摘要
箱筒型防波堤基础是一种能够适应复杂海况的新型基础形式。利用室内模型试验对箱筒型防波堤基础在水平静载荷及水平循环荷载作用下的稳定特性进行了研究。结果表明:砂性土地基中箱筒型防波堤基础破坏可分为准弹性、塑性及破坏三个阶段,以荷载位移曲线出现明显拐点判断箱筒型防波堤基础极限承载力约为0.08 kN。以循环过程中施加荷载与静载荷水平极限承载力比值定义荷载循环比ζ_(b),当ζ_(b)=0.5、ζ_(b)=1.0时,防波堤基础前10次累计位移最为明显,分别占总循环累计位移的96.70%、91.88%,这主要是由于砂土发生剪胀,土颗粒重新排列所致;而后40次循环累计位移不明显,分别占总循环累计位移的3.30%、8.12%,此时土体发生剪缩,土颗粒之间致密化。当ζ_(b)=0.5时,循环结束后防波堤基础抗滑移系数K_(1)、抗倾覆系数K_(2)分别为1.619、3.372;当ζ_(b)=1.0时,抗滑移系数K_(1)、抗倾覆系数K_(2)分别为0.839、-18.063,说明ζ_(b)=0.5循环荷载作用下砂性土地基防波堤基础稳定性良好,但ζ_(b)=1.0循环加载时,基础首先发生滑移破坏进而发生严重的倾覆破坏。
The box-and-barrel breakwater foundation is a new type of foundation which can adapt to complex sea conditions.In this research,the stability characteristics of box-and-barrel breakwater foundation under horizontal static load and horizontal cyclic load are studied by means of indoor model test.The results show that the failure of box-and-barrel breakwater foundation in sandy soil foundation can be divided into three stages:quasi-elastic,plastic and failure,and the ultimate bearing capacity of box and tube breakwater foundation is about 0.08 kN according to the obvious inflection point of load displacement curve.The cyclic load ratio ζ_(b) was defined by the ratio of the applied load to the horizontal ultimate bearing capacity of the static load in the cyclic process.When ζ_(b)=0.5 and ζ_(b)=1.0,the first 10 cumulative displacements of the breakwater foundation were the most obvious,accounting for 96.70%and 91.88%of the total cumulative cyclic displacements,respectively,mainly caused by the dilatation of sand and the rearrangement of soil particles;the cumulative displacements of the last 40 cycles were not obvious,accounting for 3.30%and 8.12%of the total cumulative displacements,respectively.At this time,the soil shrinks and densification occurred among soil particles.When ζ_(b)=0.5,the anti-slip coefficient K_(1) and anti-overturning coefficient K_(2) of breakwater foundation were 1.619 and 3.372,respectively;when ζ_(b)=1.0,the anti-slip coefficient K_(1) and anti-overturning coefficient K_(2) were 0.839 and-18.063,respectively,indicating that the breakwater foundation in sandy soil foundation had good stability under cyclic load when ζ_(b)=0.5,but when ζ_(b)=1.0,the foundation first slippage failure and then serious overturning failure occurred.
作者
周超
寇海磊
闫正余
刁闻宙
周楠
陈琦
ZHOU Chao;KOU Hailei;YAN Zhengyu;DIAO Wenzhou;ZHOU Nan;CHEN Qi(College of Engineering,Ocean University of China,Qingdao 266100,China;Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone,Qingdao University of Technology,Qingdao 266033,China)
出处
《海洋工程》
CSCD
北大核心
2021年第6期47-56,共10页
The Ocean Engineering
基金
国家自然科学基金项目(51879246)。
关键词
防波堤基础
模型试验
循环累计位移
抗滑移系数
抗倾覆系数
breakwater foundation
model test
cyclic cumulative displacement
anti-slip coefficient
anti-overturning coefficient
