Six ½ years after the earthquakes there are still a few demolitions taking place. This one is a block of council owned flats. Whether the whole complex is being demolished or not I don't know., but here the centre block of three is being demolished. The green grass is what was sections and houses demolished in 2012-2015 as it is too close to t...
A Phoenis Palm (Phoenix canariensis) that was in someone's back yard prior to the demolition of houses post the 2011 earthquake.
Earthquake demolition work in Christchurch has made way for an urban farm that is equipping young people with life and work skills.
An impressive Cabbage Tree (Cordyline australis) that was in someone's back yard prior to the demolition of houses post the 2011 earthquake.
Way back in the winter of 2012, at the height of the post-earthquake demolition, I was pretty excited to learn we were going to get the chance to investigate the site of John and Charlotte Godley’s house in Lyttelton. John … Continue reading →
The Christchurch City Council has confirmed the demolition of the earthquake-damaged Lancaster Park sports stadium will begin this year. Lancaster Park Cricket club was one of the sports ground's first tenants when it was established in 1881. An act of parliament means the ground has to be used for sport and recreation. "We're certainly looking foward to being able to get back on the ground and for it to be turned back into green space," Ric Horsfall from the cricket club says.
The 2010–2011 Canterbury earthquakes, which involved widespread damage during the February 2011 event and ongoing aftershocks near the Christchurch Central Business District, left this community with more than $NZD 40 billion in losses (~20 % GDP), demolition of approximately 60 % of multi-storey concrete buildings (3 storeys and up), and closure of the core business district for over 2 years. The aftermath of the earthquake sequence has revealed unique issues and complexities for the owners of commercial and multi-storey residential buildings in relation to unexpected technical, legal, and financial challenges when making decisions regarding the future of their buildings impacted by the earthquakes. The paper presents a framework to understand the factors influencing post-earthquake decisions (repair or demolish) on multi-storey concrete buildings in Christchurch. The study, conducted in 2014, includes in-depth investigations on 15 case-study buildings using 27 semi-structured interviews with various property owners, property managers, insurers, engineers, and government authorities in New Zealand. The interviews revealed insights regarding the multitude of factors influencing post-earthquake decisions and losses. As expected, the level of damage and repairability (cost to repair) generally dictated the course of action. There is strong evidence, however, that other variables have significantly influenced the decision on a number of buildings, such as insurance, business strategies, perception of risks, building regulations (and compliance costs), and government decisions. The decision-making process for each building is complex and unique, not solely driven by structural damage. Furthermore, the findings have put the spotlight on insurance policy wordings and the paradoxical effect of insurance on the recovery of Christchurch, leading to other challenges and issues going forward.
Capacity design and hierarchy of strength philosophies at the base of modern seismic codes allow inelastic response in case of severe earthquakes and thus, in most traditional systems, damage develops at well-defined locations of reinforced concrete (RC) structures, known as plastic hinges. The 2010 and 2011 Christchurch earthquakes have demonstrated that this philosophy worked as expected. Plastic hinges formed in beams, in coupling beams and at the base of columns and walls. Structures were damaged permanently, but did not collapse. The 2010 and 2011 Christchurch earthquakes also highlighted a critical issue: the reparability of damaged buildings. No methodologies or techniques were available to estimate the level of subsequent earthquakes that RC buildings could still sustain before collapse. No repair techniques capable of restoring the initial condition of buildings were known. Finally, the cost-effectiveness of an eventual repair intervention, when compared with a new building, was unknown. These aspects, added to nuances of New Zealand building owners’ insurance coverage, encouraged the demolition of many buildings. Moreover, there was a perceived strong demand from government and industry to develop techniques for assessing damage to steel reinforcement bars embedded in cracked structural concrete elements. The most common questions were: “Have the steel bars been damaged in correspondence to the concrete cracks?”, “How much plastic deformation have the steel bars undergone?”, and “What is the residual strain capacity of the damaged bars?” Minimally invasive techniques capable of quantifying the level and extent of plastic deformation and residual strain capacity are not yet available. Although some