A photograph of the earthquake damage to a residential road in Christchurch. Road cones have been placed around lifted man holes to warn road users.
A private pool on a property on Avonside Drive. The pool has lifted out of its casing and now looks like an above ground pool.
The driveway of a house on Avonside Drive. One of the concrete slabs has broken apart from another and lifted to create a gap between them.
The driveway of a house on Avonside Drive. One of the concrete slabs has broken apart from another and lifted to create a gap between them.
A photograph of cracks in Park Terrace, where an access hole has lifted. Road cones have been placed on the road to warn and direct traffic.
Aftermath of September 4th Earthquake in Canterbury (area covers Christchurch City) NZ. Empty fuel tanks lifted out of forecourt at petrol station on Pages Road.
A crane lifts containers off a goods train stopped on the track beside SH71 near Rangiora. Trains were unable to run until buckled tracks were inspected and repaired.
A crane lifts containers off a goods train stopped on the track beside SH71 near Rangiora. Trains were unable to run until buckled tracks were inspected and repaired.
Photograph captioned by BeckerFraserPhotos, "The Butterfly Gap, a Gap Filler Project on corner of Barbadoes and Worcester Street. Such a sight to lift the spirits".
Photograph captioned by BeckerFraserPhotos, "The Butterfly Gap, a Gap Filler Project on corner of Barbadoes and Worcester Street. Such a sight to lift the spirits".
A photograph of emergency management personnel crossing the intersection between Colombo and Hereford Streets. Paving stones have lifted from the corner of the streets in the background.
Damage to the Visitors Centre in Kaiapoi, after the September 4th earthquake. The foundations have lifted at the back of the building, giving it a forward lean.
People preparing to load salvaged stock from a damaged store into a shipping container on Manchester Street. A truck with mechanical arms will be used to lift the container.
Part of the forecourt at the Shell Shirley petrol station has lifted above the rest, after the underground petrol tanks were pushed upwards by liquefaction. Liquefaction silt covers the lower part of the forecourt.
A hydraulic excavator on Kilmore Street, lifting a steel beam over a hole in the ground. The area is fenced off by wire fencing and there are road cones across the street.
A red-stickered house in Avonside. This means the house is unsafe to enter. A crack can be seen running through the lawn and a slab of concrete in the driveway has lifted up.
A photograph of an access hole in a residential street in Christchurch which has lifted out of the road. A road cone and spray-painted lines have been placed on top to warn road users.
Part of the forecourt at the Shell Shirley petrol station has lifted above the rest, after the underground petrol tanks were pushed upwards by liquefaction. Liquefaction silt covers the lower part of the forecourt. The photographer comments, "Tanks at Shell Shirley floated out of the ground".
A broken driveway on Avonside Drive. The concrete slabs on the driveway have lifted during the earthquake, creating a large crack in the driveway. The crack has been filled with tiles and wood but the rubbish bins have still fallen in.
The driveway of a house on Avonside Drive. One of the concrete slabs has lifted and the owner has tried to fill the gap with blocks of wood. Unfortunately, these have come loose and are sticking out of the hole.
Photograph captioned by BeckerFraserPhotos, "Close up of the cranes working on the Clarendon Tower. Big Red behind is now the crane in Christchurch capable of lifting the largest load. The yellow crane is a tower crane which is still being assembled".
The bell tower of St John's Anglican Church in Hororata. The top of the tower has collapsed, and many of the bricks have crumbled along the side into the roof of the church. A skip has been lifted up by a crane next to the tower with a man inside.
Damage to the Visitors Centre in Kaiapoi, after the September 4th earthquake. The foundations have lifted at the back of the building, giving it a forward lean. Cables have been attached to the balcony over the walkway and braced to posts cemented into the ground. This is to stop the building from slumping further.
Damage to the Visitors Centre in Kaiapoi, after the September 4th earthquake. The foundations have lifted at the back of the building, giving it a forward lean. Cables have been attached to the balcony over the walkway and braced to posts cemented into the ground. This is to stop the building from slumping further.
A photograph of the earthquake damage to a house on Major Hornbrook Drive. The chimney has collapsed and many of the tiles have been lifted on the roof. Tarpaulins have been laid over the holes in the roof as waterproofing, but the closest has shredded. Gaps can be seen between the bricks in the wall and the wall to the left has crumbled.
A photograph of the earthquake damage to a house on Major Hornbrook Drive. The chimney has collapsed and many of the tiles have been lifted on the roof. Tarpaulins have been laid over the holes in the roof as waterproofing, but the closest has shredded. Gaps can be seen between the bricks in the wall and the wall to the left has crumbled.
A photograph of the earthquake damage to a house on Major Hornbrook Drive. The chimney has collapsed and many of the tiles have been lifted on the roof. Tarpaulins have been laid over the holes in the roof as waterproofing, but the closest has shredded. Gaps can be seen between the bricks in the wall and the wall to the left has crumbled.
