A photograph of an earthquake-damaged building on Manchester Street. The corner of the building has cracks running through the masonry.
A photograph of the earthquake damage to the Registry Building on the corner of Montreal and Worcester Streets. Masonry around the gable has collapsed onto the footpath below. Steel bracing has been used to hold up the remaining masonry. Wire fencing has been placed around the building as a cordon.
A photograph of the earthquake damage to the Registry Building on the corner of Montreal and Worcester Streets. Masonry around the gable has collapsed onto the footpath below. Steel bracing has been used to hold up the remaining masonry. Wire fencing has been placed around the building as a cordon.
A photograph of the earthquake damage to The Press building in Cathedral Square. The top storey of the building has collapsed into the storey below, some of the masonry falling onto the pavement below. Wire fencing has been placed around the building as a cordon.
A building on the corner of Madras Street and Hereford Street, with the Canterbury Television Building visible in the background. Masonry from this building has crumbled onto the footpath below. Fire engines can be seen along Madras Street, combating the fire.
A photograph of an earthquake-damaged building on the corner of Welles and Manchester Streets. Masonry from the top floor of the building has come away and windows have been broken.
Following the magnitude 6.3 aftershock in Christchurch, New Zealand, on 22 February 2011, a number of researchers were sent to Christchurch as part of the New Zealand Natural Hazard Research Platform funded “Project Masonry” Recovery Project. Their goal was to document and interpret the damage to the masonry buildings and churches in the region. Approximately 650 unreinforced and retrofitted clay brick masonry buildings in the Christchurch area were surveyed for commonly occurring failure patterns and collapse mechanisms. The entire building stock of Christchurch, and in particular the unreinforced masonry building stock, is similar to that in the rest of New Zealand, Australia, and abroad, so the observations made here are relevant for the entire world.
During the Christchurch earthquake of February 2011, several midrise buildings of Reinforced Concrete Masonry (RCM) construction achieved performance levels in the range of life safety to near collapse levels. These buildings were subjected to seismic demands higher than the building code requirements of the time and higher than the current New Zealand Loadings Standard (NZS-1170.5:2004). Structural damage to these buildings has been documented and is currently being studied to establish lessons to be learned from their performance and how to incorporate these lessons into future RCM design and construction practices. This paper presents a case study of a six story RCM building deemed to have reached the near collapse performance level. The RCM walls on the 2nd floor failed due to toe crushing reducing the building’s lateral resistance in the east-west direction. A nonlinear dynamic analysis on a 3D model was conducted to simulate the development of the governing failure mechanism. Preliminary analysis results show that the damaged walls were initially under large compression forces from gravity loads which caused increase in their lateral strength and reduced their ductility. After toe crushing failure developed, axial instability of the model was prevented by a redistribution of gravity loads.
The city of Christchurch has experienced over 10,000 aftershocks since the 4th of September 2010 earthquake of which approximately 50 have been greater than magnitude 5. The damage caused to URM buildings in Christchurch over this sequence of earthquakes has been well documented. Due to the similarity in age and construction of URM buildings in Adelaide, South Australia and Christchurch (they are sister cities, of similar age and heritage), an investigation was conducted to learn lessons for Adelaide based on the Christchurch experience. To this end, the number of URM buildings in the central business districts of both cities, the extent of seismic strengthening that exists in both cities, and the relative earthquake hazards for both cities were considered. This paper will report on these findings and recommend strategies that the city of Adelaide could consider to significantly reduce the seismic risk posed by URM buildings in future earthquake.
Police walking down Manchester Street in the aftermath of the 22 February 2011 earthquake. Masonry from several buildings has fallen onto the road.
St Elmo Courts, a NZHPT heritage building on the corner of Hereford and Montreal Streets. The building was severely damaged during the 4 September earthquake, with diagonal cracking between the windows. Scaffolding has been placed around the bottom of the building.
The connections between walls of unreinforced masonry (URM) buildings and flexible timber diaphragms are critical building components that must perform adequately before desirable earthquake response of URM buildings may be achieved. Field observations made during the initial reconnaissance and the subsequent damage surveys of clay brick URM buildings following the 2010/2011 Canterbury, New Zealand earthquakes revealed numerous cases where anchor connections joining masonry walls or parapets with roof or floor diaphragms appeared to have failed prematurely. These observations were more frequent for the case of adhesive anchor connections than for the case of through-bolt connections (i.e. anchorages having plates on the exterior façade of the masonry walls). Subsequently, an in-field test program was undertaken in an attempt to evaluate the performance of adhesive anchor connections between unreinforced clay brick URM walls and roof or floor diaphragm. The study consisted of a total of almost 400 anchor tests conducted in eleven existing URM buildings located in Christchurch, Whanganui and Auckland. Specific objectives of the study included the identification of failure modes of adhesive anchors in existing URM walls and the influence of the following variables on anchor load-displacement response: adhesive type, strength of the masonry materials (brick and mortar), anchor embedment depth, anchor rod diameter, overburden level, anchor rod type, quality of installation and the use of metal foil sleeve. In addition, the comparative performance of bent anchors (installed at an angle of minimum 22.5o to the perpendicular projection from the wall surface) and anchors positioned horizontally was investigated. Observations on the performance of wall-to-diaphragm connections in the 2010/2011 Canterbury earthquakes and a snapshot of the performed experimental program and the test results are presented herein. http://hdl.handle.net/2292/21050
A photograph of the earthquake damage to the Fisher's Building on the corner of High and Hereford Streets. Large sections of the top storey have collapsed, the masonry spilling onto the footpath and damaging the awning.
