Biogrouting compared to jet grouting: Environmental (LCA) and economical assessment

Abstract

In order to predict consequences of replacing jet grouting with biogrouting, and identify major contributors to the cost of both technologies, a large road project in Stockholm, Sweden, was used as a case study. Jet grouting had been used to seal the contact between sheet piling and bedrock, biogrouting for the same function was computed. A comparative environmental and economical assessment was carried out using life cycle assessment (LCA). The results show that biogrouting was cheaper than jet grouting and would have had lower environmental impact. The major difference was the transport and use of heavier equipment for jet grouting. Biogrouting also used less water and produced less landfilled waste. However, the production of urea and CaCl₂ for biogrouting required much energy.

Keywords:

• Biotechnical soil improvement
• grouting economy
• microbial soil stabilisation
• jetgrout
• financial cost

Acknowledgments

This study was supported by Vinnova (contract 2007-03094 and 2007-02772), Sweden.

Notes

⁺Total amount of km driven by trucks for transport to the site of the road in Stockholm, including return of the equipment.

^# Amount fuel allocated to each m jet grouting column or m³ sealed soil.

∗ Includes only transport from supplier storage, not from material production site.

¹1 SEK was roughly 0.1 or 0.16 USD ($) 2005.