不同加筋形式的沿海高速公路拓宽路堤现场试验与数值分析

Widening Embankment of Coastal Highway with Different Reinforcement Forms Field Test and Numerical Analysis

为研究沿海高速公路路堤拓宽过程中的受力变形规律,通过拓宽路堤现场试验与数值分析,分析了施工过程中两种不同加筋形式对新路堤深层侧向位移、地表累计沉降、格栅累计变形的影响,并通过数值模拟进一步探讨了路堤拓宽过程中的受力变形规律。结果表明:随着填土高度的增加,K2130+590段和K2130+620段的深层侧向位移、地表累计沉降、格栅累计变形也随之增大;其中K2130+590段和K2130+620段的深层侧向位移随着埋置深度的增加而减小,大致呈“倒三角形”分布趋势,路堤顶部、底部的最大侧向位移与K2130+620段相比分别减小了31.83%、76.98%;且路中处最大沉降与K2130+620段相比减小了40.51%;而两个试验段格栅累计变形相差不大,基本保持一致。通过综合考虑K2130+590段与K2130+620段的深层侧向位移、地表累计沉降及格栅累计变形,建议采用格栅与格室的组合加筋形式。同时发现最大剪应变增量随着新路堤填土高度的增加而增大,新旧路堤最有可能沿台阶处发生滑移破坏,故为了拓宽路堤的稳定与安全,建议增强新旧路堤台阶处的连接强度,以此保证加筋新旧路堤结构的整体稳定性。

In order to understand the stress and deformation law in the process of embankment widening of coastal highway,through the field test and numerical analysis of embankment widening,the influence of two different reinforcement forms on the deep lateral displacement,surface cumulative settlement and geogrid cumulative deformation of new embankment in the construction process was analyzed,and the stress and deformation law in the process of embankment widening was further discussed through numerical simulation.The results show that with the increase of filling height,the deep lateral displacement,surface cumulative settlement and grid cumulative deformation of K2130+590 section and K2130+620 section increase.The deep lateral displacement of K2130+590 section and K2130+620 section decreases with the increase of buried depth,which is roughly“inverted triangle”distribution trend.The maximum lateral displacement of the top and bottom of the embankment is reduced by 31.83%and 76.98%respectively compared with K2130+620 section.The maximum settlement in the middle of the road decreases by 40.51%compared with that in K2130+620 section.The cumulative deformation of the geogrid in the two test sections is basically consistent.By comprehensively considering the deep lateral displacement,surface cumulative settlement and geogrid cumulative deformation of K2130+590 and K2130+620,it is suggested to adopt the combined reinforcement form of geogrid and geocell.At the same time,it is found that the maximum shear strain increment increases with the increase of the filling height of the new embankment,and the old and new embankments are most likely to slip along the steps.Therefore,in order to broaden the stability and safety of the embankment,it is recommended to enhance the connection strength at the steps of the old and new embankments,so as to ensure the overall stability of the reinforced old and new embankment structures.