桥隧相连结构静动力特性影响因素分析

摘要

By using the 3-D static-dynamic FEM method, the influencing factors of the static-dynamic character on the tunnel-bridge structure were studied.In calculation process, the interaction of rock, tunnel liner and abutment were considered, the simplified calculating model was put forward according the character of dynamic FEM and its reliability was testified.The effect of train speed, the ratio of height-to-span of tunnel and the length of abutment entering into tunnel on the static-dynamic characteristics of tunnel were discussed.The calculation results show that the velocity and the braking load of train and the ratio of height-to-span of tunnel have little influence on the static-dynamic character of the structure, and the variation of tunnel stress and deformation are basically within 10％ except the vertical deformation of tunnel.The length of the abutment entering into the tunnel should be over 4 m, so the single-track tunnel-bridge structure has the best mechanical behavior.%采用三维静动力有限元计算方法,对隧道洞口段桥隧相连复杂结构静动力特性的影响因素进行分析.考虑围岩、隧道衬砌以及桥台的相互作用,根据动力有限元的特点建立简化计算模型并验证其可靠性,分析列车速度、高跨比、桥台伸入隧道长度等,对隧道结构的静动力响应的影响.计算结果表明:列车速度、列车制动荷载及隧道高跨比对隧道结构的静动力受力特性影响较小,除竖向位移外,隧道其余应力及位移的变化在10%以内:对于单线桥隧相连结构,桥台伸入隧道长度应达到4 m以上,以保证桥隧相连结构处于相对较佳的受力状态.