钢纤维高强混凝土二桩承台受剪性能及承载力计算  

Shear behavior and bearing capacity calculation of steel fiber reinforced high strength concrete two-pile caps

作　　者：雷杰 陈子夏 史科 王武刚 LEI Jie;CHEN Zixia;SHI Ke;WANG Wugang(School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450046,China;School of Civil Engineering and Architecture,Zhengzhou University of Aeronautics,Zhengzhou 450046,China)

机构地区：[1]华北水利水电大学水利学院,河南郑州450046 [2]郑州航空工业管理学院土木建筑学院,河南郑州450046

出　　处：《建筑结构学报》2023年第9期234-245,共12页Journal of Building Structures

基　　金：国家自然科学基金项目(51708514);河南省高等学校重点科研项目(22A570001)。

摘　　要：为研究钢纤维高强混凝土二桩承台的受剪性能,进行了12个钢纤维高强混凝土二桩承台受剪试验,变化参数包括承台有效厚度、钢纤维体积率、配筋率和混凝土强度等级。结果表明:承台发生剪切破坏;随着承台有效厚度和钢纤维体积率的增加,承台受剪承载力显著提高;底部纵向受力钢筋配筋率在0.39%~1.18%范围内增大及采用钢纤维高强混凝土可提高承台刚度和承载力。在此基础上,分析了钢纤维高强混凝土二桩承台受剪机理,基于修正压力场理论,考虑钢纤维在高强混凝土裂缝处的应力传递,提出了钢纤维高强混凝土二桩承台受剪承载力计算公式。与JGJ/T 465—2019《钢纤维混凝土结构设计标准》中给出的计算公式进行对比,文中计算公式计算值与试验结果吻合更好。In order to study the shear behavior of steel fiber reinforced high strength concrete(SFRHSC)two-pile caps,shear tests of 12 SFRHSC two-pile caps were carried.The experimental variables include effective thickness of pile caps,steel fiber volume fraction,reinforcement ratio,and concrete strength grade.The results show that the specimen of pile caps undergo flexural-shear failure and the shear failure.With the increase of the effective thickness and the steel fiber volume fraction,the bearing capacity of pile caps is improved markedly.The reinforcement ratio increases within 0.39%-1.18%and the use of steel fiber high-strength concrete can improve the stiffness and bearing capacity of pile caps.Then,the shear mechanism of SFRHSC two-pile caps was analyzed,and a shear capacity calculation formula of SFRHSC two-pile caps was proposed based on the modified compression field theory,in which the stress transform through the steel fiber at the crack in high-strength concrete was considered.Compared with JGJ/T 465—2019‘Standard for design of steel fiber reinforced concrete structures’,the calculation formula proposed in this paper generates a good agreement with the experimental results.

关 键 词：二桩承台 钢纤维高强混凝土 受剪机理 承载力 修正压力场理论 

分 类 号：TV431.3[水利工程—水工结构工程] TV314