摘要
混凝土地下结构墙体的开裂现象较为普遍,裂缝控制难度大。目前,王铁梦的混凝土长墙模型广泛应用于裂缝控制。王铁梦模型仅考虑墙体受到地基约束,即假设墙体端部是自由的,并用实际位移计算裂缝宽度,导致墙体裂缝间距和裂缝宽度的计算结果相对于实际结果明显偏大,需要人为修正结果。笔者提出,混凝土地下结构墙体开裂严重的主要原因是墙体同时受到地基约束和端部约束的作用。据此,在王铁梦模型的基础上加入墙体端部约束条件,推导出裂缝间距的计算公式,并用约束位移计算裂缝宽度。该方法能直接得到符合工程实际的墙体裂缝间距和裂缝宽度的计算结果,为墙体裂缝控制提供了理论依据。笔者指出,墙体裂缝控制的最有效方法是诱导缝方法,给出了在墙体分段设置诱导缝的间距原则,并要求在诱导缝处将墙体水平钢筋完全断开,以消除墙体端部约束。通过工程实践验证了所提出的墙体裂缝控制方法的有效性。
The cracking phenomenon of the concrete wall of underground structure is common,and it is difficult to control the crack.Currently,Wang Tiemeng’s long concrete wall model is widely used in crack control.Wang Tiemeng’s model considers the constraints from the wall’s foundation only,that is,assuming the end of the wall is free,and the crack width is calculated by using the actual displacement.As a result,the calculation results of the crack spacing and crack width of the wall are obviously larger than the actual results,and the results need to be artificially corrected.The author points out that the main reason for the serious cracking of the wall of underground structure is that the wall is constrained both by the foundation and by the end of the wall.Based on this,the constraint at the end of the wall is added to Wang Tiemeng’s model,the calculation formula of the crack spacing is introduced,and the crack width is calculated by using the constraint displacement.This method can directly obtain results of wall crack spacing and crack width in line with engineering practice,which provides a theoretical basis for wall crack control.The author also points out that the most effective method to control the wall cracks is the inducing joint method,gives the principle of setting the spacing of the inducing joint in the wall segment,and requires that the horizontal steel bars of the wall need to be completely disconnected at the inducing joint in order to eliminate the constraint of the end of the wall.The effectiveness of the proposed method for wall crack control is verified by engineering practice.
作者
吴伟强
WU Weiqiang(Guangzhou Tianchen Real Estate Development Co.,Ltd.,Guangzhou 510250,China)
出处
《建筑结构》
北大核心
2024年第3期51-58,共8页
Building Structure
关键词
混凝土长墙
端部约束
裂缝计算
裂缝控制
诱导缝
long concrete wall
end constraint
crack calculation
crack control
inducing joint
