A photograph of Steven Cooper welding the steel frame of Crack'd for Christchurch's armchair artwork.
A photograph of a partially-demolished building with steel sticking out of the concrete.
A photograph of a concrete wall with steel reinforcement visible inside
A photograph of a broken concrete pile with steel reinforcement sticking out of it.
A photograph of a damaged support beam in the basement of the Copthorne Hotel. A section of the concrete has crumbled, exposing the steel reinforcement underneath.
Canterbury earthquakes is recommending toughening the standards for concrete buildings and structural steel.
Detail of steel bracing supporting the Colombo Street overpass. The photographer comments, "After the earthquake in Christchurch the Colombo St overpass got damaged and they used reinforcing steel beams to hold it up".
A photograph of the steel frame of Crack'd for Christchurch's ottoman artwork.Crack'd for Christchurch comments, "Mid September 2013. The ottoman frame was made by Bob Hamilton from Total Fabrications."
A photograph of the steel frame of Crack'd for Christchurch's armchair artwork.Crack'd for Christchurch comments, "Mid September 2013. The chair frame was made by Bob Hamilton from Total Fabrications."
The increasing prevalence of mixed-material buildings that combine concrete walls and steel frames in New Zealand, coupled with a lack of specific design and detailing guidelines for concrete wall-steel beam connections, underscores the need for comprehensive research to ensure that these structures behave as intended during earthquakes. Bolted web plate connections, commonly found in steel framing systems, are typically used to connect steel beams to concrete walls. These connections are idealised as pinned during design. However, research on steel framing systems has shown that these connections can develop significant stiffness and moment resistance when subjected to large rotations during seismic loading, potentially leading to brittle failure when used in concrete wall to steel beam applications. This thesis was written to understand the seismic performance of concrete wall-steel beam bolted web plate connections, providing experimental evidence, numerical modelling insights, and design recommendations to address critical gaps in current design practices. The study is divided into three phases. First, a review of 50 concrete wall-steel frame buildings in Auckland and Christchurch was conducted to understand current design practices and typical connection details. The findings revealed significant variation in design and detailing practices and a lack of specific guidelines for concrete wall-steel beam connections. Second, an experimental programme was conducted on four full-scale concrete wall-steel beam sub-assemblages, each incorporating variations in connection detailing. The tests were designed to quantify the rotation capacity of concrete wall-steel beam connections, identify failure modes and investigate the effectiveness of potential connection improvements. Results demonstrated that concrete wall-steel beam bolted web plate connections designed using current design standards and following existing practices are vulnerable to non-ductile failure characterised by concrete breakout. However, using slotted holes in the web plate and bent reinforcing bar anchors instead of headed stud anchors improved connection rotation capacity. Third, a numerical model of a case study building was developed on OpenSeesPy, with different connection conditions assumed based on the experimental results. Pushover and time history analyses were conducted to evaluate the implications of different connection conditions (pinned vs non-pinned) on global building response and local member demands. The findings revealed that using non-pinned connection conditions does not significantly affect the global building response and shear and bending moment demands on lateral load-resisting elements. However, doing so generates overstrength moments on the connections that induce different actions on out-of-plane concrete walls connected to steel beams. Synthesising findings from all three phases, this thesis concludes with a proposed design procedure for concrete wall-steel beam connections based on a capacity design approach to ensure ductile failure modes and suppress brittle ones. Key recommendations include selecting appropriate bolt hole geometry and anchorage, providing sufficient rotation capacity, and accounting for connection overstrength in global analyses.
A photograph of exposed steel and concrete from the partially-demolished Art Gallery Apartments building on Gloucester Street.
One twisted steel re-enforcing rod with parallel spine-like lines running the length of the rod; striations run in a circular pattern between these lines. The object was recovered from the shear wall in the Hotel Grand Chancellor, which was demolished following the 22 February earthquake. This steel reinforcing rod was removed from the Hotel Gr...
One twisted steel re-enforcing rod with parallel spine-like lines running the length of the rod; striations run in a circular pattern between these lines. The object was recovered from the shear wall in the Hotel Grand Chancellor, which was demolished following the 22 February earthquake. This steel reinforcing rod was removed from the Hotel Gr...
