摘要
隧道支护结构可靠性评价的位移方法中,测量得到的支护变形除因荷载引起外,还与支护材料的收缩和徐变有关。采用GL2000模型的修正形式计算支护的收缩和徐变,推导了支护轴向伸缩变形和曲率改变的计算公式,以及通过测量位移并考虑干缩和徐变时计算支护内力的公式。对兰新二线乌鞘岭隧道及北京地铁四号线黄庄车站两个隧道进行了工程实例分析,探讨了格栅钢架喷射混凝土的收缩和徐变变形对隧道安全性的影响。结果表明:考虑干缩后,计算得到的可靠指标均有所增大,但可靠指标的提高幅度不大;考虑徐变后,计算得到的可靠指标均有不同程度的增大。说明干缩对可靠指标的影响较小,在工程计算中可不考虑;徐变使可靠指标有明显提高,工程计算中一般应考虑。
In the displacement-based method for reliability assessment of tunnel structures,the measured deformation of the primary support is not only related to loads,but also to the shrinkage and creep of the material of the support.In the study,GL2000 model is modified and used to calculate the shrinkage and creep of the support.The formulas to calculate the axial deformation and curvature change of the support are derived out,and the formulas to compute the internal forces of the support with shrinkage and creep considered are given.Case studies are done at two tunnels： Wushaoling Tunnel at Lanzhou-to-Xinjiang Railway Line and Huangzhuang Station at Line 4 in Beijing subway,through which the influence of shrinkage and creep of lattice-girder-reinforced shotcrete on the safety of the tunnels is addressed.Results show：（1） shrinkage has little influence on reliability index and could be neglected in the future;（2） creep makes an obvious increase in the index and should be considered in engineering practice.
出处
《山东建筑大学学报》
2010年第5期484-489,共6页
Journal of Shandong Jianzhu University
基金
国家自然科学基金项目(50978020)
关键词
干缩
徐变
结构可靠度评价
隧道安全性
shrinkage
creep
reliability assessment of structures
safety of tunnels
