公路改扩建拓宽路基不均匀沉降因素分析

Analysis of Factors Influencing Uneven Settlement of Roadbed in Highway Reconstruction and Expansion

公路改扩建工程中拓宽路基的差异沉降控制是工程技术重点和难点,特别是新旧路基结合处不均匀沉降更为明显,因不均匀沉降的影响,极易形成了纵向裂缝,影响道路行驶品质。依托在建工程,本文就拓宽路基宽度、填土高度、路基弹性模量、地基土压缩模量四个因素在拓宽路基沉降量方面的影响进行监测,分析监测结果发现随着拓宽路基宽度增大,新路基沉降量随之增大;拓宽路基填土高度增加,新路基沉降量也随之增大;随着路基弹性模量、地基土压缩模量的增大,新路基沉降量随之减小;沉降量剧增均发生在新旧路基结合处,原因在于此位置应力分布不均。结果表明提高地基土压缩模量可有效降低新路基沉降量,设计合理的拓宽宽度和填土高度也可有效减少拓宽路基沉降量。

The differential settlement control of widened roadbed in highway reconstruction and expansion projects is a key and difficult point in engineering technology,especially the uneven settlement at the junction of new and old roadbed is more obvious.Due to the influence of uneven settlement,longitudinal cracks are easily formed,which affects the quality of road driving.Based on the ongoing construction project,this article monitors the impact of four factors:widening roadbed width,filling height,roadbed elastic modulus,and foundation soil compression modulus on the settlement of widened roadbed.The analysis and monitoring results show that as the width of widened roadbed increases,the settlement of new roadbed increases.As the filling height of the widened roadbed increases,the settlement of the new roadbed also increases.As the elastic modulus of the roadbed and the compressive modulus of the foundation soil increase,the settlement of the new roadbed decreases accordingly.The significant increase in settlement occurs at the junction of new and old roadbeds,due to uneven stress distribution at this location.The results indicate that increasing the compressive modulus of the foundation soil can effectively reduce the settlement of the new roadbed,and designing a reasonable widening width and filling height can also effectively reduce the settlement of the widened roadbed.