软土地区路基失稳机理及治理对策案例研究

A case study on mechanism analysis and treatment measures of subgrade instability in soft soil area

软土地基路基失稳治理是公路工程中的难点问题,针对某高速公路软土区路堤滑移现象,根据现场工程资料,分析了路基滑移产生的原因,采用有限元强度折减法反演复杂条件下路基模型计算参数,估算临界滑裂面,提出了有效的治理措施,并对不同工况下治理后的路基稳定性进行分析。结果表明:软土地区应注意考虑气候及地下水因素,下雨及地下水丰富的地区更易发生路基失稳现象;公路工程范围内旧河道地形及后期淤积土体性质对路基的稳定性有较大的影响;抗滑桩加固可以减小土的侧向力传递,有效降低路基对抗滑桩外侧土体的影响,提高地基稳定性;用高压旋喷桩、抗滑桩及反压护道等措施相结合治理软土路段路基是可行的,可为类似软土地基治理提供参考。

The instability of soft soil subgrades poses a significant challenge in highway engineering.This study investigated the cause of a case of subgrade slippage observed in an expressway,based on engineering data.Using the Finite Element Method(FEM)strength reduction method,the calculation parameters of the subgrade model under complex conditions were inverted,and the critical slip surface was estimated.Effective control measures were proposed,and the stability of the subgrade after the treatment of different working conditions was analyzed.The findings underscore the importance of considering climatic and groundwater influences in soft soil regions,highlighting that areas with heavy rainfall and high groundwater levels are more susceptible to subgrade instability.Moreover,the topography of ancient river channels and the characteristics of silted soil significantly impact subgrade stability.The use of anti-slide piles to mitigate lateral soil force transfer,thus reducing the impact of subgrade on soil and enhancing foundation stability,is emphasized.The study concludes that combining high pressure jet grouting piles,anti-slide piles,and counterpressure berms offers a viable solution for soft soil subgrade stabilization,providing a reference for similar future projects.