摘要
北部湾地区拥有丰富的海洋资源,海洋工程在这一地区的发展日益重要,了解海砂在不同固结应力比和密实度条件下的动力特性,对于海岸线保护、港口建设、堤防工程等都至关重要。为探究北部湾海砂的动力特性,针对北部湾海砂开展了一系列的固结不排水循环动三轴试验,分析了相对密实度和固结应力比对北部湾海砂的轴向累积应变、动弹性模量、动孔压以及滞回曲线的影响。研究表明:在相同振次水平下,随着固结应力比和相对密实度的增大,海砂的轴向累积应变随之减小;动孔压随着固结应力比的增大线性减小,在低相对密实度(Dr≤50%)下,动孔压随振次的增大而增大,在高相对密实度(Dr=70%)下,动孔压随振次先增后减;动弹性模量随着振次的增加出现刚度软化现象,增大相对密实度与固结应力比,较明显地减缓了动弹性模量的衰减速率;随着固结应力比和相对密实度的增大,滞回曲线包围的面积减小,滞回曲线由不封闭曲线转为封闭曲线。这些研究成果可以为北部湾围填海工程提供一定的参考。
There are abundant marine resources in Beibu Gulf area,and the development of marine engineering in this area is becoming increasingly important.To understand the dynamic characteristics of sea sand under different consolidation stress ratio and density conditions is very important for coastline protection,port construction and dike engineering.In order to explore the dynamic characteristics of Beibu Gulf sea sand,a series of consolidation undrained cyclic dynamic triaxial tests were carried out on Beibu Gulf sea sand,and the effects of relative compacting degree and consolidation stress ratio on the axial cumulative strain,dynamic elastic modulus,dynamic pore pressure and hysteresis curve of Beibu Gulf sea sand were analyzed.The results show that the axial cumulative strain of sea sand decreases with the increase of consolidation stress ratio and relative density at the same vibration level.The dynamic pore pressure decreases linearly with the increase of consolidation stress ratio.At low relative density(D_r≤50%),the dynamic pore pressure increases with the increase of vibration times.At high relative density(D_r=70%),the dynamic pore pressure increases first and then decreases with the increase of vibration times.The dynamic elastic modulus appears stiffness softening phenomenon with the increase of vibration times,and the relative density and consolidation stress ratio are increased,which obviously slows down the attenuation rate of dynamic elastic modulus.With the increase of consolidation stress ratio and relative density,the area enclosed by the hysteresis curve decreases,and the hysteresis curve changes from an unclosed curve to a closed curve.These research results can provide some reference for the reclamation project in Beibu Gulf.
作者
王家全
和玉
祝梦柯
钱弘毅
WANG Jiaquan;HE Yu;ZHU Mengke;QIAN Hongyi(Guangxi University Key Laboratory of Disaster Prevention and Mitigation and Prestress Technology,Guangxi University of Science and Technology,Liuzhou 545006,China;Guangxi Zhuang Autonomous Region Engineering Research Center of Geotechnical Disaster and Ecological Control,Liuzhou 545006,China)
出处
《安全与环境工程》
CAS
CSCD
北大核心
2024年第4期20-28,共9页
Safety and Environmental Engineering
基金
国家自然科学基金项目(41962017)
广西自然科学基金重点项目(2022GXNSFDA035081)
广西高等学校高水平创新团队及卓越学者计划项目(桂教人才[2020]6号)
广西科技大学研究生教育创新计划项目(GKYC202328)
广西大学生创新创业训练计划资助项目(202210594057)。
关键词
北部湾海砂
相对密实度
固结应力比
滞回曲线
动三轴试验
sea sand in Beibu Gulf
relative density
consolidation stress ratio
hysteresis curve
dynamic tri-axial test
