可液化砂土地铁列车振动作用下沉降特性分析

Liquifiable sandy settlement characteristics analysis under metro train vibration load

地层的不均匀以及一些特殊地层的存在,对列车振动荷载作用下的长期差异沉降具有较为显著的影响,直接影响到地铁列车营运期的长期安全问题。以佛山地铁2号线为例,通过数值模拟的方法对加固前与加固后可液化砂土层中的结构受力与地层沉降进行了具体分析,研究结果表明列车振动荷载对结构和地层整体影响较小,产生的位移较小。在列车长期循环振动荷载作用下,隧道会产生长期的沉降,沉降量初期发展较快、后期发展缓慢。对可液化地层进行注浆加固可以显著减少隧道沉降量。

Stratigraphic inhomogeneity and special strata have the significant impact on long-term differential settlement under the train vibration loads,which even directly affect long-term safety in the process of train operation.Considering the Foshan Metro Line 2 as an example,the structure stress and the stratum settlement are analyzed in detail through numerical simulation methods before and after strengthening.The study results indicate that the metro train vibration load has less influence on structure and the overall stratum.The tunnel has a long-term settlement under the long-term train vibration load circularly.The settlement value develops rapidly in early stages but turns slowly in later stages,which is reduced significantly after the grouting reinforcement of liquefiable stratum.