某公司办公楼建于1979年,为4层砖混结构,开间3.3m,进深5.1m,层高3.5m。由于使用功能的改变,要将部分小开间小房间改造成为大开间大房间(图1)。在改造时,拟先拆墙上部,增设钢筋混凝土梁来替换原墙体受力,再拆除梁下墙,即可形成大开间。如何在拟拆墙上增设钢筋混凝土梁,是个施工难题。在施工中,我们采用了钢支托支顶,直接 A company office building was built in 1979, for the 4-story brick structure, room 3.3m, depth 5.1m, storey 3.5m. Due to the use of functional changes, we should transform some of the small rooms into large rooms (Figure 1). In the transformation, it is proposed to demolish the upper part of the wall first, add a reinforced concrete beam to replace the original wall force, and then remove the beam under the wall to form a large room. How to add the wall to be reinforced concrete beams, is a construction problem. In the construction, we use the steel support branch, direct