CONSTRUCTION METHOD AND DESIGN OF OVERPASSES AND BRIDGES UNDER CONDITIONS OF PERMAFROST Russian patent published in 2014 - IPC E01D21/00 

FIELD: construction.

SUBSTANCE: invention relates to road construction of overpasses and bridges for motor and railway roads under conditions of permafrost, seismic active regions, and also in mountain and uneven terrain, on swamps and weak soils. The method includes erection of guncrete supports and installation of a solid reinforced concrete span on them from box-shaped blocks tightened and stressed with steel ropes to a lengthy structure - a beam. Guncrete supports are installed in the permafrost layer for the depth of at least 1 m from the surface of the stable layer of permafrost with isolation of upper and lower parts of the supports with elastic tight reservoirs filled with air compressed to pressure of at least 2 atm. Blocks of the span are tightened and stressed with steel ropes in pairs and symmetrically to each other by above-support blocks, and the entire span is installed with a clearance-airway between the lower surface of the beam and the surface of soil of at least 1 m. Elastic tight reservoirs of compressed air are arranged in the upper part in the form of car tyres, and in the lower part - in the form of a cylindrical reservoir with a groove for insertion of the lower ends of supports and are connected with a compressor by steel tubes embedded into the concrete of the guncrete support. Above-support blocks of the span are equipped with a vertical wall arranged in the middle part of the block across the cloth with anchor seats for fixation of anchors arranged symmetrically at both sides of the wall. Tightening and stressed steel ropes are arranged in pairs in holes of ledges-crossbars of symmetrical span blocks, excluding the middle one.

EFFECT: invention makes it possible to speed up construction, to reduce operating costs and to increase safety of traffic.

2 cl, 5 dwg