Following the 2010/2011 Canterbury earthquakes a detailed campaign of door to door assessments was conducted in a variety of areas of Christchurch to establish the earthquake performance of residential dwellings having masonry veneer as an external cladding attached to a lightweight timber framing system. Specifically, care was taken to include regions of Christchurch which experienced different levels of earthquake shaking in order to allow comparison between the performance of different systems and different shaking intensities. At the time of the inspections the buildings in the Christchurch region had been repeatedly subjected to large earthquakes, presenting an opportunity for insight into the seismic performance of masonry veneer cladding. In total just under 1100 residential dwellings were inspected throughout the wider Christchurch area, of which 24% were constructed using the older nail-on veneer tie system (prior to 1996) and 76% were constructed using screw fixed ties to comply with the new 1996 standards revision (post-1996), with 30% of all inspected houses being of two storey construction. Of the inspected dwellings 27% had some evidence of liquefaction, ground settlement or lateral spreading. Data such as damage level, damage type, crack widths, level of repair required and other parameters were collected during the survey. A description of the data collection processes and a snapshot of the analysis results are presented within. http://15ibmac.com/home/
A photograph of detail of a piece of masonry removed from the Cranmer Centre and placed on the ground in front.
A photograph of detail of a piece of masonry removed from the Cranmer Centre and placed on the ground in front.
A photograph a detail of a piece of masonry removed from the Cranmer Centre and placed on the ground in front.
A photograph a detail of a piece of masonry removed from the Cranmer Centre and placed on the ground in front.
A photograph a detail of a piece of masonry removed from the Cranmer Centre and placed on the ground in front.
A crumbling wall of the Cramner Courts. The wall's collapse has exposed the thick, unreinforced masonry that it is made of.
A splintered doorway in the remains of the Durham Street Methodist Church. A pile of broken masonry is sitting in front.
A house on The Spur in Clifton. Masonry has fallen down from the rock wall at the base of the building.
A photograph of the Durham Street Methodist Church on Durham Street. The church has almost completely collapsed and only a small section of the structure is still standing. Masonry and other rubble has spilled onto the footpath and street in front. To the right a plywood sign has been propped against the front fence. USAR codes have been spray-painted on the sign.
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.
A photograph of the Cranmer Centre. Below a collection of masonry has been removed from the building and placed on the ground.
A photograph of the Cranmer Centre. Below a collection of masonry has been removed from the building and placed on the ground.
A photograph of a window of the Cranmer Centre. The masonry around the windows has been removed and placed on pallets below.
A bent drain pipe supporting a section of collapsed masonry on the A and T Burt building on Ferry Road in Woolston.
Churches are an important part of New Zealand's historical and architectural heritage. Various earthquakes around the world have highlighted the significant seismic vulnerability of religious buildings, with the extensive damage that occurred to stone and clay-brick unreinforced masonry churches after the 2010-2011 Canterbury earthquakes emphasising the necessity to better understand this structural type. Consequently, a country-wide inventory of unreinforced masonry churches is here identified. After a bibliographic and archival investigation, and a 10 000 km field trip, it is estimated that currently 297 unreinforced masonry churches are present throughout New Zealand, excluding 12 churches demolished in Christchurch because of heavy damage sustained during the Canterbury earthquake sequence. The compiled database includes general information about the buildings, their architectural features and structural characteristics, and any architectural and structural transformations that have occurred in the past. Statistics about the occurrence of each feature are provided and preliminary interpretations of their role on seismic vulnerability are discussed. The list of identified churches is reported in annexes, supporting their identification and providing their address.
A photograph of the Cranmer Centre. Below a collection of masonry has been removed from the Cranmer Centre and placed on the ground.
A photograph of the eastern corner of the Cranmer Centre. The masonry around the windows has been removed and placed on pallets below.
A corner of the Cranmer Courts on Montreal Street. The masonry has collapsed onto the footpath, bringing steel and wooden bracing with it.
Scattered masonry that has fallen from St John the Baptist Church in Latimer Square. Some of the stones have been stacked on pallets.
Masonry gable of the Christchurch School of Music broke off during the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
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 adhesive anchor connections than for through-bolt connections (i.e., anchorages having plates on the exterior facade 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 mesh sleeves. In addition, the comparative performance of bent anchors (installed at an angle of minimum 22.5° 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, a summary of the performed experimental program and test results, and a proposed pull-out capacity relationship for adhesive anchors installed into multi-leaf clay brick masonry are presented herein. AM - Accepted Manuscript
The Catholic Cathedral is classified as a category 1 listed heritage building constructed largely of unreinforced stone masonry, and was significantly damaged in the recent Canterbury earthquakes of 2010 and 2011. In the 2010 event the building presented slight to moderta damage, meanwhile in the 2011 one experienced ground shaking in excess of its capacity leading to block failures and partial collapse of parts of the building, which left the building standing but still posing a significant hazard. In this paper we discuss the approach to develop the earthquake analysis of the building by 3D numerical simulations, and the results are compared/calibrated with the observed damage of the 2010 earthquake. Very accurate records were obtained during both earthquakes due to a record station located least than 80 m of distance from the building and used in the simulations. Moreover it is included in the model the soil structure interaction because it was observed that the ground and foundation played an important role on the seismic behavior of the structure. A very good agreement was found between the real observed damage and the nonlinear dynamic simulations described trough inelastic deformation (cracking) and building´s performance.
Damage to the Community of the Sacred Name building on Barbadoes Street. Masonry from one of the building's gables has collapsed onto the footpath.
A vehicle that was smashed by fallen masonry from the Cathedral of the Blessed Sacrament. In the background, the broken building can be seen.
The huge tremor shook the masonry gable off this apartment block in the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
The huge tremor shook the masonry gable off this apartment block in the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Seismic behaviour of typical unreinforced masonry (URM) brick houses, that were common in early last century in New Zealand and still common in many developing countries, is experimentally investigated at University of Canterbury, New Zealand in this research. A one halfscale model URM house is constructed and tested under earthquake ground motions on a shaking table. The model structure with aspect ratio of 1.5:1 in plan was initially tested in the longitudinal direction for several earthquakes with peak ground acceleration (PGA) up to 0.5g. Toppling of end gables (above the eaves line) and minor to moderate cracking around window and door piers was observed in this phase. The structure was then rotated 90º and tested in the transverse (short) direction for ground motions with PGA up to 0.8g. Partial out-of-plane failure of the face loaded walls in the second storey and global rocking of the model was observed in this phase. A finite element analysis and a mechanism analysis are conducted to assess the dynamic properties and lateral strength of the model house. Seismic fragility function of URM houses is developed based on the experimental results. Damping at different phases of the response is estimated using an amplitude dependent equivalent viscous damping model. Financial risk of similar URM houses is then estimated in term of expected annual loss (EAL) following a probabilistic financial risk assessment framework. Risks posed by different levels of damage and by earthquakes of different frequencies are then examined.
A photograph of the earthquake damage to the Cathedral of the Blessed Sacrament on Barbadoes Street. The tower on the right has crumbled and the masonry has fallen to the pavement below. A car has been crushed by the fallen rubble. The dome of the left tower has collapsed and the cross at the top of the building is on a lean.
A photograph of the earthquake damage to the Iconic bar on the corner of Manchester and Gloucester Streets. Large sections of the outer walls have collapsed, the bricks and masonry spilling onto the footpath below, crushing several cars. USAR codes have been spray-painted near the door and a red sticker has been taped above. The red sticker indicates that the building is unsafe to enter.