Over the last week, TV news reported why CTV multi-storey, Madras St / Cashel St, collapsed during 22 February 2011 Quake, killing 115 people. Yet across the road, IRD multi-storey stood firm during four major quakes so far.
A TV reporter went to USA, speaking to a US building expert who experimented on quake-shaking of modern buildings. He opined that CTV collapsed, as reinforcement-steel was not strong enough in concrete-columns, which collapsed & reinforcement-steel-mesh in concrete-floors broke at weld-joins which sheared joins to the concrete lift-shaft. Pity the CTV lift-shaft was demolished soon after the rest of CTV site was rubble- cleared. That stopped any forensic investigation!
Before the 22 February 2011 Quake, people who'd worked in CTV multi-storey complained the building shook when heavy vehicles passed. That was long after 4 September 2010 Quake, M7.1, & after Christchurch City Council green-stickered CTV three times! Were more modern bldgs in such a parlous state too? Since quakes, building-codes would be revised to obviate such a disaster again.
Over recent weeks I saw many small cracks in Northlands Mall undercover-carpark, ground floor, on concrete-columns & concrete-roof / floor beams. Cracks were cleaned, making roof / floor beams look like zebra-stripes, scores of squiggly, vertical stripes on horizontal concrete- beams.
Langdons Rd: Monday 21.08.11. Northlands Mall, north-western carpark: I noticed 100s of plastic-injection-nipples glued on concrete-cracks, on three sides of white-painted concrete-beams, presumably to strengthen horizontal concrete-roof / floor beams. Those ground-floor concrete-roof / floor beams carried great weight, as the carpark continued upwards, two concrete-roofs / floors above.
I saw plastic-injection-nipples on concrete-columns, south side of the carpark building near the lift-shaft.
During my quake-trekking, I'd seen long, steel roofbolts installed on Moncks Bay cliff-side, Main Rd, & Sumner cliff-side, Nayland St, to stop rockfalls on housing below. As rock strengtheners, hose rock roofbolts reminded me of much smaller plastic-injection-nipples I saw at Northlands Mall carpark.
During my quake-trekking, I'd seen several crushed cars, crunched by fallen-bricks & fallen-concrete. I'd seen leaning blocks of flats, with leaning undercover-parking, a crushed car under a Springfield Rd block of flats where undercover-parking collapsed!
Tuesday 23.08.11. Around midday I went for my last shoping at Northlands Mall's Pak 'n Save & a closer look at undercover-parking. What I found:
Langdons Rd side, Northlands Mall, northwest ground-floor carpark: Hundreds of plastic-injection-nipples, each about three centimetre diameter with a central screw & nipple on top, glued to grey-filler on concrete-column cracks & roof / floor concrete-beam cracks. Plastic-injection-nipples were sold at Bunnings, $4.95 each.
23.08.11. Plastic, injection nipples (left broken) with grey filler, Northlands Mall carpark, post June 13 quake
23.08.11. Back entrance, Northlands Mall, north-west carpark, Langdons Rd, post June 13 quake
23.08.11. Injection nipples & filler on outside quake cracks, first floor, north-west carpark, concrete driveway, Northlands Mall, Langdons Rd, post June 13 quake
23.08.11. Injection nipples & filler on outside quake cracks, north-west wall, concrete column, supporting first floor, concrete carpark driveway, Northlands Mall, Langdons Rd, post June 13 quake
23.08.11. Injection nipples & filler on inside quake cracks, north-west wall, concrete column, supporting first floor, concrete park driveway, Northlands Mall, Langdons Rd, post June 13 quake
23.08.11. Injection nipples & filler on quake cracks, ground floor, north-west concrete roof, Northlands Mall carpark, Langdons Rd, post June 13 quake
23.08.11. Quake cracks ready for filler, central concrete roof beam, ground floor, north-west carpark, Northlands Mall, Langdons Rd, post June 13 quake
23.08.11. Injection nipples & filler, central concrete roof beam, ground floor, north-west carpark, Northlands Mall, Langdons Rd, post June 13 quake
23.08.11. Quake cracked cnr column, ready for filler, Langdons Rd, north-west carpark entrance, Northlands Mall, post June 13 quake
23.08.11. Nr Langdons Rd, injection nipples & filler on concrete southern wall in lift alley, north-west carpark outside concrete wall, Northlands Mall, post June 13 quake
23.08.11. Langdons Rd view, quake cracked, central concrete, roof beam, ground floor, north-west carpark, Northlands Mall, post June 13 quake
23.08.11. Langdons Rd side view, Northlands Mall entrance, with injection nipples on filler, inside north-west, concrete column & roof beam, post June 13 quake
23.08.11. Nr Langdons Rd, injection nipples on filler, inside southern concrete roof beam, ground floor, north-west carpark, Northlands Mall, post June 13 quake
23.08.11. Quake cracked, central concrete roof beam, ready for filler, ground floor, north-west carpark, Northlands Mall, post June 13 quake
Langdons Rd side, northwest first-floor carpark: No plastic-nipples. Nine central, flat concrete-columns, each with a thick blue horizontal stripe around the yellow-painted column. It was alarming that each column near the roof had two horizontal strips of recently cut concrete filled with new cement, like someone had angle-grinded investigation slits through each column then sealed with cement, exactly the same height on each column.
