改扩建工程路基差异沉降研究综述

Review on differential settlement of subgrade in reconstruction and expansion projects

随着我国经济社会的快速发展及交通量的持续增长,早期建成的高速公路已经开始出现通行能力差、服务水平低等问题。为了解决这一问题,我国在近年来积极开展了高速公路的改扩建工作,目前已完成了多条高速公路的改扩建工程并投入运营,取得了显著成效。然而,高速公路的改扩建与新建公路有所不同,高速公路在改扩建过程中涉及新老路基拼接、变形协调等问题,特别是新老路基拼接引起的差异沉降,对路基路面结构危害巨大。为此,国内外学者致力于对减小新老路基差异沉降进行研究,探索了许多新的理念和技术。从差异沉降的理论、影响因素以及路基拼接处的处治措施3方面对现有研究成果进行了回顾和梳理,发现对减小新老路基差异沉降的措施,尤其是对加筋结构的布置、路基内部排水结构的研究还比较缺乏。建议开展此类研究,并从理论和影响因素上对差异沉降进行分析,提出适用于多种工况的拼接措施,从而起到控制差异沉降的作用,旨在为实际工程项目提供理论和实际指导。

With the rapid development of China's economy and society and the continuous growth of traffic volume,early built highways have begun to show poor traffic capacity and low service levels.In order to solve this problem,China has actively undertaken the reconstruction and expansion of expressways in recent years.At present,many expressway reconstruction and expansion projects have been completed and put into operation,and remarkable results have been achieved.However,the reconstruction and expansion of expressways is different from that of new highways.This process involves issues such as splicing new and old roadbeds and coordinating deformations.In particular,the differential settlement resulting from the splicing of new and old roadbeds poses a significant threat to the roadbed and pavement structure.Therefore,scholars at home and abroad are committed to reducing the differential settlement of new and old roadbeds,and have explored many new ideas and technologies.This paper reviews and combs the existing research results from three aspects:the settlement theory of differential settlement,the influencing factors and the treatment measures of subgrade splicing.It is found that the measures to reduce the differential settlement of new and old subgrade,especially for the arrangement of reinforced structure,the research on the internal drainage structure of subgrade is still relatively lacking.Therefore,it is recommended to conduct further research in these areas,comprehensively understanding the mechanisms and influencing factors of differential settlement in subgrades,and proposing splicing measures suitable for diverse working conditions.This endeavor aims to provide theoretical and practical guidance for practical engineering projects.