I'm working on an existing house that has several continuous strip footings that are sloped. This means that the sill plate is also sloped, and the stud ends are cut at an angle so they can rest on this sloped sill. I'm not sure why they didn't step the footing, but slope it they did and now we...
I have a project where I was engaged to provide calculations for a set of steel stairs that a fabricator had designed. Being in California, it is important that these stairs satisfy Section 13.5.10 of ASCE 7-16 with connections that can accommodate drift. Unfortunately, these stairs were hard...
I have a contractor who wants to use 2500 psi concrete, but usually use a minimum of 3000 psi on all of my projects. The thing is, this has just become standard operating procedure for me over the years and I have no real reason to back it up other than "It's what I've always done." So, does...
I have a project where the architect is applying a waterproofing membrane over the top of some concrete work we are doing. The architect does not want the waterproofing to be damaged when the concrete cracks and would like to know how long he should wait after placement before applying the...
I have a set of specifications for the testing of shotcrete test panels that require 3 cores for compression tests, 3 cores for grading by a special inspector, and for the test panels to be cut in quarters for additional observation of the cut edges for adequate shotcrete placement. My question...
So, Chapter C gives 3 analysis methods and I'm wondering if anybody out there has experience with the 2 alternative methods. I usually use the direct analysis method, but am curious when it might be useful to use the effective length or first-order analysis methods. When are those more...
Is Table 4-22 in the AISC Steel Construction Manual applicable for members with slender elements? I ask because I did a RISA analysis of a WT7x15(compact web and slender flange) and it didn't match the allowable compression value I got using Table 4-22. Also, if this is in fact not applicable...
Does anybody have a good method for finding the torsional strength and stresses in I-beams and channels? I looked through the AISC design guide, but their process seems too cumbersome and time consuming for easy use. If that is the only way to do it then so be it, but if there is a simpler way...
I am adding a new steel HSS entry portal (50' wide x 26.5' tall x 10' deep) to the front of an existing building and want to make sure the drift is within allowable limits. The problem is that I have classified my portal frame as a nonstructural component, and am now trying to figure out how to...
Hi All,
I'm currently designing the anchorage for some mechanical units and ran into something in the new code that I hadn't realized. Section D.3.3.4.2 of ACI 318-11 specifies that we need to ensure anchor ductility, but there used to be a provision in the IBC (Section 1908.1.9 in the '09...
Hi all. I'm planning on taking the 16 hour NCEES SE Exam this coming October and am compiling all of the books I need. Currently NCEES says that their April Exam will utilize codes such as the '09 IBC, '08 ACI-318, '05 NDS, and 13th Edition of the AISC Manual. However, after speaking with...
Does anybody have good rules-of-thumb for member deflection limits when the member supports glass? I don't really see much direction on this in the code and have heard from others that they use more stringent criteria than L/360 when considering a sensitive material such as glass. Any ideas?
Does anybody out there use this table? I decided to check it out recently, but it doesn't seem to be very user friendly. A few questions.
-Why do they bill it as a "Uniform" load table when they give it to you in kips? Assuming it means kips/foot will give you a moment far higher than the...
I have run into this case on numerous ocassions and want to make sure I'm looking at it correctly. I have an existing 4x12 beam that needs to be reinforced for a new loading. The new load produces a moment of 1763 ft-lb, and I will support this by sistering a 2x8 on either side of the beam...
The project I'm working on has a dual structural system in one direction that includes steel braced frames and moment frames. In Section D of Table 12.2-1 it talks about the moment frames being designed to resist at least 25% of the seismic forces. How do people read this? Do you assume that...
Can anybody out there give me their opinion on the relative merits of using the "Beam on Elastic Foundation" vs the basic "General Footing" or "Wall Footing" modules? I understand the underlying differences between the 2 modules, but am struggling to see a real-world application where the...
Does anybody know where the 2010 CBC (or 2009 IBC for that matter) specifies the minimum weight of a rooftop that needs to be analyzed by an engineer? I seem to remember 400 lbs. being the cutoff that requies an analysis, but just want to find the specific section. Thanks.
Does anybody out there have a good handle on this section because I don't. Here are a few of my questions. IPSW=Intermediate Precast Structural Walls. Also, I will number the sections of 21.4 based on the modifications in Section 1908.1.3 from the CBC '10/IBC '09.
1. Are IPSW's required to...
I'm working on an existing building and trying to justify that the tilt-up walls can be classified as "Intermediate Precast Structural Walls". It looks like the main difference between "ordinary" and "intermediate" is Section 21.4 in ACI318-08. My problem is that I don't understand exactly...
Does anybody out there have a good handle on this section because I don't. Here are a few of my questions. IPSW=Intermediate Precast Structural Walls. Also, I will number the sections of 21.4 based on the modifications in Section 1908.1.3 from the CBC '10/IBC '09.
1. Are IPSW's required to...
