I have a structural slab-on-grade system with grade beams and girders. I am trying to determine how to run the vapor retarder below the slab. Is it typical to run the vapor retarder continuous below the grade beams or can the vapor barrier be turned down at the face of the grade beam? I have...
I am editing a specification section for Auger Cast Piles. I am unsure what flow cone test parameters I should be issuing to the contractor. The subsurface soils on the site are very poor, basically extremely soft silt & clays to a depth of 65-70 feet. We are using 16" diameter ACIP piles...
I am editing a specification section for Auger Cast Piles. I am unsure what flow cone test parameters I should be issuing to the contractor. The subsurface soils on the site are very poor, basically extremely soft silt & clays to a depth of 65-70 feet. We are using 16" diameter ACIP piles...
When determining the shear capacity of a significantly coped web, does the reduced h of the web need to be accounted for in the web compactness calculations in Chapter G of AISC? I have a W16x31 that has more than 50% of the web coped due to a sloping roof and I am trying to determine the shear...
I have been involved in a discussion with a coworker about the requirements for serviceability design. There is some confusion about what the required load combinations are for the checking of deflections and building drifts. I have a few questions that I was hoping to get some help on. All...
Our handrail & railings spec indicates that the when railing posts are to be anchored into the stair concrete itself, that posts are to be anchored with core-drilled holes or pre-set sleeves of diameter at least 3/4" more than the diameter of the post being anchored, not less than 5" deep. Fill...
What types of restrictions do you usually put on the placement of horizontal construction joint in basement walls or interior shear walls? It seems that requiring a Class 'B' tension splice of your reinforcing bars and requiring the concrete surface to be roughened to a 1/4" amplitude would...
Question concerning the ASD load combinations in Section 16-5.3.1 of IBC 2006. Exception 2 indicates "flat roof snow loads of 30 psf or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf, 20% shall be combined with seismic loads.
Load combination 16-13 (or...
I have a situation where I need to specify the tensile prestress force in cable rail used for a vehicle barrier system in a precast garage. The contractor is trying to use 3/8" diameter Grade 250 strands. I cannot find any documentation by the manufacturer concerning recommended prestress...
I am investigating a building that was designed back in 1960. I am looking at a coverplated column with a 14WF320 designation. I have looked at the AISC 5th Edition which appears to be the governing AISC version at that time, and the section of the manual with the WF shapes does not include...
I have a slab penetration that the architect wants to slap directly between two columns. Bay spacing is approximately 20'-0" x 29'-0", penetration would be located in a column strip-middle strip intersection. I took a look at the ACI slab opening provisions, 13.4, and I cannot use the...
I have always used a 30 foot minimum on beam length in order to specify any camber. I believe this requirement appeared in the Manual of Standard Practice in the 9th edition.
I cannot find a length minimum in the new 13th Edition specification or Code of Standard Practice. Does anyone know...
I have a question concerning vertical reinforcement in a cantilevered retaining wall (or a restrained retaining wall) for that matter. ACI 14.3.4 requires 2 layers of reinforcement when the wall thickness exceeds 10". Now assuming that the flexural reinforcement on the backfill face satisfies...
I'm looking at a wide flange beam loaded about its weak axis and attempting to calculate the shear capacity. Is the correct method of analysis to substitute bf/tf in all of the web shear coefficient calculation equations? I am looking at AISC G.7 which refers back to G.2. The way I am reading...
I have a dilemma that I am hoping I can get some help with. I am currently designing perimeter cantiliver retaining walls for a below-ground precast garage directly adjacent to an existing garage. The geotechnical engineer has recommended a permanent sheeting & shoring system of secant pile...
I have been designing some large scale multi-family wood residential projects and wanted some clarification on a few issues I am having with the lateral design.
1. The exterior of the buildings often have continuous offsets in the wall line which interrupts the continuity of the chord member...
