巨型深埋式沉井施工过程力学特性及环境效应研究进展

Mechanical Behaviors and Geo-environmental Effects Due to the Installation of Giant Deep-Buried Open Caissons: State of the Art

巨型深埋式沉井作为重型基础的重要组成部分,其沉贯过程的力学特性与环境效应是工程人员关注的焦点问题.通过大量的文献调研并总结国内外相关研究现状,阐述了沉井基础施工工艺及施工过程可能存在的问题、施工过程力学特性及周边环境效应等重要科学问题,梳理与对比了沉井沉贯过程的侧壁摩阻力与土压力计算方法,进一步探讨了侧壁摩阻力与土压力分布规律.结果表明,巨型深埋式沉井基础承载性能良好,可为大型基础建设提供强有力保障,极具工程应用前景;但已有成果在其沉贯机制与力学机理、井-土界面相互作用模型及土性参数的演变过程、环境效应及其表征方法、后期服役性能等方面研究尚存不足,能够综合考虑沉贯机制与力学机理的设计方法亟待提出;同时给出了今后的研究方向,可为巨型深埋式沉井(群)成套施工技术的形成提供理论指导.

Giant deep-buried open caisson is a significant type of foundations for bearing the heavy structures, its construction technologies and environmental effects have been thus commonly studied by geo-engineers.This paper presented the key scientific problems about the construction technologies, construction process and mechanical behaviors and surrounding geo-environmental effects due to the installation of giant deep-buried open caissons.Additionally, the calculation methods to frictional resistance and earth pressure acting on caisson sidewalls during installation were summarized and compared, the corresponding distribution laws were then discussed.The results indicate that giant deep-buried caissons with high bearing capacity can strongly support the large-scale infrastructure, and will be widely applied in practice.However, there are still some deficiencies in the present research on the penetration mechanisms, interaction model for caisson-soil interfaces and evolution law of soil parameters, geo-environmental effects and corresponding characterization methods, as well as serviceability.The design methods which can comprehensively consider installation effect and mechanical mechanisms need to be urgently proposed.The future research works are also given to improve the construction technologies of giant deep-buried open caissons.