波浪引起海床内部孔隙迁移试验研究

Experimental Study on Wave Induced Pore Migration in Seabed

本文通过室内方形水槽开展了波浪荷载对孔隙迁移过程影响的试验研究。结果表明,对于松软土体,波浪荷载会导致土体发生剪切破坏形成滑动层,而孔隙水则会在累积孔压作用下沿着滑动层形成的孔隙发生迁移。波浪荷载导致土体内部孔隙迁移,其迁移过程受外界荷载以及土体性质影响显著。含气泡的孔隙会在波浪循环荷载过程中的负压作用和气体自身浮力作用的共同影响下发生迁移,循环荷载中的负压作用越强,含气泡的孔隙越容易发生迁移。孔隙向上迁移后会导致底部土体的密实度增加而上方土体的密实度下降。土体的松软程度会影响滑动面的形成,越松软的土体越容易形成滑动面。相比于密实土体,孔隙在滑动面中更容易发生迁移。

This paper carried out an experimental study on the influence of wave loads on the pore water migration process through an indoor square tank.The results show that for soft sediments,wave loads would cause the sediments to undergo shear failure and therefore forming the flow slide,while the accumulated pore-space will follow along the flow slide to migrate.For the formation of the drainage channel,sediments compaction has a significant impact on the accumulation process of wave induced pore water pressure.The denser the sediments,the smaller amplitude of cumulative pore pressure will be.Wave load causes the internal pores of sediments to migrate.In general,the migration process is affected by the external load as well as the nature of sediments.The pore of bubbles will migrate under the combined influence of the negative air pressure in the process of wave cyclic loading and the buoyancy of the gas itself.The stronger the negative air pressure in the cyclic loading,the easier the pore of bubbles will migrate.The upward sediments migration of pore spaces results in an increase in the compactness of the sediments at the bottom and a decrease in the compactness of the sediments above.The sediments compaction will affect the formation of the gliding surface.The softer the sediments,the easier it is to form the gliding surface.Compared with the compact sediments,the pore spaces are more likely to migrate on the gliding surface.