高铁隧道支护参数多目标优化研究

Research on multi-objective optimization of support parameters of high-speed railway tunnel

隧道在施工和运营期的安全及建设成本问题是隧道设计关注的首要问题。本研究基于多目标粒子群算法开发了Matlab支护优化程序,选取隧道总支护阻力及支护成本为目标函数,建立了隧道支护优化模型,结合FLAC 3D有限差分软件,以阳山隧道为工程算例进行隧道施工的数值模拟,研究了隧道支护多目标优化问题。结果表明:多目标粒子群算法引入变异算子可提升粒子群空间探索能力,避免陷入局部最优;设置外部存储器可有效提高算法计算速度及精度。多目标粒子群优化算法能够快速搜寻到非劣解集,经筛选、修正得到工程最优解。施工数值模拟表明,与原有设计相比,优化设计的围岩最大竖向位移值增大4.002%,围岩横向位移值无明显变化,围岩最终位移值均低于设计预留变形值,符合工程安全要求;优化设计控制围岩横向变形效果略优于原有设计;优化设计的锚杆轴力无明显变化,保证锚杆的作用效果;优化设计的喷射混凝土最大压应力提高1.614%,最大拉应力降低15.277%,可有效发挥喷射混凝土材料性能,提高岩体整体性及承载力。与原有设计相比,优化设计的支护成本降低10.641%,算法优化效果明显,可保证工程收益。该方法对隧道工程支护方案设计及优化具有一定的参考价值。

The safety and construction cost of tunnels during the construction and operation are primary concerns of tunnel design.In this study,Matlab optimizer for support was developed on the basis of multi-objective particle swarm optimization(MOPSO)algorithm.An optimization model of tunnel support was established with the total support resistance and support cost of tunnels as objective functions.The numerical simulation of tunnel construction was performed in combination with the finite-difference software FLAC 3D and with Yangshan Tunnel as an engineering example and the multi-objective optimization of tunnel support was studied.The results showed that the introduction of mutation operator by the MOPSO algorithm can improve the space exploration capabilities of particle swarms and avoid falling into local optimizations.The installation of external memory can effectively improve the computational speed and accuracy of the algorithm.The MOPSO algorithm can quickly find the non-inferior set for the optimal solution of the project through screening and modification.The construction numerical simulation shows that when compared with the original design,the maximum vertical displacement of the optimized design is increased by 4.002%,and the lateral displacement of the surrounding rock has no obvious change.The final displacement of the surrounding rock is lower than the design reserved deformation value,which meets the requirements of engineering safety.The effect of optimizing design on restraining convergence deformation of surrounding rock is slightly better than original design.When compared with the original design,the axial force of optimized bolt has no obvious change,and the optimal design ensures the effect of the bolt after the optimization.The maximum compressive stress of sprayed concrete is increased by 1.614%,and the minimum tensile stress is decreased by 15.277%.The optimized design can effectively give play to the performance of sprayed concrete,and improve the integrity and bearing capacity of the rock mass.Compared with the original design,the support cost of the optimized design is reduced by 10.641%,and the optimization effect of the algorithm is obvious,which can ensure the engineering income.This method is of certain reference value for the support scheme design and optimization of tunnel engineering.