锚索预应力长期损失与岩土体蠕变耦合模型研究  

Coupled Model for the Long-term Pre-stress Loss of Anchor Cable and Geotechnical Creep

作　　者：邓东平[1] 李亮[1] 

机构地区：[1]中南大学土木工程学院,长沙410075

出　　处：《长江科学院院报》2015年第8期65-71,共7页Journal of Changjiang River Scientific Research Institute

基　　金：教育部博士研究生学术新人奖项目(114801045);湖南省研究生科研创新项目(CX2012B056);贵州省交通运输厅科技项目(2010-122-020)

摘　　要：锚索通过反力支座与边坡岩土体紧密接触,当给锚索施加一定预应力后,岩土体同样受到预应力作用而发生形变。该形变不会瞬时完成,而是随时间变化,将导致锚索预应力出现长期损失。将锚索等效成弹性体和广义Kelvin体(考虑锚索应力松弛)这2种模型,并假设岩土体为考虑蠕变特性的H+n K体(n≤3),结合锚索与岩土体的耦合变形和初始条件,推导出锚索张拉力随时间变化的计算式。经与以往研究成果对比,验证了模型的正确性。同时,研究分析表明,在理论模型中增加岩土体蠕变模型的K体个数及考虑锚索应力松弛现象,可使得拟合曲线更接近于实测的锚索预应力变化。Anchor cable is closely contacted with geotechnical body through reaction support. After a certain prestress is applied on anchor cable,the geotechnical body also deforms under the action of pre-stress. Due to the creep property of geotechnical body,its deformation doesn＇t complete instantaneously but changes with time,which causes the long-term loss of pre-stress. In this research,anchor cable is equivalent to two models（ elasticity body and generalized Kelvin body）,and geotechnical body is assumed to be model of H ＋ n K（ n≤3） which could simulate the creep property of geotechnical body. According to the coupling deformation between anchor cable and geotechnical body and the initial conditions,formulas of calculating the pre-stress of anchor cable with the change of time are obtained. Through comparison with the results of previous studies,the correctness of this model is verified. Moreover,the fitting curve could be more consistent with the measured pre-stress variation if the number of K in creep model of geotechnical body is increased and the relaxation of anchor cable stress is considered in the theoretical model.

关 键 词：锚索 蠕变 耦合模型 应力松弛 预应力损失 

分 类 号：TU45[建筑科学—岩土工程]