山区公路半填半挖路基沉降控制指标与标准研究  

Study of index and criterion for settlement control applicable to cut-and-fill subgrade in mountain-highway

作　　者：高成雷[1] 赵文忠 凌建明[3] 王丙兴 

机构地区：[1]石家庄铁道大学道路与铁道工程安全保障省部共建教育部重点实验室,石家庄050043 [2]河北省高速公路邢汾筹建处,河北邢台054001 [3]同济大学道路与交通工程教育部重点实验室,上海201804

出　　处：《岩土力学》2014年第1期151-158,共8页Rock and Soil Mechanics

基　　金：河北省交通运输厅科技计划项目(No.Y-2010025-2)

摘　　要：为了避免路基沉降导致路面结构破坏,对适用于山区公路半填半挖路基的沉降控制指标和标准进行了研究。首先,基于常泊松比假定,推导了三维Merchant模型的Prony级数表达式,并以ABAQUS为工具建立了半填半挖路基沉降计算模型。计算结果表明,半填半挖路基工后沉降曲线为"勺"形或"S"形,曲线形状的差异揭示了路基沉降的时空耦合效应。其次,基于路基工后沉降机制分析,提出了如下假定:半填半挖路基工后沉降曲线为中心对称的"S"形,对称中心两侧的曲线段为抛物线。通过沥青路面结构对抛物线形路基沉降的力学响应分析,揭示了路面结构附加弯拉应力与抛物线方程的二次项系数a具有线性关系,据此提出采用a值作为半填半挖路基沉降控制指标。最后,基于沥青路面结构在交通荷载和路基沉降共同作用下的破坏模式,提出了半填半挖路基沉降控制标准的确定方法。研究成果为合理控制半填半挖路基工后沉降提供了明确的技术依据。To avoid pavement structure failure induced by subgrade settlement, index and criterion for settlement control applicable to cut-and-fill subgrade for mountain-highways are studied. Firstly, the Prony series expressions for three-dimensional Merchant model are deduced based on constant Poisson＇s ratio hypothesis; and the settlement calculation models of cut-and-fill subgrade were established with ABAQUS. The calculations indicate that post-construction settlement curves of cut-and-fill subgrade are spoon-shaped or S-shaped. The difference in curve shape reveals the time-space coupling effect in subgrade settlement. Secondly, the following hypothesis is proposed based on post-construction settlement mechanisms： the post-construction settlement curves of cut-and-fill subgrade are central symmetric S-shaped curves composed of two parabolic segments. The mechanical response of asphalt pavement under parabolic subgrade settlement indicates that the additional flexural-tensile stress is linear with quadratic term coefficient of parabolic equation which, consequently, can be adopted as settlement control index applicable to cut-and-fill subgrade. Finally, the method of defining settlement control criterion applicable to cut-and-fill subgrade is presented based on the failure modes of asphalt pavement under traffic load and subgrade settlement. The research findings provide a technical foundation for post-construction settlement control of cut-and-fill subgrade.

关 键 词：道路工程 沉降控制指标 沉降控制标准 数值计算 半填半挖路基 

分 类 号：U416.1[交通运输工程—道路与铁道工程]