软基上吸力式沉箱抗拔承载力的改进极限平衡法  

A Modified Limit Equilibrium Analysis Method for Determining Pull-Out Resistance of Suction Caissons Located in Soft Ground

作　　者：范庆来[1,2] 栾茂田[2] 孟祥波[1] 

机构地区：[1]鲁东大学岩土工程重点实验室,山东烟台264025 [2]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《中国矿业大学学报》2009年第3期346-350,372,共6页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(50579006;50179006;50639010)

摘　　要：为了计算软土地基上吸力式沉箱的抗拔承载力，在简化极限分析方法的基础上，进一步考虑沉箱侧壁与土之间的界面摩擦效应，提出了一种改进的极限平衡分析方法．通过与相应的三维有限元数值计算以及离心模型试验结果的比较，验证了所提出的改进极限平衡分析方法的合理性．采用该方法探讨了结构长径比、软基的不排水抗剪强度、荷载作用点位置等因素对于沉箱承载力的影响．结果表明，沉箱与土之间的界面摩擦系数对于其抗拔承载力具有一定影响；沉箱的最优系缆点位置一般位于筒顶以下0．55～0．7倍的筒高之间．A modified limit equilibrium method is presented to determine the ultimate pull-out resistance of suction caissons located in soft ground. The method is based on a simplified failure model that considers the friction at the interface between the soil and the caisson wall. The validity of the modified method was verified by comparing it to results computed by finite element analysis and to centrifuge model test data. The effect of the aspect ratio, the undrained subsoil strength profile and the position of the loading point upon the bearing capacity of the caisson was studied. The results show that the pull-out resistance of suction caissons is strongly influenced by the interracial friction coefficient. The optimal position of the attachment point is about 0.55 to 0.7 of the embedded length below the caisson top cap.

关 键 词：软土地基 吸力式沉箱 极限抗拔承载力 界面摩擦 极限平衡分析 

分 类 号：TU48[建筑科学—结构工程]