土工格栅加筋黏性土动力性能的试验研究  

TEST RESEARCH ON DYNAMIC BEHAVIOR OF GEO-GRID REINFORCED CLAYS

作　　者：李文旭[1,2] 王宁[1] 韩志型[1] 姚勇[1] 

机构地区：[1]西南科技大学土木工程与建筑学院,四川绵阳621010 [2]湖南省地质矿产勘查开发局416队,湖南株洲412007

出　　处：《工业建筑》2011年第7期66-69,113,共5页Industrial Construction

基　　金：国家自然科学基金项目(10602048);四川省自然科学基金项目(2009YJ0060);西南科技大学重点项目(07zx2104)

摘　　要：对土工格栅加筋黏性土进行不固结不排水的动态三轴振动试验。试验结果表明,在黏性土中布置格栅筋材,在一定程度上能提高加筋土体的动抗剪强度;加筋层数越多,加筋土动强度越大;土工格栅加筋黏性土的加筋效果在高围压下能够更好地发挥。加筋土动强度指标提高体现在动黏聚力的增大上,而对动摩擦角几乎没有影响,循环荷载振动次数对动强度指标影响很小;动应力幅值对于周期荷载下加筋土的变形影响很大,在动应力幅值大的周期荷载作用下变形增加很快,在较小的振动周次作用下就可使试样破坏,相反,动应力幅值低的试样,则需要大的振动周次才能达到破坏应变;加筋土体存在一临界破坏动应力,当设置的动应力振幅小于临界值时,无论振动多少次,试样都达不到破坏应变;并且动应力幅值过大时,刚开始振动试样就破坏,破坏形式为瞬时破坏。Based on unconsolidated undrained dynamic triaxial compression test,the reinforced clays were researched.Test results proves that disposing reinforced geo-grid material in clay can increase its dynamic shear strength.The more reinforced geo-grid layers is,the bigger dynamic strength is.Reinforced dynamic reinforcement effect can be better to play on high confining pressures.The dynamic reinforcement effect of reinforced clays with geo-grid reflect just on increasing of dynamic cohesion,but almost no influence on increasing of the dynamic friction angle.Cycle times of dynamic vibration force had little impact on dynamic strength index.The cycle dynamic stress amplitude exert a tremendous influence on reinforced deformation.The deformation increases quickly under large cycle dynamic stress,the sample destructs in smaller vibration times.Conversely,the sample destructs in larger vibration times under small cycle dynamic stress.There is a critical damage dynamic stress,when the setting dynamic stress amplitude is less than the dynamic critical stress,regardless of how many vibrating times,sample can not attain to damage strain,and when the dynamic stress amplitude is too large,the sample is instantaneous destroyed on the beginning vibration.

关 键 词：加筋土 动三轴试验 加筋效果 动强度指标 

分 类 号：TU411[建筑科学—岩土工程]