摘要
为了研究填料颗粒级配对带齿土工格栅拉拔特性的影响,首先采用标准砂配置级配良好砂、级配不良的粗砂、中砂、细砂4种填料,并用扎带将角铝和土工格栅组装成带齿土工格栅。其中,土工格栅分为双向拉伸塑料土工格栅和聚酯经编土工格栅2种。然后分别将2种带齿土工格栅埋置于含水率为0.5%、压实度为95%的4种砂性填料中,利用YT型土工合成材料直剪拉拔摩擦仪开展不同法向应力(10~60 kPa)和不同齿筋高度(0~10 mm)条件下的拉拔模型试验。研究结果表明:由于带齿双向拉伸塑料土工格栅横肋较厚,当填料粗颗粒含量(质量分数)较多时,模型箱窄缝处砂粒排出不畅,从而可能导致拉拔力-拉拔位移(T-ΔL)试验曲线出现小幅波动;随着齿筋高度和粗颗粒含量的增加,2种带齿土工格栅的拉拔力、似黏聚力和似摩擦角均有所增大,且其对似黏聚力的影响远大于似摩擦角;颗粒级配和齿筋高度对带齿双向拉伸塑料土工格栅界面似黏聚力的影响远大于带齿聚酯经编土工格栅;2种带齿土工格栅的似摩擦因数均随粗颗粒含量的增多而增大,而拉拔系数与填料粗颗粒含量呈负相关性;在相同工况下,带齿双向拉伸塑料土工格栅的拉拔力、界面剪切参数、似摩擦因数和拉拔系数等特征值均大于带齿聚酯经编土工格栅,故对于砂土来说前者具有更好的加筋效果,采用带齿塑料格栅更能提升界面摩擦特性;在加筋土工程应用中,砂土加筋可优先采用带齿双向拉伸塑料土工格栅。
In order to study the effect of particle size distribution of fillers on the pullout characteristics of denti-geogrids,four types of fillers were prepared from standard sand,well graded sand and poorly graded coarse/medium/fine sand,and the angle aluminum and geogrids were assembled into denti-geogrids using zip ties.The geogrids were classified into two categories,biaxially stretched plastic geogrids and polyester warp knitted geogrids.Subsequently,two denti-geogrids were emplaced in four kinds of sandy fillers with a water content of 0.5%and a compaction degree of 95%.The YT geosynthetic material friction tester was used to conduct pull-out model tests under different normal stresses(10 to 60 kPa)and tooth heights(0 to 10 mm).The results show that due to the thick transverse ribs of the biaxial stretched plastic geogrid,when the content of coarse particles(mass ratio)of the filler is high,the sand particles at the narrow gap of the model box are not capable to be discharged smoothly,which may lead to small fluctuations on the pullout force-pullout displacement(T-ΔL)curve.With the increase of tooth height and coarse particle content,the pullout force,pseudo cohesion,and pseudo friction angle of two types of denti-geogrids both increase,while their influence on pseudo cohesion is much greater than that on pseudo friction angle.The influence of particle size distribution and tooth height on the interfacial cohesion of toothed biaxially stretched plastic geogrids is much higher than that of toothed polyester warp knitted geogrids.The quasi friction coefficients of two types of denti-geogrids increase with the growth of coarse particle content,while the pullout coefficient is negatively correlated with the coarse particle content of the filler.Under the same working conditions,the characteristic values of the pullout force,interfacial shear parameters,quasi friction coefficient,and pullout coefficient of the toothed biaxially stretched plastic geogrid are greater than those of the toothed polyester warp knitted geo
作者
方薇
刘恬
王骄
沈洪宇
FANG Wei;LIU Tian;WANG Jiao;SHEN Hong-yu(School of Traffic and Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,Hunan,China;Changsha Li Gong Detection and Consulting Co.Ltd.,Changsha 410076,Hunan,China)
出处
《长安大学学报（自然科学版）》
CAS
CSCD
北大核心
2024年第6期1-10,共10页
Journal of Chang’an University(Natural Science Edition)
基金
国家自然科学基金项目(51408059,52178413)
湖南省自然科学基金项目(2022JJ30593)
国家留学基金项目(202208430046)。
关键词
道路工程
带齿土工格栅
拉拔试验
界面摩擦特性
颗粒级配
road enginerring
denti-geogrid
pullout test
interfacial friction characteristic
particle gradation
