公路隧道扩建力学特征研究

发布时间：2019-03-20 13:06

【摘要】：结合依托工程,运用自制的模型试验平台,针对原有隧道不同服役状态系统开展了5组室内模型试验,分析了隧道新旧衬砌结构的受力特点,研究了不同类型隧道扩建的围岩压力分布规律,并将试验结果与有限元计算结果进行了对比验证。结果表明:病害工况下隧道扩建施工中,衬砌与围岩的力学行为变化与无病害情况相类似,其病害主要影响上台阶施工;不同病害工况对衬砌结构受力的影响程度和范围不同;各工况围岩压力分布特征也不同;扩建完成后,新隧道衬砌结构各部位应力为扩建前的1.3倍,围岩压力整体水平为扩建前的1.2倍;病害对隧道扩建施工力学行为的影响程度为仰拱位置出现病害比拱腰位置出现病害影响小,拱腰位置衬砌背后围岩出现空洞比衬砌强度不足影响大,仰拱位置衬砌强度不足比仰拱底部回填不密实影响大。
[Abstract]:Based on the engineering and using the self-made model test platform, five groups of indoor model tests were carried out according to the different service conditions of the existing tunnel, and the mechanical characteristics of the new and old tunnel lining structures were analyzed. The distribution of surrounding rock pressure in different types of tunnel expansion is studied, and the experimental results are compared with the results of finite element calculation. The results show that the mechanical behavior change of lining and surrounding rock is similar to that of no disease in tunnel expansion construction under the condition of disease, and the disease mainly affects the construction of up-steps, the influence degree and scope of different disease conditions on lining structure are different, and the mechanical behavior of lining and surrounding rock is similar to that of non-disease-free construction. The pressure distribution characteristics of surrounding rock under different conditions are different. After the expansion, the stress in each part of the lining structure of the new tunnel is 1.3 times as much as that before the expansion, and the overall level of surrounding rock pressure is 1.2 times as much as that before the expansion. The influence degree of the disease on the mechanical behavior of tunnel expansion construction is that the disease in the inverted arch position is less than that in the arch waist position, and the cavity in the surrounding rock behind the lining at the arch waist position has more influence than the insufficient strength of the lining. The inadequacy of lining strength in the position of inverted arch is greater than that of backfill at the bottom of inverted arch.
【作者单位】：长安大学陕西省公路桥梁与隧道重点实验室;亚利桑那大学土木工程与工程力学系;宁波顺和路桥设计有限公司;广州地铁设计研究院有限公司;
【基金】：国家自然科学基金项目(51008029,51378071) 陕西省自然科学基础研究计划项目(2013JQ7030) 中央高校基本科研业务费专项资金项目(CHD2012ZD019) 国家留学基金资助项目
【分类号】：U451.2

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