Laserfiche WebLink
<br />LESSON 4 <br /> <br />STREAM STABILITY - LEVEL 1 ANALYSIS PROCEDURES <br /> <br />I. GENERAL SOLUTION! PROCEDURE <br /> <br />A. A stable channel does not change in size, shape, form, or position with <br />time; however, all alluvial channels change to some extent and are <br />somewhat unstable, The next three lessons consider a systematic <br />approach to evaluation of stream stability at highway crossings and provide <br />a stepwise procedure to facilitate such analyses by highway engineers. <br /> <br />B. The basic solution approach involves three levels of analysis of increasing <br />complexity: <br /> <br />level 1: <br /> <br />Application of simple geomorphic concepts and other <br />qualitative analysis techniques, <br /> <br />level 2: <br /> <br />Application of basic hydrologic, hydraulic, and sediment <br />transport engineering concepts. <br /> <br />level 3: <br /> <br />Application of mathematical or physical modeling studies. <br /> <br />C, The completion of each level of analysis results in an assessment of <br />stream stability and leads to a conclusion regarding the nE~ed for more <br />detailed analysis, or a decision to proceed directly to design/scour <br />evaluation of the bridge or selection and design of countermeasures based <br />on the results of the current level of analysis, <br /> <br />4.1 <br />