Search results for query: *

Geotechnical engineers, I have typically specified static load tests for our projects involving driven H piles to verify pile capacities. Some pile contractors are pushing to use dynamic testing instead. Can anyone provide some good resources that compares the two methods and perhaps highlights...

It is a braced frame and where possible I do place both columns on the same footing. Under lateral load I'm getting a substantial net uplift and there is no realistic way (the footing size is not practical) to get a footing to work without the assistance of a tension element. This is where the...

I'm designing a combined footing supported on geopiers where one column has uplift and the other does not. I've not encountered this condition before, so I'm looking for some input. The geopiers will be designed to resist the uplift, so I have to size the footing for bearing and then design it...

KootK the NEHRP publication on Steel Special Concentrically Braced Frame Systems would tend to agree with what you're saying.

Can you put it back on the PEMB engineer to design for the moments in the frames themselves as opposed to transferring the moments to the foundation? I've designed several foundations for PEMBs and haven't seen them try to transfer moments at least not this magnitude.

mike20793, thanks for the detail. It looks like you are resisting both shear and tension by the bolts. I would be a little concerned about the bolts trying to transfer the shear through the grout bed. In other words as the shear acts upon the bolts I would think they would undergo some localized...

KootK, thanks for the time and effort. I was going to do the embedded plate as you have shown for tension resistance. The shears are not so large, so I was going to recess the column into the footing a few inches and rely on concrete bearing for the shear resistance. But I do like your double...

Thanks mike 20793. I reviewed the NEHRP publication and one recommendation is to embed a plate near the bottom of the footing connected to the anchor bolts and the uplift is resisted through punching shear of the embedded plate. KootK 1) yes 2) I will use some tie grade beams but this is to...

For the base plate to foundation connection at braced frame columns, what order of magnitude for tension do you consider significant enough to warrant a more robust connection than just anchor bolts and shear plates? I'm working on a project that has around 450 kips net uplift (ULT). I'm...

Thanks all, I appreciate it!

Is it possible to construct an inclined bond beam? I have a shear wall that follows the slope of the roof. The total vertical distance from the top of the wall from one end to the other is about 4ft. Thanks in advance.

For those structural engineers who have post tension design experience, what is a quality software that should be considered for purchase? I have used ADAPT-PT version 8 but had some issues with it. Plus it only designs slabs and beams, with no cosideration of how the compressive forces affect...

VTPE, it is exactly as you stated, the slab is post tensioned in the direction perpendicular to beam post tensioning, and some T&S stressing parallel to the beams.

Teguci, to my recollection the cracks do appear on both sides of the beams. The centroid of the tendons was located at the centroid of the beams at the ends vertically. One end detail had one tendon in the slab on one side of the beam and two on the other side. This slight horizontally eccentric...

I have attached a simple sketch of the two span conditions. http://files.engineering.com/getfile.aspx?folder=cdacb99a-1bf7-405f-bea4-01dc91c35662&file=sketch.pdf

Teguci, the IBC 2009 has added a new increased height of impact load check of 27 inches now. This will control most designs for moments now. I have designed many retaining walls with considering impact loads, and I have used a 45 degree distribution with acceptable results. As Teguci has...

hokie66, 2-3 days has been pretty standard in my experience. No I couldn't see cracks in the top of the slab. The majority of the cracks take place at the end support. The first crack is a couple of feet away from the column face (end support) and the next crack is about 12 inches from the first...

Teguci, 2-3 days between pouring and stressing. Early concrete strength monitoring was implemented to allow the contractor to stress as soon as f'c reached 3000-3500 psi. The beams are 36 inches total depth. There are top, bottom, and each face bars continuous end to end with both the top and...

Fellow structural engineers, do you know of a good reference for guidance in classifying crack types for several types of construction? I recently made a site visit for a cast in place post tensioned parking garage that we designed. The only cracking I noticed were a few beams have 1 to 3...

Thank you all for your valuable input. Teguci you make a good point.