• Title/Summary/Keyword: Bed load

Search Result 268, Processing Time 0.026 seconds

Prediction of total sediment load: A case study of Wadi Arbaat in eastern Sudan

  • Aldrees, Ali;Bakheit, Abubakr Taha;Assilzadeh, Hamid
    • Smart Structures and Systems
    • /
    • v.26 no.6
    • /
    • pp.781-796
    • /
    • 2020
  • Prediction of total sediment load is essential in an extensive range of problems such as the design of the dead volume of dams, design of stable channels, sediment transport in the rivers, calculation of bridge piers degradation, prediction of sand and gravel mining effects on river-bed equilibrium, determination of the environmental impacts and dredging necessities. This paper is aimed to investigate and predict the total sediment load of the Wadi Arbaat in Eastern Sudan. The study was estimated the sediment load by separate total sediment load into bedload and Suspended Load (SL), independently. Although the sediment records are not sufficient to construct the discharge-sediment yield relationship and Sediment Rating Curve (SRC), the total sediment loads were predicted based on the discharge and Suspended Sediment Concentration (SSC). The turbidity data NTU in water quality has been used for prediction of the SSC in the estimation of suspended Sediment Yield (SY) transport of Wadi Arbaat. The sediment curves can be used for the estimation of the suspended SYs from the watershed area. The amount of information available for Khor Arbaat case study on sediment is poor data. However, the total sediment load is essential for the optimal control of the sediment transport on Khor Arbaat sediment and the protection of the dams on the upper gate area. The results show that the proposed model is found to be considered adequate to predict the total sediment load.

Behaviour of geocell reinforced soft clay bed subjected to incremental cyclic loading

  • Hegde, A.;Sitharam, T.G.
    • Geomechanics and Engineering
    • /
    • v.10 no.4
    • /
    • pp.405-422
    • /
    • 2016
  • The paper deals with the results of the laboratory cyclic plate load tests performed on the reinforced soft clay beds. The performances of the clay bed reinforced with geocells and geocells with additional basal geogrid cases are compared with the performance of the unreinforced clay beds. From the cyclic plate load test results, the coefficient of elastic uniform compression ($C_u$) was calculated for the different cases. The $C_u$ value was found to increase in the presence of geocell reinforcement. The maximum increase in the $C_u$ value was observed in the case of the clay bed reinforced with the combination of geocell and geogrid. In addition, 3 times increase in the strain modulus, 10 times increase in the bearing capacity, 8 times increase in the stiffness and 90% reduction in the settlement was observed in the presence of the geocell and geogrid. Based on the laboratory test results, a hypothetical case of a prototype foundation subjected to cyclic load was analyzed. The results revealed that the natural frequency of the foundation-soil system increases by 4 times and the amplitude of the vibration reduces by 92% in the presence of the geocells and the geogrids.

MEASUREMENT OF TURBULENCE CHARACTERISTICS BY USING PARTICLE TRACKING VELOCIMETRY

  • Yoon, Byung-man;Yu, Kwon-kyu;Marian Muste
    • Water Engineering Research
    • /
    • v.3 no.2
    • /
    • pp.135-142
    • /
    • 2002
  • This study investigates the effects of sediment on the flow characteristics such as velocity distribution, friction velocity, turbulent intensities, Reynolds stress, etc. Particle tracking velocimetry (PTY) is used to measure the vertical flow field. Results show that flow over the high bed-load concentration region has larger values of mean velocity and friction velocity and smaller values of turbulence intensities, compared to those for flow over the low bed-load concentration region.

  • PDF

Development of Tire Test Bed for Dynamic Behavior Analysis of Vehicles on Off-roads (비포장노면 차량 거동 분석을 위한 타이어 테스트베드 개발)

  • Lee, Dae-Kyung;Sohn, Jeong-Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.21 no.3
    • /
    • pp.29-35
    • /
    • 2022
  • When a vehicle is driven off a road surface, the deformations of the road surface and tire are combined. Consequently, the dynamic behavior of wheel movement becomes difficult to predict and control. Herein, we propose a tire test bed to capture the dynamic behavior of tires moving on sand and soil. Based on this study, it is discovered that the slip rate can be controlled, and the vertical force can be measured using a load cell. The test results show that this test bed can be useful for capturing the dynamic behavior of the tire and validating dynamic simulations. In fact, the tire test bed developed in this study can be used to verify the results of computer simulations. In addition, it can be used for basic experiments pertaining to the speed control of unmanned autonomous vehicles.

Examination of Dust Trapping Mechanism in a Metal Fiber Filter-bed (금속 섬유 필터층을 이용한 미세 분진 집진 성능 관찰)

  • 이경미;조영민
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.20 no.3
    • /
    • pp.361-369
    • /
    • 2004
  • A metal fiber bed has seldom been applied to the practical filtration process despite its excellent mechanical and chemical stability. The filter-bed used in this work was highly porous with open structure, of which apparent porosity was 80 ∼ 90%. Although pressure loss across the filter-bed was very low, separation efficiency was found to be quite high. This paper focuses on the basic filtration mechanisms of a metal filter-bed and a thin ceramic filter from fly ash for reference. The experimental parameters were face velocity, dust loading and porosity of filter-bed. Pressure drop increased with increasing face velocity and dust feeding load for both filters. It also showed that dust particles deposited in the deep flow path, finally resulting in clogging the pore channels. It thereby indicates that the dominating mechanism of the metal filter-bed would be depth filtration. Meanwhile, the thin fly ash composite filters trapped the aerated dust mainly on the surface of the filter medium, so that the instantaneously formed dust layer might cause a steep increase of pressure drop across the filtration system.

