Evaluation of the characteristics of sediment in coastal shallow sea area and development of the prediction method for maddiness environment

从河流运来的细颗粒沉积在海湾的内部，形成一个巨大的潮滩。在海上施工过程中，河口悬浮物和泥沙颗粒会带来一些环境问题。需要建立估算浆状粘土沉降和海水中淤泥扩散的方法。本文研究了潮滩表层沉积物的物理化学性质、机械性质和底栖生物的分布，以及悬浮泥沙的输移规律。结果表明，表层沉积物的粘土矿物组成在整个深度上是恒定的，从沉积物的抗剪强度和固结特性来看，表层沉积物处于超固结状态。研究还表明，在今津河口区，泥质中粘粒和有机质含量之间存在正相关关系， ...更多信息 在-150mV左右氧化还原电位时，单位面积上的apitata最大。提出了浆状粘土沉降的岩土参数确定方法，用考虑环内摩擦的固结方程解释了固结时间与固结量的关系，用泥浆抗剪强度与沉积物表层屈服应力的相对关系来描述浑浊的发生。根据伊沙亚湾环形水槽试验和现场潮流流速、悬浮泥沙浓度观测结果，通过明渠试验发现，悬浮泥沙颗粒的紊动扩散系数和沉降速度与脉动速度功率谱的形状有关，据此编制了近岸海域泥沙浓度估算程序，并对有明海进行了数值模拟，成功地编制了数值模型。少

Fine particles transported from rivers are deposited in an inner part of the bay, forming a vast tidal flat. The suspended materials and mud particles in estuaries bring about some environmental problems during the construction work in the sea. Establishment of the methods is needed to estimate the settlement of slurry clay and diffusion of muddiness in sea water. In the present work, some characteristics of the sediments and the transportation of the suspended mud particles have been studied.The physico-chemical and mechanical properties of the surface sediment and the distribution of benthos in a tidal flat have been investigated. The results showed that the surface sediment exhibits constant clay mineral composition throughout depth, and overconsolidated state in view of the shear strength and consolidation characteristics of the sediment. It was also indicated for Imazu estuary area that a positive correlation exists between clay and organic contents in the mud, and the weight of c … More apitata per unit area was the maximum at around-150mV redox potential. A method was proposed to determine the geotechnical parameters for the settlement of slurry clay, and the relationship of the time and the amount of consolidation was explained by the consolidation equation which took into account the friction inside of the ring.The occurrence of turbidity was formulated in terms of the relative correlation of the shear strength of mud against the yield stress of the sediment surface zone, based on the annular flume experiments and the on-site observation of tidal current velocity and the concentration of suspended mud particles in Isahaya Bay. Turbulent diffusion coefficient and settling velocity of the suspended mud particles were found, from the open channel experiments, to be dependent on the shape of power spectrum of the velocity fluctuation.Based on the results thus obtained, the code to estimate the muddiness in coastal sea has been developed and numerical simulations were conducted for Ariake Sea, and the numerical model was successfully coded. Less