With all existing quarry sites in Hong Kong nearing the end of their production lifetimes, Arup assisted the Hong Kong government in preparing the Quarry Development Masterplan for the territory, identifying and assessing the feasibility of potential quarry sites and investigating the potential for underground quarry development. Another crucial part was to ensure that steps are taken for sustainable re-use of good quality construction spoil and explore potential mechanisms for the use of non-granitic rocks as aggregates for concrete.
10 potential surface quarry sites assessed
19potential underground quarry sites assessed
3preferred sites taken forward for more detailed studies
Secure and stable supply sources
With the progressive closure of local quarry sites, Hong Kong has become increasingly reliant on the import of aggregate from overseas over the last 30 years, with over 90% of all aggregates consumed now being imported. This has had notable impacts on both the supply security as well as the product cost for aggregates and associated downstream construction materials such as concrete and asphalt.
Although significant reliance on import could not be fully eradicated, the Quarry Development Masterplan outlined mechanisms under which at least 30% of the forecast demand for aggregates could be sourced locally, resulting in a more stable and secure construction materials market.
Even a well-designed surface quarry will still bring negative impact to the environment. To help minimise the impact, we undertook feasibility and business case studies for the development of underground quarry sites in Hong Kong together with territory-wide site identification and ranking. As a result, detailed site-specific assessments are now underway for several potential underground quarry sites.
Sustainable upcycling of construction spoil
One of the key benefits provided by quarries in Hong Kong has been the ability to receive good quality construction spoil – typically string granitic rock from the various site formation and tunnelling projects – and turn this into aggregates. With the gradual closure of local quarry sites, this ability has been lost in recent years, with a notable quantity of good quality rock being used for low-grade end-uses, exported or sent to public fill banks. A key part of the Quarry Development Masterplan was the integration of construction spoil upcycling within the supply chain, ensuring that nothing goes to waste in the future.
To fully demonstrate the feasibility of the potential quarry sites identified, we also prepared high quality preliminary designs for key surface and underground quarries. These included a full suite of planning, geotechnical, environmental, traffic and business case analysis, showing how the sites could be developed, operated and then rehabilitated upon completion of the mineral extraction phase.