饱和密砂切削过程中的孔压发展规律  

Laws of Pore Pressure Development in Cutting Process of Densely Compacted Sand under Water

作　　者：谢立全 张佳灵[2] 秦少华[2] 洪国军[1] 

机构地区：[1]中交疏浚技术重点实验室,上海200120 [2]同济大学水利工程系,上海200092

出　　处：《中国港湾建设》2011年第4期10-12,共3页China Harbour Engineering

基　　金：国家自然科学基金资助项目(50979071);高等学校博士学科点专项科研基金资助项目(20090072120001);上海市教委科研创新重点项目(11ZZ28)

摘　　要：密实粉砂,以其显著的剪胀特性使得自航耙吸挖泥船耙头疏浚效率大大降低,耙齿行进阻力增大,疏浚适用土质受到了较大限制。在考虑饱和密实粉砂的剪胀特性基础上,将砂土应力应变与渗流耦合,通过有限元计算,分析了饱和砂土在切削过程中的孔压发展规律。结果表明,饱和密砂在切削过程中有着较强的剪胀效应,随着切削速度的增加,在耙齿刀尖前方产生越来越高的孔隙真空负压,致使土体有效应力显著增加,从而导致切削阻力明显提高。The dredging efficiency decreases and the cutting force increases greatly for drag-heads on trailing suction hopper dredgers （TSHD）, which is mainly dominated by the dilatancy of densely compacted sand, so the soil for dredging is greatly restricted. Based on FEM simulation, the dilataney of dense sand was considered and the interactions of stress-strain-seepage were coupled in the calculation of pore pressure in sand cutting. The numerical results illustrated that dilatation causes the development of pore vacuum pressure at the front side of the blade in cutting water-saturated sand which results in an increase of the grain stresses, resulting in higher cutting forces with higher cutting speed.

关 键 词：砂土 切削 剪胀 孔隙水压力 真空负压 耦合模型 

分 类 号：U616.1[交通运输工程—船舶及航道工程] TU431[交通运输工程—船舶与海洋工程]