盾构隧道横向刚度有效率研究

对现有国内外盾构隧道横向刚度有效率的取值进行了整理分析,认为目前通错缝隧道刚度有效率的取值常凭经验判定,缺少足够的验证。基于二环盾构隧道相似结构模型加载试验的结果以及相关研究成果,发现隧道加载时变形与荷载存在着明显的线弹性关系,隧道刚度有效率为一常数,符合修正惯用设计法的理论基础。对上海地铁盾构隧道的研究表明,通缝拼装时刚度有效率为0.67,错缝拼装时刚度有效率为0.75,软弱土体抗力对隧道有效刚度的影响可以忽略。通过与已有经验公式、结构试验结果的比较,表明相似模型结构试验具有简单、可操作性强、数据丰富、结果可信、经济的特点,可成为研究通错缝拼装盾构隧道刚度有效率的较理想方法。

Study on transverse effective rigidity ratio of shield tunnels

After a detailed discussion on the transverse effective rigidity ratio of shield tunnel, it was shown that the effective rigidity ratio was always an emperical value. Based on the model test of two-ring tunnel structures and the analysis of the test results, some conclusions could be drawn. The relation of deformation of tunnel structure with the load was clearly linear elastic, so the effective rigidity of shield tunnel was constant in elastic stage, which was agreeable to the rule of the modified conventional design method; the effective rigidity ratios of tunnel with nonstaggered and staggered installation were 0.67 and 0.75 respectively for Shanghai Metro; the effect of soil resistance on the effective rigidity of shield tunnel was very small in soft ground. Compared with empirical formulas and structural tests, the model test could be done conveniently, with abundant believable results and economical cost, and would be a good method to study the effective rigidity of shield tunnels.