考虑弯距影响的混凝土键齿接缝抗剪承载力计算方法  

Calculation method for shear strength of concrete keyed joints considering bending effects

作　　者：王景全[1,2] 刘桐旭[1] 王震[1] Wang Jingquan;Liu Tongxu;Wang Zhen(Key Laboratory of Concrete and Prestressed Concrete Structure of Ministry of Education, Southeast University, Nanjing 210096, China;National Prestress Engineering Research Center, Southeast University , Nanjing 210096 ,China)

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 [2]东南大学国家预应力工程技术研究中心,南京210096

出　　处：《东南大学学报（自然科学版）》2017年第3期553-558,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51438003);"十二五"国家科技支撑计划资助项目(2011BAJ09B02)

摘　　要：为建立能反映多键齿折减效应的混凝土接缝抗剪承载力计算公式,考虑弯矩对键齿剪切面正应力分布的影响,基于应力莫尔圆计算理论求得接缝面的剪应力分布,通过假设正应力中拉应力部分不提供承载力,提出了考虑弯矩影响的混凝土键齿接缝抗剪承载力计算方法,并采用既有试验对公式进行验证.结果表明:既有计算式对单键齿承载力存在不同程度的低估,AASHTO计算式虽能较好地预测单键齿接缝的承载力,但对多键齿干接缝的承载力存在明显的高估.相比AASHTO计算式,建议式针对单键齿干接缝承载力的计算结果较为保守,计算值与试验值比值的平均值为0.84;多键齿干接缝的计算值与试验值更加吻合,计算值与试验值比值的平均值为0.95;针对键齿胶接缝的计算结果与AASHTO计算式结果差别不大.所提方法能考虑不同键齿布置、键齿深度对承载力的影响,解释了多键齿干接缝的折减效应,适用于混凝土键齿接缝的抗剪承载力计算.To establish the calculation formula for the shear strength of concrete keyed joints reflecting the multiple-keyed reduction effects,the shear stress distribution of the key joints was calculated based on the calculation theory of Mohr^stress circle by considering the effects of bending on the normal stress distribution in the shear plane.With the assumption that the part whose normal stress was tensile without providing the capacity,a calculation method for the shear capacity of the concrete keyed joints considering the bending effect was proposed and verified by the existing tests.The results show that the existing calculation formula underestimates the shear strength of the single-keyed joints in different degrees.The AASHTO(American Association of State Highway and Transportation Officials)formula can predict the shear capacity of the single-keyed joints but obviously overestimates that of the dry multiple-keyed joints.Compared with the AASHTO formula,the proposed formula provides conservative values for the dry single-keyed joints and the average ratio of the calculated results to the experimental results is0.84.As for the dry multiple-keyed joints,the calculated results are in better agreement with the experimental results and the average ratio is0.95.As for the epoxy-keyed joints,the calculation results of the proposed formula are similar with those of the AASHTO formula.The proposed method can consider the effects of different layouts and depths of the keyed joints on the capacity,and partially explain the reduction effect of the dry multiple-keyed joints.It is suitable for calculating the shear capacity of the concrete keyed joints.

关 键 词：键齿接缝 多键齿折减效应 弯矩影响 抗剪承载力 

分 类 号：TU398.6[建筑科学—结构工程]