锚索内锚段荷载分布及其随时间变化规律  

Load Distribution and the Law of Its Variation in the Inner Segment of Prestressed Anchor Cable

作　　者：景锋[1] 成传欢[1] 余美万[1] 陈昊[1] 刘元坤[1] 

机构地区：[1]长江科学院水利部岩土力学与工程重点试验室,武汉430070

出　　处：《长江科学院院报》2011年第5期50-54,共5页Journal of Changjiang River Scientific Research Institute

基　　金：水利部公益性行业科研专项项目(201001009);国家重点基础研究发展计划973项目(2011CB710604);中央级公益性科研院所基本科研业务专项资助项目(YWF0910)

摘　　要：现关于预应力锚索的研究多集中在荷载传递与加固机理方面,而对于运行期内锚段载荷分布随时间变化及其与锚索有效预应力的关系研究则较少。基于某水电站预应力锚索现场试验,研究了锚索张拉过程中的内锚头变位与内锚段载荷的非线性传递,及运行初期内锚段载荷分布随时间的调整变化规律及其与预应力变化间的影响。研究发现,拉力集中型锚索张拉后内锚段应力集中现象很严重,运行初期荷载从内锚段起始端向尾部发生了转移和调整,即是在锚索预应力快速下降阶段;但随着锚索预应力的持续降低和趋稳,内锚段荷载从起始端向尾部转移停止,随之沿整个内锚段的受荷均减小并趋于稳定,其后期变化规律与锚索预应力变化规律趋于一致。Though load distribution and anchoring mechanism of prestressed cable have been studied by lots of tests and theoretical analysis,the load distribution variation over time of inner-anchor segment and its relationship with anchor effective prestress are seldom studied.Based on in-site test of prestressed cable in a hydraulic power station,the authors analyzes the displacement of inner-anchor head and the nonlinear load transfer of inner-anchor segment during anchor pulling,and the variation of load distribution over time in inner-anchor segment.The relationship between load distribution variation and anchor effective prestress variation after anchor locked is studied also.Through the research,it is found that the stress of inner-anchor segment of tension-concentrated anchor cable is seriously concentrated,and the loads are transferred and adjusted from the initial point of inner-anchor segment to the end at the early stage of cable lock.But with continuous decreasing and stabilizing of cable effective prestress,the load transfer of inner-anchor segment stops;and subsequently the loads of the whole inner-anchor segment are reduced to a steady state.At last,the variation laws of interior bond section and cable effective prestress become similar.

关 键 词：预应力锚索 预应力损失 载荷分布 内锚固段 变化规律 

分 类 号：TU765[建筑科学—建筑技术科学]