膨胀土地区复合防排水板基床动力特性现场试验  

Field Test on Dynamic Characteristics of Composite Waterproof Plate Subgrade Bed in Expansive Soil Areas

作　　者：段君义[1] 杨啸[1] 杨果林[1] 徐亚斌[1] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《铁道学报》2016年第11期120-125,共6页Journal of the China Railway Society

基　　金：国家自然科学基金(51478484;51278499);铁道部科技研究开发计划(2010G016-B)

摘　　要：为研究膨胀土地区高速铁路复合防排水板基床在不同服役环境中的动力特性,在云桂铁路典型膨胀土路段进行大型现场激振试验,测试基床动应力、振动速度、振动加速度和动位移分布规律。试验结果表明:复合防排水板基床动力特性与服役环境有关;与自然状态相比,降雨工况下动应力较大,振动速度较小;动应力随深度自然状态时呈指数函数衰减,降雨工况时呈自然对数函数衰减;振动速度衰减主要在基床底层,振动加速度随深度大致呈线性衰减;相同深度处,振动速度、振动加速度最大值均发生在轨道中线处或轨道中线侧0.76 m处;路基面动位移随振源距离呈指数函数衰减。In order to study the dynamic characteristics of high-speed railway subgrade bed with composite waterproof plate in expansive soil areas, subjected to different working conditions, a large-scale field excitation test was performed in typical expansive soil section of Yunnan-Guizhou railway, where dynamic stress of sub-grade bed. vibration velocity,vibratory acceleration,and dynamic displacement were tested. The results showed that dynamic characteristics of composite waterproof plate subgrade bed were related to working condi-tions. Compared with the natural state, the dynamic stress was larger under the condition of simulated rainfall, while the vibration velocity was smaller. The dynamic stress went down exponentially along depth in a natural state,and decreased in natural logarithm function in simulated rainfall. The vibration velocity decayed primarily in the underlying subgrade while the vibratory acceleration showed linear attenuation along the depth. At the same depth, the maximum value of vibration velocity and acceleration appeared at the center line of the track or at 0.76 m away from the track center line.The dynamic displacement of subgrade surface went down exponentially with the distance from the vibration source.

关 键 词：膨胀土 动力特性 复合防排水板 基床 现场试验 

分 类 号：TU443[建筑科学—岩土工程]