浅层滑坡中乔木直根阻滑效应及变形特性试验研究—前后双根

Experimental study of effect of slide resistance and deformation of tree's tap root in shallow landslide——the double root located in the front and back

乔木根系在土中所处位置不同,其对土体的强化作用以及自身的变形情况也就不同。通过自行研制的可用于模拟不同深度浅层滑动面的层叠式根土复合体直剪仪对海口橡胶树(乔木)直根进行了根土复合体大型直剪试验,得到了不同深度剪切面处根系对土体的强化效果以及根系通长范围内的变形情况。试验结果表明:乔木根系的存在有助于提高土体的强度和具备阻止或延缓小型浅层滑坡产生的能力;乔木根系的变形主要集中在相邻剪切面之间,此范围之外基本无变形;随着剪切深度的下移,深入稳定土层的根系长度则逐步减少,含根土所能承受的推力值不降反升;树根的存在可改变土体的破坏曲线形式,出现应变硬化现象;前后根系在土中的变形并不一致,剪切面处前根的变形始终最大,剪切面之上前根变形小于后根,剪切面及其之下前根变形大于后根。试验结果得出,乔木根系可对边坡的稳定性起到积极作用,有阻止或延缓边坡下滑的趋势,其试验数据及结论可为乔木根系在浅层滑坡中的锚固理论提供依据。

The reinforcement effect and itself deformation of root were vary from the location in the location. It have conducted root-soil complex large-scale shear test with self-made instrument that can simulate different shear plane of shallow sliding surface at difference depth. Experiment results show that the root can improve the strength of soil, and it has the ability to stop the small shallow landslide. The roots deformation mainly focus on adjacent shear plane, with the falling of shear plane the root length in stable layer was corresponding reduced, but the strength of soil have been improved. Root can affect the destroying form of soil by produce strain harderning phenomenon in later test. The front root＇s deformation was the biggest at the current shear plane, and the deformation of front root were less than the back in the above the current shear plane, contrary to the other measuring point of roots. Test results show that the roots can play a important role to the stability of the slope, it also can stop the produce of the slope, and the test data and conclusion also have positive role in anchoring theory of root in shallow landslide.