		2009 NZSEE Conference
	Abstracts

Keynote Address Session 1 Session 2 Session 3A Session 3B Session 4A Session 4B Session 5A Session 5B Session 6 Session 7 Poster Session

Research on Used Car Tyre Strap Reinforced Adobe Construction in Peru

Andrew Charleson

After summarizing a new proposed reinforcing system for adobe housing using straps cut from used car tyres, the paper outlines a period of research in Peru to continue to develop the technology. Three full-scale experiments and some field work are described and qualitative results presented. Full quantitative analyses are yet to be undertaken. The most significant outcome consisted of a one room adobe house reinforced by tyre straps successfully withstanding strong shaking that would have definitely collapsed unreinforced adobe dwellings.

Paper P34: [Read] [Presentation]

Inherent Strength-based Approach for Collapse Seismic Assessment of Low-rise Masonry Buildings

Ray Su and Kevin Zhou

Confined masonry structures are a widely applied structural system in China. In the Great 512 Wenchuan Earthquake, buildings in the affected areas were subjected to seismic intensities as high as three to five times the design intensity; numerous confined masonry buildings collapsed, while many others suffered damage. The subsequent comprehensive investigation together with the post-earthquake field studies undertaken by the authors revealed that, inherent strength rather than ductility protected confined masonry buildings from collapse or serious damage, a simple calculation of the inherent strength of masonry buildings is given in this paper. The shortcoming of ductility design approach for low-rise masonry buildings is discussed. It is believed by the authors that the ductility design approach is mistakenly adopted by the Chinese Seismic Design Codes for design of low-rise masonry buildings. Hence, a new assessment and design approach, namely, the inherent strength-based approach is introduced.

Paper P35: [Read] [Presentation]

Earthquake Strengthening and Ground Improvement of the Cobham Bridge, Wanganui

P. Brabhaharan, D.K. Kirkcaldie and G. Gregg

The State Highway 3 Cobham Bridge in Wanganui was assessed for its performance in earthquakes, and ability to provide access for traffic across the Wanganui River after large events. Detailed assessment of the bridge using a displacement based assessment approach enabled a cost effective strengthening design to be developed.

The retrofit works comprised strengthening the plastic hinge region of two of the piers for shear and ground improvement at the abutments to reduce damage from liquefaction and consequent lateral spreading.

Ground improvement comprised an optimum combination of stone columns, vertical drains, and ground replacement. Stone columns and wick drains were installed in a triangular shaped area to economically protect each abutment. The stone columns strengthen the ground against instability and provide drainage in earthquakes. The vertical drains facilitate dissipation of pore pressures generated during stone column vibro-compaction and provide additional drainage capacity during earthquakes.

The stone columns were constructed by drilling temporarily cased holes and compacting gravel in place using vibration of the casing and a central probe, as the casing is withdrawn, to maximise drainage capacity and strength.

The strengthening measures adopted were designed to provide an acceptable level of performance, that is quick reinstatement of access after major events, cost effectively.

Paper P36: [Read] [Presentation]

Structural Collapse Rescue: Building Engineering Capability to Deal With the Consequences

Dave Brunsdon, Des Bull and Jim Stuart-Black

Urban Search and Rescue (USAR) is an integrated multi-agency response which is beyond the capability of normal rescue arrangements, and involves the location, rescue and initial medical stabilisation of victims trapped in confined spaces following a structural collapse.

New Zealand has in place a heavy rescue USAR capability that meets international standards, with specific arrangements for responding to a range of emergency events including earthquake.

Engineers represent one of the key specialist skills inputs into USAR, providing a range of advice and input to the USAR Task Forces that are conducting rescue operations.

Although a small group of dedicated and capable structural, civil and geotechnical engineers have become operationally involved in USAR in New Zealand over the past eight years, there is a pressing need to broaden this capability in order to provide the required level of support for the specialist rescue technicians.

This paper summarises the USAR arrangements in place in New Zealand, with particular reference to post-earthquake situations. The new strategy for the development of New Zealand’s rescue engineering capability and ongoing engagement of engineers is outlined.

Paper P37: [Read] [Presentation]

Keynote Address Session 1 Session 2 Session 3A Session 3B Session 4A Session 4B Session 5A Session 5B Session 6 Session 7 Poster Session