ings. — Modern truck loadings. — Decrease of live load with span-length. — Electric-railway car loads. — Standard steam-railway loadings. — Electric-railway loadings. — Highway loadings. — Loadings for cantilevers. — Impact loadings. — Widths for roadways. — Three-line-travel decks are unsatisfactory. — Footwalk widths. — Pedestrian traffic. — Gauntleted tracks. — Economic arrangement of decks to accommodate several kinds of traffic. — Combined-railway-and-highway-bridge traffic. — Screens. — Division of combined bridges into six classes and dissertation concerning economics of each class. — Author's Sioux City Bridge. — Author's East Omaha Bridge. — Author's Fraser River Bridge at New Westminster, B. C. — Design for Second Narrows Bridge over Burrard Inlet at Vancouver, B. C. — Author's Fratt Bridge at Kansas City. — Keeping live loads down to least legitimate limits. — Extreme and illegitimate reduction of live loads. — Determination of unit stresses. — High-carbon steel not good for reinforcing bars. — Infrequent loadings permit live-load reduction. — Fallacy of abnormally high live loads and correspondingly greater unit stresses. — Selection of live load important for very-long-span bridges. — Forced increase in unit stresses. — Skimping of details. — Combination of stresses in trestles. — Increments of intensities for various combinations of stresses, and dissertation on the economics involved. — Impracticability of eliminating entirely the personal equation in trestle designing. — Combination of stresses in cantilever bridges and arches. — Caution against inadvertently adding stresses of opposite kinds. — Combination of stresses of opposite kinds. — Conclusion re best policy for combining reversing stresses. — Combinations of live and dead-load stresses with secondary stresses. — Proper relation between intensities of working stresses in tension and compression. — Report of the Committee on Column Tests of the A.S.C.E. and author's comment thereon in Engineering News Record. — Suggested tests of members when actually in full-size bridges ..............125 |