挖填交界区格栅加筋路堤的试验和数值模拟分析  

Field test study and numerical analysis of a cut-and-fill embankment reinforced with geogrid

作　　者：马强[1] 李丽华[1] 肖衡林[1] 

机构地区：[1]湖北工业大学土木工程与建筑学院,武汉430068

出　　处：《岩土力学》2013年第10期3011-3017,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51208187);教育部重点项目(No.2010133);湖北省科技厅重点项目(No.2010CDA063)

摘　　要：在对半挖半填路堤病害及成因分析的基础上,分析了加筋路堤格栅工作机制。通过现场试验,对采用格栅加筋法处理的路堤挖填交界区域进行了原位观测,观测了路堤填土完成时路面沉降、竖向土压力及格栅变形情况。通过建立有限元分析模型,对路堤填筑完成时格栅的拉力及位移进行了分析,并对不同路面荷载和格栅刚度条件下,格栅的拉力与位移进行了计算。结果表明:路堤挖填交界处铺设格栅后,路面局部差异沉降较小。填方区域格栅底部土压力与填土自重应力相当,格栅存在有效加筋长度,在挖填交界面附近产生较大变形和拉力。上层格栅比下层格栅沉降曲线平缓,下层格栅的拉力在交界区域会陡然增大。路面荷载对格栅拉力和位移有一定影响,随埋深增加影响减小,格栅的竖向位移随着荷载增大略有增大,格栅在挖填交界面附近拉力增大。随格栅刚度增大,其拉力也增大,而位移变化很小。Based on analyzing the mechanisms of the pavement diseases in the cut-and-fill embankment, the working mechanism of the geogrid reinforcement is analyzed. A series of field tests are carried out to investigate the vertical displacements of the pavement, the vertical earth pressures in the embankment fill and the tensile forces of the geogrid. In addition, a numerical model is established for simulations according to the dimensions of the embankment in situ. Through the numerical simulations, the tensile forces and the vertical displacements are observed after the period of construction of the embankment. The tensile forces and the displacements of the embankment are studied, in condition, different vertical loads act on the pavement, and the geogrid with different elongation stiffnesses is spread. The results show that, the geogrid used for cut-and-fill embankment treatment can alleviate the differential settlement of the cut-and-fill embankment. The vertical earth pressures are almost equal to the weight of the overlying embankment fill. The reinforcement of the geogrid has an effective length, the tensile forces and displacements of the geogrid layers are greater at the junction of the cutting and filling areas; the settlement of the upmost geogrid is the smoothest, while the tensile force of the geogrid at the bottom of the embankment increases sharply at the junction. Vertical loads have limited influences on the tensile forces and the displacments of the geogrid layers; and the influences are gradually reduced with the increase of buried depth of the geogrid. The settlements of the geogrid layers increase slowly with the increase of the vertical loads on the pavement; and the geogrid layers at the junction area have the greatest tensile forces. With the increase of elongation stiffness of the geogrid, the tensile forces of the geogrid increase obviously, while the displacement changes very negligible.

关 键 词：半挖半填路基 土工格栅 原位测试 数值模拟 拉力 位移 

分 类 号：O241[理学—计算数学]