一、工程概况 某中学教学楼为三层砖混结构,建筑面积为2769平方米。平面基本呈对称布置,中部是9米宽的大厅及楼梯间,两侧南向各布置两个10.8×6米的教室,教室对面为教学辅助房间,在楼两侧端部是6.6×9米的实验室,各层布置相同。见图1。1984年建成,1987年发现进大厅及楼梯间梁严重开裂、变形,支撑大梁的墙角也有裂缝出现,因此进行了加固处理;1989年起6米跨进深梁出现裂缝,1995年发现第三层顶6米进深梁裂缝较一、二层发现的严重,经方案比较对第三层梁,采用在梁两侧夹钢架加固,对一、二层有裂缝的进深梁进行观察,并申请了经费,准备逐步处理。由于该工程是无证设计,找不到设计人,也没有施工记录及验收资料,主要靠现场观察测试进行分析判断 I. Project Overview The teaching building of a middle school is a three-story brick-concrete structure with a building area of ​​2,769 square meters. The plane is basically arranged symmetrically. The center is a 9-meter-wide hall and staircase. Two 10.8-by-6-meter classrooms are arranged on both sides of the center in the middle. The classroom is opposite the teaching-aided room. The sides of the building are 6.6-by-9 meters. The laboratory has the same layout on each floor. See Figure 1. Built in 1984, in 1987, serious cracks and deformations were found in the entrance hall and stairwell beams, cracks appeared in the corners supporting the girders, and reinforcements were applied; It was found that the cracks in the first 6 meters deep in the third layer were more serious than those in the first and second layers. After the comparison of the schemes, the third beam was reinforced with steel frames on both sides of the beam, and the first and second layers of deep beams with cracks were observed. And apply for funding to prepare for the gradual processing. Since the project is unlicensed, designers cannot be found, and there are no construction records and acceptance data, mainly relying on on-site observation and testing for analysis and judgment.