02807nam a2200253   450000500170000000800410001703500150005810000190007324500510009226000520014330000100019549000270020550001420023250200580037452017440043265000170217670000400219370000530223370000420228670000460232871000550237481000590242985600650248820260818100429.0050698         th                  eng    a.b102544071 aSahoo, Narayan10aErodibility of cohesive soils in overland flow  aBangkok :bAsian Institute of Technology,c1988  a61 p.1 aThesis ;vno. WA-88-13  aA thesis submitted in partial fulfilment of the requirement for the degree of Master of Engineering, School of Engineering and Technology  aThesis (M.Eng.) - Asian Institute of Technology, 1988  aThe entrainment ratio, which is a · soil erodibility parameter  for estimation of cohesive sediment transport, was studied  experimentally using two different cohesive soils namely reddish  colour silty sand soil and greyish colour silty sand soil. These  two types of cohesive soils had been collected from National  Park, Khaoyai, Thailand. Each soil type was used in a laboratory  flume and experiments were carried out with controlled flow and  mild slope conditions. The observed parameters were discharge,  flow depth, flow velocity and sediment transport. Actually  twenty-two sets of experiments were carried out for each type of  soil with different combinations of slope and discharge.  Analysis of the obtained data showed that both slope and  discharge conditions affected the entrainment ratio. It was also  noticed that with increase in discharge rates, the entrainment  ratio for reddish colour silty sand soil decreased for a given  slope condition of the channel bed. But no such trend was found  in case of the greyish colour silty sand soil. Moreover, the  entrainment ratio decreased with increase in slope for any  constant discharge in case of both types of soil used in the  experiment. It was also evident from regression analysis that the  cohesive sediment transport could be related linearly with the  sediment transport capacity with high coefficient of  determination for both the soil types. In addition a stepwise  multiple regression analysis revealed that for both soils there  was a exponential relationship between the cohesive sediment  transport and the flow velocity. The flow depth and slope had  only an indirect effect on the cohesive sediment transport  through their effect on the flow velocity. 0aSoil erosion1 aNielsen, Steen Asger, eChairperson0 aPreecha Kamronrithisorn, eExamination Committee1 aMurty, V.V.N.,eExamination Committee1 aPaudyal, Guna N., eExamination Committee2 aThe Government of Switzerland, eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. WA-88-13  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B18861