From BBC News: Nine people have 3

[dik]

From BBC News:

Nine people have been held in connection with the collapse of a building in Jerusalem that killed at least 23 people attending a wedding party.

A judge ordered seven of them to be detained until Thursday, and two more to be held until Tuesday while investigations go forward.

The court hearing was held on Saturday night as a memorial service and funerals took place.

Rescue workers called off their efforts on Saturday after 42 hours.

Among those held is the inventor of a construction method that was banned in 1996.

The so-called Pal-Kal method of construction, which was used in building the hall that collapsed on Thursday night, was used in 3 million square metres (32 million square feet) of construction after its invention in the 1980s.

The four owners of the building, the owner of the company involved in the original construction, the contractor responsible for renovations several months ago, and an engineer were among those held.

A BBC correspondent in Jerusalem says they could face charges of causing death through negligence.

 

[IJR]

dik

That is a great bit of info. But dont they have minimum code requirements in Israel. I find Israelis very capable people(The ones I know of course)

I once was informed that the problem had to do with some columns removed. Hard to believe that one too.

Regards
IJR

 

[dik]

So much for the Code of Hummarabi (sp?)...

 

[IJR]

It is Hammurabi I guess, but the sp is no big deal. I got your point, some old code. However one thing I know about Hammurabis code is that it was very strict on punishment. If a building crushes and kills a son of a tenant, then the son of the contractor had to be killed. That is the historical side from which a joke can be made but I have to take the matter very seriously.

God bless the families, and thanks dik for opening up this thread because I will probabley follow this question to the edge.

Here is what I think of sometime whenever engineering failures occur. A social system could have played part in it. All over the world I have noticed, there are responsible engineers who have a lot of problem getting what they think is right done. Old but established building habits tend to be tough to remove. I remember a bricklayer who noticed blocks of bricks being used for partition wall protesting the practice because as far as he is concerned, the brick should be able to take structural loads and thus should have lintels at the top to carry the loads. This one is exxaggerating, but there are at lower levels such a restraint imposed by society against engineering application. At mid levels a restraint may take the form of corruption. Where structural code enforcers can not be taken seriously, good engineers can not do much.

May God put the victims to a sacred rest. And help the world of engineering attain purity, so that no one dies from a mass of concrete.

Regards
IJR



IJR

 

[ag89]

I have been seeing the details of the collapse and the horrific video. Does anybody have details of what type of floor system that was used and eventually banned. As far as I can tell it was a "hollow core" type slab.

 

[IJR]

ag89

Guess what I am thinking right now: It has been almost a week since the event occured and we have yet to hear of the nature of the collapse. I am beginning to feel it could be something else.

Israelis, according to reuters are apparently angry at whoever holds the construction technique responsible because the party hall has been there for 15years.

Lets wait and see.

IJR

 

[breaks]

I saw a story about the collapse on Dateline last night.

From what the story said, the slab system consisted of two layers of concrete separated by a layer of sheet metal-type material. I did not hear anything about rebar or hollowcore slabs being utilized. This description leaves many questions to which I don't know the answer. Was there any rebar used in the slab? Did the sheet metal have shear studs attached to it?

The show also mentioned that the removal of ONE support column may have contributed to the collapse.

I plan on following this story closely. What a horrific tragedy.

 

[IJR]

breaks

Guess what, now they are talking about earthquake possibility. For the last few days reporters from Reuters have been busy telling stories that the building was shaking a couple of minutes before collapse and was noticeable enough to have someone try to make a phone call to report the "earthquake"

Regs

IJR

 

[Deebee]

I would also like to learn whatever lessons come out of this tradgedy.
I also have sympathy for the construction professionals who have been rounded up in what sounds like a "witch hunt". Perhaps the true location of the blame will emerge in due course.

 

[breaks]

IJR -

I've heard the earthquake rumors, too, but I don't think they hold much water. The shaking felt by persons in the building was most likely due to the vibration of the floor prior to it's collapse.

Like Deebee says, we should have a better indication of what went wrong in due time.

 

[IJR]

Breaks, you are right.

Seems like the press is not going to spit anymore. My only hope is in structural or civil engineering journals

Regs

 

[austim]

Hi, all.

At last there seems to be some serious technical info re the Pal-Kal floor collapse in Jerusalem.

The July edition of New Civil Engineer International has a half-page article headed 'Crisis looms in Israel over use of Pal-Kal floors'.

The article makes no mention of any removal of columns, which was suggested in Australian press at the time of the collapse.

I cannot find a web link to the full text, and am reluctant to breach copyright laws, so I will not copy the full text here. The following is an Austim precis.

The basic form of construction of the floor system is a simple voided in-situ concrete slab. Top and bottom flange slabs are approx 50mm thick, and the webs are 150mm. There ia a layer of structural reinforcement in the bottom slab, anti-cracking reinforcement in the top slab, and NO REINFORCEMENT IN THE WEBS.

Construction sequence goes like this:
1. pour bottom (reinforced) slab;
2. place void formers. These are inverted steel U shapes, pushed 10-15mm into the hardening concrete of the bottom slab.
3. pour webs and top slab.

This simple method of construction was originally concieved as a low-tech method requiring no skilled labour.

Israeli authorities have recognised a basic weakness in shear, which can be seriously aggravated by the existence of cold joints at the bottom of the webs. Despite the method having been effectively outlawed by the Israeli Standards Institution in 1996 for failing to meet design code requirements for shear resistance, contractors have continued to use it, and it is still being used.

The Israeli Supreme Court is to set up an enquiry into the safety of all public buildings. It is hoped that this should find out why the system was still in use, despite warnings AND A SERIES OF FAILURES.

So far no use of the system has been discovered outside Israel. Its inventor is known to have tried to market it in the USA, but without success. He is still in custody.

 

[dik]

Thanks...