Bed Load Transport Analysis for Gravel Bed River

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GRD Journals- Global Research and Development Journal for Engineering | Volume 4 | Issue 6 | May 2019 ISSN: 2455-5703

Bed Load Transport Analysis for Gravel Bed River Shashikant V Singh P.G. Student Department of Civil Engineering GEC, Surat, Gujarat, India

S. I. Waikhom Associate Professor Department of Civil Engineering Government Engineering College, Surat, Gujarat, India

Abstract Prediction of bed load transport is important in many river engineering projects, including hydraulic structures like piers, reservoir life of dams, etc. The maximum bed load transport per unit width that a particular discharge can transport at a certain slope is defined as bed load transport rate. In the present study, analysis of steep slope river data is carried out using bed load functions of Parker (1979) Parker et.al (1982), Parker (1990),Graf (1998) and Wong and Parker (2006b).The computed dimensionless bed load transport rate are compared for analysing the prediction by selected equations. The predicted bed load transport rate is compared with the actual measured values for all data set to identify the equation which gives best prediction of bed load transport rate. Keywords- Alluvial Channel, Steep slope, Bed load transport

I. INTRODUCTION Water is the most precious natural asset of any civilization and is very important for physiological processes. The processes of erosion of land surfaces, transportation of eroded material, deposition of this material in river and streams and such other processes depend upon flow and hydrological parameters. These factors can be classified into following categories: Characteristics of sediment, Characteristics of the fluid, Characteristics of the flow and Characteristics of the channel. Among the different categories stated above, sediment characteristics such as shape, size, density and fall velocity plays a decisive role in different stages of the phenomenon of sediment transport and these properties are governed to a large extent by the origin of sediment and process of its formation. When flow conditions exceed the criterion for incipient motion, sediment particles along an alluvial bed start to move. If the motion of sediment particles is rolling, sliding, or occasional jumping along the bed, it is called as bed load transport. Prediction of bed load transport is important for river engineering projects. River characteristic can be understood well by studying the bed load composition and movement of various size particles to evaluate the vertical sorting and refining processes along the bed. For some cases engineers use field measurements to calibrate a sediment curve, but in most cases measured data does not exist because measurement of bed load in the field is difficult, expensive, and time-consuming task. This is why engineers employ computational methods, often established with flume experiments (Recking, 2013). Results obtained from different approaches often differ drastically from each other and from observations in the field. The present study tested the accuracy of applicability of bed load transport models suggested for gravel bed River using published field data of steep slope river.

II. DATA COLLECTION For the present research river data is used for comparative analysis of bed load models. River data of United States - East St. Louis Creek, St. Louis River site-1 and site-2 and Fall creek, are collected from Hinton, D., Hotchkiss, R., Ames, D.P. (2016) for analysis. St. Louis River is the largest tributary of Lake Superior and carries a heavy bed load from non-point sources. The river also has a number of sites known to contain contaminated sediments. Fall Creek is the tributary of white river in the U.S. state of Indiana. It begins near the town of honey creek, Indiana. The selected river data has high slope (Table 1). For fair comparison, Parker’s original bed load transport model and modified bed load transport models and Wong and Parker (2006,b) bed load transport model are selected for present study. The range of hydraulic parameters collected is given in Table 1. Sr.No

Name River

1 2 3

East St. Louis Creek Fall Creek St. Louis Creek Site 1

Depth (m) 0.12- 0.4 0.07-0.22 0.16-0.62

Table 1: Range of Hydraulic Parameter width Velocity Discharge Observed Bed load transport (m) (m/s) (m^3/s) (kg/s) 2.84-3.03 0.264-1.32 0.09-1.24 0-0.06244 1.68-2.11 0.15-1.16 0.04-0.5 0-0.03085 6.4-7.25 0.38-1.77 0.39-6.95 0.0002-0.44706

Slope m/m 0.051-0.0617 0.052-0.056 0.01-0.0280

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