a hyperbola.All shear stress-shear displacement curves under various slurry thicknesses have the softening form,and with the increase of slurry thickness,both the degree of softening and the shear stress decrease gradually.Corresponding to the same normal stress,shear stress-shear displacement curves at the beginning of shear are the same under various slurry conditions.The cohesive force and the internal friction angle of the interface will be greatly decreased because of slurry.With the increase of slurry thickness,the cohesive force of interface decreases gradually,and its changing rate decreases too,while the internal friction angle changes a little.
作者
张磊
刘慧
王铁行
Zhang Lei;Liu Hui;Wang Tiehang(College of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,P.R.China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,P.R.China;Guizhou Zhengye Engineering and Investment Incorporation Limited,Guiyang 550012,P.R.China;Guizhou Karst Foundation Engineering Technology Research Center,Guiyang 550012,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2020年第S02期564-568,575,共6页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51508455)
陕西省自然科学基础研究计划(2019JM-232)
西安建筑科技大学青年科技基金(QN1614)
关键词
黄土
接触面
大型直剪试验
泥皮
抗剪强度
loess
interface
large-scale direct shear tests
slurry
shear strength
作者简介
张磊(1981—),男,山东临沂人,博士,讲师,主要从事岩土工程领域的教学与科研工作。E-mail:zh888lei@163.com
