体外预应力独立矩形齿块锚固区的拉压杆模型及配筋设计  

STRUT-AND-TIE MODEL AND REINFORCEMENT DESIGN METHOD FOR ISOLATED RECTANGULAR ANCHOR BLOCK FOR EXTERNAL TENDONS

作　　者：林波[1] 刘钊[1] 吕志涛[1] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096

出　　处：《工程力学》2011年第12期59-64,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(50778038);教育部博士点基金项目(20070286097);江苏省交通科学研究计划项目(09Y11)

摘　　要：针对体外预应力混凝土箱梁桥中的独立矩形齿块锚固区,研究了拉压杆模型构形及其配筋设计方法。首先通过应力场分析、传力路径的拓扑优化找形、裂缝分布模式试验验证以及抗剪钢筋作用机理分析,揭示了产生局部拉应力集中的3种作用效应以及锚固力由承压面经独立齿块向壁板传递过程中2种荷载传递机制。在此基础上,提出了一种新的精细化桁式拉压杆模型,该模型能恰当反映独立齿块各部位受拉、受压、受剪规律及配筋设计需求。以所提出的拉压杆模型为基础,并结合美国AASHTO桥梁设计规范,给出了独立矩形齿块锚固区的配筋设计方法,设计示例表明该方法具有良好的实用性,可供工程设计参考。The strut-and-tie model（STM） and reinforcement design method for isolated rectangular anchor block with external tendons were studied in this paper.Firstly,through spatial stress analysis,experimental verification based on crack distribution pattern,topology optimization and mechanism analysis on shear reinforcement,the paper revealed that the stress concentration was caused by three typical local actions and the anchor force was transferred to the slab through the arch and truss mechanisms.On this basis,a new refined trussed STM for isolated rectangular anchor block was proposed,which was capable to reflecting the distribution of tension,compression and shear in anchor block.Moreover,the reinforcement design method was given by the combination of the proposed STM and AASHTO LRFD Specification.Finally,a design example was presented to demonstrate the effectiveness and convenience of the proposed method.

关 键 词：独立矩形齿块锚固区 拉压杆模型 配筋设计 有限元分析 传力机理分析 

分 类 号：U448.35[建筑科学—桥梁与隧道工程] TU318.1[交通运输工程—道路与铁道工程]