METHOD FOR THE REPLACEMENT OF TOP STEEL STRUCTURE FOR RAILWAY BRIDGES AND DEVICES FOR ITS IMPLEMENTATION

The method and the device for its implementation shall find application in the repair of railway sections of intensive operation. They are used for replacing the existing worn-out structure in a short time without using heavy lifting equipment, complex technological operations and very expensive bearing units. By the method the existing structure is dismantled and a new one is mounted in its place which has been prepared in advance by side lateral insertion and new platforms (10) under the bearings are built after the temporary support of the railtrack (1) in the places of the existing support (3) of the bridge. The lower rails (15) of the supporting bearing unit are fixed on platforms (10) and along the whole length of the insertion path, and the new structure (5) is executed parallel to it to which the upper rails (15) of the bearing supporting unit are fixed. After the removal of the existing structure (4), the new structure (5) is slid laterally along the lower rails (15) of the bearing supporting unit until it occupies its operational position by means of a device for lateral insertion, after which the structure (5) is aligned and fixed by slotted (21) plates. The new construction (5) is made of reinforced concrete or of prestressed reinforced concrete, or of a combined structure and can be either of a single block type or be longitudinally divided into two blocks. The bearing supporting unit for performing the method includes fixed lower and upper parts made of r.w. rails (15 & 15'), rail (15) being positioned horizontally, and rail (15') - vertically, where the head of the vertical rail (15') is fitted in the notch between the head and the foot of the horizontal rail (15). The lateral insertion unit performing the method includes a horizontally acting press and consists of two extension rods (19) positioned horizontally one above the other in prefabricated holes (18) at the supporting lateral beams (20) of structure (5), which rods (19) have threadings at both their ends are fixed by nuts (19') on both sides to vertical profile shims (22), a hydraulic or screw-type press (23) is fitted between them and the external vertical wall of the lateral beams. 8 claims, 8 figures