本文選題：剪脹特性 + 三向土工格柵��； 參考：《施工技術(shù)》2015年S2期

【摘要】：采用大型直剪儀,對(duì)三向土工格柵加筋北京地區(qū)砂土的界面剪脹特性進(jìn)行了試驗(yàn)研究,通過大型直剪試驗(yàn)?zāi)M砂土加筋時(shí)的剪切作用過程,得出了以下結(jié)論:1砂土在剪切過程中都是由短暫的剪縮效應(yīng)發(fā)展為穩(wěn)定的剪脹效應(yīng);2在低含水率時(shí)砂土的剪脹效應(yīng)較明顯,隨著含水率的增加,剪脹效應(yīng)有一個(gè)先降低后升高的過程,當(dāng)含水率增大到12%且豎向應(yīng)力為215~323k Pa時(shí),砂土的剪脹效應(yīng)會(huì)超過含水率為2.5%時(shí)的剪脹效應(yīng);3當(dāng)豎向壓力小,砂土較為松散時(shí),砂土基本沒有剪脹效應(yīng),但是隨著豎向壓力的增大,砂土的剪脹效應(yīng)經(jīng)歷從無到有并且是先升高后降低的過程。當(dāng)豎向應(yīng)力在215~323k Pa時(shí)剪脹效應(yīng)最顯著;4格柵加筋可以降低砂土的剪脹效應(yīng),并且壓力越大降低效果越明顯。
[Abstract]:In this paper, the interfacial shear dilatancy of sand reinforced by three direction geogrid in Beijing area is studied by using a large direct shear apparatus, and the shear process of reinforced sand is simulated by large scale direct shear test.The following conclusions are drawn: the shear dilatation effect of sand with low moisture content is obvious, and the shear dilatation effect is obvious with the increase of water content, and the shear dilatation effect of sand is changed from the transient shear shrinkage effect to the stable shear dilatancy effect in the shear process.When the moisture content increases to 12% and the vertical stress is 215323kPa, the shear expansion effect of sand will exceed that of 2.5 when the vertical pressure is small and the sand is looser.There is no shear expansion effect in sand, but with the increase of vertical pressure, the shear expansion effect of sand goes from scratch to existence and then decreases.When the vertical stress is at 215223kPa, the shear expansion effect is the most obvious and the shear expansion effect can be reduced with the reinforcement of the grid, and the greater the pressure is, the more obvious the shear expansion effect is.
【作者單位】： 北京工業(yè)大學(xué)城市與工程安全減災(zāi)教育部重點(diǎn)實(shí)驗(yàn)室;
【基金】：高等學(xué)校博士學(xué)科點(diǎn)專項(xiàng)科研基金(20121103110022) 北京工業(yè)大學(xué)研究生科技基金(ykj-2014-10632)
【分類號(hào)】：TU411
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本文編號(hào)：1750331