波浪作用下开孔沉箱疲劳与承载能力研究  

Study on fatigue and bearing capacity of perforated caissons under wave action

作　　者：孙德成 方辉 刘勇 SUN Decheng;FANG Hui;LIU Yong(Department of Ocean Engineering,College of Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学工程学院海洋工程系,山东青岛266100

出　　处：《海洋工程》2020年第6期42-52,共11页The Ocean Engineering

基　　金：国家自然科学基金项目(51725903,11572300)。

摘　　要：开孔沉箱孔洞周围存在以三轴循环应力为特征的复杂承载区,其中混凝土损伤速度远大于单轴应力条件,局部疲劳损伤快速累积使结构整体承载能力迅速下降。考虑迎浪面入射波浪与消浪室内反射波浪的循环作用,针对开孔区域复杂应力状态下的疲劳损伤问题,基于不可逆损伤力学发展的数值计算方法模拟开孔板疲劳过程,得到循环荷载作用下不同类型开孔板的损伤演化历程,并计算损伤后整体结构极限承载力大小,通过综合对比孔洞损伤发展规律和结构极限承载能力,建立了疲劳作用下开孔沉箱极限承载能力判断依据。现有规范依据设计使用年限、波浪条件、作用效应组合等确定材料与结构强度,但并未充分体现开孔结构的优势与承载特点,在此基础上文中补充了开孔结构的优化设计以及实际寿命判断。There is a complex bearing area around the holes of perforated caissons characterized by three-axis cyclic stress,that makes the speed of concrete damage larger than the uniaxial stress condition,and the rapid accumulation of local fatigue damage makes the structure bearing capacity decrease rapidly.Considering the circulation effect of the incident waves on the seaside and the reflected waves in the wave-absorbing chamber,the fatigue process of perforated wall is simulated based on the numerical calculation method of irreversible damage mechanics,then the damage evolution history of different kinds of perforated walls under cyclic loading is obtained,and the ultimate bearing capacity of the whole perforated-wall structure after damage is calculated.By comprehensively comparing the damage development around the holes and the structure ultimate bearing capacity,the judgment basis of ultimate bearing ability of the caisson under fatigue damage is established.The existing specifications determine the material and structural strength according to the design life,wave parameters,loading effect combination,etc.,but do not fully reflect the advantages and bearing characteristics of the perforated-wall structure.Based on this,optimization design and actual life judgment of perforated wall are supplemented.

关 键 词：开孔板 疲劳损伤 极限承载能力 开孔沉箱 波浪作用 循环荷载 

分 类 号：U657.3[交通运输工程—港口、海岸及近海工程] TV139.2[交通运输工程—船舶与海洋工程]