摘要
首先介绍了传统设计方法的优缺点,并分析了数值极限分析方法在隧道设计中的可行性。给出了隧道围岩、初期支护和二衬安全系数计算方法,对隧道结构安全性评价提出了量化指标。指出了该方法不仅可计算每个施工步的安全系数还可通过安全系数优化设计方案,同时考虑隧道的安全性和经济性。其次强调了隧道初期支护的重要性,认为初期支护在保证隧道施工安全中起到了关键作用,传统计算方法将初期支护视为弹性材料是不合理的。将初期支护视为弹塑性材料,认为初期支护作为围岩加固材料并承担主要围岩压力,二衬视为安全储备承担较少荷载,且初期支护和围岩最先进入塑性阶段。最后通过工程案例说明了数值极限分析方法在土体隧道设计中的应用。
Firstly,the advantages and disadvantages of the traditional design method were introduced,and the feasibility of the numerical limit analysis method was analyzed. The calculation method of the safety factor of tunnel surrounding rock,primary support and secondary lining was given,and the quantitative index was put forward to test the tunnel structure. It is pointed out that this method can not only calculate the safety factor of each construction step but also optimize the design scheme by the safety factor. Secondly,it emphasized the importance of the primary support,believing that primary support played a key role in ensuring the safety of tunnel construction. It is unreasonable to consider the primary support as an elastic material in traditional calculation method. The primary support is regarded as an elastic-plastic material,which is considered as a supporting material for surrounding rock and bears the main surrounding rock pressure,the secondary lining is considered as a safe reserve,and the primary support and surrounding rock is the most advanced into the plastic stage. Lastly,the application of numerical limit analysis method is illustrated by the given engineering case in tunnel design.
出处
《地下空间与工程学报》
CSCD
北大核心
2017年第S2期720-725,共6页
Chinese Journal of Underground Space and Engineering
基金
交通运输部应用基础研究项目(2014319771190)
山西省基础研究(青年科技研究基金)项目(2015021121)
关键词
安全系数
土体隧道
数值极限分析
弹塑性
初期支护
二衬
safety factor
soil tunnel
numerical limit analysis
elastoplasticity
primary support
secondary lining
