基于剪压强度准则的UHPC键齿接缝抗剪承载力  

Shear Bearing Capacity of Ultra-High Performance Concrete Keyed Joints Based on Shear-Compression Strength Criterion

作　　者：徐略勤[1,2] 徐意宏 陈亮[3] 江林松 周建庭[2] XU Lueqin;XU Yihong;CHEN Liang;JIANG Linsong;ZHOU Jianting(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory of Moun-tain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;College of Civil Enginee-ring,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学山区桥梁及隧道工程国家重点实验室,重庆400074 [3]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《西南交通大学学报》2025年第2期253-261,共9页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金项目(51978113);重庆市英才计划(cstc2022ycjh-bgzxm0133);重庆交通大学研究生科研创新项目(2022S0004)对本研究工作的资助.

摘　　要：为探明超高性能混凝土(UHPC)键齿接缝的抗剪承载力及其计算方法,以接缝类型、侧压应力为参数开展5个UHPC键齿接缝和1个UHPC平接缝的足尺模型试验,研究UHPC接缝试件的破坏模式和抗剪承载力变化规律;基于混凝土剪压强度准则,采用八面体应力公式推导UHPC键齿接缝的抗剪承载力计算公式,并与试验结果进行对比验证;通过收集62个UHPC键齿接缝的已有试验数据,对本文所提的计算公式进行精度分析.研究结果表明:UHPC键齿接缝因键齿根部出现竖向贯通主裂缝而破坏,具有明显的脆性特征;在相同侧压应力下,胶接缝试件的极限荷载比干接缝大21.3%,当侧压应力由3 MPa增大至12 MPa时,胶接缝试件的极限荷载增大了26.9%;本文计算公式可较准确地预测UHPC键齿接缝的抗剪承载力,且离散性较低,计算结果总体偏保守,其中本文5个键齿接缝试件的平均绝对误差为11%,62个已有试件的平均绝对误差为21%.To find out the shear bearing capacity and its calculation method of ultra-high performance concrete(UHPC)keyed joints,a full-scale model test of five UHPC keyed joints and a UHPC flat joint were carried out with the joint type and lateral compressive stress as parameters.The failure mode and the variation of shear bearing capacity of the specimens with UHPC joint were studied.Then,based on the shear-compression strength criterion of concrete,the octahedral stress formula was used to derive the formula for calculating the shear bearing capacity of UHPC keyed joints,which was then validated by the test results.Finally,the experimental data of 62 UHPC keyed joints were collected and used to verify the accuracy of the developed formula.The results show that the UHPC keyed joint is damaged by vertical major cracks developed at the root of the keys and has obvious brittle characteristics.The ultimate load of the specimen with an epoxied joint is greater than that with a dry joint by 21.3%under the same lateral compressive stress.When the lateral compressive stress increases from 3 MPa to 12 MPa,the ultimate load of the specimen with an epoxied joint increases by 26.9%.The developed formula can accurately predict the shear bearing capacity of UHPC keyed joints with low dispersion and conservative results in general.The average absolute errors of the specimen with five keyed joints are 11%,and those of 62 existing specimens are 21%.

关 键 词：UHPC键齿接缝 试验 抗剪承载力 剪压强度准则 八面体应力公式 

分 类 号：U443.3[建筑科学—桥梁与隧道工程]