Thursday, 31 January 2013

Structural damage presented by flooding in Queensland

Australia floods
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.

Tuesday, 22 January 2013

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

Thursday, 17 January 2013

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.