Mornington Peninsula Shire Council 1

REPORT TO Council Meeting ITEM NO. 2.6

MEETING DATE Monday, 24 September, 2012

SUBJECT Southern Peninsula Aquatic Centre Geotechnical Investigation

PREPARED BY David Hampton, Project Manager Capital Works

AUTHORISED BY Director Sustainable Infrastructure

ATTACHMENT(S) NO

PURPOSE The purpose of this report is to inform Council of the findings of geotechnical investigations carried out on the Rosebud Foreshore at the proposed site for the Southern Peninsula Aquatic Centre (SPA). SUMMARY Consultants AECOM have completed a report on the geotechnical and engineering site conditions for the Rosebud Foreshore site of the proposed SPA development. Their report findings relate to the site ground and water table conditions, proposed construction methods and allowances for climate change and project cost. BACKGROUND Council resolved at its meeting on 18 June, 2012 that prior to the appointment of a SPA Project Manager, that appropriate geotechnical and engineering reports be prepared for the designated site for SPA and be presented to Council to inform of feasibility and cost of the project before any design work is undertaken. A detailed consultant brief was developed for this investigation which included the following tasks: 1. Complete a desktop assessment of the subject site using information readily available from

public sources and Council records. 2. Using the findings of the desktop study and sufficient additional site testing, provide

preliminary advice on the geotechnical conditions that will need to be addressed in the development of the proposed SPA on the subject site.

3. Give opinion on the adequacy of the quantity surveyors allowances for SPA construction and

associated utility services based on the findings of the desktop study and any additional on-site testing carried out on the subject site. Advise if any significant additional items need inclusion.

4. Identify any limitations on the design life of the proposed SPA based on the findings of the

desktop study and any additional on-site testing carried out on the subject site.

5. Provide advice on suitable construction methods for the proposed SPA based on the findings of the desktop study and any additional on site testing carried out on the subject site.

6. Provide advice as to whether there are any geotechnical or other engineering reasons why the

project should not proceed to concept design stage.

7. Give advice on how any further geotechnical and engineering services studies would be programmed as part of the design development.

Council Meeting Monday, 24 September, 2012 Southern Peninsula Aquatic Centre Geotechnical Investigation ITEM NO. 2.6

Mornington Peninsula Shire Council 2

BACKGROUND (CONTD) Two days of geotechnical field work was undertaken by AECOM in July 2012. A total of four soil borings were drilled to depths of up to 15 metres below existing ground surface. Laboratory soil testing of soil samples was undertaken. The key outcomes of this investigation are: The site conditions are typical for a coastal site and consist of 15 metres of sand with

groundwater close (within one metre) to natural surface level; Conventional construction methods may be used for this development including dewatering and

concrete piling;

The building design should allow for the effects of climate change during the design life of the facility. It is anticipated sea and groundwater levels may rise by 0.8 metres by 2100;

With good design and quality workmanship the design of the building will not be compromised

by site conditions;

The high groundwater levels may increase building foundation costs; and

An independent review of the cost plan indicates a more generous allowance for contingency (or unforeseen) costs at this preliminary stage of development is appropriate.

DISCUSSION The findings of AECOMs investigations indicate the site is suitable for development and an increase in cost to allow for proven site conditions and contingencies is appropriate. Project cost will be determined more accurately once a detailed concept plan is developed. Factors which may influence project cost include the size of the facility/building footprint, finished floor level, standard of material finishes, building design life and any proposal to stage development works. Consultants have not been appointed to undertake the architectural design of SPA. The geotechnical investigation is part of the site selection due diligence and will assist to inform the conceptual design development and project cost. OFFICER DIRECT OR INDIRECT INTEREST No person involved in the preparation of this report has a direct or indirect interest requiring disclosure. CONCLUSION The geotechnical investigations are consistent with the findings of earlier reports and confirm that the subsurface conditions are representative of a typical coastal location. This preliminary investigation did not identify any geotechnical concerns that would preclude the successful completion of the proposed SPA development using conventional engineering construction methods. The report also recommends that at this early stage of the project, additional allowances should be made for specific design and construction issues associated with building in a coastal location and in the project contingency.

Council Meeting Monday, 24 September, 2012 Southern Peninsula Aquatic Centre Geotechnical Investigation ITEM NO. 2.6

Mornington Peninsula Shire Council 3

RECOMMENDATION

1. That the Southern Peninsula Aquatic Centre Preliminary Geotechnical Site Investigation Report prepared by AECOM Australia in August 2012 be received and noted.

2. That a copy of the Preliminary Geotechnical Site Investigation Report prepared by

AECOM be placed on the Shires website.