地下室剪力墙裂缝演化规律及治理措施研究

RESEARCH ON THE EVOLUTION LAW AND CONTROL MEASURES OF SHEAR WALL CRACKS OF BASEMENT

以某房建项目中4栋不同施工进度楼体的地下室剪力墙为研究对象,借助HC-U81混凝土超声波检测仪,分析地下室剪力墙上裂缝的宽度、深度、长度等监测指标的变化规律。研究发现,该项目地下室剪力墙上裂缝的宽度、深度和长度的增加与上部荷载的关联性较小,受养护方式、温度变化等因素的影响较大;剪力墙上的裂缝呈斜向或竖向的区域分布特征;裂缝形成的主因是混凝土在塑性阶段的泌水作用和在养护期间的水分蒸发使墙体表面产生的拉应力超过了混凝土的抗拉强度值,导致墙体开裂;针对地下室剪力墙的开裂问题,分别从改善美观、增强抗渗性和耐久性、提高安全性等方面提出了有针对性的治理措施。

Taking the shear walls of basements of four buildings in different construction progress in one housing construction project as research objects,the evolution law of monitoring indicators(e.g.width,depth and length)of shear wall cracks of basements is analyzed with the HC-U81 concrete ultrasonic detector.Results show that the increase in the width,depth and length of shear wall cracks of basements has little correlation with the upper load,but is greatly affected by the curing method,temperature change and other factors;shear wall cracks are inclined or vertically distributed;main reasons for shear wall cracks include the concrete bleeding at the shaping stage and the tensile stress on the wall surface exceeding the tensile strength of concrete as a result of evaporation at the curing stage;and targeted control measures are proposed for more beautiful appearance and high impermeability,durability and stability,in order to solve the problem of shear wall cracks of basements.