剪力作用下钢筋混凝土大尺寸无腹筋构件安全性研究  

Safety of large reinforced concrete members without web reinforcement subjected to shear

作　　者：车轶[1] 于磊[1] 

机构地区：[1]大连理工大学建设工程学部,辽宁大连116023

出　　处：《建筑结构学报》2014年第2期144-151,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(50778034);国家自然科学基金重点项目(50838001)

摘　　要：结合一钢筋混凝土厚板桥梁的剪切破坏实例，对GB50010--2010（（混凝土结构设计规范》的无腹筋构件受剪计算公式的安全性进行了分析。根据完成的截面高度为500～1200mm大尺寸梁的剪切试验结果及收集的其他文献的大尺寸梁和厚板试验数据对规范公式进行了验证，分析了最小配箍率和纵向分布钢筋对构件受剪承载力的影响。结果表明，无腹筋梁存在明显的尺寸效应，规范公式虽然引入了截面高度影响系数，但尚不能充分考虑截面高度对受剪承载力的影响；规范公式对纵筋配筋率较低且截面高度大于1000mm的小剪跨比构件（a／h0〈2．0）以及纵筋配筋率小于1．00％和截面高度大于1000mE的大剪跨比构件（a／h0〉t2．0）计算偏于不安全；规范规定的最小配箍率能够有效避免大尺寸构件发生剪切破坏，而配置纵向分布钢筋则不能有效避免截面高度大于1000mm的无腹筋构件的剪切破坏。The safety of shear design method in the ＇ code for design of concrete structures＇ （ GB 50010--2010） for reinforced concrete members without web reinforcement was examined based on the analysis of the thick slab in a bridge that failed in shear. Based on the results of shear tests conducted on large beams with depths ranging from 500 mm to 1 200 mm, and test data of large beams and thick slabs from other researchers, the code expressions for shear strength of members without web reinforcement were evaluated. The influence of minimum web reinforcement and distributed longitudinal reinforcement on shear strength of large members was also discussed. It is shown that the shear strength of large members without web reinforcement exhibits significant size effect such that the code expressions into which a size effect factor has been incorporated are unable to characterize the influence of depth on shear strength of members, resulting in unsafe results when applying to deep beams （ a/h0 〈 2. 0） with low longitudinal reinforcement ratio and with depth greater than 1 000 mm, and to slender beams （a/h0 t〉2. 0） with longitudinal reinforcement less than 1.00% or with depth greater than 1 000 mm. Minimum stirrups required by code provisions are found to be effective for large members to avoid brittle shear failure, while distributed longitudinal reinforcement is less effective for member with depth over 1 000 mm without web reinforcement.

关 键 词：钢筋混凝土无腹筋构件 受剪承载力 尺寸效应 

分 类 号：TU375.1[建筑科学—结构工程]