Hydraulics & Waterways
396641 - Soil and water temperature effects on the fluvial erosion of remolded cohesive soils
Wednesday, June 6
4:00 PM - 2:00 AM
Location: Greenway CD
Theresa Wynn-Thompson, Blacksburg – Virginia Tech; Celal Olgun, Blacksburg – Virginia Tech; Faik Cuceoglu, Turkey – General Directorate of State Hydraulic Works; Saied Mostaghimi, Blacksburg – Virginia Tech
One of the major challenges of water resource engineering is an understanding of the fundamental processes governing the erosion of cohesive streambank soils. Despite decades of research in the field of cohesive soil scour and transport, models which can be used to predict the occurrence and rate of cohesive scour remains elusive. To surmount this problem, the erosion response of cohesive soils to pertinent flow and environmental conditions have to be clearly understood. Therefore, the objective of this study was to evaluate the effects of flow and soil temperatures on the fluvial erosion of remolded cohesive soils.
Three natural soils with different dominant clay types were chosen for this study: montmorillonite- dominated fat clay, vermiculite-dominated lean clay and kaolinte/illite-dominate silty sand. These soils, prepared at their maximum dry densities and corresponding optimum moisture contents, were remolded in a 5-cm by 5-cm cylindrical ring and tested in a flume at multiple combinations of soil and eroding water temperatures.
Test results show that, irrespective of soil type, erosion rate increases with water temperature but decreases with soil temperature. The results also show that when soil and water temperatures are equal, there is no significant change in the erosion rate. These results show the importance of these factors in cohesive soil tests and further highlight the need for soil preparation and testing protocols in cohesive soil erosion research.