Laserfiche WebLink
<br />Lesson 3 <br /> <br />Culvert Design - Participant Workbook <br /> <br />~ <br />ti <br />- <br /> <br />.1 <br />u <br /> <br />3.5 INLET CONTROL <br /> <br />A. Inlet control occurs when the culvert barrel is capable of conveying more <br />flow than the inlet will accept. <br /> <br />3.20 Types of Inlet Control <br /> <br />3.21 Example of Inlet Control <br /> <br />I <br />n <br />B <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />II <br />I <br /> <br />B. The hydraulic control section of a culvert operating under inlet control is <br />located just inside the entrance. Critical depth occurs at or near this <br />location and the flow regime immediately downstream is supercritical. <br /> <br />C. Hydraulic characteristics downstream of the inlet do not affect culvert <br />capacity. The upstream water surface elevation and inlet geometry are <br />the primary factors influencing culvert capacity. <br /> <br />lJNSUBMtRGEIIINlEl <br /> <br />SUBME~GEn INlET <br /> <br /> <br />"0' <br /> <br />INLET CONTROL <br /> <br />A~I <br /> <br /> <br />E D <br /> <br />>r:~+l~~ <br />OS',;!; \4LtF y,': <br />n >n""'~. ,. Jhi';<" ;.,"~.~ .... .:'.iiii1: ...... .. '"':.:....: .. <br />X ~.,>..>'* ~~"*_..'*_~.._... <br /> <br />D. Slide 3.20 illustrates typical inlet control conditions. The type of flow <br />depends on the submergence of the inlet and outlet ends of the culvert; <br />however, in each case the control section is at the inlet end of the culvert. <br />For low headwater conditions the entrance of the culvert operates as a <br />weir, and for headwaters submerging the entrance the entrance operates <br />as an orifice. <br /> <br />3-8 <br /> <br />- <br />