Elevated bridge infrastructure and design method for designing the same

A method for designing a seismic frame structure including a reinforced concrete rigid frame having a pair of spaced pillars and a beam extending between ends of the pillars, a V-shaped brace disposed in a structural plane of the reinforced concrete rigid frame and having two leg portions arranged in a V shape with an end of each leg portion being connected to a respective one of the pillars, and a damper interposed between the beam and other ends of the two leg portions, said method comprising:

• providing a first model for the reinforced concrete rigid frame, wherein the pair of spaced pillars is represented by a pair of spaced pillars that are each provided with a rotational spring at both ends thereof, and the beam is represented by a beam that is connected to ends of the pair of spaced pillars via the rotational spring at one of the ends of each of the spaced pillars;
• providing a second model for the seismic frame structure, wherein the pair of spaced pillars is represented by a pair of virtually rigid spaced pillars and the beam is represented by a virtually rigid beam, with the pair of virtually rigid spaced pillars being connected to the virtually rigid beam at ends of the pair of virtually rigid spaced pillars, wherein the V-shaped brace is represented by a V-shaped brace having two leg portions arranged in a V shape with an end of each leg portion being connected to a respective one of the virtually rigid spaced pillars, and wherein the damper is represented by a damper that is disposed between the virtually rigid beam and other ends of the two leg portions;
• obtaining a burden Pdb for said second model from the equation
• Pdb=(h′/h)Hb,
• wherein h corresponds to a distance from an end of said virtually rigid spaced pillars to said virtually rigid beam, h′ corresponds to a distance from said virtually rigid beam to the location at which said two leg portions are connected to said virtually rigid spaced pillars, and Hb corresponds to a damper load displacement characteristic;
• obtaining a burden Prc for said first model from the equation
• Prc=P−Pdb,
• wherein P corresponds to an external force that is to be applied to the seismic frame structure;
• applying Pdb to said second model to perform an elasto-plastic analysis thereof;
• applying Prc to said first model to perform an elasto-plastic analysis thereof;
• and
• performing a section design of the seismic frame structure according to the elasto-plastic analyses.