Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations JAE on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: mrlm
  • Order by date
  1. mrlm

    NCC 2022 Vol 1 S8C2: Precast panel height to thickness ratio

    I haven't had a lot of experience dealing with this situation, however, I would find it unlikely that it should be treated as effective height and should be true height. The attached paper makes reference to a couple of situations and recommendations on slenderness limits. Similar to what...
  2. mrlm

    Revised internal pressure calculation in AS/NZS 1170.2:2021 Part 2

    Then they should add another note that simply says "KL when referenced by T5.1(B) is applicable to the whole structure and not just the elements directly supporting cladding." Problem solved. As the code is written, that definition in the video goes directly against it. The reference to Cl...
  3. mrlm

    Revised internal pressure calculation in AS/NZS 1170.2:2021 Part 2

    Apologies, take 2 (although not sure I've got it right this time either...) Paragraph 3.2.1 Example B.3
  4. mrlm

    Revised internal pressure calculation in AS/NZS 1170.2:2021 Part 2

  5. mrlm

    Revised internal pressure calculation in AS/NZS 1170.2:2021 Part 2

    I didn't initially agree with sdz's interpretation, however, after reading the reference provided by rowingengineer; I believe they have got it correct. See below from WIND LOADING HANDBOOKFOR AUSTRALIA & NEW ZEALAND: Background to AS/NZS 1170.2 Wind Actions From Paragraph 3.2.1 From example B.3
  6. mrlm

    Revised internal pressure calculation in AS/NZS 1170.2:2021 Part 2

    T5.1(B) directs the reader to Cl 5.4.4 which clearly states that KL is 1.0 unless applied to cladding, their fixings, the members that directly support the cladding, and the immediate fixings of these members. Surely it does not apply primary members. I watched a bit of the youtube video...
  7. mrlm

    AS3600 cl 11.2.1 vs 11.7.3 - Two Layers fo reinforcement in walls

    I agree that section 8 is not applicable to shear walls but in just about every ultimate design situation, the tensile strength of concrete is ignored. I used that as a reference as in the column or wall section I could not find a comment on it, however, it was my underlying assumption the...
  8. mrlm

    AS3600 cl 11.2.1 vs 11.7.3 - Two Layers fo reinforcement in walls

    I tend to agree with your interpretation. I think the reference to tensile strength in 11.7.3 is poorly worded. When we are designing slabs and beams, 8.1.2 b) states that the concrete has no tensile strength. So I take the meaning of 11.7.3 to be when the tensile strength is exceeded (which is...
  9. mrlm

    AS 3600 Cl 10.8 Transmission of Axial Force through floor systems

    The f'ce you calculate is just for the sandwiched section of slab. You may need additional reinforcement, at the column-slab junction, if your axial on the columns and being transfer through the slab is greater than 9880kN (using your 300x1000 column with about 1% reinforcement). Your slab...
  10. mrlm

    Australian Engineer Registration Discussion (NER vs RPENG, Member vs Non-member)

    It's not that NSW don't require registration, it's that the Building Commissioner doesn't like EA so is choosing to ignore them as a professional body for registration. I agree with Just Some Nerd. I see little benefit in being CPeng or RPeng, save for the need for accreditation.
  11. mrlm

    Repairing Post-tension slab

    Hi Rapt, I think the photos still show the same thing. See attached for reference. That crack shown in the photo on the left is hidden or shadowed by the direction the photo was taken on the right. But I believe the crack can still be...
  12. mrlm

    Deflection Limits for Australian Flooring

    Are you designing a concrete floor, steel, timber, something else? Incremental deflections aren't really a load combination, it's more of a load condition. It is the difference between the total deflections and the initial deflections: Delta.Inc = Delta.Total - Delta.Initial Your total...
  13. mrlm

    Deflection Limits for Australian Flooring

    I'd be looking towards the concrete code where they recommend designing for an incremental deflection of L/500 or 15mm (industry standard) for brittle finishes. Incremental deflection is total - initial (where initial is deflection under dead load and prestress). Obviously this is for a concrete...
  14. mrlm

    Deflection Limits for Australian Flooring

    See attached a paper from the ASI for steel deflections, extracts from a portal frame design textbook, recommendations from Timber design handbook HB108-2013 and AS 1720.3:2016. I find the criteria from AS 1720.3 confusing as most other references allow L/360 for dead load and a less strict...
  15. mrlm

    AS3600 - CL14.6.2

    If only we had the code commentary we could put it to bed..... I jest. Well, I'm happy to be wrong. I can see why using the wording in the code it could be read that way. When the 2018 requirements first came out the company I was working for 'borrowed' another companies details to form the...
  16. mrlm

    AS3600 - CL14.6.2

    Definitely applies to a closed core box too. As 14.6.2.3 states "in any area of the wall".
  17. mrlm

    AS 1170.4 Clause 1.1 - Building with a Period Greater than 5s

    For a building to have a period of >5s it would have to be in the order of 200m tall or 50 storeys (using the old approximations). Surely there would be issues with accelerations exceeding occupancy comfort in the structure?
  18. mrlm

    Minimum Base Shear requirements for Dynamic Analysis

    That initially wasn't how I would have read that clause but would agree with what you have said. See below clause C7.4.2.4(a) from the 1993 commentary to AS 1170.4 "The Clause requires the base shear force resulting from a dynamic analysis be increased to that required by Section 6. All...
  19. mrlm

    Minimum Base Shear requirements for Dynamic Analysis

    I believe AS 1170.4 (R2018) states that the base shear from a rigorous structural analysis should not be less than 70% of the value obtained from using the code period (i.e. static analysis). Refer to clause 6.2.3 As far as I am aware, this clause has not been removed.
  20. mrlm

    AS3600 wall design

    Columns and walls should be designed using Lu, "unsupported length of a column, taken as the clear distance between the faces of members capable of providing lateral support to the column." In short, 4m would be the correct height for your wall. Apologies if I am assuming too much, but if you...

Part and Inventory Search

Back
Top