Goh, KH and Mair, RJ (2009) Geotechnical observations of construction OF A large shallow SCL tunnel in soft ground. Geotechnical Engineering, 40. pp. 67-80. ISSN 0046-5828Full text not available from this repository.
The Fort Canning Tunnel is the first road tunnel in Singapore to be built using the sprayed concrete lining (SCL) method. The major technical challenge of this was to construct a 15m wide tunnel by mining in soft ground under a shallow overburden of 3m to 9m. This paper describes the geotechnical investigations and monitoring controls for the safe and progressive execution of the works, such as soil investigations, trial forepoling works, surface settlement monitoring, tunnel settlement monitoring, face movement monitoring, and the observational approach to construction. The monitored field data showed the volume loss to range from 0.4% to 2.1%, and the observed surface settlement trough was found to agree well with the theoretical Gaussian trough. Other observations made include substantial surface settlements induced by the stress relief at and ahead of the tunnel face in spite of the forepoling umbrella, and the higher volume losses associated with higher overburden. Tunnel face movements were observed during installation of forepoling. These observations are of interest to engineers planning future SCL tunnels in similar conditions.
|Uncontrolled Keywords:||Construction Settlement Soft ground|
|Divisions:||Div D > Geotechnical and Environmental|
|Depositing User:||Cron Job|
|Date Deposited:||07 Mar 2014 12:36|
|Last Modified:||27 Nov 2014 19:19|