土工格栅拉拔特性及加筋土剪胀性试验研究

TEST RESEARCH ON PULL-OUT BEHAVIOR OF GEOGRID AND DILATANCY OF REINFORCED SOIL

土工格栅通过筋土界面相互作用能起到很好的加筋效果,在许多工程中得到了广泛运用。拉拔试验是研究筋土界面相互作用的重要手段之一。通过室内拉拔试验,对竖向荷载、填料密实度以及试验类型对格栅拉拔力的影响规律开展研究,试验结果表明:在高密实度的填料中,随着筋-土界面位移的发展,填料的剪胀现象越明显;填料密实度小,竖向压力大时,剪胀趋势不明显;填料密实度越大,土体剪胀趋势越明显;土体的密实度将直接影响到格栅的加筋效果;对于土体的剪胀,存在一临界点,当格栅拉拔位移大于此临界点时,土体的剪胀趋势将显著发生。

Geogrid has a perfect reinforced effect through reinforcement-soil interaction and has been employed in many projects. Pull-out test is one of important methods to study the interaction between soil and geogrid. Therefore,the influencing law of compactness of filler,vertical load and experiment type on the pull-out force was researched.The experimental results showed： for filler with high compactness,as development of the pull-out displacement,the dilation phenomenon would be more obverious; the soil dilation phenomenon was not evident when the soil compactness was relatively smaller and the vertical load was relatively larger. And when the soil compactness was relatively smaller,the dilation was not obverious. The soil compactness would directly affect the dilation and the reinforced effect of the geogrid. There was a critical displacement for reinforced earth,when the pull-out displacement was larger than the critical one,there would be more evident dilation phenomenon.