摘要
盾构法由于具有掘进速度快、自动化程度高、对环境影响小等优势,在我国城市轨道交通隧道施工中得到了广泛应用。实际施工时,盾构隧道有时会偏离原设计值,需通过调线调坡进行调整。但可能会造成部分地段轨道结构高度低于设计值,如果减薄道床结构,会影响整体道床的安全性。以实际工程为例,考虑钢轨、扣件、轨枕和道床等结构,建立仿真分析模型,通过结构强度及耐久性检算,对列车垂向荷载作用下整体道床减薄结构的力学特性进行研究。计算结果表明:相对于原设计的740 mm,轨道结构高度降低到700 mm或691 mm/690 mm时,道床和轨枕结构的应力均小于规范规定的设计值;各向变形量也很小,远小于1 mm。由计算结果分析可知,道床结构减薄40~50 mm,轨道结构仍是安全、可靠的,但需在隧道基底上采用可靠方式加强与道床结构之间的连接。
Shield tunnels are widely applied in urban rail transit tunnel construction due to their advantages of high driving speed,high degree of automation and low environmental impact.In actual construction,adjustment by tuning the route and slope is needed occasionally because of the deviations from design values generated by shield tunnels.The height of track structure is lower than the design value in some sections,roadbed structure is thinned,and the safety of integral roadbed is affected.Taking an actual project as an example,simulation analysis model is established,considering rail,fastener,sleeper and roadbed.By the check of structural strength and durability,mechanical characteristics of thinned structure of integral roadbed under vertical load of train are analyzed.The results show that,compared to originally designed 740 mm,with the track structure height reduced to 700 mm or 691 mm/690 mm,the stresses of roadbed and sleeper are less than the design values specified in the code and the deformations in each direction are less than 1 mm.The analysis of the calculation results shows that the track structure remains safe and reliable while roadbed structure is thinned by 40~50 mm.However,it is necessary to strengthen its connection with the track bed structure in a reliable way on the tunnel base.
作者
曲村
孙大新
陈鹏
QU Cun;SUN Daxin;CHEN Peng(Beijing Urban Construction Design&Development Group Co.,Ltd.,Beijing 100037,China;Beijing Engineering Research Center of Track Structure,Beijing 100037,China;National Engineering Laboratory for Green&Safe Construction Technology in Urban Rail Transit,Beijing 100037,China)
出处
《铁道标准设计》
北大核心
2022年第4期49-54,61,共7页
Railway Standard Design
基金
北京市科技计划课题(Z151100001315008,Z171100002117003)。
关键词
城市轨道交通
盾构隧道
整体道床
结构减薄
列车垂向荷载作用
力学特性
urban rail transit
shield tunnel
integral roadbed
thinned structure
vertical load of train
mechanical characteristics
