摘要
小净距上下重叠地铁隧道的地基土在列车的长期运营振动作用下相较于一般地铁隧道的地基土更易出现长期变形。在此背景下,采用2.5维数值方法,对成都地铁6号线某小净距上下重叠隧道区段地基土在上下侧隧道单独行车及上下侧隧道同时行车情况下的动力响应进行了计算及分析,明确了该区段地基土在不同列车荷载作用下的动力响应特征。分析结果表明:①在近隧道位置,地铁列车运行引发的垂向正应力往往比其他应力分量更大,但列车引发的沿线路纵向的切应力也具有较大的量值;②上侧隧道行车会造成下侧隧道地基土产生相当量值的主压应力;③相比于单一列车到达,上下侧隧道中列车同时到达会显著增大地基土的动应力量值;④对考虑的小净距上下重叠地铁隧道地基土在运营期间的长期变形及稳定性应给予足够的重视。
Under metro train loads,the foundation soil surrounding small-spaced vertical-overlapped metro tunnels is more likely to incur long-term deformation than that surrounding the common metro tunnel.With this context,the dynamic responses of the foundation soil surrounding small-spaced vertical-overlapped tunnels at a section of Chengdu Metro Line 6 was computed and analyzed by the 2.5-dimensional(2.5D)numerical method,and the dynamic response characteristics of the foundation soil under different train loads were clarified.The analysis results show that:①in the foundation soil near the tunnel,the vertical normal stress induced by the moving metro train is generally greater than other stress components,but the longitudinal shear stress induced by the moving train also has a considerable magnitude;②the metro train that operates in the upper tunnel will cause considerable principal compressive stress in the foundation soil of the lower tunnel;③compared with the arrival of a single train,the simultaneous arrival of two trains operating in both the upper and lower tunnels will significantly increase the dynamic stress in foundation soil;④sufficient attention should be paid to the long-term deformation and stability of the foundation soil of small-spaced vertical-overlapped metro tunnels during their operation.
作者
有智慧
马龙祥
农兴中
张超
YOU Zhihui;MA Longxiang;NONG Xingzhong;ZHANG Chao(Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010,China;Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第22期223-227,267,共6页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(51608456)
中央高校基本科研业务费专项资金资助项目(2682017CX003)。
关键词
上下重叠隧道
地基土
列车荷载
振动响应
2.5维方法
vertical-overlapped tunnels
foundation soil
train load
vibration response
2.5D approach
