论文部分内容阅读
以黄河水下三角洲埕岛海域5种典型层序粉质土海床为模型,以Biot理论为基础,采用有限差分法计算10m深度内海床土应力场、位移场和超静孔隙水压力场分布,并与实际观测结果进行对比。研究揭示在波浪荷载作用下,多层海床土位移、孔隙水压力除在表层粉质土中出现1个极大值点外,在下覆软弱层中还将出现第2个极大值点,而应力在界面位置将急剧减小。表层粉质土中出现的第1个极值是引发小规模浅表地质灾害的动力学因素,而大规模地质灾害的发生和下覆软弱层中第2个极值直接相关。海床土沉积层序对土层稳定性影响大,其中“上硬下软”的沉积结构最不稳定,在强浪作用下容易发生大规模地质灾害。
Taking the five types of typical sequence silty seabed in Chengdao area of the Yellow River subaqueous delta as a model and based on the Biot theory, finite element method was used to calculate the distribution of stress field, displacement field and excess pore water pressure in the seabed within 10m , And compared with the actual observation results. The results show that under the action of wave load, the displacement and pore water pressure of multi-layer seabed in addition to one maximum point in the surface silty soil, the second maximum point will appear in the next weak layer, The stress in the interface position will be drastically reduced. The first extremum in surface silty soil is the dynamic factor that triggers small-scale superficial geological disasters, whereas the occurrence of large-scale geological disasters is directly related to the second extremum in the overlying weak layer. The sedimentary sequence of the seabed soil has a great influence on the stability of the soil layer, and the sedimentary structure of the “upper and lower soft” structure is the most unstable and prone to large-scale geological disasters under the action of the strong waves.