Method of rebuilding a viaduct without interrupting service on the old structure

Abstract

A method of rebuilding a viaduct without interrupting service on the old structure by over topping it with a new, higher viaduct well above existing traffic, includes the following: Erecting new span supporting columns arrayed along either side of the old viaduct. New columns are temporarily connected to old viaduct to strengthen it for a temporary scaffold role transporting heavy subassemblies into position atop the new columns. The subassemblies or their components would typically arrive at a staging area alongside the old viaduct for preparation and hoisting the subassemblies onto a high dolly atop the old viaduct. The subassemblies are assembled into spans on the high dolly atop the old viaduct roadbed surface to transport and position the spans sequentially onto respective columns beginning with columns at extreme ends of the old viaduct and successively hoisting and transporting more subassemblies until a new higher viaduct roadbed is assembled well over the still functioning old viaduct.

1 . A method of rebuilding an elevated roadway or viaduct without interrupting service on the old viaduct by over topping it with a new, higher viaduct above existing traffic, comprising the steps of:
 a) erecting new span supporting columns arrayed adjoining the route of said old viaduct,   b) assembling roadway subassemblies on a high dolly atop the old viaduct roadbed surface to transport and position the subassemblies sequentially onto respective said columns beginning with columns at extreme ends of the old viaduct and successively transporting more subassemblies until said new higher viaduct roadbed is assembled at a height that does not interfere with traffic on the still functioning old viaduct and,   
     whereby normal traffic on the old viaduct can continue except during brief transport of subassemblies. 
   
   
       2 . The method of  claim 1  in which the new columns are connected temporarily to the old viaduct to strengthen it for a temporary scaffold role to carry heavy subassemblies into positions atop the new columns beginning at said extreme ends of the old viaduct. 
   
   
       3 . Said dolly of  claim 1  in which arrays of wheelsets or air cushion pallets are set into the dolly bottom to provide a low friction means to transport heavy loads. 
   
   
       4 . Said dolly of  claim 1  in which arrays of omni directional wheelsets or air cushion pallets are set into two diamond shaped bogies swivel mounted to the base of the dolly designed to make turns on a viaduct that is not straight. 
   
   
       5 . Said dolly of  claim 4  provided steering means for swiveling the said bogies independent of the dolly. 
   
   
       6 . A method of rebuilding an old viaduct without interrupting service on the structure by building a new, higher viaduct directly above said old viaduct, above existing traffic, comprising the steps of:
 a) erecting new span supporting columns arrayed along either side of an old viaduct,   b) temporarily connecting said new columns to the old viaduct to strengthen it for a temporary scaffold role to carry heavy subassemblies into position atop the new columns beginning at extreme ends of the old viaduct, and   c) assembling said subassemblies on a high dolly atop the old viaduct roadbed surface to transport and position the subassemblies sequentially onto respective columns beginning with columns at said extreme ends of the old viaduct and successively transporting more subassemblies until said new higher viaduct roadbed is assembled well over the still functioning old viaduct.   
   
   
       7 . Said dolly of  claim 6  in which arrays of wheelsets or air cushion pallets are set into the dolly bottom to provide a low friction means to transport heavy loads. 
   
   
       8 . Said dolly of  claim 6  in which arrays of wheelsets or air cushion pallets are set into two diamond shaped bogies swivel mounted to the base of the dolly designed to make turns on a viaduct that is not straight. 
   
   
       9 . Said dolly of  claim 8  provided steering means for swiveling the said bogies independent of the dolly. 
   
   
       10 . A method of launching spans of a new viaduct erected above an old viaduct beyond the ends of said old viaduct without interrupting service on the old viaduct as a means to lengthen the viaduct or to launch a roadbed transition ramp to lower or to raise the said new viaduct roadbed path to the roadbed continuing beyond the old viaduct roadbed, comprising the steps of:
 a) placing additional subassemblies sufficient to assemble approximately 3 spans atop said new viaduct also atop an array of wheelsets or air cushion pallets interspersed between the new viaduct roadbed and said subassemblies,   b) transporting said spans to an end of the new viaduct,   c) erecting a cablestay mast centered upon a central span directly behind the far end span of the transported spans,   d) arraying cablestays along the length of the said far end span and along the rear span,   e) tensioning said cablestays to put the two end spans in suspension,   f) moving the assembled cablestays, mast and spans one span length beyond the end of the new roadbed putting the far end suspended span in cantilever,   g) lowering the far span with tall supporting jacks into level alignment with the new viaduct roadbed,   h) repeating the process as often as necessary while the extended spans are level, and   i) creating said transition ramp of requisite length by raising or lowering the far end of the transition ramp with said tall supporting jacks and erecting supporting columns or columns and span supporting beams to replace all tall jacks.