三角洲形成作用

Sediment from river is not the main source of the Rushan Bay now any more ,which leads to the change of balance of sedimentation power. Sediment will transport because of the drive of hydrodynamic elements in macroscopic view .Direction of suspended load is basicly the same as tidal current .Flood tide makes suspended load transport to tip of the inner Bay and to the Mouth in exterior Bay .The direction of longside sediment transport in two sides of the Mouth mainly focus in the Mouth .Because the coastline along the exterior Bay is very meandering and it belongs to the type of bedrock ,besides some sediment going into the inner Bay ,so actual net sediment discharge rate is less than calculation .It develops an ebb delta out of the Mouth and forms tidal sand ridge ,tidal washing canal ,barrier bar and marine physiognomy ;The result of model simulation disclosures that differences of sediment erosion and siltation between single tidal action and wave-current action are very big .From the analysis of sediment composition、sediment sources and stability of beach and ridge ,this article gets the conclusion that the channel has the possibility to silt ,though the course maybe very slow.

通过分析研究文章得出如下结论：沉积物平面分布与水动力的时空变化存在很好的相关性；口门外发育落潮流三角洲，形成潮流沙脊、潮流冲刷槽、浅滩、拦门沙等水下动力地貌；乳山湾河流来沙已不是湾内泥沙主要来源导致沉积水动力平衡发生改变，宏观上表现在泥沙受水动力驱动发生不断运移；悬沙运移方向与涨潮流方向基本一致，湾内涨潮流带来的悬移质泥沙向湾顶运移，湾外悬移质泥沙主要向口门方向运移；湾口两侧岸段沿岸输沙方向均指向口门方向，由于乳山湾外海岸线曲折，两侧岸段以基岩为主，加之部分泥沙进入湾内，实际净输沙量小于计算值；数值模拟发现潮流单独作用与波流共同作用下泥沙蚀淤模拟差别较大；从沉积物组成、泥沙来源及滩槽稳定性三个方面分析，文章认为研究区存在航道淤积的可能性，但过程相对较慢。

In the prodelta, the fine sediments spread around with the help of floatage and settle down under the force of gravity.

整体上，扇三角洲的形成是一个沉积物不断前积和垂向加积的过程，湖平面变化不同，二者作用强度不同，致使扇体形态有所差异，但扇面各部分基本维持相对固定的坡度，且沉积物的整体粒度分布趋势一致。

By field-testing methods, such as static cone penetration test, field vane shear test, and pore water piezometer test, the variation of strength and the pore water pressure are measured at real time, and the marine hydrodynamics' impaction on the consolidation process of the sediments in the Yellow River Estuary was studied. It is shown that the self-consolidated sediments have a very fast consolidation rate, under self-consolidation, in 72h, the consolidation degree reaches 37% and about 142h the pore water pressure disperse over, while under the hydrodynamics, in 72h the consolidation degree reaches 52% and about 195h the pore water pressure disperse over.

在黄河三角洲刁口叶瓣潮坪上，开挖2m×1m×1m的试坑，现场取土配置黄河口快速沉积形成的流体状堆积物，以铁板部分覆盖试坑隔绝波浪和潮流作用，利用微型贯入、静力触探、十字板剪切试验、孔隙水压力监测等原位测试手段，实时测定快速沉积的海床土强度发展以及孔隙水压力消散情况，研究快速沉积的粉质海床土分别在自重条件下以及在波浪和潮波等水动力作用下的固结过程。

The sediments of delta front around wave base plane are eroded by wave action and took along to redeposit below wave base plane, during which turbidite is formed.

波浪作用可以侵蚀浪基面附近的三角洲前缘砂体，并在回流作用下携带至最大浪基面之下再沉积，沉积过程中形成小型浊积体。

Furthermore, in order to improve the interpretation of the deltaic sedimentary record, e.g., to identify climate and environmental changes using the record, the various parameters derived from analyses of the cores should be standardized by evaluating the temporal changes caused by early diagenesis and decay, and by determining the rate of deltaic shoreline changes which control the relative position of the record within the deltaic sedimentary system.

此外，在长江三角洲沉积记录的分析方面，为了更好地提取气候、环境演化信息，应充分考虑沉积记录形成后所经历的自身变化（如成岩作用变化、分解和衰变等）和相对于岸线迁移的空间位置变化。

It indicates that crevasse channel is a kind of very narrow and shallow short range small channel with a fixed path which is formed among wide-ranged channels by the major channel after the avulsion crevasse in a fluvial and deltic sedimentary system.

指出决口水道是在河流及三角洲沉积体系中，由主河道于大洪水期冲裂决口后，在广阔河道间形成的具有固定路径及一定限流作用的极窄、浅的短程小型水道。

The medium-grained sandstones and medium-fine-grained sandstones form good reservoirs and the poststones medium reservoirs, while siltstones form poor reservoirs and pelitic siltstones poorest reservoirs. Sand bodies mostly develop in sand-flats, tidal channels and distributary channels of braided stream delta microfacies. The reservoir rocks of sand-flat and tidal channel are best with the physical property. Diagenesis such as compaction, cementation and dissolution has strongly reformed the reservoir rocks and the late dissolution has greatly improved their porosity and permeability.

中粒砂岩、中细粒砂岩属好储层，细粒砂岩属中等储层，粉细砂岩，粉砂岩属较差储层，而泥质粉砂岩则属差储层；砂坪、潮道和辫状河三角洲分流河道微相中的砂体最发育，它们决定了储集岩的发育、分布及原始物性条件；砂坪和潮道储集岩的物性最好，辫状河三角洲分流河道储集岩的物性次之，砂泥混合坪、辫状河三角洲分流河道间储集岩的物性较差；成岩作用对本区CⅠ油组的储层有强烈的改造作用，尤其是较晚期的溶蚀作用对岩石的储集性能有明显的改善，对本区CⅠ油组中孔高渗透储层的形成有很大的贡献。

Weaker wave action in the estuary area, the river for several groups of bifurcation into the sea at the same time, the cross-flow of silt accumulation in both the volume of more than wave erosion, silt accumulation along the Fork Road extension to form a long strip big spit into the sea, so that was a bird foot delta-shaped appearance.

在波浪作用较弱的河口区，河流分叉为几股同时入海，各叉流的泥沙堆积量均超过波浪的侵蚀量，泥沙沿各叉道堆积延伸，形成长条形大沙嘴伸入海中，使三角洲外形呈鸟足状。

The fluid sediments imitating the rapidly deposited seabed silts were made in-situ, and an iron plate covered part of the test pit to cut off the effect of the marine hydrodynamics. By field-testing methods, such as static cone penetration test, field vane shear test, the variation of strength is measured at real time, and the marine hydrodynamics' impaction on the consolidation process of the sediments in the Yellow River Estuary was studied.

在黄河三角洲刁口叶瓣潮坪上，开挖2m ×1m×1m 的试坑，现场取土配置黄河口快速沉积形成的流体状堆积物，以铁板部分覆盖试坑隔绝波浪和潮流作用，利用微型贯入、静力触探、十字板剪切试验等原位测试手段，实时测定快速沉积的海床土强度，研究快速沉积的粉质海床土分别在自重条件下以及在波浪和潮波等水动力作用下的固结过程。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。