To serve the needs of Carnarvon and the Gascoyne region, Western Power are constructing a $73 million, 18 megawatt dualfuel (diesel and gas) power station, located approximately 6.5km east of the Carnarvon town centre. The power station development proposed for the approximately 5.4 hectare site includes tanks, generators, transformers, pump skids and gas receiving skids.
Western Power previously commissioned two geotechnical site investigations for the project. These investigations did not provide sufficient information to the structural engineer (GWB Plant) for detailed design due to the presence of collapsible soils (Pindan sands) across the site.
- Undertake a desktop study based on the existing information. Preliminary design parameters for deep and shallow foundation options and recommendations for further investigation were to be included in the study. The effects of transient loads such as wind and machine loads were also considered for shallow foundation options;
- Based on the desktop study, geotechnical investigation works were carried out to assess the extent and collapse potential of the load bearing stratum. The investigation included insitu plate load testing in dry and saturated conditions, and double odometer laboratory testing; and
- Provide a number of foundation and ground improvement options for the various proposed structures.
Based on the more rigorous collapse potential testing carried out as part of the investigation, a less conservative approach to ground remediation was provided.
In order to mitigate risks of ground collapse, a mixture of deep and shallow foundation options were recommended for the various structures across the site. Ground improvement was also provided as an option, and was recommended for areas of the site with deep filling.
Information was provided in the form of both interim and final reports to meet the programme of the project.