摘要
采用三维有限元法,以广州地铁使用的管片为研究对象,将管片在施工阶段受到的千斤顶顶力、不均匀注浆压力和正常使用阶段受到的土压力、水压力、周围土层的弹性抗力概化为5种荷载,共10个计算模型,利用通用有限元软件ADINA,分析了单块管片的应力、裂缝分布、极限荷载与薄弱之处。计算结果表明:管片的制作和安装精度极大地影响了管片在施工状态时应力分布;环缝面的不平整更容易造成管片的应力集中而产生开裂,裂缝主要沿盾构推进方向发展;正常使用状态下管片的薄弱之处为螺栓孔,裂缝主要在螺栓孔及其附近区域出现;比较各阶段的裂缝发展形式可以认为,管片在施工阶段所需配筋量在一般情况下成为控制配筋量,在正常使用阶段,配筋所起作用不显著。
3 D finite element method （FEM） was used to analyze single segment that used in Guangzhou metro in construction period and regular service period. Loadings of construction period include jacking force, non-uniform injected pressure ; loadings of regular service period include earth pressure, water pressure and elastic resisting force, all loadings were abstracted into 5 kinds of loadings and totally 10 calculated models. The finite element pro- gram ADINA was used to analyze the stress, crack distribution, ultimate loadings and vulnerable area of single segment. The results indicate accuracy of production and erection of segments obviously influences the stress distribution in construction period;out-of-flatness of surface of circumferential seam easily cause stress concentration that lead to longitudinal cracks ;in regular service period, the vulnerable area of segment is bolt hole. cracks mainly appear in bolt hole and adjacent area;compare to crack distributions in different period, construction period is the control work condition and the effect of steel bar is inconspicuous in regular service period.
出处
《科学技术与工程》
北大核心
2012年第8期1795-1800,共6页
Science Technology and Engineering
关键词
盾构隧道
管片
力学特性
三维有限元分析
shield tunnel segments mechanical characters finite element analysis
