SWMM Modelling of Automated Hydraulic Flushing Gate as a Flow Control Structure

This study explores the concept of hydraulic flushing gate with an automated control system as a flow control structure of the urban storm water system. The research team has implemented a flush gate with the automated control system to the flow of the water in a drainage channel. The flow control structure was used to determine the effectiveness of such design by applying the concept of virtually on a real-world drainage system at Jalan Astana, Kuching. Computer representations of the existing drainage system and flow control structure were built using EPA SWMM 5.0 model. The series of flow control structure was proven to hold the runoff from 10-year storm. The modelling result shows that there is 25.9% of flow reduction at outlet node. As a modification of the existing drainage system in the urban area involves high construction cost, by installing a flow control structure in the drainage system is an innovative way to control the flow of the water

A Review on the Self-Cleansing Design Criteria for Sewer System

Sediment deposits in sewer system had been known to have adverse effects on the hydraulic performance of the system and also on the environment. Thus, the need for sewer system to carry sediment has been recognized for many years and self-cleansing criteria have been proposed in the literature for design purposes. Conventionally, a minimum critical velocity or critical shear stress was specified and although this approach had been successful in many cases; it was appreciated that a minimum critical velocity or critical shear stress which is unrelated to the characteristics and concentration of the sediment or the hydraulic behavior of the sewer could not properly represent the ability of the sewer flows to transport sediments. A more viable approach for self-cleansing design is to incorporate some aspect of the sediment and sewer characteristics into the design criteria; hence, various self-cleansing design criteria for sewer have been proposed in the literature. This paper presents a review on the various self-cleansing design criteria for sewer and proposed some further studies that could be conducted to improve the existing self-cleansing design criteria

Study of flow in a non-symmetrical compound channel with rough flood plain

The intention of this project is to study the flow characteristics and the discharge calculation due to the significant interaction between main channel and flood plain. However, most of the research work was done for symmetrical compound channel

Effect of Deposition Thickness on Critical Shear Stress for Incipient Motion of Sediments

The current understanding on how sediment deposition thickness could affect the incipient motion of sediment is still lacking in the literature. Few existing literature suggested that the current equation for incipient motion in rigid boundary channel with limited sediment depth become less accurate as the sediment bed thickness increased. The current study highlights the effect of sediment deposits thickness on critical shear stress of sediment in rigid rectangular channel. Results of experimental work on incipient motion were used to establish the effect of sediment deposits thickness on critical shear stress. Findings from the analysis shows that sediment deposits thickness has effect on the critical shear stress at low sediment bed thickness and the effect will reduce with the increased in sediment bed thickness. A new equation for predicting critical shear stress was proposed by incorporating the sediment deposits thickness and appears to be more consistent and was not much affected by the sediment deposits thickness as compares to the existing rigid boundary equations. The new equation is an attempt toward unifying the equations for both rigid boundary and loose boundary conditions

Tools for Integrated River Flood Management (Hydraulics Modeling and Logical Framework Analysis)

Hydraulics simulation can be used as a supporting tool for planning and developing a framework, such as Integrated Flood Management for river management. To demonstrate this, a hydraulics model for the Sarawak River Basin was run using InfoWorks RS software by Wallingford Software, UK. InfoWorks River Simulation (RS) was chosen because its applicability has been proven and widely used to model Malaysian rivers. The extraction of computed floodwater level and flood maps for different time intervals would produce the rate of floodplain submergence from river bank level. This information could be incorporated into a logical framework to support decisions on flood management measures. Thus, hydraulics models can be used as tools to provide the necessary decision parameters for developing logical frameworks which would act as to guide the planning when it involved various stakeholders’ participation

Sediment Incipient Motion in Sewer with a Bed Deposit

This paper analyses experimental data on sediment incipient motion with varying sediment bed thickness (of d50, 5, 10 and 24 mm). Sediment particles (with sizes ranging from 0.5 mm to 4.78 mm) were used to evaluate the effect of deposited bed. Variation of shear velocity estimation was investigated where the critical Shields parameter was expressed using bed-slope product u∗cb, log-law u∗cl and was extended in terms of critical mean velocity. The critical Shields parameters obtained were significantly lower than the traditional Shields curve when u∗cl was used compared to u∗cb. Higher critical mean velocity is needed for shallower deposits