01044098

Component

Although finite element analysis techniques are becoming more reliable for modeling tunneling operations in soft ground, they are still relatively complicated and expensive, particularly at the early stages of a design. Therefore simpler semi-empirical methods are still employed to estimate the likely ground movements above tunnels. However, although the most common method based on the application of a Gaussian curve is good for estimating the ground movements above single tunnels, the application to twin tunnels, via summation of two Gaussian curves, has been shown to be inaccurate. An improved semi-empirical method is presented in this paper for predicting the ground movements above multiple tunnels in a side-by-side alignment. This method, based on modifying the summation of Gaussian curves, is shown to provide significant improvements over the traditional method. The paper shows the application of the modified method to some laboratory physical model test data and also to a case history example involving twin tunnel constructions at Heathrow in the UK, with promising results.

01042056

07-0423

English

26p

2007

Transportation Research Board 86th Annual Meeting

CD-ROM

Figures; Photos; References (21) ; Tables (1)

Case studies; Finite element method; Ground settlement; Soft soils; Tunnel supports; Tunneling; Tunnels

Heathrow Airport

Gaussian distributions; Ground movement (Tunneling)

Aviation; Bridges and other structures; Construction; Geotechnology; Highways; Terminals and Facilities; I42: Soil Mechanics; I54: Construction of Tunnels

Transportation Research Board Annual Meeting 2007 Paper #07-0423

TRIS, TRB

Feb 8 2007 5:00PM