A Study on the Topography Change of Hyeya River and Jinha Beach (회야강 하구 및 진하해수욕장의 지형변화에 관한 연구)

  • 민병형;민일규;이동수
    • Journal of Ocean Engineering and Technology
    • /
    • v.8 no.1
    • /
    • pp.84-95
    • /
    • 1994
  • In recent years Jin-Beach and Hyeya River mouth have experienced severe erosion phenomena. The cause of erosion is examined using a 3-dimensional nunumerical sediment transport model. The model is composed of three components : wave model, wave-induced current model and 3-dimensional sediment transport model. In the wave analysis component we consider refraction, diffraction and reflection based on Maruyama and Kajima method. For the wave-induced current model we use depth-integrated continuty equation and momentum equations. For the 3-dimensional sediment transport model we consider bed load and suspended load simutaneously. Model results obtained for Jin-ha Beach and Hyeya River mouth agreed well with experimental results.

  • PDF

Study on the Bed-Materials movement and Sedimentation. (유사운동과 유사량에 관한 연구)

  • 홍승만
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.18 no.1
    • /
    • pp.4052-4063
    • /
    • 1976
  • The observation and Studies on the two stations in the Ansung river are included that were justified types of Bed-materials movement and were estimated loads volume of sediment applied by sediment rating curve and/or drivel formulars according to both stream conditions. The results of evaluation for above purpose are given as follows 1) Drived formulas for sediment computation in accordance with river situations are given as follows. -Suspended load Yu-chun Ts=135H4.55 Hye-hwa Ts=454H3.71 -Bed load Yu-chun Tb=75.4H191 Hye-hwa Tb=134.5H1.82 2) Annual volume of surface erosion in the catchment area were obtained at yu-chun of 0.236mm Hye-hwa of 0.200mm and mean depth of 0.22mm 3) The Bed-materials movement with water depth were represented that ripple is bellow than 0.067 meter at yu-chun and bellow than 0.096 meter at Hye-hwa stream, Dunes is 0.067-0.22 at yu-chun and 0.096-0.23 at Hye-hwa, Transition is 0.22-0.46 at yu-chun and 0.23-0.58 at Hye-hwa and Antidunes is higher than 0.46 at yu-chun and 0.58 of water depth at Hye-hwa stream

  • PDF

Bed Design of Inducement Nets for Chrysanthemum Cultivation (국화재배용 유인네트의 베드 설계)

  • Suh, Won-Myung;Kim, Young-Ju;Bae, Yong-Han;Min, Young-Bong;Park, Joong-Choon;Huh, Moo-Ryong;Yoon, Yong-Cheol
    • Journal of agriculture & life science
    • /
    • v.43 no.2
    • /
    • pp.47-53
    • /
    • 2009
  • This research is intended to study the induction net of chrysanthemum used in its greenhouse and requiring lots of time for manual work and review the structural safety of a bed and existing greenhouses after designing the bed of a net which increases cropping period by sharply reducing the time of work and provides the bed of induction nets for cultivating chrysanthemum with its existing and new greenhouse. The review of sectional and biodynamic properties in 15 kinds of materials has revealed that the pipes of ${\phi}38.1{\times}1.7t$and ${\phi}38.1{\times}2.0t$ didn't exceed stress ratio but did 10mm drooping allowance. For this reason, the pipe of ${\phi}48.1{\times}1.5t$ net both stress ratio and drooping allowance. For the safety, the middle chamber should be designed into Truss type owing to bed load, wind load, and snow load when the bed of an induction net is installed in the middle chamber. When installing the middle chamber with a truss type, the greenhouse of chrysanthemum in Geochang area needs proper reinforcements because the stress in colullllls and wind proof walls exceeds stress allowance regardless of the installation of a bed.

Study on Plastic Deformation of Cohesionless Soil through Cyclic Triaxial Test (반복삼축압축실험을 통한 사질토의 소성변형 특성에 관한 연구)

  • Shin, Eun-Chul;Kang, Hyoun-Hoi;Choi, Chan-Young;Yang, Hee-Aaeng
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2008.10a
    • /
    • pp.1370-1376
    • /
    • 2008
  • The structure of railroad or subway is that low fare transportation system of the large traffic volume. Like this structure is subjected to the cyclic load of moving vehicle. Consequently the result of the settlement analysis or plastic deformation prediction of railroad bed could be used as an important factor in safety of the railroad. The results of cyclic triaxial test were used in the numerical analysis of power model which Li and Selig(1994) developed. The soil samples were obtained from the construction site of railroad. Cyclic triaxial test was conducted with the variation of the magnitude of cyclic load and soil types. The large magnitude of plastic deformation in the railroad bed is caused of structure failure of the railroad.

  • PDF