Facade of the Repertory Theatre ended on the ground following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Facade of the Repertory Theatre ended on the ground following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Masonry gable of the Christchurch School of Music broke off during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
This building at the Barbadoes Street / St Asaph Street intersection was so badly gamaged it had to be demolished.
Quake-damaged shops on Manchester Street; aftermath of the magnitude 7.1 earthquake that struck Christchurch on Saturday 3 September 2010.
Rescue services out in full force at the Christchurch Arts Centre following the magnitude 7 earthquake in Christchurch on Saturday 4-9-2010.
This 2 storey building has been condemned after its roof collapsed during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Front parapet of this building toppled onto Moorhouse Ave; aftermath of a magnitude 7.1 earthquake that struck Christchurch on 4 September 2010.
These diggers finished off what the quake failed to completely destroy; aftermath of the magnitude 7.1 earthquake that struck Christchurch on Saturday 4 September 2010.
Quake-damaged shops on Manchester Street; aftermath of the magnitude 7.1 earthquake that struck Christchurch on Saturday 3 September 2010.
Quake-damaged shops on Manchester Street; aftermath of the magnitude 7.1 earthquake that struck Christchurch on Saturday 3 September 2010.
Car damaged by the collapse of the building parapet following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
No traffic on Tuam Street which was in the area cordoned off following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
This 2 storey building has been condemned after its roof collapsed during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
I could have sworn there was another storey above the corner shop; aftermath of a magnitude 7.1 earthquake that struck Christchurch on 4 September 2010.
Cross cracks in the brick wall of St Elmo Courts apartment block at the Hereford Street / Montreal Street intersection.
Quake-damaged shops on Manchester Street; aftermath of the magnitude 7.1 earthquake that struck Christchurch on Saturday 3 September 2010.
Hostel along Bealey Ave with its chimney missing afetr the magnitude 7.1 earthquake that struck Christchurch on Saturday 4 September 2010.
Part of the parapet of this building was shaken loose by the magnitude 7.1 earthquake that hit Christchurch on 4 September 2010.
Part of the parapet of this building was shaken loose by the magnitude 7.1 earthquake that hit Christchurch on 4 September 2010.
St John the Baptist Church at Latimer Square in the aftermath of the magnitude 7.1 earthquake that struck Christchurch on 4 September 2010.
St John the Baptist Church at Latimer Square in the aftermath of the magnitude 7.1 earthquake that struck Christchurch on 4 September 2010.
This house along Bealey Ave lost its chimney stack in the magnitude 7.1 earthquake that struck Christchurch on Saturday 4 September 2010.
The front and side walls of this Christchurch building had completely collapsed after being struck by the the magnitude 7,1 earthquake on 4 September 2010.
This hostel along Bealey Ave lost its chimney stack in the magnitude 7.1 earthquake that struck Christchurch on Saturday 4 September 2010.
This manuscript provides a critical examination of the ground motions recorded in the near-source region resulting from the 22 February 2011 Christchurch earthquake. Particular attention is given to reconciling the observed spatial distribution of ground motions in terms of physical phenomena related to source, path and site effects. The large number of near-source observed strong ground motions show clear evidence of: forward-directivity, basin generated surface waves, liquefaction and other significant nonlinear site response. The pseudo-acceleration response spectra (SA) amplitudes and significant duration of strong motions agree well with empirical prediction models, except at long vibration periods where the influence of basin-generated surface waves and nonlinear site response are significant and not adequately accounted for in empirical SA models. Pseudo-acceleration response spectra are also compared with those observed in the 4 September 2010 Darfield earthquake and routine design response spectra used in order to emphasise the amplitude of ground shaking and elucidate the importance of local geotechnical characteristics on surface ground motions. The characteristics of the observed vertical component accelerations are shown to be strongly dependent on source-to-site distance and are comparable with those from the 4 September 2010 Darfield earthquake, implying the large amplitudes observed are simply a result of many observations at close distances rather than a peculiar source effect.
The aim of this report is to investigate the ductile performance of concrete tilt-up panels reinforced with cold-drawn mesh to improve the current seismic assessment procedure. The commercial impact of the project was also investigated. Engineering Advisory Group (EAG) guidelines state that a crack in a panel under face loading may be sufficient to fracture the mesh. The comments made by EAG regarding the performance of cold-drawn mesh may be interpreted as suggesting that assessment of such panels be conducted with a ductility of 1.0. Observations of tilt-up panel performance following the Christchurch earthquakes suggest that a ductility higher than μ=1.0 is likely to be appropriate for the response of panels to out-of-plane loading. An experimental test frame was designed to subject ten tilt-panel specimens to a cyclic quasi-static loading protocol. Rotation ductility, calculated from the force-displacement response from the test specimens, was found to range between 2.9 and 5.8. Correlation between tensile tests on 663L mesh, and data collected from instrumentation during testing confirmed that the mesh behaves as un-bonded over the pitch length of 150mm. Recommendation: Based on a moment-rotation assessment approach with an un-bonded length equal to the pitch of the mesh, a rotation ductility of μ=2.5 appears to be appropriate for the seismic assessment of panels reinforced with cold-drawn mesh.
The abundance of cone penetration test (CPT) data from subsurface explorations in Christchurch and the surrounding areas provides a useful source of information for a characterization of the near surface shear wave velocity ( ) profile for the region. A portion of the investigations were conducted using seismic CPT, enabling the comparison of measured shear wave velocity with CPT data, and subsequently the evaluation of existing CPT- correlations for applicability to Canterbury-specific soils. The existing correlations are shown to be biased, generally over-predicting the observed with depth, thus demonstrating the need for a Canterbury-specific CPT- correlation.
A one story, two bays, approximately half scaled, perimeter moment frame containing precastprestressed floor units was built and tested at the University of Canterbury to investigate the effect of precastprestressed floor units on the seismic performance of reinforced concrete moment resisting frame. This paper gives an overview of the experimental set up and summarizes the results obtained from the test. The results show that elongation in the beam plastic hinges is partially restrained by the prestressed floor, which increases the strength of the beams much more than that being specified in the codes around the world.
The susceptibility of precast hollow-core floors to sustain critical damage during an earthquake is now well-recognized throughout the structural engineering community in New Zealand. The lack of shear reinforcement in these floor units is one of the primary reasons causing issues with the seismic performance of these floors. Recent research has revealed that the unreinforced webs of these floor units can crack at drift demands as low as 0.6%. Such observation indicates that potentially many of the existing building stock incorporating hollow-core flooring systems in cities of relatively high seismic activity (e.g. Wellington and Christchurch) that probably have already experienced a level of shaking higher than 0.6% drift in previous earthquakes might already have their floor units cracked. However, there is little information available to reliably quantify the residual gravity load-carrying capacity of cracked hollow-core floor units, highlighting the need to understand the post-cracking behavior of hollow-core floor units to better quantify the extent of the risk that cracked hollow-core floor units pose.