麦冬和多花木蓝根系抗拉拔特性试验研究

目的]揭示麦冬和多花木蓝根系根土界面的抗拉拔力特性,为根土界面摩擦特性的进一步研究提供依据。方法]通过控制5个梯度的土壤含水率,采用直接施加垂直拉拔荷载的单根拉拔试验方法。结果]麦冬和多花木蓝单根的最大抗拉拔力随根径的增加而增大且呈非线性幂函数关系;在相同土壤容重条件下,麦冬和多花木蓝单根的最大抗拉拔力随土壤含水率的增加而呈先增加后减小的趋势。在土壤含水率介于一定范围内时,多花木蓝根的最大抗拉拔力大于麦冬根的最大抗拉拔力,而在其它土壤含水率条件下,麦冬根的最大抗拉拔力大于多花木蓝根的最大抗拉拔力;并发现麦冬根的最大抗拉拔力的最大值在含水率为10.43%附近,而多花木蓝根的最大抗拉拔力的最大值则在含水率为13.00%附近。结论]根径、土壤含水率和植物种类影响根土界面的抗拉拔力。

Experimental Study on Pull-out Resistive Properties of Ophiopogon Japonicus and Indigofera Amblyantha Roots

Objective] The pull-out resistive properties of Ophiopogon japonicus and Indigofera amblyantha root were tested in order to provide guides for further research on the friction characteristics of the root soil interface.Methods] Five levels of soil moisture content were designed to carry out single-root direct pull-out tests with vertical outward load.Results] The maximum pull-out resistive force of the two plant root were both increased by nonlinear power function with root diameter as independent variable. Under the condition of constant soil bulk density, the maximum pull-out resistive force of root experienced an increases firstly and then declined as soil moisture content increased. The maximum pull-out resistive force of Indigofera amblyantha root was greater than that of Ophiopogon japonicus within a certain range of soil moisture content. While the maximum pull-out resistive force of Ophiopogon japonicus root was greater than that of Indigofera amblyantha under other conditions. Results also revealed that the pull-out resistive force of Ophiopogon japonicus root reached the maximum when the soil moisture content was close to 10.43%, while the pull-out resistive force of Indigofera amblyantha root reached the maximum when the soil moisture content was close to 13.00%.Conclusion] Root diameter, soil moisture content and plants species have influences to some extent on the pull-out resistive force of root-soil interface.