Bridge Engineering (8) Superstructure – Cable-stayed Bridges 1. *Components of Cable-stayed bridges 1.1 (tensioned) inclined cables/stays; 1.2 orthotropic deck; 1.3 (stiffened) continuous girders; and 1.4 towers. 2. *Stays 2.1 Materials: high-strength steels 2.2 Types of stays: parallel steel bars; steel wire cables: parallel wire strand (PWS), parallel wire cable (PWC); stranded wired cables: parallel stranded wired cables, locked coil cable. 1 Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016

Bridge Engineering (8) Superstructure – Cable-stayed Bridges 2.3 Stay arrangement: space system, (modified) fan- shaped, harp-shaped (parallel-type). 2.4 Anchorage of stays: hot-cast anchorage, cold-cast or HiAm anchorage, buttonhead anchorage ( 镦头 锚）， looped anchorage ( 环套锚）， anchorage with ring plug ( 环销锚）， anchorage with wedges ( 片销式 / 夹片式锚）， anchorage with tapered plug （锥销式锚）. 2.5 Wire rust prevention: galvanizing; antirust grease, antirust varnish/lacquer/paint 2.6 Stay rust prevention: painting; coiling; sleeve 2 Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016

Bridge Engineering (8) Superstructure – Cable-stayed Bridges 3. Features of cable-stayed bridges A cable-stayed bridge is a highly statically indeterminate system with high-strength steels, an orthotropic type deck, development of welding techniques and progress in structural analysis. 3.1 Advantages of orthotropic deck It results in the creation of new types of substructure which can easily carry the horizontal thrust of stay cables with almost no additional material, even for very long spans The stiffened plate with its large cross-sectional area acts not only as the upper chord of the main girders and of the transverse beams, but also as the horizontal plate girder against wind bracings used in old systems. 3 Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016

Bridge Engineering (8) Superstructure – Cable-stayed Bridges All elements of the roadway and secondly parts of the superstructure participate in the work of the main bridge system resulting in reduction of the depth of the girders and economy in the steel It is geometrically unchangeable under any load position on the bridge, and all cables are always in a state of tension It provides the continuity of the deck structure at the towers and in the center of the main span. 3.2 The important characteristic of the three-dimensional bridge is the full participation of the transverse structural parts in the work of the main structure in the longitudinal direction. 3.3 The considerable increase in the inertia moment of the construction permits a reduction of the depth of the girders and a consequent saving in steel. 4 Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016

Bridge Engineering (8) Superstructure – Cable-stayed Bridges 3.4 Cable-stayed bridges fill the gap that existed between deck type and suspension bridges. 3.5 The cable-stayed bridges are pleasing in outline, clean in their anatomical conception and totally free of meaningless ornamentation. 5 Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016Thursday, June 02, 2016