框架预应力锚杆柔性支护结构的锚杆预应力损失研究  

Research on the anchor prestress loss of grillage flexible supporting structure with prestressed anchors

作　　者：周勇[1] 朱彦鹏[1] 

机构地区：[1]兰州理工大学土木工程学院,兰州730050

出　　处：《工程勘察》2010年第9期1-6,共6页Geotechnical Investigation & Surveying

基　　金：国家自然科学基金资助项目(50978129);兰州理工大学博士科研基金项目(BS04200902)

摘　　要：框架预应力锚杆柔性支护结构是用于提高边坡稳定性的一种新技术,锚杆作为其中的核心受力构件,其预应力值的大小是有效限制边坡位移的关键,但在实际工程中锚杆产生预应力损失是必然的。为深入了解锚杆的工作性能和作用机理,对其预应力损失进行研究,分析总结了影响锚杆预应力损失的主要因素,包括张拉系统的摩阻、锁定后的锚具回缩、钢材的应力松弛、土体蠕变、群锚效应和张拉顺序、降雨入渗等。综合考虑其它各种因素的影响,可粗略估算一般锚杆预应力损失范围大约在25%～40%之间。另外,为进一步验证锚杆预应力的损失大小,对框架预应力锚杆柔性边坡支护结构的锚杆预应力损失问题进行了试验研究,结果表明本文给出的简单定量估算是可行的。Grillage flexible supporting structure with prestressed anchors is a new technique used to improve slope stability,in which the anchors belong to core forced component,its prestress values are critical for the effective control of slope displacement,but in actual projects,the anchors prestress loss is inevitable.In order to study the behaviors and working mechanism of anchors,the prestress loss of anchors is studied.The major influencing factors of anchors prestress loss of prestressed anchors are analyzed, including the frictional force of tensioning system,retraction of anchorage device after locked,stress relaxation of reinforcement,soil creep,group anchoring effect and tension sequence,as well as rainfall infiltration,etc.Then,considering the various other factors,it can be roughly estimated that the general range of anchor prestress loss is approximately between 25% and 40% .In addition,to further verify the values of anchors prestress loss,the test study aiming at the anchors prestress loss of grillage flexible supporting structure with prestressed anchors is carried out,the testing results show that the simple quantitative estimation propounded in above is feasible.

关 键 词：框架锚杆柔性支护结构 预应力损失 影响因素 试验研究 

分 类 号：TU473[建筑科学—结构工程]