基于模糊物元模型的节理岩体隧道安全施工方案优化

以大沙湾隧道为背景,为合理选择出节理岩体隧道安全施工方案,从安全、时间和经济三方面综合分析,运用数值模拟分别对双侧壁导坑法、交叉中隔壁法、三台阶七步开挖法进行研究。分析得到隧道围岩位移和应力变化情况,并以3种施工方案下的拱顶下沉、最大主应力、最小主应力、隧道施工成本、施工复杂程度为指标,构建施工方案优选的模糊物元模型,通过计算得出3种施工方案的关联度分别为0.778 9,0.802 1,0.869 0,并按最大关联度原则确定出最优方案为三台阶七步开挖法,与现场所用方法一致。结果表明,在隧道对施工方案优化时考虑隧道施工成本和隧道施工复杂程度是合理的,采用模糊物元模型进行分析是可行的。

Safety Construction Scheme Optimization of Jointed Rock Mass Tunnel Based on Fuzzy Matter Element Model

In the background of Dashawan Tunnel, a construction method for joint tunnel construction of rock masses is chosen rationally, a comprehensive analysis is conducted from three aspects of safety, time, and economy and the numerical simulation is carried out to study the double-sidewall pilot tunnel method, cross-middle wall method and three-step seven-step excavation method respectively. The displacement and stress variation of tunnel surrounding rock are analyzed, and the indexes of vault settlement, maximum principal stress, minimum principal stress, tunnel construction cost and construction difficulty degree under the three construction schemes are taken as indexes. Through calculation, the correlation degree of the three construction schemes is 0.778 9, 0.802 1 and 0.869 0 respectively. According to the maximum correlation principle, the optimal scheme is three steps and seven steps excavation method, which is consistent with the field method. The results show that it is reasonable to consider the tunnel construction cost and the difficulty of tunnel construction when optimizing the construction scheme, and it is feasible to use fuzzy matter-element model to optimize the scheme.