Flowers float down the Avon River during the River of Flowers memorial event. In the background, residents and workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
A dragon boat is rowed along the river during the River of Flowers memorial event. In the background, workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
Flowers float down the Avon River during the River of Flowers memorial event. In the background, residents and workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
Flowers float down the Avon River during the River of Flowers memorial event. In the background, residents and workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
A woman with a megaphone speaks to gathered residents at the River of Flowers memorial event. In the background, workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
Residents gathered for the River of Flowers memorial event watch a dragon boat being rowed along the river. In the background, workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
A woman with a megaphone speaks to gathered residents at the River of Flowers memorial event. In the background, workers look on. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
Photographs of central Christchurch after the 2010-2012 earthquakes taken 25 February 2012 by Sean McMahon. Locations are chiefly Manchester, Saint Asaph, Cashel, Columbo and Lichfield Streets, and the Bridge of Remembrance. Images show fencing around areas closed to the public, damaged and collapsed commercial buildings, cleared sites, re-opened Cashel Street area with shops and a cafe. Source of title - Title supplied by Library Quantity: 34 digital photograph(s).
With the land dropping about 1metre to 1.4metres after the earthquakes, a few roads besides the Avon and Heathcote Rivers are flooded with very high tides. Extra stop banks (on right) erected after the quakes have helped, but the road is now well below high water level. New Brighton Road, just short of New Brighton. The Pages Road bridge may b...
Impact between structures of bridge sections can play a major, unexpected role in seismic structural damage. Linear and non-linear models are developed to analyze structural impact and response of two single-degree-of-freedom structures, representing adjacent buildings or bridge sections. The analyses presented assess probability of impact, displacement change due to impact, and the probability of increased displacement due to impact. These are assessed over a matrix of structural periods for each degree-of-freedom, different impact coefficients of restitution, and a probabilistically scaled suite of earthquake events. Linear versus non-linear effects are assessed using a Ramberg-Osgood non-linear model for column inelasticity. The normalized distance, or gap-ratio (GR), defined as a percentage of the summed spectral displacements, is used to create probabilistic design requirements. Increasing GR and structural periods that are similar (T2/T1~0.8-1.25) significantly decrease the likelihood of impact, and vice-versa. Including column inelasticity and decreasing coefficient of restitution decrease displacement increases due to impact and thus reduce potential damage. A minimum GR~0.5-0.9 ensures that any displacement increases will be less than 10% for 90% of ground motions over all structural period combinations (0.2-5.0sec). These results enable probabilistic design guidelines to manage undesirable effects of impact– an important factor during the recent Canterbury, New Zealand Earthquakes.
The small wharf area of the now gone Pleasant Point Yacht Club has already been taken over by the Pied Shags (cormorants). It is under water now except for low tide. Note the dead pine tree in background. Many have died because of the salt water their roots are in.
A linear and non-linear model are developed to analyze the structural impact and response of two single degree of freedom structures, representing adjacent buildings or bridge sections. Different impact coefficients of restitution, normalized distances between structures and a range of different structural periods are considered. The probability of impact and the displacement changes that can result from these collisions are computed. The likelihood of an increase in displacement is quantified in a probabilistic sense. A full matrix of response simulations are performed to individually investigate and delineate the effects of inter-structure gap-ratio, period ratios, structural non-linearity and impact elasticity. Column inelasticity is incorporated through the use of a Ramberg-Osgood type hysteresis rule. The minimum normalized distance, or gap-ratio, required between two structures to ensure that the likelihood of increased displacement of more than 10% for either structure for 90% of the given earthquake ground motions is assessed as one of many possible design risk bounds. Increased gap ratio, defined as a percentage of spectral displacement, is shown to reduce the likelihood of impact, as well as close structural periods. Larger differences in the relative periods of the two structures were seen to significantly increase the likelihood of impact. Inclusion of column inelasticity and higher plasticity of impact reduce displacement increases from impact and thus possible further damage to the structures. Such information can be used as a guideline to manage undesirable effects of impact in design - a factor that has been observed to be very important during the recent Canterbury, New Zealand Earthquakes.