RAJENDRA SAHAI
Engineering in Berkeley, CA

6412237, Jul 2, 2002

Dec 3, 1999

09/454487

Rajendra Sahai - Berkeley CA

Structural Design Engineers - San Francisco CA

E04B 198

521671, 52690, 526551

An improved framed structure incorporating a coupled-girder system provides enhanced seismic energy dissipation by as much as 30% over that provided by conventional yielding of the girders. The coupled-girder system includes a pair of spaced-apart girders coupled by one or more girder-to-girder links which are preferably vertical links. Energy dissipation takes place when the structure drifts beyond its elastic limit and the differential displacement of the pair of girders causes the web of each vertical link to shear yield. The links are proportioned to remain in the elastic regime under wind loads and moderate earthquakes as prescribed by building codes. Beyond the elastic limit, preferably the yielding in the links will take place prior to that in the girders. In this way, the links will be the first line of defense for dissipating seismic energy before the girders themselves. The other advantages of the coupled-girder system are improved effective stiffness of the column and girders and ease of post-earthquake inspection and repair of the vertical links.

2004000, Jan 8, 2004

Feb 28, 2003

10/377481

Rajendra Sahai - Berkeley CA, US

Structural Design Engineers

E04B001/98, E04H009/02

052/167100

An improved framed structure incorporating a coupled-girder system provides enhanced seismic energy dissipation by as much as 30% over that provided by conventional yielding of the girders. The coupled-girder system includes a pair of spaced-apart girders coupled by one or more girder-to-girder links which are preferably vertical links. Energy dissipation takes place when the structure drifts beyond its elastic limit and the differential displacement of the pair of girders causes the web of each vertical link to shear yield. The links are proportioned to remain in the elastic regime under wind loads and moderate earthquakes as prescribed by building codes. Beyond the elastic limit, preferably the yielding in the links will take place prior to that in the girders. In this way, the links will be the first line of defense for dissipating seismic energy before the girders themselves. The other advantages of the coupled-girder system are improved effective stiffness of the column and girders and ease of post-earthquake inspection and repair of the vertical links.

2002016, Nov 7, 2002

Jul 2, 2002

10/187519

Rajendra Sahai - Berkeley CA, US

E04B001/98, E04H009/02

052/167700

An improved framed structure incorporating a coupled-girder system provides enhanced seismic energy dissipation by as much as 30% over that provided by conventional yielding of the girders. The coupled-girder system includes a pair of spaced-apart girders coupled by one or more girder-to-girder links which are preferably vertical links. Energy dissipation takes place when the structure drifts beyond its elastic limit and the differential displacement of the pair of girders causes the web of each vertical link to shear yield. The links are proportioned to remain in the elastic regime under wind loads and moderate earthquakes as prescribed by building codes. Beyond the elastic limit, preferably the yielding in the links will take place prior to that in the girders. In this way, the links will be the first line of defense for dissipating seismic energy before the girders themselves. The other advantages of the coupled-girder system are improved effective stiffness of the column and girders and ease of post-earthquake inspection and repair of the vertical links.