I would not do cores. I would contact a carbon fiber manufacturer and get their input on how to reinforce the members for shear, using carbon fiber. The likely hood of you getting the concrete strength required is not good. Now the client has spent money for cores and you are still back to...
I would like to get your opinions on the following stud rail layout. The column is oriented 45 degrees to the normal layout of the typical columns - see attachment. As I read the code, the rails are supposed to perpendicular to the face of the column. The structure is a post-tensioned slab. If I...
We have designed many CFS stud structures. We specify that the studs align with the trusses. We have found that the contractor had rather add a full height stud than use any king of distribution member on top of the wall. Using a wood distribution member may violate the fire ratings for the...
I generally use CRSI's design handbook for designing pile caps. However, they have taken the pile cap design out of the latest handbook and made it a separate publication. Which is fine. However, that publication is no longer available on their web site. Does anyone have a good reference to use...
I was thinking wind loads are considered by codes as static loads, but could not find that statement in the code or commentary. Do you know where in the code or commentary it says wind loads are considered static equivalent loads?
We are having a discussion in our office as to whether wind loads are considered static or dynamic. We have a geotechnical report that give 2 different allowable axial capacity. The report gives one value for static loads and a lower value for seismic loads. It does not mention wind loads. We...
I have a building that is 326' to the roof. The owner wants to put the cooling towers on the roof and hide them by extending the parapet up 30'. When I calculate the wind loads on the parapet using MWF pressures, the total base shear is 2700 kips with 631 (23%) being applied at the roof due to...
Thanks for the input. This question has come up due to existing conditions not clearly shown on existing drawings. That is the reason for the detailing in the sketch. I think I can make 6 anchors work - 3 in top row. But two of the anchors will fall outside the column bars. We like to keep them...
I have a unusually condition where I am anchoring into an existing side of an concrete beam. The the center of the anchor plate aligns with the center of column above and below the beam. I would have said I am anchoring into the side of the column except the column is set back 2" from the face...
I worked for a firm in the 80s that did audits for the PCI certification program. I cannot remember seeing a double tee that did not have weld plates at the sides of the flanges to connect the tees together. Particularly if it was an untopped tee. It not only provided for some diaphragm action...
I am designing a mat foundation using SAFE. We have significant overturning issues and are considering using rock anchors into the bedrock that our foundations are bearing on. We are wanting to model the rock anchors as springs. We are looking at #10 bar. How would you determine the spring...
I am looking for a design guide for designing concrete elements using a strut and tie model. Does anyone know of such a guide. I have looked and have not found anything that is really gets into the weeds of the method. They did not teach this 30 years ago when I was in school and the ACI code is...
Have been a Risa user for many years. Not impressed with new interface. It takes too long to open, slow in accepting new inputs into the spreadsheet, takes longer to run on smaller models. Takes two clicks to get anything done. Most of the engineers in my office opt for using the older version...
