梯田式填筑-降雨时序作用下沟谷区高填方地基变形与边坡稳定性分析

山区城镇化建设力度逐步加大,削山填沟工程广泛分布,高填方地基沉降变形与边坡稳定性是安全建设最重要的问题之一。本文提出了梯田式填筑—降雨时序作用下沟谷区高填方地基变形与边坡稳定性分析方法,首先依托地质资料建立梯田式填筑数值仿真模型,然后通过试验确定填筑体的力学参数,分析梯田式填筑过程中边坡内部响应规律,最后在降雨时序作用下模拟高填方地基多场非完全耦合变形规律,并将此方法运用到湖北省十堰市郧西县扶贫产业园项目。研究表明：填筑体随含石量增加,粘聚力总体呈波动式下降趋势,内摩擦角相对变化不大,饱和作用下试样抗剪强度具有显著弱化作用；填筑时步过程中,填筑层对边坡变形影响具有一定的时空限制范围；降雨时序作用下,填方区降雨影响深度为距地表12 m范围附近,结合测斜长期监测数据,与模拟结果较为相似。研究成果能为削山填沟高填方边坡风险评估与地质灾害防治提供技术与实践经验。

Analysis of Deformation and Slope Stability of High-fill Foundation in Gully Area under Terraced Filling-rainfall Sequence

The construction of urbanization in mountainous areas is gradually increasing, and the mountain-cutting and gully filling projects are widely distributed. The settlement deformation of high-fill foundation and the stability of slope are one of the most important problems in the safety construction. A method is proposed to analyze the deformation of high fill foundation and slope stability in the gully area under terraced filling and rainfall sequence. Firstly, a numerical simulation model of terraced filling is established based on geological data to analyze the internal response law of the slope in the terraced filling process, then the mechanical parameters of the filling body are determined through tests. Finally, multi-field incomplete coupling deformation law of high fill foundation is simulated under rainfall series, and the method is applied to Yunxi County poverty alleviation Industrial Park project in Shiyan City, Hubei Province. The results show that with the increase of the stone content, the cohesion of the fill body generally shows a fluctuation downward trend, the internal friction Angle keep constant, and a significant weakening effect is responsed in the shear strength of the sample. In the process of filling, the influence of filling layer on slope deformation has a spatiotemporal limit range. Under rainfall series, rainfall influence depth in the fill area is around 12 meters from the surface. Combined with the long-term monitoring data of inclinometer, the results are similar to the simulation results. The research results can provide technical and practical experience for the risk assessment and geological hazard prevention of high fill slope in mountain cutting and filling gully.