锚固加强植被系统约束膨胀土变形模型试验研究

Model test study of constraint to deformation of expansive soil by anchor reinforced vegetation system

利用锚固加强植被系统(ARVS)约束膨胀土变形是一种新的尝试。为研究ARVS系统对膨胀土变形的约束效果,采用ARVS系统的室内简化装置,对南宁中等膨胀土进行有、无防护措施的浸水模型对比试验,对不同约束情况下膨胀土的变形进行对比分析,并根据模型受力情况采用有限元方法验证膨胀力的传递规律。结果表明,采用ARVS约束后膨胀土的吸湿变形过程仍然为3个阶段;ARVS系统能使膨胀土的膨胀量大幅降低,但ARVS系统在植草前后对膨胀土膨胀变形的约束效果差别不是很大,植草后膨胀土的变形能够较快到达稳定阶段;作用在高性能植被保护垫(HPTRM)上的膨胀力先通过锚头板传递至地锚,地锚再将膨胀力传递到土层中。锚固加强植被系统(ARVS)为膨胀土边坡的防护和治理提供了新的方法。

It is a new attempt to use the anchor reinforced vegetation system (ARVS) to constrain the deformation of expansive soil. To investigate the constraint effect of ARVS on the deformation of expansive soil, water immersion model tests with and without protective methods are performed adopting medium expansive soil in Nanning, using the simplified indoor ARVS device. The deformations of expansive soil under different constraints are analyzed; and then the transfer law of expansion force is verified by finite element method according the force conditions of two different models. The results show that: with the constraint of ARVS, the deformation of expansive soil can still be divided into three stages; the ARVS can reduce the amount of expansion of expansive soil significantly; but the constraint effect of ARVS on the deformation of expansive soil before and after planting vegetation, and after planning vegetation the deformation of expansive soil can quickly reach the stable stage; the expansive force acting on the high performance turf reinforcement mats (HPTRM) firstly is transferred to the earth anchor by the anchor plate, and then the expansive force is transferred to the soil layer by the earth anchor. Anchor reinforced vegetation system provides a new method for the protection and treatment of expansive soil slope.