Portal frame

About: Portal frame is a research topic. Over the lifetime, 1778 publications have been published within this topic receiving 7210 citations.

Structural repair of reinforced concrete portal frame

Abstract: The Paper describes repairs carried out on a reinforced concrete portal frame that had suffered damage over the previous 25 years as a result of alkali–silica reaction (ASR). This particular structure has been the subject of intense study since 1978 and several previous papers have described its behaviour.3,5 The repair consisted of partly demolishing and rebuilding the upper beam of the portal, while keeping the motorway it supports open to traffic. Results are given for the shrinkage of the replacement concrete, and for depropping movements and surface strain measurements taken on the structure over the year following the repair.

Height-limited portal frame

Abstract: The utility model discloses a height-limited portal frame, which comprises upright columns and a cross beam disposed at upper ends of the upright columns. The height-limited portal frame is characterized in that the lower end of the cross beam is provided with anti-impact short beams and a movable hanging object, the distance from the lower end of each anti-impact short beam to the lower end of the cross beam ranges from 15mm to 20mm, and the distance from the lower end of the movable hanging object to the lower end of the cross beam ranges from 30mm to 40mm. The anti-impact cross beams are short beams which are arranged at intervals. The anti-impact short beams can stop ultra-high vehicles from passing forcedly, and when the ultra-high vehicles can produce sound when impacting to the movable hanging object so as to remind drivers of the ultra-high vehicles to drive the vehicles away from the roadway. Compared with the prior art, the height-limited portal frame emphasizes people foremost, reduces damage to vehicles, drivers and passengers to the utmost extent while protecting bridges, not only stops the ultra-high vehicles, but also guides the ultra-high vehicles to be away from the roadway by aid of height-limited marks on the portal frame.

Sign indicating number device is beaten in side wall automatic positioning of all steel tire

Abstract: The utility model relates to a sign indicating number device is beaten in side wall automatic positioning of all steel tire. Include: the base frame frame, mechanism in deciding, install in on the base frame frame, for the centre gripping warp transport mechanism carries the tire that comes, transport mechanism, install in on the base frame frame for carry the tire, photoelectric switch, install in on the base frame frame for detection wheel puts the position of a foetus, the portal frame, install in base frame puts up upper portion, the diaxon removes the manipulator, install in on the portal frame, beat the ink recorder and construct, install in the diaxon removes on the manipulator for beat the sign indicating number to the tire. Beneficial effect: the utility model discloses a this automatic coding device of configuration can satisfy the sign indicating number work of beating of different specification tires, has improved the tire side wall and has beaten sign indicating number degree of automation, reduces the manufacturing cost of enterprise.

Three-dimensional modeling of steel portal frame buildings

Abstract: The realistic strength and deflection behavior of industrial and commercial steel portal frame buildings are understood only if the effects of rigidity of end frames and profiled steel claddings are included. The conventional designs ignore these effects and are very much based on idealized two-dimensional (2D) frame behavior. Full-scale tests of a 1212 m steel portal frame building under a range of design load cases indicated that the observed deflections and bending moments in the portal frame were considerably different from those obtained from a 2D analysis of frames ignoring these effects. Three-dimensional (3D) analyses of the same building, including the effects of end frames and cladding, were carried out, and the results agreed well with full-scale test results. Results clearly indicated the need for such an analysis and for testing to study the true behavior of steel portal frame buildings. It is expected that such a 3D analysis will lead to lighter steel frames as the maximum moments and deflections are reduced.

Construction method of secondary tunnel lining

Abstract: The invention discloses a construction method of a secondary tunnel lining The construction method comprises the steps of S1, mounting a shape steel portal frame in the middle of a tunnel; S2, setting up a scaffold at the outer part of the shape steel portal frame; S3, laying and fixing square timber at the outer part of the scaffold; S4, erecting a steel tube mold base on the square timber to fill a clearance between a preset position of the secondary lining and the scaffold; S5, laying steel moulding plates on the steel tube mold base, wherein the size of each steel moulding plate is one square meter or below; S6, arranging closure plates at the ends of the two sides of the laid steel moulding plates; and S7, pouring concrete on the periphery of the steel moulding plates, so as to from the secondary lining According to the method provided by the invention, the secondary lining construction can be carried out without a formworktrolleywhen the fracture surface landform is quiet complex; and the size of the steel moulding plates is not large, so that the splicing and disassembly are convenient, the adjustment for the partial shape is quiet convenient, the construction cost is reduced, and the construction time is saved