机构地区:[1]华东交通大学轨道交通基础设施运维安全保障技术国家地方联合工程研究中心,江西南昌330013
出 处:《交通运输工程学报》2019年第6期54-64,共11页Journal of Traffic and Transportation Engineering
基 金:国家自然科学基金项目(51908215);江西省自然科学基金项目(20181BAB216030);江西省教育厅科学技术研究项目(GJJ170399)。
摘 要:为研究铁路路基翻浆冒泥的发生机理,进行了大量调查,总结了目前铁路2种较易发生翻浆冒泥的路基模型;建立了循环列车荷载作用下土中振动孔压增长与消散规律的控制微分方程,计算了土中孔压比的增长规律,判断其是否会液化而引发翻浆冒泥;分析了普铁和高铁列车运行速度、列车轴质量、土的固结系数、固结应力比和围压对翻浆冒泥的影响。分析结果表明:路基在列车荷载和水的持续共同作用下,土中孔压比随列车荷载振次的增加而迅速增大,但是其增长速度处于持续减小的状态,最终趋于稳定;土中孔压比随深度的增加呈先增大后减小的变化形式,且其最大值通常在距土层表面0.6 m处;列车运行速度越大,土中孔压比增长越快,越容易发生翻浆冒泥,当速度为200 km·h-1时,普铁路基土发生翻浆冒泥所需振次为高铁路基的19%;列车轴质量越大,土中孔压比增长越快,当轴质量为18 t时,普铁路基土液化所需振次为高铁的24%;增大土的固结系数能降低孔压比的增速,路基土达到液化所需振次就越多,从而越难发生翻浆冒泥;等压固结时路基土比偏压时更容易发生液化而形成翻浆冒泥;增大围压能够降低孔压比的增速,路基土也就更难发生液化,发生翻浆冒泥的可能性就越小;普铁路基发生翻浆冒泥的可能性比高铁线路中更高。In order to study the mechanism of mud pumping in railway subgrade, many investigations were conducted and two subgrade models that prone to mud pumping in current railways were summarized. A governing differential equation for the description of the increase and dissipation rule of vibration pore-water pressure in subsoil under cyclic train load was established. The growth law of pore-water pressure ratio in subsoil was calculated, which accordingly decided whether the subsoil was liquefied to cause the mud pumping. The effects of different parameters, such as train operation speeds, axle weighings of train, consolidation coefficients of subsoil, consolidation stress ratios and confining pressures on mud pumping, were analyzed for the general-speed and high-speed railways. Analysis result indicates that when the subgrade is under the continuous combined action of train load and water, the pore-water pressure ratio in subsoil grows quickly with the increase of vibration number of train load, but its growth rate continuously decreases and its value stabilize in final. With the increase of the depth, the change pattern of the pore-water pressure ratio in subsoil grows first and then falls. Its value is normally largest at 0.6 m under the surface of subsoil. The faster the train speed is, the quicker the pore-water pressure ratio grows, and the simpler the mud pumping takes place. When the train speed is 200 km·h-1, the vibration numbers for mud pumping to appear in subsoil under general-speed railway are 19% of that under high-speed railway. The pore-water pressure ratio grows quicker as the axle weighing of train increases. When the axle weighing is 18 t, the vibration number for mud pumping to appear in subsoil under general-speed railway is 24% of that under high-speed railway. Increasing the consolidation coefficient of subsoil can reduce the growth rate of the pore-water pressure ratio, and the subsoil will need more vibration number to liquefy, which makes it more difficult for mud pumping to appear. The sub
关 键 词:铁道工程 翻浆冒泥 路基模型 列车荷载 振动孔压 影响因素
分 类 号:U216.41[交通运输工程—道路与铁道工程]
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