土体劈裂灌浆力学机理分析

Mechanism analysis of fracture grouting in soil

为了在塑性力学和大变形理论的基础上分析土体在劈裂灌浆初始阶段的力学机理,将劈裂灌浆的初始阶段视为无限土体中的圆孔扩张问题,并将圆孔周围土体中的应力分布分为3个区域。在弹性区中土体服从小变形假设,在软化区和流动区中土体服从大变形假设。根据应力平衡方程以及应力和应变连续的边界条件,推导出劈裂灌浆初始阶段的最终扩孔压力和最终扩孔半径的理论解答。同时,还分析了灌浆压力、最终扩孔半径、土体的泊松比和大变形以及压缩模量之间的相互关系。该理论的计算结果与工程实测结果比较接近,初步证实了该理论的可靠性。

in order to analyze the mechanical mechanism of fracture grouting during the early phase by using the theory of large-deformation and plastic mechanics, the early phase of fracture grouting is regarded as the question of cavity expansion in infinite soil. The stress distribution due to the cavity expansion in soil is considered as three zones. The deformation following little deformation in elastic zone and large-deformation in plastic zone is taken into consideration. On the bases of the stress eciuilibrium equation and continuous boundary condition of stress and deformation, the stress distribution in three zones, the terminal radius and grouting pressure are obtained. According to the compassion, the results of the present theory is very near to the outcome of the engineering practice.