基于Prandtl破坏模式的吸力式沉箱基础抗拔承载力极限分析上限解  

Upper bound solution for ultimate bearing capacity of suction caisson foundation based on Prandtl failure mode

作　　者：朱文波[1] 戴国亮[1,2] 龚维明[1,2] 赵学亮[1,2] ZHU Wenbo;DAI Guoliang;GONG Weiming;ZHAO Xueliang(School of Civil Engineering,Southeast University,Nanjing 210096,China;Key Laboratory of Concrete and Prestressed Concrete Structure of Ministry of Education,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]东南大学混凝土及预应力混凝土结构教育重点实验室,江苏南京210096

出　　处：《中南大学学报（自然科学版）》2019年第1期158-164,共7页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划专项项目(2017YFC0703408);国家自然科学基金资助项目(51678145;51478109)~~

摘　　要：为了研究吸力式沉箱基础竖向抗拔荷载作用下极限承载力上限解,引入"反向地基承载力",基于Prandtl破坏机构,选择合适的地基破坏模式及机动位移速度场,使原Prandtl机构中主动区变为被动区,对数螺旋线反向,并考虑土体自重、黏聚力及土压力因素,推导吸力式沉箱基础抗拔荷载作用下极限承载力上限解。分析上限解与黏聚力、内摩擦角、土压力以及摩擦因数关系,采用Matlab软件编程计算出上限解,并与有关试验值和上限解进行对比分析。研究结果表明:反向Prandtl破坏机构符合实际受力情况。文中上限解与试验值相对误差基本上控制在40%以下,最大相对误差为44%,最小相对误差为3%,接近试验值,证明其破坏模式的合理性及方法的适用性。In order to study the upper bound solution of the uplift ultimate bearing capacity of suction caisson foundation,the viewpoint of reverse bearing capacity and the reverse Prandtl failure mode were introduced for study.The reverse Prandtl failure mode means that the active area of Prandtl failure mode becomes the passive area and the logarithmic spiral direction was opposite.At the same time,the relationship between the upper bound solution and cohesion,internal friction angle,soil pressure and friction coefficient were analyzed.Then,the upper bound solution was calculated by using the Matlab calculation program and was compared with the previous experimental data and other upper bound solution.The results show that the proposed equations are verified by the corresponded test results.And the upper bound solution agrees reasonably well with the other test results.The error between upper bound solutions and the experimental values are basically controlled to be less than 40%,with the maximum error being 44%,and the minimum error being 3%.It can be proved that the failure mechanism is reasonable and more consistent with the actual force condition.

关 键 词：吸力式沉箱基础 Prandtl破坏模式 极限分析 上限定理 能量耗散率 

分 类 号：TU473[建筑科学—结构工程]