CEGAS - Centre for Environmental and Geotechnical Applications of Surface waves

Purpose

To develop more effective passive seismic methods and improved collaborative geophysical, geotechnical and engineering design studies, including involvement of industry partners from the engineering and open-cut mining enterprises

Collaborating groups & people

Monash University, School of Geosciences

• Prof. Michael Asten Professorial Research Fellow
• Prof Jim Cull Professor of Geophysics and Head of School
• Dr Gary Gibson Honorary Research Fellow (employed by Environmental & Engineering Systems Ltd)
• Max Claprood PhD candidate
• James Roberts PhD candidate
• Camilla Sorensen PhD candidate

Geoscience Australia

• Dr Phil Cumins
• Dr Trevor Dhu
• Dr Trevor Allen

University of Melbourne, Faculty of Engineering

• A/Prof John Wilson Assoc. Prof.
• A/Prof Nelson Lam Assoc. Prof.
• Srikanth Venkatesan PhD Candidate

University of Hong Kong, Faculty of Engineering

• Prof Adrian Chandler Professor, Univ. of Hong Kong
• Tsang Hing Ho PhD Candidate
• Neaz Sheikh PhD Candidate

Current Research Funding and Projects

• Geoscience Australia
• US Geological Survey
• Xstrata PLC, Coal Division
• University of Hong Kong
• Collaboration with IGNS New Zealand (internally funded) “Microtremor survey at sites in the Wellington City area, NZ”

Proposed

A Centre combining geoscience, civil engineering and structural engineering skills, to

• develop and evaluate methodologies for the use of seismic surface wave methods (especially microtremors) in site classification, regolith studies and geotechnical studies;
• optimise passive seismic methodologies to have low environmental impact for use in sensitive areas such as coastal lands and urban areas;
• develop methodologies for the seismic assessment of vulnerable structures (especially in the mitigation of earthquake hazard);
• develop and evaluate methodologies for optimising inputs to excavation design in geotechnical and open-cut mine planning.

Justification

Surface wave methods offer opportunity for passive seismic methodologies which are well-suited to use in urban areas where conventional seismic investigations are impractical.

Surface-wave methods yield shear-velocity information of soils, sand fill and rock, which is of direct importance in calculation of ease of excavation, site safety and relative site risk in the event of an earthquake.

Increased awareness of commercial and legal risk associated with site conditions means that measurement of geotechnical parameters is of increasing demand; direct studies using drill-holes or seismic cone penetrometer holes are invasive, costly, and limited in their ability to provide spatial sampling. Surface-wave methods are non-invasive and hence “environmentally friendly” as well as effective. Techniques are most strongly established in Japan, but their full potential is yet to be realised in the western world.

The Melbourne-Hong Kong research team has co-developed a new seismic attenuation modelling methodology which when integrated with the inexpensive passive shear wave velocity modelling technique, has the potential capability of developing realistic seismic attenuation models for regions with little or no earthquake data. There are substantial potential contributions from this collaboration to the modelling of seismic hazard worldwide.

Publications resulting from these Collaborations (and prior related publications)

• Publications on Microseisms
  author/co-authored by Michael Asten, BSc, PhD, FRAS