Thanks everyone for your comments... I'll try to answer some of the questions raised.
Equations are typed in as simple text. Equations are a paragraph that uses a particular style, so other text doesn't get accidently get entangled.
Equation are type as simple text. For example -...
Thanks for your replies. Yes I've heard of MathCAD, SMath and TEDDS and Slydrule is a bit like each but also a bit different to each.
Firstly, as a Word add-in, it is very accessible to everyone and extremely easy to learn. You can simply add a few equations to any document, rather than working...
Hi
I’d like to get some feedback from experienced engineers on a new tool we have developed for documenting calculations. It is a add-in for Word that allows updatable, unit based equations to be added directly in a Word document. It provides an alternative to spreadsheets, “black box”...
And there needs to be some mechanism to limit the exposure of the third party checker to damages to reflect their reduced fee, otherwise no one may be interested in the work.
So just to be clear, you believe the correct interpretation of 11.7.4 requires all walls designed as columns that are over 50MPa must be restrained to 14.5.4. In other words 11.7.4(a) cannot be used, even though not clearly stated.
Moving to 14.5.4, this clause in intended for an IMRF ie mu=3...
11.7.4 is very badly drafted as the final paragraph appears to contradict (b) since the strength must be <50Mpa, if the last paragraph is read in isolation.
The reference to 14.5.4 should only be relevant, reasonably, if mu > 1.
If the design is based on mu=1, then the higher moment is probably...
AS3600-2018 gives cases, in 11.7.4, where wall can be designed as columns not requiring restraint of vertical steel according to 10.7.4. The new last paragraph says vertical reinforced is to be restrained to 14.5.4 if over 50MPa. I believe the correct interpretation of this only if restraint...
I can totally understand why the developer, builder and engineer wants to keep it quiet but do they have an obligation to explain more when there is such public interest and the entire industry is being brought into disrepute
ShearForceEng
A great diagram showing what has happened!
The interesting point is the crack in the lintel beam in vertical indicating a tensile crack. A true shear crack would be on an angle. The drop in the floor is a secondary effect.
The fact that is has tension suggests that the grout and...
Am i correct in reading the latest photo as a vertical crack in the wall over the centre of the column? If so, it would appear that a tensile force existed in the base of the wall due to the rectification of the dispersed column force into the wider wall. This force would be say 10% of the axial...
rscassar
You give the capacity of the wall over the column as 4050kN. This presumably includes a phi of 0.6. This is a safety factor and shouldn’t be considered in assessing an actual failure. Similarly the 5% eccentricity is a contingency but probably doesn’t actually exist with a symmetric...
A quick calc...
30m2 x 10kPa x 23 floors = 6900kN
The area and load generous I think.
(0.7 + 2 x 0.2) x 0.2 = 0.22m2
Assuming a 45 degree dispersion
6900 / 0.22 = 31MPa.
Seems maybe a bit high for a wall but unlikely to cause an actual failure since the service load would only be about 70%...
I know that we are all talking about something were we don’t know all the facts. What we do know is something serious failed under normal service. That is at about a third of what should be its actual capacity. There are twenty similar details in the structure. Although they may not have failed...
The “transfer” you are talking about looks to be only a 200 slab, like all the rest. The floor to floor height looks consistent. With 20 floors above, you can’t expect any reasonable redistribution without punching the slab.
The problem with propping to ground is how the get a say 10000kN...
If a wall is designed as a column then its capacity is limited to about 0.45f’c. If designed a a simple wall it would be less. The load at the time of failure would be only about 0.75 of the design load. The failure therefore occurred at about one third of the expected capacity.
It seems...
This plan of level 3 shows what looks like 3 supporting columns below the grid 20 wall.
It is statically indeterminate how these three will share the load.
Assuming vertical stress will flow through a joint at 45 degrees means that there are very large horizontal stresses in the lower edge of the wall in order to pull the forces back to vertical. I’m not sure the wall would have this horizontal reinforcement along the lower edge. A detailed FE will...
This image is from Google maps. It clearly shows the wall at L10 is load bearing with no column as shown in the DA plan. The wall is sitting on the L9 column with a limited bearing area.
The wall above L10 is supported appears supported on 3 columns, so is statically indeterminate. Depending on...
