超高无面板式土工格栅加筋路堤现场试验研究

发布时间：2018-07-29 08:16

【摘要】：结合在建宜巴高速公路50 m高的加筋填土断面进行现场试验,对超高无面板式土工格栅加筋路堤的格栅变形、垂直土压力、水平土压力、分层沉降以及深层水平位移等内容进行了近2 a的测试,研究超高无面板式土工格栅加筋土路堤的受力、变形规律,分析了其作用机理。结果表明:不同层位土工格栅的最大拉应变出现在离返包面约4~6 m处,格栅应变沿筋长呈双峰值分布,施工期土工格栅应变具有明显的滞后性,且工后1.5 a格栅出现明显的收缩回弹;土工格栅的存在对土压力分布具有明显的调整作用,格栅末端附近实测垂直土压力值略超过理论值,中间和近坡面部位实测土压力值小于理论值;水平土压力沿路堤高度呈非线性形式分布,路堤中部的水平土压力值略大于顶部,其值小于主动土压力;分层沉降量在施工期存在较大波动,在垂直高度上,上部和底部偏小,中下部偏大;深层水平位移随着深度的增加逐渐减小,填土结束后深层水平位移仍有一定程度增大。
[Abstract]:Combined with field test on reinforced soil section of 50 meters high in Jianyiba Expressway, the grid deformation, vertical earth pressure and horizontal earth pressure of super-high non-faced geogrid reinforced embankment are studied. The delamination settlement and deep horizontal displacement were measured for nearly 2 years. The stress and deformation law of super-high slab geogrid reinforced earth embankment were studied and its action mechanism was analyzed. The results show that the maximum tensile strain of different layers of geogrid occurs at about 4 ~ 6 m from the back envelope, and the strain of geogrid is distributed with two peaks along the reinforcement length, and the strain of geogrid has obvious hysteresis during the construction period. The earth pressure distribution was adjusted obviously by the existence of geogrid, and the measured vertical earth pressure near the end of the grid slightly exceeded the theoretical value. In the middle and near slope, the measured soil pressure is less than the theoretical value, the horizontal earth pressure distributes in nonlinear form along the embankment height, the horizontal earth pressure in the middle of the embankment is slightly larger than that in the top, and its value is smaller than the active earth pressure. In the vertical height, the upper and bottom parts are smaller, and the middle and lower parts are larger. The deep horizontal displacement decreases gradually with the increase of depth, and the deep horizontal displacement increases to a certain extent after the end of the fill.
【作者单位】：同济大学地下建筑与工程系;同济大学岩土及地下工程教育部重点实验室;浙江省交通规划设计研究院;
【基金】：国家自然科学基金项目(40972214) 湖北省交通科学研究计划项目(2011700342)
【分类号】：U416.12

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