HDPE和PET土工格栅加筋路堤作用的对比研究

为了研究高密度聚乙烯（HDPE）和聚对苯二甲酸乙二醇酯（PET）两种土工格栅在返包式加筋路堤中的加筋效果，基于HDPE和PET的拉伸试验结果，采用FLAC3D有限差分程序并结合现场监测数据对比，分析了加筋路堤中两种土工格栅的受力变形规律。结果表明，土工格栅特性对返包式加筋路堤变形具有明显影响，影响程度与其上部土压力大小密切相关；在加筋土路堤的中下部，土压力较大，HDPE格栅前1/3段和后1/3段的应变存在较大差别，PET格栅的应变沿长度分布相对均匀；随着上部土压力的减小，格栅材料特性的影响减弱，两种格栅的应变曲线趋于接近；PET格栅对加筋路堤水平变形的控制作用更为明显；HDPE格栅加筋路堤的垂直和水平土压力值及其分布与PET加筋路堤差别很小。

Comparison study of reinforcement effect of HDPE/PET geogrids in fill embankment

In order to figure out the difference of reinforcement effect between high-density polyethylene(HDPE) geogrids and polyethylene terephthalate(PET) geogrids in fill embankment with wrapped face, based on tensile tests of two geogrids, this paper analyzes the force-deflection characteristics of two different geogrids-reinforced embankment by means of FLAC3D and some in-situ tested data. The results show that the mechanical properties of geogrids have an obvious influence on the displacement of reinforced embankment; and the influence is related to its overlying earth pressure. In the middle and lower part of the embankment, because of the higher earth pressure value, there exists a relatively huge variance in strain value of HDPE geogrids along its length, and the variance of strain value of PET geogrids is within a narrow range; in the upper part of the embankment, the less earth pressure value leads to the lower strain value of geogrids and there is no various strain difference between the two types of geogrids. PET geogrids are better than HDPE geogrids in the effect of controlling displacement of the reinforced embankment. The distribution of vertical and horizontal earth pressures has less difference between PET and HDPE reinforced embankment.