预应力钢结构托换拆墙应用技术

Application of Steel Prestressed Structure in Removing Main Walls of a Building

上海市某三层砖砌体建筑物因建筑功能发生改变,需将顶层两间办公室中间的承重墙抽除以形成一大空间的会议室。抽除承重墙体形成一大空间后,必将导致原结构体系中传力途径的改变,因此需对原有结构进行改造加固。根据预应力结构原理,采用楼层下面的预应力筋加固方案。在梁两侧的三折线型预应力筋上采用张拉配置,可减小需抽除的承重墙中的竖向轴力,最终达到抽墙而不影响结构正常使用的目的。当原梁截面较小或混凝土强度较低时,张拉预应力的支承结构可由梁两侧增设的承压钢梁充当。本工程托换的各项技术指标达到了设计要求,竣工验收后实际使用效果良好。

The main wall between two offices in the highest storey is to be removed to form a spacious meeting room because the building function of a certain three-storey building build of brick in Shanghai has been altered. But the force conducting way of the prior structure system will change after the main wall is removed, so the prior structure has to be rebuilt and reinforced. According to the principle of prestressing structure, the under-storey prestressing tendon reinforcing plan can be adopted when the conditions can be met with. The prestressing tendon of three-twist type of tensioned collocated beside grider is adopted in this project to reduce the vertical axis force of the main wall removed at the aim of avoiding affecting the structure's normal use when the main wall is removed. When prior girder's section is smaller or the concrete's intensity is lower, the supporting structure can be replaced by bearing spandrel which is added to the girder's sides. All the technique indexes used in this project have met with the design requirement and the effect is good actually.