摘要
在传统平面土工格栅基础上增加横肋厚度构成立体格栅网,其增强型横肋产生的被动阻抗作用可有效限制土体变形。为了研究立体格栅网中增强型横肋对筋土界面剪切特性的影响,基于3D打印技术,制作了5种不同横肋厚度(t=3,6,9,12,15 mm)的土工格栅模型,通过室内大型直剪试验分析不同横肋厚度和竖向应力(σ=20,40,60 kPa)对立体格栅网界面直剪特性的影响;并在试验基础上,进一步探讨了剪切模式下增强型横肋厚度对被动侧阻力的影响,提出横肋侧阻力的理论计算公式。结果表明:不同竖向应力下立体格栅网界面(t=6,9,12,15 mm)的破坏剪应力平均值较平面土工格栅(t=3 mm)分别提高了4.2%、19.3%、29.7%和39.1%,界面最终剪胀量分别增加了0.093、0.192、0.282、0.337 mm;增强型横肋的存在提高了界面的似黏聚力和摩擦角,似黏聚力和摩擦角值随着横肋厚度的增加而呈现出递增趋势;建立了横肋对土颗粒提供的被动侧阻力计算公式,并通过直剪试验结果对侧阻力计算公式进行了修正,修正后的理论计算值与试验结果吻合度较好。
The thicknesses of the transverse ribs in conventional geogrids can be increased to form three-dimensional geogrids.The passive resistance provided by strengthened transverse ribs can effectively limit the deformation of soil.By using 3 D printing technology,five geogrids with different thicknesses of transverse ribs(t=3,6,9,12,and 15 mm)were fabricated and the effects of the thicknesses of transverse ribs and normal stress(σ=20,40,and 60 kPa)were investigated through a large-scale direct shear test.The influencing factors of passive resistance in terms of strengthening transverse ribs are discussed and a theoretical calculation formula for passive resistance is proposed.The results demonstrate that the average failure shear stresses of three-dimensional geogrid-sand interfaces(t=6,9,12,and 15 mm)under different normal stresses are increased by 4.2%,19.3%,29.7%,and 39.1%,respectively,compared to a conventional geogrid(t=3 mm).Additionally,the final dilatancy is increased by 0.093,0.192,0.282,and 0.337 mm,respectively.Based on the presence of strengthened transverse ribs,the interfacial apparent cohesion c and friction angleφare also improved and the values of c andφexhibit an increasing trend with increasing thickness of the transverse rib.A theoretical calculation formula for the passive resistance of transverse ribs is established and experimental results are used to verify the theoretical formula.The modified calculation results are in good agreement with the experimental results.
作者
刘飞禹
武文静
符洪涛
王军
王朝亮
李明枫
LIU Fei-yu;WU Wen-jing;FU Hong-tao;WANG Jun;WANG Chao-liang;LI Ming-feng(Department of Civil Engineering,Shanghai University,Shanghai 200444,China;College of Architecture and Civil Engineering,Wenzhou University,Wenzhou 325035,Zhejiang,China;Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation,Wenzhou University,Wenzhou 325035,Zhejiang,China;Innovation Center of Tideland Reclamation and Ecological Protection,Wenzhou University,Wenzhou 325035,Zhejiang,China;Wenzhou Mass Transit Railway Investment Group Co.Ltd.,Wenzhou 325024,Zhejiang,China;Ruian Economic Development Zone Development Co.Ltd.,Wenzhou 325200,Zhejiang,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2022年第4期60-68,共9页
China Journal of Highway and Transport
基金
国家自然科学基金项目(52078285,51878402,51878512)
浙江省重点研发计划项目(2018C03038).
关键词
道路工程
加筋土
直剪试验
立体格栅网
3D打印技术
road engineering
reinforced soil
direct shear test
three-dimensional geogrid
3D printing
