高速铁路土工格栅加筋土挡墙服役期力学行为研究

为揭示高速铁路加筋土挡墙服役期间的力学行为,对山东省青(岛)荣(成)城际铁路土工格栅加筋土挡墙进行了竣工后48个月的长期远程观测试验,研究加筋土挡墙工后力学行为的演化规律,分析加筋土挡墙墙面、墙体内及墙背位置的侧向土压力,墙体基底竖向应力及筋材拉力的实测数据分布规律和服役期的变化情况。试验结果表明:加筋土挡墙墙面及墙内位置的侧向土压力随时间基本保持稳定,工后48个月期间墙面板背部的侧向土压力约为竣工时的98.2%。加筋土挡墙墙体竖向应力在工后48个月期间基本保持稳定。墙面处土工格栅的拉力是约束墙面变形并减小墙面侧向土压力的主要因素之一,加筋土挡墙的工后变形能够满足高速铁路对于路基变形的要求。

Research on Mechanical Behaviour of High-speed Railway Geogrid Reinforced Soil Retaining Wall During Service Period

In order to reveal the mechanical behavior of high-speed railway geogrid reinforced soil(GRS)retaining walls during service,a 48-month long-term observation experiment was conducted on the GRS wall of Qingdao to Rongcheng intercity railway in Shandong province after the completion of the project.The pattern of post-construction mechanical behaviors of reinforced earth retaining walls was studied.An analysis was made on the lateral earth pressures on the panel,inside and at the back of the GRS wall,and the measured data distribution of the vertical stress of the wall base and the tensile strength of the reinforcements as well as their changes during the service period.The test result shows that the lateral earth pressure on the wall panel and inside the wall maintains stable over time,and the lateral earth pressure at the back of the panel during the 48 months after project completion is about 98.2%of that at the time of project completion.The vertical stress inside the wall is basically constant during the 48 months after construction completion.The tensile force of the geogrid at the wall surface is one of the main factors that restrain the deformation of the wall and reduce the lateral earth pressure on the wall.The post-construction deformation of the reinforced earth retaining wall can meet the deformation requirements of the high-speed railway subgrade.