In looking at many older concrete structures, it seems to be very common to see stirrup spacing on the order of the member depth. I've generally ignored any contribution of these stirrups since they would not intercept the assumed 45 degree failure plane. A couple of questions to anyone who has...
We are involved in a building project with a sloped site that has grades in the 1.5:1 range. The preliminary proposal for handling excavation on the up-slope side is to excavate using soil nailing, and then place a basement wall approximately 10 feet in front of the soil nail wall. The soil nail...
I'm in the schematic phase of a warehouse expansion. The existing exterior walls are non-load bearing insulated precast panels. It has been suggested to relocate the panels from the existing structure, at the tie-in, to the exterior wall of the new structure. There are elevation differences that...
I am in the schematic design stage of a small commercial project, and I need a non-combustible roof framing system. I am looking at either fire retardant wood trusses or light gage metal trusses. Does anyone have any experience with relative cost differences between these two system? I've called...
NDS appendix E gives design guidance for the net section effect of wood connections for loading conditions parallel to the grain (similar to block shear checks for steel). The equations are based upon the allowable tension values parallel to the grain and allowable shear values parallel to the...
Anyone ever tried using glass as a shear panel. Application would be for a small enclosure (still not sure the building offical will accept it just yet). Boundary members would be steel attached to glass with adhesive. Any experience or literature that you could share, I'd appreciate it.
Thanks
We have a potential client that wants assistance in providing seismic calculations to qualify their transformer in a nuclear plant application. I am a little unclear (as I think they are) of what the scope of work actually is. My understanding is they are referencing IEEE standard 344...
I am reviewing calcualtions for a braced frame connection. The contractor took the liberty of fabricating and erecting the steel, before we even recieved design calcs or shops drawings. The connection is what is typically shown in AISC heavy diagonal brace connections where a beam, column, and...
We have written the spec to allow a tolerance of 3" on the plan location of the top of the pile. The pile contractor in this case routinely is falling outside of this tolerance. This requires that we re-analyze caps. The largest variance has been 9". Is this large discrepancy common in the...
I have an application where I am expoxy bolting a plate to an existing concrete beam. On this plate I will be welding a shear tab to carry a beam reaction. Hilti provides a nice little program for the design of the expoxy anchors; however, I'm not so sure about how it is handling (if at all)...
A few general questions on designing foundations supported by augercast piles:
1) It appears augercast piles are usually specified with small diameters (10"-16" diameter range). Does a typical auger cast pile for gravity loading need to be reinforced, or is it assumed to derive all of it's...
I've got a 5 story steel frame building 50'x200'. Concentric braced frames (chevron braces) to resist longitudinal shear are at the corner bays of the building (exterior). In one corner, this is adjacent to a stair opening (only place architect will give it to me). There is no slab adjacent to...
Trying to find design approaches taken for sloped roof steel rafters (W shape, with W shape structural ridge) under dead, live, and wind loads? I'm considering just using a horizontal projection of all the loads and applying to the horizontal projection of span length to determine moments and...
I'm investigating adding some windows to a four story office structure that was built in the 1960's (Maryland). It's very difficult to tell what the original designer intended for lateral resistance (beginning to suspect if it was even considered). The majority of the exterior walls have 5 foot...
