高速公路顺层路堑边坡优化设计方法

OPTIMUM DESIGN METHOD FOR BEDDING SLOPE OF EXPRESSWAY

高速公路顺层路堑边坡的稳定与否 ,直接影响着公路的运行安全 ,因此对该类边坡特点进行总结 ,确定其研究方法是一项十分重要的任务 .首先对高速公路顺层路堑边坡特点进行了总结 ,提出了高速公路顺层路堑边坡从野外调查 -稳定评价 -开挖坡角确定 -加固设计的优化设计路线 .在此基础上 ,以京珠高速公路大悟县境南段为例 ,按照高速公路顺层边坡设计思路 :即在分析工程地质条件的基础上 ,采用剩余推力法和Sarma法计算了其稳定性 ,对影响边坡的各因素进行了敏感性分析 ;并根据计算成果确定了最优设计坡角 .在保证边坡总体稳定的前提下 ,提出了边坡开挖方案及经济合理的边坡锚喷加固设计方案 .结果表明该设计方案对工程建设具有很强的系统性和实用性 .

It is known that the stability of the bedding slope of expressways directly affects the running safety of road, so it is important to summarize its characteristics and determine its study methods. Thus this paper presents a summary of its characteristics and an optimum design method and clue for field investigation, stability evaluation, determination of the optimum excavation slope angle and slope improving design. Then, taking the southern part of Dawu Section of Jingzhu (Beijing-Zhuhai) expressway as an example, we discuss the application of this optimum design method. Namely, the slope stability is evaluated with the method of residual pushing force and the Sarma method based on the analysis of the engineering geology conditions. After that, the sensitivity analysis for the slope stability is done using the residual pushing force method. On the precondition of ensuring the whole stability of slope and the economic reasonability, the paper also advances the optimum angle of design, the slope excavation scheme and the anchor and spray concrete scheme of the slope improvement design. The example shows that this optimum design method and clue are systematic and practicable for the construction.