Method for constructing overpass gate-type pier spanning over electrified railway

Abstract

The invention discloses a method for constructing an overpass gate-type pier spanning over an electrified railway. In the method, a stretcher-type temporary beam formed by a longitudinal beam and a plurality of cross beams is placed between a pier cap and a carrier cable and the point of application of a template falls on the top surface of the cross beam, and the height of the cross beam is far smaller than that of a steel trussed beam and that of an I beam, thus the requirement on safe distance specified in rule No.111 of TIEYUN(2007) No.69 catenary running and maintenance procedures issued by Ministry of Railways can be met and normal current collection of a pantograph of an electric locomotive can not be influenced. Besides, the total height of a gate-type pier can be reduced by adopting the construction method disclosed by the invention, thus the construction cost can be greatly reduced; and the slope of a bridge deck is gentler, thus a vehicle climbs more easier, and the economic and social benefits are quite outstanding.

Description

technical field [0001] The invention belongs to the technical field of bridge construction, in particular to a construction method for a portal pier of an overpass over an electrified railway. Background technique [0002] In electrified railways, a row of catenary struts are usually set on the outside of the rails, and the load-bearing cables and contact wires extending in the direction of the rails are suspended on the upper part of the catenary struts, and the bow heads of the pantographs on the electric locomotive touch in a sliding manner. The contact line, which relies on the pantograph to take electricity from the contact line as power to travel on the rails. When the highway intersects with the above-mentioned electrified railway, it is necessary to build an overpass at the intersection. At present, when the included angle between the road or the added railway crossing the existing electrified railway is small, the piers of the overpass are mostly portal piers. Col...

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Problems solved by technology

[0003] But, there is following problem in this prior art gantry pier construction method: in Ministry of Railways " Catenary Operation Overhaul Regulations " Tieyun (2007) No. 69 Article 111 stipulates: "the live part of catenary is separated from the fixed ground object. Clearance, normal value ≥ 50cm, difficult value ≥ 30cm", this is the safe distance requirement for the construction of portal pier caps

Since the force point applied by the above-mentioned formwork to the longitudinal beam is located on the top surface of the longitudinal beam, the height of both the steel truss beam and the I-beam is relatively large (I56a I-beam height is 56cm, and the height of the steel truss beam is higher than that of I56a The I-beam is even larger), so if it is placed under the pier cap of the portal pier, the overall height of the portal pier will be increased accordingly under the premise of meeting the above-mentioned safety distance, which will greatly improve the project cost, and the slope of the bridge deck is large, which makes it difficult for vehicles to climb the slope

And if you want to lower the pier cap to the closest to the catenary, when using this construction method, it is possible that the distance between the steel truss girder or I-beam and the catenary cable is too close, and it may even touch the catenary cable. and affect the normal current intake of electric locomotive pantograph

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