Stress-transfer in concrete encased and filled tube square columns employed in top-down construction
Stress-transfer in concrete encased and filled tube square columns employed in top-down construction
复制标题
DOI：
10.12989/scs.2016.22.1.063
复制
发表时间：
2016-09
影响因子：
4.6
通讯作者：
Sun-Hee Kim;K. Yom;Sung-Mo Choi
中科院分区：
文献类型：
--
作者：
Sun-Hee Kim;K. Yom;Sung-Mo Choi
.逆作法施工是一种基坑开挖与结构施工同时进行的施工技术。该技术缩短了施工时间，减少了噪音和振动对邻近结构的影响，广泛应用于城市建筑。虽然H型钢柱通常被用作核心柱，但钢管混凝土（CFT）柱是关注的中心，因为后者比前者具有更小的轴向方向性和更大的横截面效率。与圆形钢管混凝土柱相比，方形钢管混凝土柱更容易与楼板结构连接，冲击旋转钻孔（PRD）的面积较小。因此，方钢管混凝土柱被用作地下楼层混凝土外包填充方（CET）柱的核心柱。然而，CET柱的结构性能和混凝土应力传递的研究还没有进行。由于混凝土是按施工顺序浇筑的，因此必须对核心柱内部混凝土的应力和保护层混凝土的应力进行验算。本文介绍了结构测试和分析的结果进行评估CET柱的可用性和安全性的自上而下的施工中，钢管混凝土柱被用作核心柱。试验参数为荷载条件、混凝土强度和覆盖层厚度。对试件的抗压承载力和破坏行为进行了评价。此外，还分析了CET柱在地下楼层的2个现场应用实例。
. Top-down construction is a construction technique in which pit excavation and structure construction are conducted simultaneously. Reducing construction time and minimizing noise and vibration which affect neighboring structures, the technique is widely employed in constructing downtown structures. While H-steel columns have been commonly used as core columns, concrete filled steel tube (CFT) columns are at the center of attention because the latter have less axial directionality and greater cross-sectional efficiency than the former. When compared with circular CFT columns, square CFT columns are more easily connected to the floor structure and the area of percussion rotary drilling (PRD) is smaller. For this reason, square CFT columns are used as core columns of concrete encased and filled square (CET) columns in underground floors. However, studies on the structural behavior and concrete stress transfer of CET columns have not been conducted. Since concrete is cast according to construction sequence, checking the stress of concrete inside the core columns and the stress of covering concrete is essential. This paper presents the results of structural tests and analyses conducted to evaluate the usability and safety of CET columns in top-down construction where CFT columns are used as core columns. Parameters in the tests are loading condition, concrete strength and covering depth. The compressive load capacity and failure behavior of specimens are evaluated. In addition, 2 cases of field application of CET columns in underground floors are analyzed.