One twisted steel re-enforcing rod with parallel spine-like lines running the length of the rod; striations run in a circular pattern between these lines. The object was recovered from the shear wall in the Hotel Grand Chancellor, which was demolished following the 22 February earthquake. This steel reinforcing rod was removed from the Hotel Gr...
One twisted steel re-enforcing rod with parallel spine-like lines running the length of the rod; striations run in a circular pattern between these lines. The object was recovered from the shear wall in the Hotel Grand Chancellor, which was demolished following the 22 February earthquake. This steel reinforcing rod was removed from the Hotel Gr...
A photograph of a pile of twisted steel reinforcement and other rubble at the entrance to the Smiths City car park on Dundas Street. In the background a section of the collapsed car park has not been demolished yet. Many cars are still parked on the top floor.
A photograph of the steel frame of Crack'd for Christchurch's armchair artwork.Crack'd for Christchurch comments, "Mid September 2013. The chair frame was made by Bob Hamilton from Total Fabrications. It is shown here with Chris Raateland who did a lot of heavy lifting for Crack'd."
A photograph of an excavator on a building site.
A photograph of Jonathan Hall transferring Crack'd for Christchurch's ottoman artwork onto a wooden base in Helen Campbell's garage. The ottoman has been made out of polystyrene, wood, mesh, and concrete, laid over a steel frame.Crack'd for Christchurch comments, "December 2013. Jonathan delivers the footstool to Helen's garage where it will be mosaicked.."
A photograph of the steel frame of Crack'd for Christchurch's armchair artwork. The frame is on a pallet in the Greening the Rubble workshop. Two cast-iron bath feet have been attached to the front legs.Crack'd for Christchurch comments, "Mid September 2013. The chair frame was made by Bob Hamilton from Total Fabrications."
A photograph of Crack'd for Christchurch's partially-constructed armchair artwork. The armchair is on a pallet in Greening the Rubble's workshop. Jonathan Hall has moulded polystyrene, wood, mesh, and concrete over the steel frame to construct the armchair. Two cast-iron bath feet have attached to the front legs.
A photograph of the partially-demolished Smiths City car park, taken from Dundas Street. The front section of the car park has mostly been cleared, though there is still a scattering of rubble and steel reinforcement. The back section has collapsed, but the floors are largely intact, with many cars still parked on the top floor.
One steel, brick and concrete brooch created from debris collected after the 22 February 2011 earthquake; steel from a gas heater has been woven to create three enclosures for the piece of brick and two pieces of concrete; a stainless steel pin has been woven on the reverse for attachment. Worn by numerous people as part of the Host A Brooch pro...
A photograph of groups of people walking down Dundas Street after the 22 February 2011 earthquake. The front of the Wraggs building is being supported by steel bracing.
Steel reinforcements supporting the side of a house.
A photograph of steel bracing keeping up a section of the ceiling on the ground floor of the Crowne Plaza. The column to the left is damaged.
A photograph of the earthquake damage to a house in Christchurch. One of the side walls has crumbled, exposing the inside. Steel bracing is being used to hold up the ceiling inside.
A photograph of Crack'd for Christchurch's partially-constructed armchair artwork. The armchair is on a pallet in Greening the Rubble's workshop. Jonathan Hall has moulded polystyrene, wood, mesh, and concrete over the steel frame to construct the armchair. Two cast-iron bath feet have been attached to the front legs.
A photograph of Crack'd for Christchurch's partially-constructed armchair artwork. The armchair is on a pallet in Greening the Rubble's workshop. Jonathan Hall has moulded polystyrene, wood, mesh, and concrete over the steel frame to construct the armchair. Two cast-iron bath feet have been attached to the front legs.
A photograph of Crack'd for Christchurch's partially-constructed armchair artwork. The armchair is on a pallet in Greening the Rubble's workshop. Jonathan Hall has moulded polystyrene, wood, mesh, and concrete over the steel frame to construct the armchair. Two cast-iron bath feet have been attached to the front legs.