施工降水引起房屋墙体开裂的事故处理

某6层砖混住宅楼,由于附近河道内施工降水作业,出现1层阳台下沉、开裂等情况。裂缝为旧缝,裂缝最大宽度达到50mm,主体结构墙体并无裂缝。经鉴定,主要原因是主体结构下方为桩基础,1层阳台下方为条形毛石基础,建筑物下方的填土层为欠固结土层,固结过程中发生了较大的沉降差,施工降水加快了填土层的固结作用,使裂缝变大。采取降水过程中在建筑物与降水井之间设旋喷桩作为止水帷幕,在裂缝处贴石膏饼等处理措施,同时对裂缝的稳定性和地下水位的变化情况加强观测。加固后对建筑物沉降重新进行观测,未发现明显变化。

THE TREATMENT OF WALL CRACKS CAUSED BY CONSTRUCTION DE-WATERING

Due to the construction de-watering in the vicinity river ,several cracks appearced in an brick and reinforced concrete building and the first floor balcony had unequal settlement ,these are mainly previous cracks,the maximum width of the cracks is up to 50 mm,there are no cracks on the main wall. After appraisal,the main reason is that there is a pile foundation under the main structure of the building,but under the first floor balcony there is only the strip footing . The soil layer under the building is underconsolidated soil deposit,during the consolidation, large unequal settlement occurred in the building,the construction de-watering promoted the consolidation,which made the cracks be wider. So using these treatment measures,such as constructing chemical churning piles as the barrier-wall,pasting gypsum on the cracks and so on,at the same time intensive observation of the stability of the cracks and change in underground water level was done. After reinforcement it was observed the settlement again and found on obvious change.