地震工况下铁路路基边坡极限状态法设计研究

当前铁路路基设计理论正处于容许应力法向极限状态法转轨中,《铁路路基极限状态法设计暂行规范》(Q/CR9127—2015)针对路基边坡稳定性,仅提出了持久设计工况下的边坡稳定性的极限状态设计表达式及其分项系数,而对地震设计工况下规范没有给出相应的内容。在考虑地震力的条件下,提出地震设计工况下路基边坡稳定性分析公式,引入地震作用效应及其分项系数,通过对地震设计工况下路基边坡极限状态法与容许应力法对比分析,得出地震工况下路堤和路堑边坡各自的极限状态法分项系数优化幅度,为相应规范的修编提供参考。

Study on Limit State Design of Railway Subgrade Slope under Seismic condition

The current design theory of railway subgrade is transferred from allowable stress design to limit state design. As far as the stability of subgrade slopes is concerned, the Interim Code for Limit State Design of Railway Earth Structure(Q/CR9127—2015) only presents the ultimate state design expression and partial coefficients of the slope stability under the condition of long-lasting design, but fails to offer corresponding details under the condition of seismic design. Considering seismic forces, this paper proposes the formula for subgrade slope stability under the condition of seismic design, and introduces the effect of earthquake action and its partial factors. Compared with limit state design and allowable stress design of the subgrade slope under seismic design condition, the optimization ranges of the partial coefficients of the limit state design for embankment and cutting slope under seismic condition are obtained, which may provide references for the revision of relevant standards.