摘要
针对浮式海洋结构采用的桩基础,考虑土的循环软化效应,将软土的循环强度与Mohr-Coulomb屈服准则相结合,基于拟静力弹塑性分析建立了循环波浪载荷作用下斜向抗拔桩循环承载性能的计算模型,确定了斜向上载荷作用下抗拔桩的循环承载力,并与单调加载作用下的斜向抗拔桩的极限承载力进行了对比,进一步探讨了桩长、桩径、桩体模量及载荷循环次数等因素对斜向抗拔桩循环承载力的影响。研究结果表明:循环波浪荷载的作用导致了斜向抗拔桩土体循环强度的分布不均匀,从而降低了地基的循环承载力。斜向抗拔桩的动态极限承载力随循环次数的增加而降低,随桩长、桩径及桩体模量的增大而增大。
Accompanying the development of ocean engineering, research on the bearing capacity of pile foundation under the action of wave cyclic loading has been given special attention for the design of offshore structures. Based on the concept of cyclic-softening effect, cyclic strength of the soft soil and Mohr-Coulomb yield criterion are combined together to numerically evaluate cyclic bearing capacity of inclined uplift pile under wave cyclic loading. A perfect elastoplastic finite element method for numerical assessment of bearing capacity of inclined uplift pile is developed. Dynamic ultimate bearing capacity of inclined uplift pile under cyclic loading is studied. The influences of load cycle times, static stress ratio, pile length, pile diameter and pile modulus on the cyclic ultimate bearing capacity of inclined uplift pile are analyzed. It can be concluded that the bearing capacity of the foundation under cyclic loading is less than that of under static load. The effects of wave cyclic loading lead to nonuniform distribution of cyclic strength of soil beside the inclined uplift pile and reduce the cyclic bearing capacity of pile foundation. The results also show that the ultimate bearing capacities of inclined uplift pile improve gradually with the increase of the load inclination, pile length, pile diameter, pile modulus, soil cohesion and soil modulus.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2012年第1期301-306,共6页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51179026)
关键词
海洋工程
波浪循环荷载
循环强度
循环承载力
桩基础
ocean engineering
wave cyclic loading
cyclic strength
cyclic bearing capacity
pile foundation
作者简介
范书立，男，1978年生，博士，讲师，主要从事工程结构抗震分析和结构防灾减灾方面的研究工作。E-mail：shuli@dlm．edu．cn