23.08.11. Horizontal slits on yellow, central concrete columns, near concrete & / or steel roof beams. Horizontal slits sealed with cement in all 9 central columns, first floor, north-west carpark, Northlands Mall, post June 13 quake
Langdons Rd side, northwest first-floor carpark, south wall: 11 white-painted concrete-pillars, each with fine cracks, gutter-pipes attached with drain holes by each pillar. Two more pillars beyond, both ends of the building, without drain-pipes.
23.08.11. Cement repaired, quake cracked, southern concrete column, with gutter pipe, first floor, north-west carpark, Langdons Rd entrance, Northlands Mall, post June 13 quake
Sissons Rd side, Northlands Mall, northeast carpark: A stream by the north side of the carpark. Ground-floor, fewer plastic- nipples on horizontal roof / floor beams. Six concrete-columns, south side, three corner concrete-columns had plastic-nipples glued to cracks.
23.08.11. Injection nipples & filler on ground floor quake cracks, cnr concrete column & roof beam, north-east carpark, Sissons Rd side, Northlands Mall, post June 13 quake
23.08.11. Injection nipples on concrete filler, outside cnr column, first floor, north-east carpark, Sissons Rd side, Northlands Mall, post June 13 quake
23.08.11. Quake cracks & some filler repairs on concrete column & roof beam, gutter pipe attached, north-east ground floor carpark, Northlands Mall, post June 13 quake
Sissons Rd side, northeast carpark: First-floor, middle horizontal concrete roof-beams were OK, white-painted, some with recent, patchy cement repairs.
Sissons Rd side, northeast carpark: First-floor, south side, outside, six concrete columns, more plastic-nipples glued to filled cracks.
23.08.11. Nr Sissons Rd, injection nipples on filler, southern, outside, concrete column, first floor, north-east carpark, Northlands Mall, post June 13 quake
23.08.11. Nr Sissons Rd, quake cracked, concrete column & repair, with gutter pipe & drain, first floor, North-east carpark, Northlands Mall, post June 13 quake
Near driveway exit: cracked concrete-footpath, polystyrene-filler between carpark floor & side driveway. The polystyrene-filler was covered with a steel-strip.
23.08.11. Polystyrene filler between first floor, north-east carpark & driveway join, by quake spalled, concrete footpath, Northlands Mall, post June 13 quake
Two workmen were outside, one wearing an orange, Hi-Vis vest, another wearing a yellow, Hi-Vis vest, a WATERPROOFING" label on his back. Double-speak for leak-proofing quake-cracked concrete!br />
26.10.11. Sissons Rd entrance, north-east carpark showing stream along north side of the car park, Northlands Mall
Quakes or no quakes, why did all that cracked-concrete on two carpark ground-floor & first-floor roof / floor beams & support-columns need leak-proofing?
I disliked tons of cracked-concrete glued by epoxy-resin above my head! Never mind weakened rebars inside concrete! After four XL quakes & 8 000 aftershocks, I would shop elsewhere.
*Trekked Langdons Rd, Sissons Rd. 74 snaps.
Coda:
Post 23 December Xmas Quake Swarm 2011, including M5.8, M5.3, M6.0 quakes, Northlands Mall undercover carpark would be closed & steel-mesh- fence-cordoned for safety-checking. Langdons Rd entrance's glass-sliding-doors were broken & boarded. Why did planners, engineers, architects, builders continue using glass-sliding-doors in a quake zone? In power-cuts glass-sliding-doors jammed closed. Imagine the mayhem.
Across Langdons Rd, the Public Library would be closed. On nearby Main Nth Rd, National Bank would be closed for safety-checking.
