Abstract: Ring reinforced gravel pile composite foundation has been widely used in the reinforcement of soft foundation engineering.The stability of the embankment on composite foundation reinforced by geosynthetic-encased stone columns is an important factor that affects engineering safety.In this paper,by establishing a three-dimensional finite element model of embankment on ring reinforced gravel pile composite foundation,the failure mode of the ring reinforced gravel pile is revealed and the stability of embankment slopes under different soil strengths is analyzed.On this basis,the applicability of Sweden slice method,Bishop slice method and circular arc slice method in calculating the stability of embankment slope are compared and analyzed.The results show that the numerical model established in this paper can reflect the stability of embankment on ring reinforced gravel pile composite foundation.When the embankment is unstable,the stone columns confined by geosynthetics will suffer bending failure.Due to the lack of consideration of the restraint effect of the geosynthetics,the results of Sweden slice method,Bishop slice method and standard circular arc slice method are conservative.Bishop method is the closest to the numerical results.

Key words: ring reinforced, stone column, stability, numerical simulation

摘要： 环向加筋碎石桩复合地基在加固软基工程中得到了广泛应用,在加固路基工程中,路堤边坡稳定性计算对工程设计具有重要意义。文中通过对采用环向加筋碎石桩加固路堤时边坡失稳破坏模式进行三维有限元分析,揭示了路堤失稳时环向加筋碎石桩的破坏模式和路堤失稳模式,研究了地基土强度对路堤边坡的安全系数的影响。在此基础之上,对比分析了采用瑞典条分法、毕肖普条分法和规范圆弧条分法计算环向加筋碎石桩复合地基路堤边坡稳定性的适用性。研究表明:文中建立的数值模型能够较好地反映环向加筋碎石桩复合地基路堤稳定性;路堤失稳时环向加筋约束碎石桩发生受弯破坏;由于没有考虑环向加筋碎石桩的约束作用,瑞典条分法、毕肖普条分法和规范圆弧条分法的计算结果均较为保守,但毕肖普法计算结果最为接近数值计算结果。

关键词: 环向加筋, 碎石桩, 路堤, 稳定性, 数值模拟