摘要
基于上海北横通道工程西段盾构隧道双层清水混凝土内部结构实施案例,着重容易忽视的细节,从设计角度谈谈双层盾构隧道内部结构清水混凝土的几个控制要点。实践表明:双层盾构隧道内部结构构件、钢筋骨架等应保持纵向的连续性、顺滑性,以适应大型可移动不锈钢模板的工艺需求;还须预留浇筑孔、增加钢筋间距,以适应狭小空间内的浇筑与振捣,比如用“菱形”箍筋代替“井”形箍筋。此外,内部竖向构件宜通过植筋基座与管片连接,从而使植筋精度不影响竖向构件(侧墙)钢筋的精度。最后,增加分布钢筋数量(配筋率由0.2%提高到0.3%),提高纵向抗裂能力,对侧墙、基座等强边界约束下大体积清水混凝土质量控制极为有利。
Based on the implementation case of double-layer fair-faced concrete internal structure of shield tunnel in the west section of Shanghai Beiheng Passageway Project,it focuses on the details that are easy to be ignored.Several control points of fair-faced concrete internal structure of double-layer shield tunnel are discussed from the perspective of the design.The practice has shown that:the internal structural components and steel frame of the double-layer shield tunnel should maintain longitudinal continuity and smoothness to meet the technological requirements of large-scale movable stainless steel formwork;pouring holes and increase the spacing of steel bars must also be reserved to accommodate for pouring and vibrating in narrow spaces,for example,diamond-shaped stirrups are used instead of#-shaped stirrups.In addition,the internal vertical components should be connected to the pipe segments through the planting base,so that the accuracy of the planting does not affect the accuracy of the vertical components(side walls).Finally,increasing the number of distributed steel bars(increasing the reinforcement ratio from 0.2%to 0.3%)and improving the longitudinal crack resistance is extremely beneficial to the quality control of large-volume fair-faced concrete under strong boundary constraints such as side walls and foundations.
作者
吴华柒
孙威
刘念
WU Hua-qi;SUN Wei;LIU Nian(Shanghai Chengtou Highway InvestmentCo.,Ltd.,Shanghai 200336,China;Shanghai Municipal Engineering Design InstituteCo.,Ltd.,Shanghai 200092,China)
出处
《中国市政工程》
2021年第5期108-111,122,共5页
China Municipal Engineering
关键词
盾构
内部结构
双层车道结构
清水混凝土
结构设计
shield
internal structure
double lane structure
fair-faced concrete
structure design
