摘要
为研究土工格栅与砾性土的界面特性,通过室内拉拔试验研究了拉拔速率、法向应力对界面参数的影响,分析了拉拔力峰值、界面摩擦参数及界面摩擦系数比的变化规律.试验结果表明:不同拉拔速率下的拉拔力与拉拔位移曲线均呈现出应变软化特征,且随着拉拔速率的增大,相同法向应力下拉拔力峰值对应的拉拔位移基本相同;随着法向应力的增大,相同拉拔速率下拉拔力峰值对应的拉拔位移逐渐增大;土工格栅-砾性土界面的似摩擦角在拉拔速率(v≤0.9 mm/min)下变化较小,随着拉拔速率的进一步增加,界面的似摩擦角略有提升,且随着拉拔速率的增加,存在一个临界拉拔速率(v=0.9 mm/min),此时土工格栅-砾性土界面的似黏聚力达到最大,为最小界面似黏聚力的1.9倍左右;界面摩擦系数比K随着拉拔速率的增加呈现出先增后减的趋势,拉拔速率在0.3~4.5 mm/min时,K的变化范围为1.29~1.58;从偏安全角度考虑,实际加筋土工程设计中应选择低速率试验工况下的界面摩擦系数比.
To study the interface characteristics of geogrid-gravel soil,the effects of pullout velocity and normal stress on interface parameters were studied through indoor pullout tests.The variation law of the peak pullout force,the interface friction parameters and the interface friction coefficient ratio were analyzed.The test results show that the curves of pullout force and pullout displacement under different pullout velocities all show strain softening characteristics,and with the increase of the pullout velocity,the pullout displacement corresponding to the peak pullout force of the same normal stress is basically the same;with the increase of normal stress,the pullout displacement corresponding to the peak pullout force gradually increases at the same pullout velocity;The friction-like angle of the interface geogrid and gravel soil changes little at the pullout velocity(v≤0.9 mm/min).With the further increase of the pullout velocity,the friction-like angle of the interface is slightly increased,and with the increase of the pullout velocity,there is a critical pullout velocity(v=0.9 mm/min).At this time,the cohesive force of the geogrid-gravel soil interface reaches the maximum,which is about 1.9 times of the minimum interface cohesion.The interface friction coefficient ratio K shows a trend of first increasing and then decreasing with the increase of the pullout velocity,When the pullout velocity is 0.3 mm/min-4.5mm/min,the change range of K is 1.29-1.58;From a safety perspective,the interface friction coefficient ratio under low velocity test conditions should be selected in the actual engineering design of reinforced soil.
作者
祁航翔
王家全
林志南
唐滢
QI Hangxiang;WANG Jiaquan;LIN Zhinan;TANG Ying(School of Civil Engineering and Architecture,Guangxi University of Science and Technology,Liuzhou 545006,China)
出处
《广西科技大学学报》
2021年第2期13-19,共7页
Journal of Guangxi University of Science and Technology
基金
国家自然科学基金项目(41962017)
广西自然科学基金项目(2017GXNSFAA198170)
广西研究生教育创新计划项目(YCSW2020222)资助.
关键词
砾性土
土工格栅
界面特性
拉拔速率
应变软化
gravel soil
geogrid
interface characteristic
pullout velocity
strain softening
