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  1. jchi

    Foundation/Slab Design Un-Heated Building

    Good point Dik - I will look at that. What do most use 1" rigid insulation = 1' depth, thus 4'=4" of rigid insulation. Jeff
  2. jchi

    Foundation/Slab Design Un-Heated Building

    I should have the soils report in the next week. They want to pour concrete 1st of October and still have not provided the report... How do they expect me to complete a design. Now - They want to pour this 12,000sqft building foundation and slab in northern Montana this October and November...
  3. jchi

    Foundation/Slab Design Un-Heated Building

    How do others address designing foundations/slabs in unheated PEMB. Here is my problem - 4' frost, PEMB, unheated, large horizontal thrust reaction. My concerns: 1. Slab moves due to frost heave - do you pour foundation wall with curb and attach panel to curb, let slab float - do you try to...
  4. jchi

    Drill Concrete Pier - Bells

    Thanks! 3X is what I thought, but it has been awhile. Jeff
  5. jchi

    Drill Concrete Pier - Bells

    Designing a job on drilled concrete piers in Texas (expansive soils). What is the typical diameter (or most cost effective) and maximum bell diameter. Looking a 12" diameter aprox. 10'-15' deep -- what can I use for a maximum bell diameter? Jeff
  6. jchi

    RISA - Diverging Error Message

    DWHA That was the problem, THANKS FOR THE HELP!!! Jeff
  7. jchi

    RISA - Diverging Error Message

    I am designing a 30' tall 17'x17' square tower to support a loadout bin (245k DL+LL). Problem is that my model keeps diverging under DL+LL and load cases with wind perpendicular to drive through dimension. The structure is braced on all sides with x-bracing except where it is open for the...
  8. jchi

    Horizontal floor bracing

    X-bracing so I am only looking at the tension loading.
  9. jchi

    Horizontal floor bracing

    Thanks Paddingtongreen, I agree, I like the L-shaped clip the best.... Was getting late yesterday and I was stuck! Thanks for all the replies! Jeff
  10. jchi

    Horizontal floor bracing

    I have horizontal floor bracing (grating floor-no diaphragm) to transfer seismic loads to my exterior wall vertical bracing. The angle shown is resisting 53 kips seismic. I have sketched two possible bracing senarios: W.P. at column flange - much easier detail, however creates a...
  11. jchi

    Wind Contributary Area on Grating

    I am working on a 160'+ tower and calculating wind loads. Question is what is the contributary area for floor grating blowing perpendicular to the bearing bars. If I figure the area of each bar, like I do with the depth/web of a beam, my reactions become very large. Will the wind blow against...
  12. jchi

    Fall Protection

    Here is a twist... Three guys tied off to the same beam. 5000lbs x 3 = Way Too Conservative. How do others handle this situation: Permenant fall restraint beam for doing maintenance on the roof with (3) rolling fall restaint tie-off trolleys.
  13. jchi

    Agricultural Structure-Engineered Design

    archeng59-Thanks, two very good points for referance!
  14. jchi

    Agricultural Structure-Engineered Design

    JAE - I agree with you. I am an expert witness on the farmers side stating the inadequacy of all these structures. He has quite using the facility and the court battle has begun. I am now reviewing expert reports from the other side's engineers stating this is a farm, thus it is code...
  15. jchi

    Agricultural Structure-Engineered Design

    It is county jurisdiction which states "farms are exempt from the Building Code". However this has turned into a legal case between the farmer and contractor. I have checked and found nearly everything underdesigned, not by 5 to 10% but by 200 to 300%. Example: 140,000 lb unloading bin 15' in...
  16. jchi

    Agricultural Structure-Engineered Design

    When does an agricultural building/structure need to be reviewed and signed off by a licensed engineer. I am reviewing a grossly underdesigned farmers grain recieving and storage facility which is clearly structurally unsafe. 140'+ distribution tower on next to nothing footings. These once...
  17. jchi

    IBC / OSHA STAIRS

    IBC 2003 section 505.5 commentary: "Additionally, if a stair is used to access an equipment platform, it would be subject to all the dimensional requirements for stairs in accordance with Section 1009.1" I see no way out of designing all equipment access stairs per IBC... I have also received...
  18. jchi

    IBC / OSHA STAIRS

    We mainly design/construct industrial/grain/seed facilities and this question keeps coming up: What are the strair/handrail/guardrail requirements for equipment access? Do equipment access stairs need to be 36" wide with 7" rise and 11" run? Do equipment access stairs need the 42" guardrail...
  19. jchi

    50 KSI Beams, When?

    Thanks to all the posts! I did inform the owner, he wants to add posts and not hang off the existing. I still did inform them that based on 36 ksi steel this structure/beams are underdesigned. I now have another structure (different location) with beams at 158% (36ksi) and 200% (50ksi) as it...
  20. jchi

    50 KSI Beams, When?

    I am checking an existing (25-year old) seed corn tower supporting (4) surge bins. The problem I have is that I cannot get the existing support beams to check out. They fail under flexure at 150% using 36ksi steel. If I check with 50ksi they just barley work 103%. However, I do not believe...

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