摘要
目的研究大悬挑钢结构施工卸载过程混凝土楼板的开裂行为.方法通过有限元计算方法对卸载过程进行施工模拟,由混凝土楼板的应力应变响应探讨楼板的初始开裂及开裂可能的发展方向.结果卸载过程中,裙楼楼板的混凝土在内边缘处出现最大主应力值,当最大主应力值达到开裂应力后,裂纹会沿着内边缘的角点处呈对称性向四周扩散.应力和应变响应都表现出明显的混凝土楼板的裂纹初始开裂及扩展趋势.在卸载前浇筑现浇混凝土楼板,必然导致混凝土的开裂,影响工程质量.如果在卸载之后浇筑混凝土,那么混凝土楼板在初始凝结后基本处于无应力状态,不会发生混凝土楼板开裂.结论对于大悬挑钢结构,应该在胎架卸载之后浇筑悬挑部分的楼板混凝土.
The cracking behavior of the concrete floor structure has been studied. Based on the finite element during the unloading process of large cantilever steel method, the cracking behavior and the potential cracking developed orientation can be obtained through the stress and strain responses of the concrete floor. During the unloading process, the maximum stress firstly appears at the inside edge of the concrete floor. When the maximum stress reaches the cracking stress, the cracks will spread along the comer points of the inside edge symmetrically. Therefore,if pouring the in-situ concrete floor of large cantilever steel structure before the unloading process, it will inevitably leads to the cracking of the concrete floor, which will affect the project quality. If pouring the in-situ concrete floor of large cantilever steel structure after the unloading process, the concrete floor will be free-stress state after its initial condensation. Then, the cracking of the concrete floor will not occur. So, the cantilevered concrete floor should be poured after unloading for the cantilevered steel structure.
出处
《沈阳建筑大学学报（自然科学版）》
CAS
北大核心
2012年第2期275-280,共6页
Journal of Shenyang Jianzhu University：Natural Science
基金
国家自然科学基金项目(51178365)
关键词
悬挑钢结构
混凝土开裂
卸载过程
数值模拟
cantilever steel structure
concrete cracking
unloading process
numerical simulation
作者简介
方胜利（1971～），男，博士研究生，主要从事工程结构研究
