真空-堆载联合预压处理路堤软基相关问题分析  

Analysis of Problems Related to Reinforcement of Soft Foundation of Embankment with Vacuum Combined Surcharge Preloading

作　　者：陈华明[1] 李时亮[1] 

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道工程学报》2010年第11期18-22,共5页Journal of Railway Engineering Society

摘　　要：研究目的:真空-堆载联合预压技术已在港口、道路等工程领域得到推广应用,但其加固机理、地基沉降计算方法等尚存在争议或不明确,影响到该项技术的发展及应用。本文结合工程试验资料,对真空-堆载联合预压作用下真空度传递规律、孔隙水压力变化及消散特点、地基沉降变化规律及工后沉降控制效果等进行了分析,对真空-堆载联合预压在工程应用中的地基沉降计算方法、工后沉降影响因素等设计、施工方面的相关问题进行了分析和探讨。研究结论:在消除地基土中真空度的影响后,真空-堆载联合预压加固区地基土中超静孔隙水压力增加、消散规律与单纯堆载作用基本一致,在加固机理上没有本质区别。真空预压在附加应力及加固影响深度等方面与堆载预压有明显区别,在地基沉降计算时应予以考虑。真空-堆载联合预压工后沉降控制与地基条件、路基填高等因素密切相关,工程应用时应根据技术标准在设计、施工等方面加以考虑。Research purposes： The vacuum combined surcharge preloading technology has been widely applied in construction of port and road.However,its reinforcement mechanism and settlement calculation methods are still in controversy or unclear to affect its development and application.Combining the engineering test data,this paper analyzes the characteristics of vacuum combined surcharge preloading technology,including the transferring law of vacuum degree,change and dissipation characteristics of pore water pressure,foundation settlement rule and control effect of post-construction settlement and so on.,and discusses the relative problems in design and construction with vacuum combined surcharge preloading,such as the calculation methods for the foundation settlement and the influence factors on the post-construction settlement.Research conclusions：After eliminating the effect of vacuum degree,the increases and dissipation characteristics of excess pore water pressure under vacuum combined surcharge preloading foundation is basically consistent with that of single surcharge preloading,and there is no essential difference in reinforcement mechanism of them.Additional stress and reinforcement depth of vacuum preloading foundation is obviously different with that of single surcharge preloading,so it should be considered in settlement calculation.At last,the control of the post-construction settlement under vacuum combined surcharge preloading is closely related to foundation conditions and embankment height and so on,so its application must be considered in design and construction according to technical standard.

关 键 词：真空预压 软基 真空度 工后沉降 

分 类 号：U21[交通运输工程—道路与铁道工程]