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. 1914 Excerpt: ...stability of the abutment of an arch is determined by finding the resultant Rj of the dead weight W of the abutment acting at its centre of gravity and the thrust R of the arch ring on the abutment. If the resultant Rj passes within the middle third of the base AB, the conditions are satisfied (Fig. 260). In the case ...
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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. 1914 Excerpt: ...stability of the abutment of an arch is determined by finding the resultant Rj of the dead weight W of the abutment acting at its centre of gravity and the thrust R of the arch ring on the abutment. If the resultant Rj passes within the middle third of the base AB, the conditions are satisfied (Fig. 260). In the case of a pier supporting two arches, the two thrusts Rj, R2, Fig. 261, if equal and equally inclined, have a resultant vertical force R3, and the arrangement is stable. If a pier supports two arches whose thrusts are, respectively, R1; R2, Fig. 262, which are not equal, we first find the resultant R3, and combine this with the weight W of the abutment. The final resultant R4 must fall within the middle third of the base. Failure of an Arch.--If the line of resistance ABCD, Fig. A D F1g. 263. 263, of an arch passes outside the ring either on the inside, as shown at C, or on the outside as shown at B, the arch will fail by rupture. When the line passes within the ring, as at C, the forces tend to increase the curvature of the arch, and the ring will rupture, as shown at F. When the line passes outside the ring, as shown at B, the forces tend to decrease the curvature, i.e. to make the arch natter, and it will then fail by rupture as shown at E. In arches in which the line of resistance falls outside the middle third as it approaches the abutments, the voussoirs, if of stone, may be increased in depth at those points so as to include the line within the middle third of each joint. This course would not, however, be adopted in brick arches owing to the expense of cutting the bricks, and the arch ring would be increased in depth throughout. Exerc1ses. 1. Loads of 5, 6, 6, 8, 6,6, and 5 tons are placed 4 ft. apart, and two abutments are placed each 2 ft....
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Add this copy of Mechanics for Builders, Volume 2... to cart. $50.84, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2012 by Nabu Press.
