If I'm not wrong, it could be due to pattern live load factor defined in program by default. See if your issue is resolved by assigning a pattern live load factor of zero in design preferences.
Thank you hturkak for your response. Just wanted to confirm. Some of my colleagues were using total factor of dead load as sustained load for this combination.
Governing Seismic combination for column design is this:
Pu = (1.2 + 0.2Sds)D + 0.5L + Eh
As per ACI 318 Section 6.6.4.4.4.
My question is what we should take as sustained part of the load combination for calculating βdns,
1.2D or (1.2 + 0.2Sds)D.
I usually take it as 1.2D, because as I...
Can you provide the reference for this? I looked it up in the ACI code but could not find it.
I completely agree with you on this. In fact, I remember doing battle on same of these points with my boss when I first started working at this firm. I did try to sell him on the construction...
Design is based on the provisions of ACI 318-19. Structure is assigned to seismic design category C and there are no special material strength requirements for this category in ACI.
That being said, concrete compressive strength of 16.5 MPa is being used in beams and slabs only. Rest of the...
IDS,
Thank you so much for commenting. I performed the same exercise before posting here. I got the required phiMn when i considered both the side face reinforcement and reinforcement at compression face.
I'm aware that I'm only saving 2-25Dia bars by performing this whole exercise...
As I've mentioned, this is a 2 story building with a single frame along the axis under consideration (thus, dual frame is not possible). Span of the frame is 10.5 m. Bottom story height is 6.2m and top story height is 5m. One column of the frame is supporting PEB column at roof level.
Supplier...
You're right, this is a lot of steel for the beam size. I usually keep the steel percentage in beam within 0.6%. But I would not call this a small beam. I was actually anticipating a call from client to provide justification for the size of beam. It definitely caused some people to raised their...
I have a two story RCC structure with multi bays in X direction and single bay in Y direction. The building LRFS is IMRF. Flexure demand on the beams in Y direction due to seismic loads is coming out to be very high such that some compression reinforcement will be required for -Mu. The span of...
Thank you everyone for your valuable insight.
I understand the basics of the given expression and know that it’s the principal theory behind the development length expressions of deformed bars. I am seeing it first time used for anchor bolts however. The calculation in question is for a PEB...
I'm reviewing the design calculation of anchoring to concrete checks, submitted by another design firm.
The designer has calculated the pull out capacity of L bolts using the following formula, which is contrary to the one given in Chapter 17.
I am having difficulty finding out the reference...
Chapter 18 of which code?
Since we've established that rcc columns will be transfering reactions from steel structure to the footings (isolated?), then yes, you need to design the column for resulting compression or tension forces due to vertical reacrions and, bending moment due to horizontal...
I get from your post that you are only responsible for designing RCC pedestals and foundations for a steel superstructure and you’re confused about the need to recalculate seismic forces on the RCC pedestals?
If so, you do not need to do that because as you've implied your rcc columns are...
A ground motion of certain duration might or might not contain the frequency equals to (or even closer to) the natural frequency of the building, but it's a good design practice not to have fundamental periods too close to each other in principal directions, in order to avoid merging responses...
Program does not calculates lumped story masses for semi rigid diaphragms. You can obtain these values by analyzing the diaphragm as rigid in a separate model however.
Grid lines are defined just as an aid or a reference point for ease in placement of structural elements during construction. It's not necessary to define grid line at every beam. Similarly, it isn't mandatory that every grid line must have a beam aligned on center.
The intent of the rule no.3...
I don't recognize the software, so I can't really help you to find out what's causing the problem.
But I quickly made a similar model in sap2000 and it's giving me the expected results.
