砂土中带裙板防沉板基础竖向承载力的上限解  

Upper bound solutions of vertical bearing capacity of skirted mudmat in sand

作　　者：刘润[1] 陈广思[1] 

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072

出　　处：《海洋工程》2015年第4期45-52,共8页The Ocean Engineering

基　　金：国家重点基础研究发展计划(2014CB046800);国家自然科学基金创新研究群体科学基金(51021004);国家自然科学基金优秀青年基金(51322904)

摘　　要：防沉板是深海油气工程中水下生产系统的重要基础形式,因其埋深浅、水下施工方便等特点而具有广阔的应用前景。为了满足基础抗滑移的要求,可在防沉板底部设置裙板,裙板的存在增加了防沉板竖向承载力计算的难度。将防沉板基础简化为带裙板条形基础,考虑了内部土体与基础的相互作用,建立了竖向承载模式,即Terzaghi模式;运用极限分析法推导了该承载模式的上限解,引入了一个能够反映裙板与基础内部土体共同作用的经验参数—土体破坏率(η),其大小决定了地基中土体滑动面的范围;通过分析确定了在二维简化条件下带裙板防沉板基础的土体破坏率与基础高宽比的关系;并研究了土体破坏率不同时,地基承载力系数Nq和Nγ与土体内摩擦角之间的关系。The mudmat is an important foundation form for deepwater oil and gas engineering in the subsea production system. The mudmat has a wide application prospect because of lower buried depth and convenient construction in the ocean. The existence of the skirts,set up at the bottom of the mudmat in order to adapt to the requirements of foundation slip resistance,increases the difficulties of the calculation of the vertical bearing capacity of mudmat. The mudmat is simplified in to skirted strip foundation in this study,and Terzaghi mechanism,which takes the interaction between inner soil and foundation into consideration,has been proposed. The upper value of the vertical bearing capacity of the mudmat is obtained by the upper bound theorem of limit analysis. The soil damage rate as a new empirical parameter about combined action between shirts and inner soil of foundation has been defined. The value of the soil damage rate indicates the range of soil failure. The relationship between soil damage rate and aspect ratio is determined for the mudmat by the simplified analysis in two-dimensional conditions. The relationship of the bearing capacity factors Nqand Nγwith the friction angle is also discussed under this soil damage rates.

关 键 词：防沉板基础 承载模式 竖向承载力 上限解 土体破坏率 砂土 深海油气 

分 类 号：P751[交通运输工程—港口、海岸及近海工程] TU473.1[天文地球—海洋科学]