Under a normal construction procedure the contractor needs to submit the mill certificates of the reinforcement source. Testing certificates, usually at least the tensile test, will be supplied from time to time as the quality assurance procedure. Thus there should have been records of the...
The post by Sym P.le (Mechanical) possibly has the best indication of the initiation of collapse.
Sym's graphic shows two main features
(1) The first floor was the first to drop down and
(2) Columns failed as a consequential damage and then the rest of the building.
The...
A two-direction bridge has four spans in one direction suddenly collapsed during construction. Each span appears to comprise of 6 precast RC I-beams likely to have been prestressed to be installed in simply supported condition. Apparently most of the beams were in place but a removable steel...
From the recent NYSB footage it appears the demolished pier's marine works, that is the pile caps and the vertical and raking piles underneath the water (or the cassion structure if used), remains intact. The fender system seems complete and there is no visible movement in the pile caps. Only...
This photo depicts the deck was sinking in a straight line over the demolished pier. This is important as it could only occur if the pier was pushed away or knocked out underneath the bearings. Thus the pier structure has almost zero resistance against such impact. After the collapse the...
After the impact one pier remains the other was demolished.
The demolished pier does not seem to be able to withstand an impact by a containership. This looks like an under-design. If that is the case the bridge could have been protected by installed extra stronger piers before and after the...
From Wikipedia on electricity generation in UK "In 2020, total electricity production stood at 312 TWh (down from a peak of 385 TWh in 2005)". Are we talking about different country here?
The Royal Society estimated the 570TWh could happen in 2050. However historically after UK reached its...
There is some confusion regarding if this bridge collapse was intentional or not because it had suffered the first collapse during Apr 2022. The previous news reported in 2022 that the Sultanganj end collapsed owing to the impact of strong winds and rains in the intervening night of Friday and...
According to the simple Newton's law I would have expected the vertical thrust action to send off SpaceX could only materialise when there was an equal and opposition reaction provided by the apron concrete slab. This apron concrete slab has been pulverised and the soil underneath was also...
I would guard against the use of the proprietary "Fondag concrete" as a structural material to withstand 1100C. It appears its property to withstand 1100C may as a refractory shield and not necessary as a structural element to resist compressive load and abrasion.
In ACI 349M-06 for Nuclear...
The above photo was from a youtube video showing the reinforced concrete supporting structure of the SpaceX rocket before and after the yesterday's launch when it exploded 4 minutes into the flight.
It appears the RC slab was flush as one level prior to the launch but now has the ground beams...
Chain link fence differences
This is the best photo on the old chainlink fence I got from the Internet. It was dated 2008 according to the description. If you download and magnify it you will see the fence is shorter than the pedestrians at the far end. Also the fence had three fixings per...
I don't know the existing design but I would expect the channel to be structural grade. To replace 3 with 4 channels the total second moment of area or the I-value should be comparable otherwise the bending stress will not be the same as before. Scaled from the previous photo the depth of the...
If you read the text carefully I said the weight of beams, due to number increase, would go up. Similarly as well as for the weight of the chain link fence weight would go up if it is higher. These weight increases are parts of the deck's dead weight.
Since a professional engineer can be sued...
Possible issues from renovating the Morbi footbridge
(1) New deck has 4 instead of 3 longitudinal beams in the old deck
From the old bridge before renovation the deflected deck clearly shows 3 longitudinal beams, one at each side plus one at the middle, to give the above symmetrical deflected...