A sewage pumping station on Avonside Drive has been lifted out of the ground by liquefaction. In the background, the damaged Snell Place footbridge over the Avon River is closed off with cordon fencing. The photographer comments, "A Sunday afternoon ride to New Brighton, then back via Aranui, Wainoni, Dallington, and Richmond. Not a cheerful experience. Dallington footbridge. The two pieces of this foot bridge have moved towards each other, so the bridge has developed quite a peak. The sewage pumping station has been heaved out of the ground by hydraulic pressure during quakes".
A review of the literature showed the lack of a truly effective damage avoidance solution for timber or hybrid timber moment resisting frames (MRFs). Full system damage avoidance selfcentring behaviour is difficult to achieve with existing systems due to damage to the floor slab caused by beam-elongation. A novel gravity rocking, self-centring beam-column joint with inherent and supplemental friction energy dissipation is proposed for low-medium rise buildings in all seismic zones where earthquake actions are greater than wind. Steel columns and timber beams are used in the hybrid MRF such that both the beam and column are continuous thus avoiding beam-elongation altogether. Corbels on the columns support the beams and generate resistance and self-centring through rocking under the influence of gravity. Supplemental friction sliders at the top of the beams resist sliding of the floor whilst dissipating energy as the floor lifts on the corbels and returns. 1:20 scale tests of 3-storey one-by-two bay building based on an earlier iteration of the proposed concept served as proof-of-concept and highlighted areas for improvement. A 1:5 scale 3-storey one-by-one bay building was subsequently designed. Sub-assembly tests of the beam-top asymmetric friction sliders demonstrated repeatable hysteresis. Quasi-static tests of the full building demonstrated a ‘flat bottomed’ flag-shaped hysteresis. Shake table tests to a suite of seven earthquakes scaled for Wellington with site soil type D to the serviceability limit state (SLS), ultimate limit state (ULS) and maximum credible event (MCE) intensity corresponding to an average return period of 25, 500 and 2500 years respectively were conducted. Additional earthquake records from the 22 February 2011 Christchurch earthquakes we included. A peak drift of 0.6%, 2.5% and 3.8% was reached for the worst SLS, ULS and MCE earthquake respectively whereas a peak drift of 4.5% was reached for the worst Christchurch record for tests in the plane of the MRF. Bi-directional tests were also conducted with the building oriented at 45 degrees on the shake table and the excitation factored by 1.41 to maintain the component in the direction of the MRF. Shear walls with friction slider hold-downs which reached similar drifts to the MRF were provided in the orthogonal direction. Similar peak drifts were reached by the MRF in the bi-directional tests, when the excitation was amplified as intended. The building self-centred with a maximum residual drift of 0.06% in the dynamic tests and demonstrated no significant damage. The member actions were magnified by up to 100% due to impact upon return of the floor after uplift when the peak drift reached 4.5%. Nonetheless, all of the members and connections remained essentially linearelastic. The shake table was able to produce a limited peak velocity of 0.275 m/s and this limited the severity of several of the ULS, MCE and Christchurch earthquakes, especially the near-field records with a large velocity pulse. The full earthquakes with uncapped velocity were simulated in a numerical model developed in SAP2000. The corbel supports were modelled with the friction isolator link element and the top sliders were modelled with a multi-linear plastic link element in parallel with a friction spring damper. The friction spring damper simulated the increase in resistance with increasing joint rotation and a near zero return stiffness, as exhibited by the 1:5 scale test building. A good match was achieved between the test quasi-static global force-displacement response and the numerical model, except a less flat unloading curve in the numerical model. The peak drift from the shake table tests also matched well. Simulations were also run for the full velocity earthquakes, including vertical ground acceleration and different floor imposed load scenarios. Excessive drift was predicted by the numerical model for the full velocity near-field earthquakes at the MCE intensity and a rubber stiffener for increasing the post joint-opening stiffness was found to limit the drift to 4.8%. Vertical ground acceleration had little effect on the global response. The system generates most of its lateral resistance from the floor weight, therefore increasing the floor imposed load increased the peak drift, but less than it would if the resistance of the system did not increase due to the additional floor load. A seismic design procedure was discussed under the framework of the existing direct displacement-based design method. An expression for calculating the area-based equivalent viscous damping (EVD) was derived and a conservative correction factor of 0.8 was suggested. A high EVD of up to about 15% can be achieved with the proposed system at high displacement ductility levels if the resistance of the top friction sliders is maximised without compromising reliable return of the floor after uplift. Uniform strength joints with an equal corbel length up the height of the building and similar inter-storey drifts result in minimal relative inter-floor uplift, except between the first floor and ground. Guidelines for detailing the joint for damage avoidance including bi-directional movement were also developed.