摘要
利用推导出的频域内饱和土的以土骨架位移u和孔隙水压力p表示的u-p格式的2.5维有限元方程,分析列车低速和高速运行条件下不同隔振措施的隔振效果,包括空沟、填充沟(混凝土墙)和混凝土板(波阻板)。其中轨道被简化为饱和地基上的Euler梁,通过沿轨道方向的波数变换将三维空间问题降为平面应变问题,对求解的结果进行Fourier反变换,获得三维时域-空间域内的解。研究表明:弹性地基和饱和地基上设置空沟和填充沟隔振效果相差不大,而设置波阻板隔振效果存在较大差异。列车低速运行时,空沟基本无隔振效果,填充沟在一定范围内有隔振效果,波阻板隔振效果最好;列车高速运行时,空沟在较大沟宽和较深沟深条件下才能达到较好隔振效果,填充沟和波阻板只需较小尺寸就能达到理想的隔振效果。
The u-p （representing displacement of soil skeleton u and pore water pressure p） format 2.5D finite element equation of the saturated soil in the frequency domain is used to analyze the effectiveness of different vibration isolation countermeasures in isolating ground vibrations induced by trains moving at sub-and high-speeds. The vibration-isolation countermeasures considered herein include the installation of open trench, in-filled trench （concrete wall）, and concrete slab （wave impeding block, WIB）. The track and the attached sleepers are simplified as Euler beams resting on a saturated ground; the wave-number transform in the load moving direction is applied to reduce the three-dimensional （3D） dynamic problem to a two-dimensional （2D） problem. The 3D dynamic responses of the track and the ground are obtained from the inverse Fourier transform. For isolating the vibrations induced by trains moving at sub speeds, the isolation effectiveness of open trench and in-fill trench at elastic soil and saturated soil are almost the same; while quite different for WlB. In a word, open trench is not effective, in-filled trench is effective within a certain range; WIB is the best choice. For isolating the vibrations induced by trains moving at high-speeds, open trench can get certain effective at bigger width and depth, in-filled trench and WIB can achieve the desired vibration isolation effects at a smaller size.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第7期2191-2198,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.50538010
No.50678128
No.50878155)
上海市重点学科建设项目资助(No.B308)
关键词
饱和土
列车移动荷载
2.5维有限元
地面振动隔振
波阻板
saturated soil
trains moving loads
2.5D finite element
ground vibration isolation
wave impeding block （WIB）
