Sustainable Design Strategies For Tunneling Projects

By Cara Hlad, AIA, LEED AP | July 2011, Vol. 66 No. 7
Photo courtesy MWH.

1. Excavated water reuse -- Utilize for surface dust control or aquifer recharge;
2. Geothermal renewable energy system -- Ground source heat pump to heat/cool surface buildings and take advantage of excavation that is already in place for tunnel or shafts;
3. Low impact development (lid) opportunities -- Maintain pre-development hydrologic configurations;
4. Muck reuse -- Local disposal to reduce transportation emissions and cost; reuse at surface sites to raise grade or to prevent flooding; reuse high quality muck rocks for construction aggregate, community road base and concrete mixes;
5. Fly ash/slag -- Local by-products used in concrete mix. For precast segments, manufacture locally to reduce greenhouse gas emissions and cost from transportation;
6. Inclined tunneling (uphill or steep grade) -- Gravity assistance in muck removal to reduce energy (uphill); hauler braking converted into electricity or batteries (steep grade);
7. Green power -- Construction activities powered by green power from utility provider;
8. Biodiesel -- Burns cleaner and reduces emissions from machinery, trucks and muck cars;
9. Renewable hydropower -- Harness water power during excavation; and
10. Restore habitat -- Recharge disturbed areas with native vegetation and reduce ecosystem impact.

Photo courtesy MWH.

ABOUT THE AUTHOR: Cara Hlad is an architect and LEED AP at MWH Global. She serves as the Sustainable Design Director in the DESIGN Group, and teaches sustainable architecture courses at a local college, in Denver, CO. She can be contacted at