高速铁路路基全断面沥青混凝土防水封闭结构

提出1种高速铁路路基全断面沥青混凝土防水封闭结构,基于该结构工作状态,分析其主要功能特性,设计碾压密实高模量沥青混凝土。将全断面沥青混凝土防水封闭结构应用于工程试验段,跟踪监测其服役特性。结果表明:试验段轨道结构及路堤基床动力性能均满足规范限值要求;试验段基床含水量维持在8%~18%,受天气影响小,而邻近的纤维混凝土对照段基床含水量为10%~35%,随天气波动显著;试验段沥青混凝土的吸热作用,使得路肩处基床温度较对照段大;试验段路基竖向变形监测值较对照段稍大,但均满足限值要求;试验段沥青混凝土与底座等接触情况良好,无松散剥落等病害,仅在底座板接缝处有数条裂缝,而对照段出现较多的纵横向裂缝,严重影响其防水封闭效果;沥青混凝土修补方便,可维护性高。

Full-Section Asphalt Concrete Waterproof Sealing Structure for High Speed Railway Subgrade

A kind of full-section asphalt concrete waterproof sealing structure for high speed railway subgrade was proposed.Based on its working state,the main functional characteristics were analyzed,and the roller-compacted high elastic modulus asphalt concrete was designed.The full-section asphalt concrete waterproof sealing structure was applied to an engineering test section to track and monitor its service performances.Results show that both the track structure of the test section and the dynamic performance of the embankment bed meet the requirements of the specification limits.The water content in the subgrade bed of the test section is maintained at 8% ~18%,which is less affected by the weather.However,the water content in the subgrade bed of the adjacent contrastive section with fiber reinforced concrete is 10%~35%,which fluctuates significantly with the weather.The heat absorption effect of asphalt concrete in the test section makes the temperature of the subgrade at the shoulder larger than that in the contrastive section.The monitoring value of the subgrade vertical deformation in the test section is slightly larger than that in the contrastive section,but all of them meet the limit requirements.The asphalt concrete in the test section is in good contact with the base,and there are no such diseases as looseness or spalling.Only a number of cracks are found at the joints of the base plates.However,there are more longitudinal and transverse cracks in the contrastive section,which seriously affect the waterproof and sealing effects.Besides,the asphalt concrete is easier to repair,showing high maintainability.