山区沿河公路路基洪水毁损过程及机理研究

Research on Flood Damage Process and Mechanism of Mountain Area Riverside Highway Subgrade

洪水毁损路基是汛期山区沿河公路的常见病害形式,是河流洪水与公路结构之间相互作用、耦合对抗的表象。以大量山区沿河公路路基洪水毁损的实例为基础,根据山区沿河公路路基洪水毁损的宏观表象,将山区沿河公路路基洪水毁损的过程概化为三个阶段,即洪水对路基的劣化、弱化阶段;路基变形、下沉、潜在破坏面形成阶段;路基毁损破坏阶段。论述了山区沿河公路路基洪水毁损每个阶段的物理特征,指出了各阶段力学分析可采用的基础力学原理。从流固耦合动力学的角度,论述了山区沿河公路路基洪水毁损的机理,认为山区沿河公路路基洪水毁损属于一种被动洪水毁损过程,山区沿河公路路基抗冲蚀能力是该过程的关键控制因素。

Flood damage of subgrade is a kind of common disaster form for mountain area riverside highway, which is the result of interaction between flood and highway structure. Based on a great number of mountain area riverside highway subgrade damage examples, according to the macro-representation of mountain area riverside highway subgrade damaged by flood, the damage process of mountain area river- side highway subgrade damaged by flood is generalized as three stages, namely, the flood-induced highway subgrade degradation and weakening stage; roadbed deformation, sinking, potential sliding plane forma- tion stage; roadbed damage stage. The physical features of every stage of mountain area riverside highway subgrade damage are discussed, the basic mechanics principle of each phase is pointed out. From the point of view of fluid-structure coupling dynamics, the damage mechanism for flood-induced mountain area river- side highway subgrade damage is discussed, it pointed out that the flood-induced subgrade damage belongs to a kind of passive flood damage process, the erosion resistance ability of riverside highway subgrade is the key to the process control factors.