【作者】 张孝伟；

【导师】 张永兴；

【作者基本信息】 重庆大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 随着我国高等级多车道公路建设的发展,特大断面大跨度隧道越来越多。但是,我国现行的公路隧道规范只提供了三车道和两车道隧道复合式衬砌的设计参数,目前,四车道公路隧道在设计和施工时一般是借鉴三车道公路隧道的设计理论和施工方法,以及已建相似工程的资料,由此可能造成支护不力等严重问题。本文通过理论研究、经验方法和数值分析等手段研究了隧道跨度对围岩支护需求的影响,主要工作包括以下几个方面的内容:①分析了隧道围岩受力特征受跨度的影响,通过理论分析及数值模拟重点研究了应力重分布情况随跨度的变化规律。并对支护压力随跨度的变化考虑深埋隧道和浅埋隧道两种情况分别进行了分析。②在综述国内外锚喷支护参数经验方法的基础上,总结了锚喷支护参数取值与跨度之间的关系,并提出了对现行技术规范的修正意见;在围岩分级的基础上,利用弹塑性有限元法研究了三种级别围岩中不同跨度隧道的锚喷支护效果。③以白鹤咀城市公路隧道为工程实例,通过监控量测和施工过程的数值模拟分析了隧道支护方案的合理性。验证了本文研究成果在实际工程中的可行性。④研究了同级围岩不同跨度隧道开挖方法的选择与跨度之间的关系,总结了适合四车道公路隧道的开挖方法。对大跨度隧道的设计与施工提出了合理的建议。本论文的研究成果对大跨度隧道的优化设计和安全施工提供了理论指导,对保证施工安全以及提高设计针对性方面具有重要的工程实践意义。更多还原

【Abstract】 With the fast development of highway in our country, more and more large-span tunnels have been constructed. However only the support parameters of three lane and two lane road tunnel are included in Tunnel Standard Graduation Method .The four lane road tunnel just can be designed by analogy of large-span tunnel having been constructed at present. Much problem arises, for example, incorrect design and so on .The paper uses theoretical study, empirical method and numerical analysis to analyze the influence of tunnel span on the support requirement of surrounding rock, the main work of this paper are summed up as follows:①It analyzed that the stress characteristics of surrounding rock changes with tunnel spans. It is mainly the change of redistribution stress after excavating with different spans. Then it analyzed the change of support pressure with span. Deep-buried and shallow tunnels are analyzed respectively.②Based on empirical methods of bolt-shotcrete support at home and abroad. The relationships between bolt-shotcrete support parameters and span are summarized. Supplementary formulas to current technical specification are suggested. On the basis of classification of surrounding rock, the bolt-shotcrete support effect is also studied using the finite element analysis method.③Studying the case of BaiHezui urban highway tunnel, the supporting schemes of two computation cross-sections with different spans are analyzed using analysis of monitoring data and the finite element analysis method .It verified partial research results of this paper.④New Austrian Tunneling Method is frequently used all over the world recently. The relationship between the selecting of tunnel excavation method in the same rock mass and tunnel span is studied. Tunnel excavation methods of the four lane road tunnel are summarized.This paper concerns designing and construction of tunnel. It provides a theoretical guidance to optimum design and construction safety. So, the paper has important meaning for engineering practice.更多还原