Over the last week, TV news reported why CTV multi-storey, Madras St / Cashel St, collapsed during 22 February quake, killing 115 people. Yet across the road, IRD multi-storey stood firm during 4 major quakes.
TV reporter went to USA, speaking to a US bldg expert who experimented on quake shaking of modern bldgs. He opined that CTV collapsed, as reinforcing steel was not strong enough in concrete columns, which collapsed & steel reinforcement mesh in concrete floors breaking at weld joins & sheared joins to the concrete lift shaft. Pity CTV lift shaft was demolished soon after the rest of CTV site was rubble cleared. That stopped any forensic investigation.
Before 22 February quake, people who'd worked in CTV multi-storey complained the bldg shook when heavy vehicles passed. That was long after 4 September Quake, M7.1, & after Christchurch City Council green stickered CTV 3x! Were other Christchurch modern bldgs in such parlous state too? Since quakes, bldg 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: Mon 21.08.11. Northlands Mall, north-western carpark: I noticed 100s of plastic injection nipples glued on concrete cracks, on 3 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 2 concrete roofs / floors above.
I saw plastic injection nipples on concrete columns, south side of the carpark bldg near the lift shaft.
1980s: In SA I'd worked for DeBeers mining company, writing job descriptions for Paterson Job Evaluation meetings. A job descriptions I wrote was Roofbolt Installer: A mining team of rock drillers drilled holes in mine tunnel roofs, installing long, steel roofbolts, pinning, holding up rocky roofs, obviating tunnel collapse. I'd seen those roofbolts installed on Moncks Bay cliff side, Main Rd, & Sumner cliff side, Nayland St, to stop rockfalls on housing below. Rock roofbolts reminded me of plastic injection nipples I saw at Northlands Mall carpark.
During my trekking around broken Christchurch over the last months, I'd seen several crushed cars, crunched by fallen bricks & 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 had collapsed.
Tues. 23.08.11. Around midday I went for a last shop at Northlands Mall, Pak 'n Save & a closer look at undercover parking. What I found:
Langdons Rd side, Northlands Mall, NW, ground floor carpark: Hundreds of plastic injection nipples, each about 3cm 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, NW, first floor, carpark: No plastic nipples. 9 central, flat concrete columns, each with a thick blue horizontal stripe around the yellow painted column. Alarming that each column, near the roof, had two horizontal strips of recently cut concrete filled with new cement, like someone 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, NW, first floor carpark, S 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 bldg, 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, NE carpark: A stream by the north side of the carpark. Ground floor, fewer plastic nipples on horizontal roof / floor beams. 6 concrete columns, south side, 3 cnr 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, NE carpark: First floor, middle horizontal concrete roof beams OK, white painted, some with recent, patchy cement repairs.
Sissons Rd side, NE carpark: First floor, south side, outside, 6 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-constructed driveway. Polystyrene expansion / contraction filler, 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 outside, one wearing an orange, Hi-Vis vest, another wearing a yellow, Hi-Vis vest, "WATERPROOFING" label on his back. Double speak: Leak proofing, quake cracked concrete.
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 2 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 steel inside concrete. After 4 XL quakes & 8 000 aftershocks, I would shop elsewhere.
*Trekked Langdons Rd, Sissons Rd. 74 snaps.
Coda:
Post 23 December Xmas Quake Swarm, 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, 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, Public Library would be closed. On nearby Main Nth Rd, National Bank would be closed for safety checking.
03.02.12 Steel mesh fence cordoned carpark, Northlands Mall, Langdons Rd |
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 metal beams & scaffolding. Workmen continued epoxy resin glueing. 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 quake, why did Northlands Mall & engineers take so long installing steel brackets? Meanwhile 1000s of drivers used the cracked carparks.
Post quakes, that expediency was experienced all over Christchurch. Broken roads & 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 bldg 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.
Thurs 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 quake strengthened.
Early memory of damages, morning, 04 September Quake, M7.1: Papanui HS reservoir spewing stones & water across Langdons Rd, between the school & Northlands Mall, Langdons Rd, NW carpark.
Trouble with pre-quakes, bldg codes: Council allowed bldg owners to quake-strengthen bldgs a fraction of the current bldg code, many years to do so. Those bldg codes & slow strengthening of bldgs, if any, would prove lethal. Why did engineers take more than a year post 22 February Quake, M7.1, to effect closure, only after revision of bldg codes / standards?
Only reason why Council, engineers, bldg owners pulled finger, was they were being named & shamed at the Royal Commission of Inquiry, as to why so many Christchurch bldgs 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..."
Snag with bldg codes / standards: 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 bldgs to get their bldgs up to 30% code over 30 years. That fraction over years proved "She'll be right" fatal. Many CBD bldgs failed in 22 February quake, M6.3, killing 185 people, some outside the CBD.
Hence Christchurch red zone CBD became post-quake, CERA wasteland, hundreds of demolitions, as some damaged bldgs were too expensive to strengthen & repair. Bldg owners, engineers, Council had much to answer for.
Oct 2012. Like Northlands Mall carpark, quake cracks in many concrete bldgs around Christchurch had been epoxy glued. How effective would epoxy glue repairs be in future quakes?
Mar 2013. Northlands Mall carpark looked flash, cracks painted over. Mall bldg grubby, some shops board-cordoned inside. Many post-quake bldgs 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