水平荷载作用下多花木蓝根系拉拔试验研究  

Pull-out Test of Indigofera amblyantha Craib Root under Horizontal Load

作　　者：管世烽 夏振尧[1,4] 张伦[4] 胡文静[4] 张守德[2] 许文年[1,4] 

机构地区：[1]三峡大学三峡地区地质灾害与生态环境湖北省协同创新中心,湖北宜昌443002 [2]三峡大学水利与环境学院,湖北宜昌443002 [3]广西大藤峡水利枢纽开发有限责任公司,南宁530029 [4]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《长江科学院院报》2016年第6期24-28,共5页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(51278281;41202250);国家科技支撑计划资助项目(2012BAC06B02-04)

摘　　要：为探索灌木植物根系与土壤界面摩擦力的影响因素,通过改变土壤干密度条件,采用直接施加水平拉拔荷载的方法进行单根拉拔试验,研究了多花木蓝单根的抗拉拔力。结果表明:1多花木蓝单根的抗拉拔力与位移关系曲线可分为陡峭上升、陡峭下降和平缓下降3个阶段,在试验开始阶段呈线性关系,随后表现出显著的非线性关系;2在同一土壤干密度条件下,多花木蓝单根的最大抗拉拔力随着根径的增加而呈线性增大趋势,相关系数超过0.9;3当根径一定时,多花木蓝单根的最大抗拉拔力随着土壤干密度的增加而增大;4根在土壤干密度ρd为1.35,1.45,1.55 g/cm3时的拉拔破坏模式均表现为摩擦破坏,而土壤干密度ρd=1.65 g/cm3,根径r=0.586 mm是根的拉拔破坏模式从摩擦破坏到拉断破坏的临界点,表明当根径r<0.586 mm时,根的破坏模式表现为拉断破坏,而当根径r>0.586 mm时,根的破坏模式表现为摩擦破坏。因此,根径、土壤密度影响根土界面的抗拉拔力。In order to explore factors influencing the shrub plant roots and soil interface friction,we carried out the direct pull-out test on Indigofera Amblyantha Craib root to study its anti-pullout force under different soil dry densities. The results show that：（ 1） the curves of anti-pullout force vs. displacement of the roots can be divided into three phases of steep rise,steep fall and gentle decline,increasing linearly to peak value at the start phase,and then presenting non-linear trend;（ 2） the maximum anti-pullout force of Indigofera Amblyantha Craib root increases obviously linearly with the increasing of root diameter under the same soil dry density,and the coefficient of correlation reaches 0. 9;（ 3） the maximum anti-pullout force of Indigofera Amblyantha Craib root increases with the increasing of soil dry density with given root diameter,and the modes of pull-out failure of all roots are friction failure when the soil dry density varies from 1. 35 g / cm3 to 1. 45 g / cm3 and 1. 55 g / cm3,while when the density is 1. 65 g / cm3,root diameter of 0. 586 mm is the critical point from friction failure to tensile failure,which means that the pull out failure mode is tensile failure when the root diameter is less than 0. 586 mm,and friction failure when the root diameter is larger than 0. 586 mm. Therefore,root diameter and unit weight of soil have influence on the antipullout force of root-soil interface.

关 键 词：固土机理 根-土界面 拉拔试验 抗拉拔力 土壤密度 

分 类 号：Q947[生物学—植物学]