I am currently designing a concrete bridge that has typical AASHTO girders with a concrete deck. I understand that some state design manuals sometimes add a requirement for the shear stirrups in the beam to be extended into the deck at a certain depth but I cannot seem to find a specific depth...
I have a bit of confusion when it comes to determining the nominal moment of a simply supported reinforced beam. Personally, I have always stuck to the method of determination being shown in the book (determine the stress in the reinforcement @ concrete failure and plug it into Mn =...
Hello,
This is likely to be a very basic question but as most structural engineers know, AISC calculates the effective length of frames in section C7.2 utilizing stiffness ratios (G). My question is this: why are the stiffness ratios calculated using the beam/girder's moment of inertia about...
I am looking at a PS girder bridge from the 50's and trying to perform an analysis on the beams to ensure it can handle an increased load due to a deck modification. The as-builts indicate that 250 ksi high-strength, stress-relieved strands are to be used and state a working stress of 140 ksi...
It seems that the distribution for dead load from bridge parapets is constantly changing in the AASHTO Specs. The latest edition (9th/2020) states "heavier concentrated line loads such as parapets, sidewalks, barriers or sound walls should not be distributed equally to the girders. Engineering...
