【作者】 赖炯丞；

【导师】 何川；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2013， 硕士

【摘要】 近几年,由于地震频发,在震裂岩体中修建高速公路隧道越发常见。震裂岩体经过反复的挤压作用变得更为破碎,给隧道安全施工带来了极大的安全隐患。广甘高速隧道隧址区围岩多为震裂岩体且余震频发,施工期隧道曾多次发生初支及二衬开裂甚至塌方等破坏,隧道建设在动力稳定性方面和安全控制措施上缺乏经验而亟待完善。本文以广甘高速隧道科研项目为依托,首先对震裂岩体隧道施工中发生的典型灾害情况进行了统计,概括了隧道震害的影响因素和失稳特征,然后通过数值建模对典型病害断面的结构和围岩在地震作用下的动力响应特性进行了研究,并分析了典型断面的失稳破坏机理。最后综合分析结果,对施工中的安全控制措施进行了归纳。本文的主要研究内容及成果如下：(1)通过大量的文献及震害资料结合广甘高速施工现场情况,对震裂岩体区隧道灾害情况进行统计,归纳概括了地震造成岩体和隧道的损害特点和其影响因素以及广甘震裂岩体隧道的失稳破坏形式和特征。(2)针对广甘隧道典型灾害断面,结合工程地勘资料和现场情况,以数值模拟的方法研究了余震作用情况下施工期隧道不同支护结构作用下的动力响应特征以及断面灾害机理,认为支护结构的存在基本不会影响围岩的动力响应,随着支护刚度的增大结构受到的地震作用越大,并综合分析了断面的失稳病害机理。(3)通过数值模拟对广甘隧道衬砌背后可能存在的空洞情况进行了研究,并分析其对衬砌动力响应特性的影响,分析结果表明空洞的存在不会影响结构其它位置的动力响应规律,只会在空洞附近产生应力集中现象,对一定范围内的结构内力产生影响,并且空洞会降低结构的承载力,认为空洞及余震的影响是导致断面二衬开裂的主要原因。(4)根据广甘隧道群组的现场监测和调研的数据,结合上述对不同支护作用下和空洞缺陷下隧道的数值分析结果,提出相应的安全预防及控制措施。更多还原

【Abstract】 Due to frequent earthquakes in recent years, more and more highway tunnels in our country were constructed inevitably in shattered rock. Shattered rock becomes more broken after repeated rubbing effect, it brought great security risk for safety construction. Many tunnels’surrounding rock in Guanggan are shattered rocks and a number of primary support and secondary lining cracks and even landslides occurred in the construction process under the aftershock, so its method needs to be improved because of lacking experience in its seismic stability analysis and safety control measures. This dissertation is based on the Guanggan highway tunnel research project. Firstly, the disasters that occurred in shattered rock are summarized and the influencing factors of tunnels’ seismic damage are studied. Then the dynamic response characteristics of the structure and surrounding rock under seismic action are studied. Lastly, this paper summarized the possible factors and mechanism of typical section’s instability under the dynamic action and studied the safety control measures during the construction. The main research contents and results are as follows:(1) By combining extensive literature and research data with the surrounding rock case revealed by the construction site, we make a count on surrounding rock in the earthquake area, generalized the shattered rock mass damage cases and their influencing factors.(2) Based on the engineering geological survey information and site conditions of Guanggan highway tunnels, the dynamic response characteristics of tunnel support structure in typical section during construction under the earthquake are analyzed by the method of numerical modeling. The presence of the supporting structure basically will not affect the dynamic response of the surrounding rock, and support with greater rigidity has bigger earthquake response, the parts which have largest dynamic response mainly exists in the spandrels and springing.(3) Cavity may exist behind the lining of Guanggan highway tunnels. By analysis of lining’s dynamic response characteristics, the results show that the presence of cavity does not affect the dynamic response law of other position of the structure, only leaves concentration phenomenon of the stress near the cavity, the structural forces generated within a certain range, and cavities will reduce the bearing capacity of the structure. Cavity and aftershocks is the main reason that led to the cracking of second lining according to the analysis.(4) According to the on-site monitoring and research data, combined with the results of dynamic response characteristics under different lining and cavity situation, the corresponding safety prevention and control measures are proposed.更多还原