Design of a reinforced-concrete highway bridge . Wing WallEarth highway embankments are generally built on a slopeof two to one. The tops of the wing walls will therefore be builtto this slope to a point four feet above the ground. As the front-wall will slope back from the face of the abutment at an angle of30 degrees, the wing walls must necessarily be twenty three feetlong to meet with these requirements, since the elevation of theground is 86 at a point 23 feet from the side of the bridge. Thecross section of the wing walls will be the same throughout as thatof abutment. The steel in the w
Design of a reinforced-concrete highway bridge . Wing WallEarth highway embankments are generally built on a slopeof two to one. The tops of the wing walls will therefore be builtto this slope to a point four feet above the ground. As the front-wall will slope back from the face of the abutment at an angle of30 degrees, the wing walls must necessarily be twenty three feetlong to meet with these requirements, since the elevation of theground is 86 at a point 23 feet from the side of the bridge. Thecross section of the wing walls will be the same throughout as thatof abutment. The steel in the wing walls and footings will be de-termined by designing a section at the abutment and at the end ofthe wall, the steel being distributed uniformly between the twosections. As this design does not differ essentially from thatalready given it will not be shown here but the results will be indicated in Fig. 21. Because of the nature of the topography on the northside of the bridge, wing walls will be of very little benefit andwill not be used. ^_. 53. Design of the design of the piers involves the determination of cer-tain dimensions not already fixed, from a practical standpoint ratherthan from a theoretical one. For instance, the ends of the piersshould not he built at right angles to the sides but they should consist of two planes built at an angle of about for fey five degreeswith the sides, meeting in a line, the purpose of which is to cutthe water and avoid scour. The sides and ends should be built on abatter of preferably one inch in one foot; and the footings shouldextend sufficiently beyond the walls to distribute the load so thatthe pressures on the soil will not be excessive. The bottom of thefooting will be placed at an elevation of ; and since the girderis five feet deep the elevation of the top of the footing is footing must at least be 4 wide on top and 12 long not includ-ing the ends. If the sides are built on a 1:12 batter, the dimen-sions wil
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttheses, bookyear1913
