列车运行引起的CFG桩复合路基动力响应分析  

Dynamic response of CFG pile composite subgrade induced by moving train loadings

作　　者：高广运[1,2] 李绍毅[1,2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《振动与冲击》2015年第24期135-143,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(51178342)

摘　　要：结合上部列车-轨道模型与下部有限元路基模型,建立了列车-轨道-路基整体动力分析模型,分析了CFG复合路基对地面振动的影响。列车采用多质点弹簧-阻尼器模拟,钢轨采用欧拉梁模拟并考虑了钢轨随机不平顺影响,列车-轨道体系采用振型分解法求解;铁路路基经有限元离散后采用2.5维有限元方法求解,采用粘滞阻尼吸波边界减小边界反射,CFG桩采用等代模量桩墙模拟。分析了CFG桩复合路基对地面振动衰减和振动频谱的影响。结果表明:CFG桩复合路基对地面振动的影响分为CFG桩体的影响和垫层影响;CFG桩体对路基中的高频振动有波导作用,可减小远离路堤的高频振动;复合路基垫层可降低中低频振动。CFG复合路基减小了路堤边缘的高频振动,提高了路堤边坡的动力稳定性。A numerical train-track-subgrade model was established including an upper train-track model and an under subgrade FE model to analyze the influence of CFG pile composite subgrade on the ground vibration. The train was simulated by using a multiple mass-spring-damper model. The track was modeled as a Euler beam with consideration of random rail irregularities. The train-track model was solved by the modal decomposition method. The railway subgrade was discretized and solved by 2. 5D FEM with a viscous damping absorbing boundary to reduce the reflection wave. The CFG pile was modeled as a pile wall with modified elastic modulus. The influences of the CFG pile composite subgrade on ground vibration attenuation and vibration frequency spectrum were discussed. The results show that the influences of the CFG pile composite subgrade on ground vibration are comprised of the influence of CFG pile and the influence of cushion.The CFG pile has the waveguide effect on high frequency vibration and reduces the high frequency vibration originated from the embankment; the cushion of the composite subgrade affects the ground vibration by reducing low and medium frequency vibration. Besides,the composite subgrade reduces the high frequency vibration at the edge of embankment,that improves the dynamic stability of the slope of embankment.

关 键 词：地面振动 CFG桩复合路基 频谱分析 2.5维有限元 波导作用 

分 类 号：TU435[建筑科学—岩土工程]