retrofitting new openings in existing tilt-up wall

huangyhg

retrofitting new openings in existing tilt-up wall
we have a small project that involves retrofitting an existing tilt-up concrete wall building.  the work includes cutting a few new door openings in the exterior precast walls.  the kicker is that we have no drawings/design documents of the existing structure to reference for analysis purposes.  anyone have some tips on how to estimate the required reinforcing/steel channel frame installation??  i would prefer not to have to do a full-blown gravity/lateral force analysis of the entire building.  thanks for any suggestions.

to estimate rebars, have the owner hire a testing agency to figure out rebars and spacing. concrete strength can be estimated or found out by another test (taking core samples form non-critical area).
without these data to substantiate your calculations, you will be taking a huge risk. if you feel there is need for a lateral analysis, do not hesitate to tell the owner right now.