基于断裂理论的公路边坡防护体系研究

在植被护坡技术中,根系对土体的加固作用是很显著的,但大多数植物根系的加固深度,尚不能达到潜在的深层滑坡的滑面埋深,所以,植被在深层滑坡防治方面的作用是有限的。基于离心模型试验研究基础上的加筋护坡技术不仅可以满足深层护坡的要求,而且经济合理。将这两种边坡防护技术相结合,从而形成了一种新型的公路边坡防护体系。首次运用断裂力学原理,分析和解释了植物根系与筋材在边坡土体剪切过程中的阻裂机理,不仅形象地揭示了根系纤维与筋材阻止裂纹发展的过程,而且借助裂纹尖端的应力强度因子,很好地解释了该防护体系对边坡稳定的贡献度。在建立几何模型的基础上,给出了防护体系抗滑力和边坡安全系数的计算公式。

A Study on Protection System for Highway Slopes Based on Fract ure Theory

For the technology of protection slopes by vegetation,the mechanical reinforcement provided by roots is remarkable.However,the roots zones of most plants is flat,and can't reach the planes of deep seated landslides.So,the protection provided by vegetation for deep seated landslide is very limited.The reinforced technology based on the centrifugal model test can meet the protective need for deep seated landslide.Morever,more economic and scientific.A new protection system for highway slopes is proposed in the paper through combining vegetation protection with active reinforcement.Using the fracture mechanics principle for the first time,the crack arresting mechanism of the shearing failure of a slope because of the roots and reinforce is analyzed.The behaviour of roots and reinforce in the process of crack arresting are revealed fundamentally,the protective degree of slope stability provided by the new protection system is explained commendably by dint of the stress intensity factor of crack cusp.On the basis of the geometrical model,the slip resistance and safety factor are given in this paper.