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Product description This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 Excerpt: ... equals the bending stress, and the method employed is accurate, because the tension is only 106 lbs./ins.2 Now many fruitless attempts have been made to simplify the matter by considering the beam to sit on the edge of the column, or some other place, and calculating moments accordingly. Let us see what the eccentricities were in the last two examples. Example 1. „,. moment in col. 131,000. Eccentricity =--. = r = 10 = 10A ins. J reaction in col. 12,500 J It should be clear from this that if the same column monolithic with the same beam can in one case have an eccentricity of 10J ins. and in another case 1-55 ins., all such attempts are abortive. Example 3. We will now take an example including lower floors (see Fig. 68). We will adopt beams 25' span, columns 12' 6" long, load per beam 25,000 lbs., all as in Example 1, and as the columns 24 x 6 gave rather high stresses, and are in any case rather slender for this story height (both for buckling and wind pressure) we will calculate stresses on standard 24 x 12 columns (see p. 150) adopting standard 20 x 8 beams (T.B. 5) (see p. 156) as before. From p. 150, / of col. 24 x 12 is 4170 ins.4 and equivalent area A is 325 ins.2 We proceed as before. Tovtier KC-6 x il7 x A00-4-87 loptter. 5 b X 150 10,300.-. Fu (from Fig. 64) =-71, », 25,000 x 300".-. M in col. =-71 x----= 444,000 in. lbs. cu I J i. J-MV 444,000 x 6" Stress in col. due to bending =-= 4X70 = 640 lbs./ins.2 Direct stress = = 38-5 „ Max. combined stress = 678-5 „ Clearly here is considerable tension. Let us again check the value of c by making the more accurate calculation, neglecting tension resistance in the concrete. The moment of inertia of the column about the centre line, assuming the neutral axis to lie 4...