基于改进TOPSIS法研究隧道施工方案优化

Study on tunnel construction scheme optimization based on improved TOPSIS method

由于城市地铁周围环境复杂,隧道稳定性难以得到保证,故合理地选择隧道施工方案是顺利施工的前提。考虑到客观环境和人工操作等因素,选择开挖顺序,初支封闭时间,加固范围和参数作为影响隧道稳定性的主要因素,并根据影响因素构建L16(4×4)正交表进行正交试验,对试验方案进行数值模拟。以隧道收敛变形和围岩应力为评价指标,建立改进TOPSIS评估模型,并将最优方案用于北京地铁17号线天通苑站项目。研究结果表明:工况5的相对贴近度最低,其值为0.1827,故工况5为最优方案;最优方案比实际工程地表沉降小5.9%,说明改进TOPSIS法是可以广泛应用于浅埋暗挖大断面隧道工法优化,对于复杂隧道工程也有借鉴意义。

Due to the harsh environment around the city subway,poor geological conditions,and difficult to ensure the stability of the tunnel,a reasonable choice of tunnel construction plan is a prerequisite for successful completion.Taking into account the objective environment and manual operation factors,the excavation sequence,the initial support closure time,the reinforcement range and parameters are selected as the main factors affecting the stability of the tunnel,and the L16(4×4)orthogonal table is constructed according to the influencing factors.The test was carried out and the test plan was numerically simulated.Finally,based on the tunnel convergence deformation and surrounding rock stress as the evaluation index,an improved TOPSIS evaluation model was established,and the optimal scheme was applied to the Tiantongyuan Station project of Beijing Metro Line 17.The research results show that the relative closeness of working condition 5 is the lowest,its value is 0.1827,so working condition 5 is the optimal solution;the optimal solution is 5.9%smaller than the actual engineering surface settlement,indicating that the improved TOPSIS method can be widely applied to shallow burial.The optimization of the method of excavating large-section tunnels is also useful for intricate tunnel engineering.