有限元强度折减法在边坡稳定分析中的应用

Application of strength reduction FEM method in slope stability analysis

为研究渠河河堤跨河大桥桩基工程对河堤稳定性的影响,采用有限元方法对河堤边坡加固方案及施工过程进行稳定性计算分析。对渠河大桥处渠堤断面图进行概化,构建二维平面应变有限元计算模型;利用有限元强度折减法,借助PLAXIS软件实现对设计坝体加宽和桩基桩孔施工情况下边坡的稳定性分析。计算结果表明,当坝坡坡度调整为1.00∶3.00时,最小稳定安全系数达到1.179,满足规范要求值1.150;桩孔开挖过程中,边坡稳定安全系数均大于1.150,坝坡稳定性可以得到保证,但是桩孔孔壁存在渗透变形和塑性变形的安全隐患,需采取防护措施。

To study the influence of Quhe embankment cross-river bridge pile foundation project on the embankment stability,the FEM was applied to analyze the reinforcement plan of the embankment slope and the construction process.By generalizing the embankment cross-section diagram of the Quhe bridge,a two-dimensional plane strain FEM calculation model was built. The strength reduction FEM method was employed to analyze the circumstances of the designed slope broadening and pile-hole construction. The calculation results showed that the minimum stability safety factor reached 1. 179 and met the specification required value 1. 150 when the slope gradient was adjusted to 1. 00∶3. 00. The slope stability safety factor were all larger than 1. 150 during the pile hole excavation and the slope stability could be guaranteed,while the seepage deformation and plastic deformation safety problems of pile hole wall existed and protective measures should be taken.