土工格栅加筋土路基的现场对比试验研究

Field test comparison of geogrid reinforced soil embankment

依托十房高速公路加筋土路基试验段，采用HDPE土工格栅和PET土工格栅进行加筋土路基的现场对比试验研究。测试结果表明：加筋能有效地约束路基的侧向变形，实测HDPE格栅的拉伸应变范围在0.38%-1.22%之间，PET格栅的拉伸应变范围在0.29%-0.83%之间，加筋土路基的最大水平位移发生在路基的顶部附近。HDPE格栅应变沿筋材长度方向逐渐减小；PET格栅应变在底部呈现出双峰值分布；水平土压力沿加筋路基高度呈非线性分布，水平土压力在中上部接近朗肯主动土压力值，但下部小于主动土压力值；延伸率低土工格栅加筋土路基表现出更好的整体性，其墙体侧向变形小，而墙后水平土压力则较大。

To study the performance of HDPE and PET geogrid reinforced soil embankment, a series of field tests are carried out in Hubei Shiyan-Fangxian Expressway. Test results show that geogrid reinforced embankment has good performance and effectively prevent large lateral deformation of embankment. The tested tensile strain for HDPE section ranges from 0.38 %to 1.22%, and 0.29%to 0.83%PET section, the maximum horizontal displacement of reinforce soil embankment occurs near the top of the wall. For HDPE geogrid reinforced embankment, strain descends along longitudinal direction of the reinforced material;at the bottom of PET geogrid reinforced soil embankment, strain shows a bimodal distribution. Horizontal earth pressure shows non-linear distribution along the height of reinforced soil embankment;the soil pressure at the upper part approaches the active Rankine earth pressure, but the soil pressure at the bottom part is less than the active earth pressure. Reinforced soil embank-ment with geogrid with low elongation shows the good integrity, the lateral displacement of embankment is small, however, the lateral soil pressure behind the reinforced soil embankment is large.