摘要
通过两种差异较大的粘土层中预应力锚索现场试验,探讨了黏性土中预应力锚索锚固段剪应力的具体分布形式及其主要影响因素。试验结果表明,(1)锚固段剪应力并非均匀分布,而是呈单峰曲线形式;(2)土质越好,张拉荷载越大,锚固段剪应力峰值现象越明显。在相同土质条件,同样的张拉荷载作用下,锚索锚固段越短,剪应力分布峰值现象越明显;(3)极限状态下,锚固段剪应力峰值位置至锚固段起始点的距离和锚固段长度的比值在0.5左右,这也是土层预应力锚索锚固段主要受荷区域;(4)界面极限平均粘结强度受土质条件和锚固段长度的共同影响,设计中对于极限平均粘结强度的取值应灵活调整。研究为类似土质条件下的预应力锚索设计提供了一定的参考。
In order to investigate the distribution curves of the shear stress along the anchorage section and its principal influence factors,the site test about prestressed cable was carried out on two kinds of clay layer which have large differences. The study results indicate that,( 1) The shear stress is unevenly distributed along the anchorage section of anchoring rope,instead,the distribution curve obeys the unimodal curve.( 2) The hump phenomenon of shear stress increases with the tensile load and the soil property. When the soil property and the tensile load stay the same,the shorter the length of anchorage section,the hump phenomenon will be more obviously;( 3) Under the limit state,the ratio between the length from the start to the peak value and the length of the anchorage section is about 0.5,and this is also the main loading area of the anchorage section;( 4) The value of the ultimate bond stress is influenced by the length of anchorage section and the soil property,the ultimate bond stress should be adjusted flexibly in the design,The study provides reference for the design under the similar soil texture conditions.
出处
《地下空间与工程学报》
CSCD
北大核心
2015年第S2期498-502,共5页
Chinese Journal of Underground Space and Engineering
关键词
预应力锚索
黏土层
剪应力分布
单峰曲线
prestressed cable
clay layer
distribution of shear stress
unimodal curve