A photograph of the earthquake damage to the old Registry Building on the corner of Worcester and Montreal Streets. The masonry of the Worcester Street gable has crumbled and is lying on the street in front. Wire fencing has been used to cordon off the building.
A photograph of cordon fences around a building on Cashel Street. Road cones have also been placed around the building and the word "Danger" has been spray-painted on the footpath in front. Fallen masonry from the building lies on the footpath in front.
A photograph of the earthquake damage to the Canterbury Provincial Chambers Building on Durham Street. Large sections of the masonry have collapsed, spilling onto the road. Wire fencing has been placed around the building as a cordon. Scaffolding erected up the side has collapsed.
A photograph of the earthquake damage to the Canterbury Provincial Chambers Building on Durham Street. Large sections of the masonry have collapsed, spilling onto the road. Wire fencing has been placed around the building as a cordon. Scaffolding erected up the side has collapsed.
Damage to the masonry of an old building on Ferry Road in Woolson.
Damage to the masonry of an old building on Ferry Road in Woolson.
A photograph of the earthquake-damaged Canterbury Provincial Chambers on Durham Street. The roof and upper walls of the Stone Chamber have collapsed, the masonry falling onto the footpath below. The building has been cordoned off with wire fencing.
A photograph of the earthquake-damaged Canterbury Provincial Chambers on Durham Street. The roof and upper walls of the Stone Chamber have collapsed, the masonry falling onto the footpath below. The building has been cordoned off with wire fencing.
Police standing at the intersection of Manchester Street and Gloucester Street in the aftermath of the 22 February 2011 earthquake. Masonry from several buildings has fallen onto the road.
A photograph of the earthquake damage to the Canterbury Provincial Chambers Buildings on Durham Street. Large sections of the masonry have collapsed, spilling onto the road. Wire fencing has been placed around the building as a cordon. Scaffolding erected up the side of the building after the 4 September 2010 earthquake has collapsed. In the distance, a crane is parked on the street.
Seismic retrofitting of unreinforced masonry buildings using posttensioning has been the topic of many recent experimental research projects. However, the performance of such retrofit designs in actual design level earthquakes has previously been poorly documented. In 1984 two stone masonry buildings within The Arts Centre of Christchurch received posttensioned seismic retrofits, which were subsequently subjected to design level seismic loads during the 2010/2011 Canterbury earthquake sequence. These 26 year old retrofits were part of a global scheme to strengthen and secure the historic building complex and were subject to considerable budgetary constraints. Given the limited resources available at the time of construction and the current degraded state of the steel posttension tendons, the posttensioned retrofits performed well in preventing major damage to the overall structure of the two buildings in the Canterbury earthquakes. When compared to other similar unretrofitted structures within The Arts Centre, it is demonstrated that the posttensioning significantly improved the in-plane and out-of-plane wall strength and the ability to limit residual wall displacements. The history of The Arts Centre buildings and the details of the Canterbury earthquakes is discussed, followed by examination of the performance of the posttension retrofits and the suitability of this technique for future retrofitting of other historic unreinforced masonry buildings. http://www.aees.org.au/downloads/conference-papers/
A photograph of the earthquake damage to a building on Lichfield Street. Masonry from the top section of the building has broken away and spilled onto the footpath below. A red sticker has been placed on the door, indicating that the building is unsafe to enter. USAR codes have been spray-painted on the column and window to the right.
A photograph of a man standing inside the cordon fence which has been placed around a building on Cashel Street. Road cones have also been placed around the building and the word "Danger" has been spray-painted on the footpath in front. Fallen masonry from the building lies on the footpath in front.
The front wall of St John the Baptist Church in Latimer Square. Plywood and tarpaulins have been used to weather proof the gaps where masonry has fallen away from the building. Some of the fallen masonry is stacked on a pallet at the base of the building.
The front wall of St John the Baptist Church in Latimer Square. Plywood and tarpaulins have been used to weather proof the gaps where masonry has fallen away from the building. Some of the fallen masonry is stacked on a pallet at the base of the building.
A photograph of the earthquake damage to the Cranmer Courts on the corner of Montreal and Kilmore Streets. A large section of the building has crumbled, masonry spilling onto the footpath below. Wire fencing has been placed around the building as a cordon.
A photograph of the earthquake damage to the Cranmer Courts on the corner of Montreal and Kilmore Streets. A large section of the building has crumbled, masonry spilling onto the footpath below. Wire fencing has been placed around the building as a cordon.