| 摘要 |
<p>Method for increasing the length of a span of a bridge formed by a deck (1) supported by abutments (4) and piers (2, 3), by removing at least one pier (2). According to this method, the following operations are carried out: a) construction of a tower (10) having an upper part which extends above the level of the deck, b) installation or formation of a transverse so-called "header" beam, at a short distance from the top of the pier which is to be destroyed, the header being placed under the deck or passing through the lower part of the latter, c) installation of at least one stay cable (19) connecting a point on the tower located above the deck to a header point, d) tensioning of the stay cable (19) until the vertical component of the force which it exerts on the header is more or less equal to the vertical reaction of the pier, e) removal of the pier (2). The method is particularly advantageous when it is desired to widen a dual carriageway, for it avoids having to destroy and rebuild the bridges which pass over this carriageway. <IMAGE></p> |
