四面包裹式托换承台承载力试验研究  

Experimental research on bearing capacity of four-sided wrapped underpinning cap

作　　者：贾强[1,2] 刘宝凯 黄坤 JIA Qiang;LIU Baokai;HUANG Kun(School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering(Shandong Jianzhu University),Ministry of Education,Jinan 250101,China)

机构地区：[1]山东建筑大学土木工程学院,山东济南250101 [2]山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室,山东济南250101

出　　处：《山东建筑大学学报》2022年第4期1-8,共8页Journal of Shandong Jianzhu University

摘　　要：既有建筑地下增层过程中,柱周围设置四面包裹式托换承台是将上部结构荷载传递至新设置的桩基础的有效途径。为了研究该托换承台的承载力性能,设计了11组对比试验,研究了不同冲跨比、承台底纵筋配筋率、纵筋设置方向以及托换承台浇筑方式等工况对承台承载性能的影响。结果表明:随着冲跨比减小和承台底纵筋配筋率增大,托换承台承载力增加;再结合面凿毛、做插筋可保证不发生结合面破坏。基于试验结果和拉-压杆模型,推导出托换承台承载力公式,其计算结果与试验结果吻合良好。In the process of adding underground floors to existing buildings,setting up four-sided wrapped underpinning cap around the column is an effective way to transfer the load of the superstructure to the newly installed pile foundation.In order to study the bearing capacity performance of the underpinning cap,11 sets of comparative tests are designed to study the impact on bearing capacity made by different ratios of punching span,the longitudinal reinforcement ratios of the bottom of the cap,the longitudinal reinforcement setting directions,and the pouring methods of the underpinning cap.The results show that with the decrease of the ration of punching span and the increase of the longitudinal reinforcement ratio of the bottom of the cap,the bearing capacity of the underpinning cap increases;chiseling and inserting reinforcement on the joint surface can ensure that the joint surface does not be broken.Based on the test results and the strut-and-tie model,the bearing capacity formula of the underpinning cap is deduced,and the calculation results of the formula are in good agreement with the test results.

关 键 词：四面包裹式托换承台 冲跨比 纵筋配筋率 纵筋设置方向 承台浇筑方式 

分 类 号：TU312.1[建筑科学—结构工程]