studies had been recently conducted, a validated method is yet to be widely accepted. In this thesis, a least-invasive method for the damage-assessment of steel reinforcement is developed. Based on the information obtained from hardness testing and a single tensile test, it is possible to estimate the mechanical properties of earthquake-damaged rebars. The reduction in the low-cycle fatigue life due to strain ageing is also quantified. The proposed damage assessment methodology is based on empirical relationships between hardness and strain and residual strain capacity. If damage is suspected from in situ measurements, visual inspection or computer analysis, a bar may be removed and more accurate hardness measurements can be obtained using the lab-based Vickers hardness methodology. The Vickers hardness profile of damaged bars is then compared with calibration curves (Vickers hardness versus strain and residual strain capacity) previously developed for similar steel reinforcement bars extracted from undamaged locations. Experimental tests demonstrated that the time- and temperature-dependent strain-ageing phenomenon causes changes in the mechanical properties of plastically deformed steels. In particular, yield strength and hardness increases, whereas ductility decreases. The changes in mechanical properties are quantified and their implications on the hardness method are highlighted. Low-cycle fatigue (LCF) failures of steel reinforcing bars have been observed in laboratory testing and post-earthquake damage inspections. Often, failure might not occur during a first seismic event. However, damage is accumulated and the remaining fatigue life is reduced. Failure might therefore occur in a subsequent seismic event. Although numerous studies exist on the LCF behaviour of steel rebars, no studies had been conducted on the strain-ageing effects on the remaining fatigue life. In this thesis, the reduction in fatigue life due to this phenomenon is determined through a number of experimental tests.
The major earthquakes of 2010 and 2011 brought to an abrupt end a process of adaptive reuse, revitalisation and gentrification that was underway in the early 20th century laneways and buildings located in the south eastern corner of the Christchurch Central Business District. Up until then, this location was seen as an exemplar of how mixed use could contribute to making the central city an attractive and viable alternative to the suburban living experience predominant in New Zealand. This thesis is the result of a comprehensive case study of this “Lichfield Lanes” area, which involved in depth interviews with business owners, observation of public meetings and examination of documents and the revitalisation research literature. Findings were that many of the factors seen to make this location successful pre-earthquakes mirror the results of similar research in other cities. These factors include: the importance of building upon historic architecture and the eclectic spaces this creates; a wide variety of uses generating street life; affordable rental levels; plus the dangers of uniformity of use brought about by focussing on business types that pay the most rent. Also critical is co-operation between businesses to create and effectively market and manage an identifiable precinct that has a coherent style and ambience that differentiates the location from competing suburban malls. In relation to the latter, a significant finding of this project was that the hospitality and retail businesses key to the success of Lichfield Lanes were not typical and could be described as quirky, bohemian, chaotic, relatively low rent, owner operated and appealing to the economically important “Creative Class” identified by Richard Florida (2002) and others. In turn, success for many of these businesses can be characterised as including psychological and social returns rather than simply conventional economic benefits. This has important implications for inner city revitalisation, as it contrasts with the traditional focus of local authorities and property developers on physical aspects and tenant profitability as measures of success. This leads on to an important conclusion from this research, which is that an almost completely inverted strategy from that applied to suburban mall development, may be most appropriate for successful inner city revitalisation. It also highlights a disconnection between the focus and processes of regulatory authorities and the outcomes and processes most acceptable to the people likely to frequent the central city. Developers are often caught in the middle of this conflicted situation. Another finding was early commitment by businesses to rebuild the case study area in the same style, but over time this waned as delay, demolition, insurance problems, political and planning uncertainty plus other issues made participation by the original owners and tenants impossible or uneconomic. In conclusion, the focus of inner city revitalisation is too often on buildings rather than the people that use them and what they now desire from the central city.