Laserfiche WebLink
<br />3. Bed material <br /> <br />a. Streams Gan be classified by the dominant size of s,ediment <br />on their beds, <br /> <br />b. No direct relation between bed material size and incidence of <br />scour pmblems at bridge crossings, although dE~ep scour <br />holes are generally more probable in fine bed material. <br /> <br />4, Valley setting <br /> <br />a. Streams in mountainous regions, or areas of high relief often <br />have no hydraulic problems at bridge crossings due to coarse <br />bed material, narrow floodplains, nonalluvial type conditions, <br /> <br />b, In contrast, streams in I"egions of lower relief are usually <br />alluvial and have more problems due to more active <br />channels, <br /> <br />c. Special problems related to alluvial fans or piedmont slopes, <br /> <br />2,5 <br />