Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Glass windows shattered in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Chimney stack toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Mansonry fence toppled by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Glass windows shattered in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Shop parapet toppled in the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Damaged facade? That's the decorative mural of this restaurant located on Manchester Street in Christchurch!
Photograph captioned by Fairfax, "Aftermath of the earthquake in Christchurch where the cleanup has begun. The old Sumner Borough Council building is cordoned because of cracks".
A photograph of a room in the Diabetes Centre which has been walled off using tarpaulins. Cracks in the wall have been filled with epoxy resin.
A photograph of USAR codes spray painted in a window of the former Sydenham Post Office. Cracks can be seen in the masonry around the window.
One of the most controversial issues highlighted by the 2010-2011 Christchurch earthquake series and more recently the 2016 Kaikoura earthquake, has been the evident difficulty and lack of knowledge and guidelines for: a) evaluation of the residual capacity damaged buildings to sustain future aftershocks; b) selection and implementation of a series of reliable repairing techniques to bring back the structure to a condition substantially the same as prior to the earthquake; and c) predicting the cost (or cost-effectiveness) of such repair intervention, when compared to fully replacement costs while accounting for potential aftershocks in the near future. As a result of such complexity and uncertainty (i.e., risk), in combination with the possibility (unique in New Zealand when compared to most of the seismic-prone countries) to rely on financial support from the insurance companies, many modern buildings, in a number exceeding typical expectations from past experiences at an international level, have ended up being demolished. This has resulted in additional time and indirect losses prior to the full reconstruction, as well as in an increase in uncertainty on the actual relocation of the investment. This research project provides the main end-users and stakeholders (practitioner engineers, owners, local and government authorities, insurers, and regulatory agencies) with comprehensive evidence-based information to assess the residual capacity of damage reinforced concrete buildings, and to evaluate the feasibility of repairing techniques, in order to support their delicate decision-making process of repair vs. demolition or replacement. Literature review on effectiveness of epoxy injection repairs, as well as experimental tests on full-scale beam-column joints shows that repaired specimens have a reduced initial stiffness compared with the undamaged specimen, with no apparent strength reduction, sometimes exhibiting higher displacement ductility capacities. Although the bond between the steel and concrete is only partially restored, it still allows the repaired specimen to dissipate at least the same amount of hysteretic energy. Experimental tests on buildings subjected to earthquake loading demonstrate that even for severe damage levels, the ability of the epoxy injection to restore the initial stiffness of the structure is significant. Literature review on damage assessment and repair guidelines suggests that there is consensus within the international community that concrete elements with cracks less than 0.2 mm wide only require cosmetic repairs; epoxy injection repairs of cracks less and 2.0 mm wide and concrete patching of spalled cover concrete (i.e., minor to moderate damage) is an appropiate repair strategy; and for severe damaged components (e.g., cracks greater than 2.0 mm wide, crushing of the concrete core, buckling of the longitudinal reinforcement) local replacement of steel and/or concrete in addition to epoxy crack injection is more appropriate. In terms of expected cracking patterns, non-linear finite element investigations on well-designed reinforced concrete beam-to-column joints, have shown that lower number of cracks but with wider openings are expected to occur for larger compressive concrete strength, f’c, and lower reinforcement content, ρs. It was also observed that the tensile concrete strength, ft, strongly affects the expected cracking pattern in the beam-column joints, the latter being more uniformly distributed for lower ft values. Strain rate effects do not seem to play an important role on the cracking pattern. However, small variations in the cracking pattern were observed for low reinforcement content as it approaches to the minimum required as per NZS 3101:2006. Simple equations are proposed in this research project to relate the maximum and residual crack widths with the steel strain at peak displacement, with or without axial load. A literature review on fracture of reinforcing steel due to low-cycle fatigue, including recent research using steel manufactured per New Zealand standards is also presented. Experimental results describing the influence of the cyclic effect on the ultimate strain capacity of the steel are also discussed, and preliminary equations to account for that effect are proposed. A literature review on the current practice to assess the seismic residual capacity of structures is also presented. The various factors affecting the residual fatigue life at a component level (i.e., plastic hinge) of well-designed reinforced concrete frames are discussed, and equations to quantify each of them are proposed, as well as a methodology to incorporate them into a full displacement-based procedure for pre-earthquake and post-earthquake seismic assessment.
Christchurch woman Lavina Pockson and her family live in a house with big cracks in it, on land that's among the most damaged from the big September earthquake.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Trailer load of fallen debris following the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Masonry debris on the ground following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Roof of this building collapsed during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
This shop lost its side wall when the magnitude 7.1 earthquake struck Christchurch on 4 September 2010.
Tourists checking out destruction caused by the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Collapsed roof and parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
This shop lost its side wall when the magnitude 7.1 earthquake struck Christchurch on 4 September 2010.
Cracked parapet caused by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Cracked parapet caused by the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Outside our house after the 7.1 Richter Canterbury earthquake on September 4 2010
Photograph captioned by Fairfax, "Natalie Thomas' Birchfield Ave home looks unaffected by the earthquake but uneven floors, doors and cracks in the surrounding earth tell another tale".
A video of an interview with Shaun Gladwell, a London-based artist, about the sculptures he designed for the Christchurch central city. Gladwell talks about how the sculptures are based on skateboard forms and have been designed to be used by skateboarders. He also talks about being inspired by YouTube videos of Christchurch skateboarders who used the damaged landscape in Christchurch as a skate park after the 22 February 2011 earthquake. The video includes clips from some of these YouTube videos.