Showing papers on "Siltation published in 1986"
Journal Article•
20 citations
01 Mar 1986
TL;DR: In this paper, a theoretical analysis of fluid mud in estuaries including a review of the literature was made, and basic theories were devised and modified to describe the formation of fluid mixtures from a more dilute suspension and its motion down a sloping bed and along a flat bed.
Abstract: The movement of fluid mud has been cited as the most likely cause of rapid siltation in the majority of the ports in the world located in muddy estuaries. In the past, it has been very difficult to predict or quantify this extra siltation, which may in some cases double the annual maintenance dredging bill for a new port extension. A theoretical analysis was made of the behaviour of fluid mud in estuaries including a review of the literature. Basic theories were devised and modified to describe the formation of fluid mud from a more dilute suspension and its motion down a sloping bed and along a flat bed. The analysis casts a new light on several previously unexplained phenomena observed in estuaries.
18 citations
TL;DR: Based on the long-term hydrological and sedimental data and the hydrolographic charts of more than 100 years, comprehensive analyses and studies have been made on the river runoff, sediment, tides and waves outside the Changjiang river estuary as discussed by the authors.
Abstract: Based on the long-term hydrological and sedimental data and the hydrolographic charts of more than 100 years, comprehensive analyses and studies have been made on the river runoff, sediment, tides and waves outside the Changjiang river estuary. Origin and siltation characteristics of the entrance sandbars, recent evolution tendency of the planar axis of the, passage and the decreasing capacity of the fluvial channel are also described in this paper, which can provide basic information necessary for the realignment of the sea-traffic channel through the area.
4 citations
01 Aug 1986
TL;DR: A summary of silt monitoring techniques that can be employed to gain that knowledge is presented in this article, where the authors also present a summary of the silt measurement techniques used to predict siltation rate in harbors, at jetties and in dredged channels.
Abstract: Knowledge of the cohesive sediment transport regime of an estuary is essential to predicting the siltation rate in harbors, at jetties and in dredged channel. A summary of silt monitoring techniques that can be employed to gain that knowledge is presented.
1 citations
Journal Article•
TL;DR: In this article, a permanently installed and purpose-designed submerged sand pump was used at Nerang River, Queensland, Australia, to combat siltation, in which it features a permanently-installed and purpose designed underwater sand pump.
Abstract: A new system now operating at Nerang River, Queensland, Australia, to combat siltation is described. It challenges the conventional dredging works approach to controlling siltation, in that it features a permanently-installed and purpose-designed submerged sand pump.
1 citations
TL;DR: In this paper, a new technology of hydraulic filling of structures of a flattened profile with protection of the upstream slope by a silted gravel covering is recommended on the basis of a generalization of construction experience and experimental investigations.
Abstract: 1.
On the basis of a generalization of construction experience and experimental investigations a new technology of hydraulic filling of structures of a flattened profile with protection of the upstream slope by a silted gravel covering is recommended. Siltation of the covering is accomplished during layerwise hydraulic filling, and in certain cases the gravel covering can serve as an embankment during hydraulic filling.
2.
Siltation of the covering increases the strength and wave resistance of the upstream slope due to cohesion of clay and silt particles with the sand component of the covering and makes it possible to reduce the thickness of the gravel covering by 20–30%.
3.
For designing the technology a calculation method is recommended which consists in determining the steepness of the slope from the nomogram in Fig. 4, thickness of the coating by Eq. (3), and time of filling the pores by Eq. (6).
4.
The developed technology effects a considerable economy due to reducing the thickness of the gravel coating as a consequence of its siltation.
TL;DR: Drainage lysimeters were used to ascertain the pipe siltation risk associated with draining several wet New Zealand soil types, and results indicate that many wet soil types throughout New Zealand are likely to require a pipe filter if subsurface-drained.
Abstract: Drainage lysimeters were used to ascertain the pipe siltation risk associated with draining several wet New Zealand soil types. A simple laboratory column study, which aimed to simulate the soil conditions immediately around the apertures in a pipe drain, was also carried out. Results indicate that many wet soil types throughout New Zealand are likely to require a pipe filter if subsurface-drained. Soil types of greatest risk are mainly coarser textured, cohesionless soils under rising water table conditions. Although particle size analysis is a useful indicator of possible pipe siltation, the effects of soil structure, particle shape, and particle density should be included as an index of soil stability. The hydraulic gradient and hydraulic conductivity determine the velocity of water flow, also affecting the degree of soil stability. Results from the laboratory column study indicate that this technique could be a quick and useful method to gauge the relative siltation potential of different soi...