土工格栅横肋与砂土接触面的细观试验

Mesoscopical Study on Interface Between Transvers Rib of Geogrid and Sand

摘要:

利用拉拔模型试验设备,在不同法向压力下进行一系列的拉拔试验,应用数码可视化跟踪技术,结合土体变形无标点量测技术来研究双向土工格栅横肋与砂土界面相互作用的细观特性.以数码可视化跟踪技术跟踪拍摄土工格栅横肋与砂土界面的相互作用过程,并通过量化分析得到界面的运动变化规律.分析结果表明,拉拔试验的似摩擦系数与上部法向应力相关,细观试验表明横肋与砂土接触的上下界面厚度并不一样,上界面厚度大于下界面厚度,横肋上界面运动较为剧烈.细观试验位移应变图显示,横肋刺入的破坏与Jewell提出的计算模式非常相似,但上部区域略大于下部区域,基本验证了Jewell刺入破坏机理.

Abstract:

Through a series of pullout tests under different vertical stresses,a study was made of the mesoscopical behavior of the interface between two-way geogrid transverse rib and sand based on digital visual tracking technology and no punctuation soil deformation measurement techniques.The interface being traced with the techniques of no punctuation soil deformation measurement,a quantitative analysis was made of the changes of interface movement.Analysis results show that the apparent friction coefficient is related with the vertical stress.Mesoscopical results show the upper interface thickness of transverse rib and sand is different from the lower.In whole,the upper thickness is greater than the lower,and the rib on the interface motion is more intense.The mesoscopical displacement strain plot shows the rib damage model of this research is similar to the piercing damage model proposed by Jewell,but the upper part is slightly larger than the lower of the regional area.Jewell piercing damage model is basically authenticated.