City masonry wall collapse was completely preventable

Was this failure risk preventable?

The truth is plain thin cantilever masonry walls without specific propping  are unsafe and can blow over.  Masonry walls are particular dangerous during construction during the initial setting of the mortar.

I will add more discussion notes for this event.  Hopefully Work Place Health and Safety Departments nation wide are looking over similar site situations which are fairly common in urban renewal projects.  Buildings or parts of buildings that remain after demolition works are complete should be seen as dangerous and unstable.


melbournecitycouncil.blogspot.com.au

Sky News: Wall near 'failure' months before fall

Sky News: No permit for fallen wall hoarding

Update:
Builder Grocon-charged-over-fatal-wall-collapse-in-melbourne

Near fatal deck collapse

This time last week we saw another potentially fatal deck collapse in Lane Cove NSW.

Locally in Queensland we have had two recent failures at Morayfield in October 2009 and one at Ascot in November 2008.

Based on inspection sampling results from Victoria 2% of the decks constructed for residential use have serious design flaws which could precipitate a collapse.  8000 decks was estimated Australia wide as a total number of defective or unsafe structures.   That is an enormous level of potential loss, injury or death.

Deck collapses can be fatal but could be prevented with some care and attention.

Should you be concerned?  Queensland with its warm climate is well suited to enjoying outdoor entertaining using an elevated timber deck for parties and family gatherings.

Retaining walls - Today Tonight horror stories from Brisbane

This reinforced keystone wall was built without the reinforcement geogrid

Retaining walls exposed on Today Tonight Channel 7

Whilst conducting a structural inspection on a sub-standard failing retaining wall at a property north of Brisbane Friday last week, the client mentioned watching this program story from Today Tonight (see link above).

Property managers and owners should be aware of the risks retaining walls can pose to their structures.
Domestic pre-purchase building inspectors typically write-out in their disclaimers ."..the condition of retaining walls that may be present at this site are outside the limits of our inspection expertise.  We refer the buyer to seek further advice.."  This note may be embedded in the reports back page fine print and more often than not its passed over or noted and then just ignored.

Ex-cyclone Oswald damage in Brisbane

This outer Brisbane suburban shopping centre car-park shade structure failed

 during the ex-cyclone passage.  Given the relatively low 125km/hr gust speeds when

compared to the structures intended higher design gust speeds

we suspect a poor connection design has initiated early tube buckling failure.

 Water retention within the roof membrane (failed) was also noted as a potential contributor.

Ex-tropical cyclone Oswald moves through southeast Queensland

Gusts of approximately 125km/hr are quite noticeable in Brisbane (as predicted by the passing of ex-cyclone Osward ) but are well below the design cyclonic wind speeds that our houses are designed to withstand.  In a residential area of a typical Brisbane suburb set in flat surrounding terrain the Australian design standards would allow gust wind speeds to peek up to 144km/hr.  Exposed house sites on ridge lines or adjacent to open parks may be designed for gusts of 180km/hr.

Large exposed structures in a public places should also be designed to withstand significantly high wind speeds.  The early beam buckling failure of the shade structured pictured above suggests that its performance has been adversely reduced by a poor connection design detail.

The well known fact that most structural failures originate from poor connection design appears to be proven yet again in this instance.  From my experience connection design was given very little treatment in undergraduate course structural subjects.  There is something quite wrong about this lack of specific course treatment.

Structural damage presented by flooding in Queensland

Photograph: Blake Bodycote/EPA per Guardian story link below.

Structural damage resulting from flooding events in Queensland.

Aside from the debris and mud laden sludge that follows a severe flood event what serious structural problems may develop for a home building in Queensland?

Earlier Queenslander style colonial houses that are supported on stumps can be subject to uneven settlement following flood events.  These early period homes were originally constructed with buried timber post stumps hand placed into a hand excavated hole and backfilled with rammed soil backfill all by hand.  This construction technique was applied without site soil testing with mixed results as one would expect – one stump depth may not suit all home sites.

Looking for truth or looking for blame and lawyer fees - Flood dam operations to go to court

Wivenhoe victims deserve their day in court | The Australian

Headley Thomas has noted the courts are needed to sort out how the Dam should have been operated.  I would have thought the best way to get to the truth would have been to allow the Dam manual and the event hydrology to be modeled by professionals outside of the State's jurisdiction and allow their modelling and reporting to answer all of the difficult questions that have arisen.

A court room battle is about finding a party at fault to apportion blame, for the purpose of seeking compensation and paying lawyer fees.  The money would be best spent with the use of independent engineers from Universities in N.S.W or Victoria to seek the truth without fear or favor or "no win no fee" foreshadowing the success of their efforts.

www.floodcommission.qld.gov.au/__data/assets/pdf_file/0011/11720/QFCI-Final-Report-Chapter-16-Operation-of-Wivenhoe-and-Somerset-dams.pdf

Structural failure of shop awning on Gold Coast indicates poor design

A large awning on James Street, Burleigh Heads, collapsed leaving one man dead and several injured. Police question witnesses. Picture: Kit De Guymer - Courier Mail online picture source

This tragic awning failure claimed the life of a local developer Chis Walton and injured 5 others just near Christmas on the 23rd of December 2012.

Shop awnings are typically supported with cantilevering beams projected out from the adjacent shop building.  Other common awning support systems will rely on steel tie rods connected higher up on the shop's external wall to support a projected awning structure above the footpath.

In this case it would appear that two primary cantilevered concrete block masonry beams have been provided for awing support. Awing roof and ceiling cladding has been simply connected to minor spanning beams between a main large steel beam located at the street side external edge.

Photos indicate some surface portions of the concrete blocks have become dislodged from the ends of the cantilevered block masonry beams.  Some corrosion of the steel beam supports is also visible with only two or three minor bolt fixing present.  It is clear this connection has failed.

This failure is likely to be the result of a combination of factors.  Fixture corrosion may have reduced the available bolt shank section capacity. Rusting bolts may have also added expansive forces at the sites of these fixings into the face of the brittle concrete block units.  Once this expansive rust force can cause the surrounding concrete masonry face to crack failure may be expected.