tailieunhanh - Steel Bridge Construction-3

Steel Bridge Construction Figure Erection of individual wire loops. Figure Adjustment of individual wire loops. Figure Cable-spinning procedure for constructing suspension bridge-parallel-wire main cables, showing details of aerial spinning method for forming individual 5 mm wires into strands containing 400 to 500 wires. Each wire loop is erected as shown in Figure (refer to Figure ), then adjusted to the correct sag as shown in Figure . Each completed strand is banded with tape, then adjusted to the correct sag in each span. With all strands in place, they are compacted to form a solid round homogeneous mass. | Durkee J. Steel Bridge Construction Bridge Engineering Handbook. Ed. Wai-Fah Chen and Lian Duan Boca Raton CRC Press 2000 Figure Erection of individual wire loops. Figure Adjustment of individual wire loops. Figure Cable-spinning procedure for constructing suspension bridge-parallel-wire main cables showing details of aerial spinning method for forming individual 5 mm wires into strands containing 400 to 500 wires. Each wire loop is erected as shown in Figure refer to Figure then adjusted to the correct sag as shown in Figure . Each completed strand is banded with tape then adjusted to the correct sag in each span. With all strands in place they are compacted to form a solid round homogeneous mass of wires. The aerial spinning method was developed by John Roebling in the mid-19th century. 2000 by CRC Press LLC Figure Erection of suspended deck steelwork second Tacoma Narrows Bridge Washington 1950. The Chicago boom on the tower raises deck steelwork components to deck level where they are transported to deck travelers by material cars. Each truss double panel is connected at top-chord level to previously erected trusses and left open at bottom-chord level to permit temporary upward deck curvature which results from the partial loading condition of the main suspension cables. The main span at right is 2800 ft 853 m and side spans are 100 ft 335 m . The stiffening trusses are 33 ft 10 m deep and 60 ft 18 m on centers. Tower-base kneebraces see Figure show clearly here. Figure Moving deck traveler forward second Tacoma Narrows Bridge Washington 1950. The traveler pulling-falls leadline passes around the sheave beams at the forward end of the stringers and is attached to the front of the material car at left . The material car is pulled back toward the tower advancing the traveler two panels to its new position at the end of the deck steelwork. Arrows show successive positions of material car. a Traveler at star