[U/C] M2 North-South Motorway

[how good is he]

Shotcrete is most effective when used in conjunction with rock or soil anchors. So that’s the area I would be looking at to see if it was adequate & done correctly.
I compare what’s happened to the icing of a cake shearing off from the alcohol soaked sponge.

[claybro]

Surely this is not being blamed on rain alone? Even the heaviest of showers in Adelaide are comparatively mild with other regions. If a spell of Adelaide showers has rendered this work unsuitable, then surely the method is at fault, not the weather? Also, if the method is generally sound, it should not have to wait until the end of the rain season to complete the work. I would have thought a forecast of a few fine days should suffice.

You still in Perth? because you obviously don't know how dry the grounds been until the recent rains.

9.0mm in February 40 year average is 15.9mm
8.2mm in March 40 year average is 27.4mm
5.4mm in April 40 year average is 39.6mm

So far in May we've had 45.4mm over five days of rain, and the average for May is 61.4mm. There's up to 20mm of rain forecast for tomorrow and a further five over the following days.

I'm not suggesting the rains got anything to do with whats happening, but we're talking about months of well below average rainfall, and beyond parched soil.
45 mm of rain might not be a big deal in other parts of Australia, but they don't have the conditions we do either. It's all relative.

Rev, the conditions you describe are not unusual anywhere in Australia. Months of parched dry weather followed by torrential downpours is common both here in Perth, and in many places on the east coast. It shouldn't render a road project held up for the duration of the rainy season. Fair enough, they may have been caught by a surprise overnight downpour, but surely they had an eye on the forecast prior to the pour. I am not aware of this being an issue on the T2T section, despite 3 years of Adelaide weather both wet and dry to contend with.

[aceman]

I would say this issue will cause lengthy delays to the project timeline. they won't be opening the trench anytime soon as was originally planned.

[rev]

Rev, the conditions you describe are not unusual anywhere in Australia. Months of parched dry weather followed by torrential downpours is common both here in Perth, and in many places on the east coast. It shouldn't render a road project held up for the duration of the rainy season. Fair enough, they may have been caught by a surprise overnight downpour, but surely they had an eye on the forecast prior to the pour. I am not aware of this being an issue on the T2T section, despite 3 years of Adelaide weather both wet and dry to contend with.

I'm merely responding to your comment about the implied insignificance of the recent rains we've had. I'm not suggesting it caused the problems down south. 45mm of rain over a few days is very significant for a place considered to be the driest state.

[SBD]

Surely this is not being blamed on rain alone? Even the heaviest of showers in Adelaide are comparatively mild with other regions. If a spell of Adelaide showers has rendered this work unsuitable, then surely the method is at fault, not the weather? Also, if the method is generally sound, it should not have to wait until the end of the rain season to complete the work. I would have thought a forecast of a few fine days should suffice.

My guess is that the trench cut across an aquifer/spring or porous earth/rock that was dry at the time, so they have used shotcrete without sufficient drainage behind it. The rain has filled the aquifer and water pressure has pushed the cladding off the wall where the water was running out.

I live on the high side of a street, and did not realise I had a water leak in my front garden from a damaged pipe when we moved in, but had noticed there seemed to always be a pool of water near the front door of the house under construction across the street. That house has cut down over a metre to make the pad. When we eventually found and fixed our leak, the water across the road dried up. There was no visible indication that our water was crossing the street, so it must have been moving through the earth/rock and coming out where the excavation had been done for the other house. It demonstrated why you have to have ag-pipe and gravel behind and at the bottom of a retaining wall.

[rev]

Just on the news now.

Transport minister says water has gotten in behind the shotcrete and caused soil to move. Landslide basically.

[ghs]

Another stuff up by the state government, honestly DPTI is full of idiots.

[aceman]

I'm tipping they'll have to start the entire wall from scratch and use pre cast, any smart people out there suggest what might need to happen?

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[Furyan]

INDAILY article on the shotcrete collapse.

https://indaily.com.au/news/local/2019/ ... n-debacle/

[PD2/20]

Another stuff up by the state government, honestly DPTI is full of idiots.

Isn't this a design and construct project, so how is this a "stuff up" by DPTI?

[OlympusAnt]

Another stuff up by the state government, honestly DPTI is full of idiots.

Isn't that the case for all government departments? So much waste of our money.

[Jim]

I'm tipping they'll have to start the entire wall from scratch and use pre cast, any smart people out there suggest what might need to happen?

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Looking at the news clip tonight there appeared to be some precast already going over some of the spray on. Wondering if the spay on was just going to hold the bank to the precast covered it. Surprised if it the spray on was to be the permanent fix with out mesh in it.


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[ghs]

Another stuff up by the state government, honestly DPTI is full of idiots.

Isn't this a design and construct project, so how is this a "stuff up" by DPTI?

Who is responsible for it then ?

[Norman]

Another stuff up by the state government, honestly DPTI is full of idiots.

Isn't this a design and construct project, so how is this a "stuff up" by DPTI?

Who is responsible for it then ?

The contractor.

[ghs]

Isn't this a design and construct project, so how is this a "stuff up" by DPTI?

Who is responsible for it then ?

The contractor.

I am sorry but I don't accept that argument. DPTI shouldn't be contracting work out to a business that isn't professional.
They will now need to remove all of the shortcrete causing major delays to the project. Royal Adelaide Hospital type
problems all over again.