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| 03.02.12 Steel mesh fence cordoned carpark, Northlands Mall, Langdons Rd |
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| 03.02.12 Steel mesh fence cordoned carpark signs, Northlands Mall, Langdons Rd |
03.02.12. Post 10 000 quakes, I would take a closer look at the Langdons Rd carpark, still steel-mesh-fence-cordoned. Concrete-beams on both carpark floors were supported by steel-beams & scaffolding. Workmen continued epoxy-resin glueing. A steel-mesh-fence-cordon sign:
CARPARK CLOSED
AS A
PRECAUTIONARY
MEASURE THIS
CARPARK IS
CLOSED UNTIL
FURTHER SAFETY
CHECKS HAVE BEEN
COMPLETED
 |
| 03.02.12. Steel mesh fence cordoned carpark sign, Northlands Mall, Langdons Rd |
Mon 13.02.12. En route to the bank, trekking past Langdons Rd carpark, I saw steel-brackets were bolted from each roof / floor, concrete-panel to middle & side concrete-beams of ground-floor & first-floor of the Langdons Rd carpark, scores of steel-brackets. Thus many roof / floor concrete panels were bracket-bolted to already cracked & epoxied concrete-beams. Nearly a year post 22 February 2011 Quake, why did Northlands Mall & engineers take so long installing steel-brackets? Meanwhile 1000s of drivers had used the cracked carparks.
Post-quakes, that expediency was experienced all over Christchurch. Broken-roads & broken-bridges were used for years, until closed & / or detoured for lengthy repairs by SCIRT. Short of abandoning Christchurch as a health-hazard, Christchurch citizens just got on with it. My attitude: If a building or bridge hadn't fallen in 1000s of quakes, it would never fall.
Despite many EXTREME DANGER demolition, construction & rebuild signs, on the contrary, normal Health & Safety requirements in Christchurch were suspended for years post-quakes. Imagine all the sewage bacterial spores, liquefaction-dust, bitumen, asbestos, silicon & brick dust citizens inhaled.
Thursday 15.03.12. The Press reported 14 shops would be closed at Northlands Mall, near Hoyts cinema (closed for months post-quakes) & Langdons Rd carpark, belatedly strengthened.
My first memory of damages on the morning of the 4 September 2010 Quake, M7.1: Papanui High School's reservoir spewed stones & water across Langdons Rd, between the school & Northlands Mall's Langdons Rd northwest carpark.
Trouble with pre-quakes building-codes: Council allowed building-owners to quake-strengthen buildings a fraction of the current building-code, allowing many years to do so. Those nebulous building-codes & slow strengthening of buildings, if any, would prove lethal. Why did engineers take more than a year post 22 February 2011 Quake, M7.1, to effect closure, only after revision of building-codes?
Only reason why Council, engineers & building-owners pulled-finger, was they were being named & shamed at the Royal Commission of Inquiry, as to why so many Christchurch buildings failed in the quakes.
Wed 04.04.12. Luke visited Northlands Mall & found an information notice:
"Kiwi Income Property Trust advises that part of Northlands Shopping Centre is to be strengthened to comply with the new earthquake loadings standard now applicable in Christchurch.
14 out of Northlands 126 shops will be closed while the strengthening work is carried out. The Centre and remaining 112 stores will continue to trade as normal.
Although this may cause inconvenience, Northlands has performed well throughout the prolonged period of earthquakes and aftershocks with moderate damage only. Strengthening work however does need to be conducted in defined areas against the requirements of the New Building Standards.
Canterbury Earthquake Recovery Authority (CERA) has issued notices to more than 7 000 Christchurch building owners to undertake Detailed Engineering Evaluations (DEEs) to assess the performance of their buildings against the requirements of the New Building Standards..."
The snag with building-codes: Codes were regularly revised by engineers pre 2010-2011 quakes, but proved useless in Christchurch quakes, as Council had a laissez-faire attitude to building-codes, allowing owners of old buildings to get their buildings up to 30% code over 30 years! THIRTY YEARS! That fraction over 30 years proved "She'll be right" fatal! Many CBD-buildings failed in 22 February 2011 Quake, M6.3, killing 185 people, some outside the CBD.
Hence Christchurch's red-zone CBD became post-quake CERA wasteland with hundreds of demolitions, as some damaged buildings were too expensive to strengthen & repair. Building owners, engineers & Council had much to answer for!
October 2012. Like Northlands Mall carpark, quake-cracks in many concrete-buildings around Christchurch had been epoxy-glued. How effective would epoxy-glue repairs be in future quakes?
March 2013. Northlands Mall carpark looked flash, cracks painted over. The Mall building was grubby, some shops board-cordoned. Many post-quake buildings in Christchurch had cracks epoxy-glued & painted over!
Content & pics Copyright Mark JS Esslemont.
See Performance of multi-storey concrete buildings in the Darfield Earthquake
See Northlands mall to close 14 shops (The Press / Stuff Co).
We have a lot of cracks being filled at work - with lines of nozzles to allow the injection of some sort of resin.... and big posters everywhere to tell us why...
ReplyDeletedont trust any car parks still, let alone underground ones.
Thanks Fi, spot on. Took a while for me to suss it out.
ReplyDeleteResponded to a local email query about the safety of shops alongside Langdons Rd carpark.
ReplyDelete