Please use this identifier to cite or link to this item:
http://repositorio.udec.cl/jspui/handle/11594/7517
Title: | Scour around bridge piers in fluvial sediments. |
Authors: | Link Lazo, Óscar Eduardo; supervisor de grado Klischies Nevermann, Kai Oliver |
Keywords: | Sedimentos Fluviales;Floculación;Sedimentación;Puentes;Erosión |
Issue Date: | 2013 |
Publisher: | Universidad de Concepción. |
Abstract: | Scour at piers embedded in a bed of cohesive sediment mixture was investigated to quantify the effects of bed compaction. Experiments were conducted in a large rectangular laboratory flume, with natural clay sediment collected from a stream located at the Chilean coastal range. Non-intrusive and high-resolution topographic measurements of scoured bed in the vicinity of simulated piers were performed during the experimental runs with a laser distance sensor (LDS) that was traversed by precision step-motors. Measurements were taken by the LDS in different azimuthal half-planes to study the spatio-temporal variation of the topography of evolving scour holes. Experiments were conducted over 40 h, until an advanced stage of scour was reached, with the approaching flow having a bed shear stress equal to 95% of the Shields critical condition for the initiation of motion of sand in a sand-clay mixture. Results show that the bed was scoured in the forms of chunks of aggregates, aggregate-by-aggregate and particle-by-particle with an increase in ratio of actual to Proctor’s optimum molding water content, wˆ . Maximum scour depth was mainly observed at the wake region (on the pier downstream) ranging from 10 to 58% of that in sand-alone case with the same size of the sand fraction in the mixtures. For a given compaction energy, scour depth first decreases with wˆ < 2.6 as fine clay particles are flocculated and increases with wˆ > 2.6 as particles become more dispersed. |
Description: | Tesis para optar al grado de Magíster en Ciencias de la Ingeniería con mención en Ingeniería Civil. |
URI: | http://repositorio.udec.cl/jspui/handle/11594/7517 |
metadata.dc.source.uri: | https://go.openathens.net/redirector/udec.cl?url=http://tesisencap.udec.cl/concepcion/klischies_n_k/index.html |
Appears in Collections: | Ingeniería Civil - Tesis Magister |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Resumen.pdf | 153,65 kB | Adobe PDF | View/Open |
This item is licensed under a Creative Commons License