Observations of Ground Movements during Tunnel Construction by Slurry Shield Method at the Docklands Light Railway Lewisham Extension—East London

Grouting has been deemed as one of the most effective measures for mitigation of ground movements during tunnel construction in soft soil. Notwithstanding that, a reliable measure to quantitatively evaluate the grouting-induced ground movements during shield tunnelling in soft soil has not yet been developed. This paper presents a simple method capable of quantitatively estimating the ground movements associated with grouting for tunnel-boring operations where the grouting parameters and soil properties are taken into consideration. The grouting process is simplified as the expansion of a cylindrical cavity with a uniform radial stress applied at soil-grout interface in a half plane, and the analytical solution proposed by Verruijt is introduced for determining the ground movements by the expansion of the cylindrical cavity. The proposed method is verified with a case history undertaken in London Clay. The results obtained suggest that this procedure would be helpful in managing the grouting parameters adopted in upcoming soft ground tunnelling project and mitigating the environmental impacts on nearby properties.

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Ground Adaptability Characterization for Digging in Complex Geotechnical Conditions and Risk Mitigation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1431 ◽

2011 ◽

Vol 415-417 ◽

pp. 1431-1434

Author(s):

Wei Wei Yu ◽

Xuan Guo

Keyword(s):

Risk Factors ◽

Control Method ◽

Risk Mitigation ◽

Tunnel Construction ◽

Soil Pressure ◽

Ground Movements ◽

Construction Risk ◽

And Control ◽

Methods Of Control

Characterization of geotechnical digging and control the dynamical settlement is very necessary to mitigate construction risk. The metro tunnels of being constructed access to each other or near to the ground is high risk and physically difficult and costly. The control method becomes imperative. Some cases of digging prediction of ground movements and assessment of risk of damage to above or adjacent constructions have become an important issue especially in urban projec. Ground adaptability characterization is the key of control the tunneling in complex geotechnical conditions both in rock and soft stratum. High and changed water-soil pressure also is risk factors to effect tunneling process. Beside discussion of risk mitigation associate to tunnel construction, the developing settlement control and simulations are given to describe the methods of control risk.

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Experiment of Slurry Shield Tunnel Recycling Waste Sand in Sand-Pebble Layer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.919-921.1104 ◽

2014 ◽

Vol 919-921 ◽

pp. 1104-1109

Author(s):

Chen Rui Pang ◽

Xin Wen

Keyword(s):

Fine Sand ◽

The Other ◽

Shield Tunnel ◽

Tunnel Construction ◽

Sand Layer ◽

Large Space ◽

City Environment ◽

Slurry Shield ◽

Sand Source ◽

Waste Soil

Waste soil progressing in shield tunnel construction should occupy large space, on the other hand, do harm to city environment. If the waste sand in silt and fine sand layer can be used as sand source of synchronous grouting, it will bring benefits for the enterprise and society. In indoor experiment, we select waste sand in different layers, sieved as sand source, then use the waste sand to produce slurry and compare their strength with the construction slurry’s. The study found, sieved waste sand in silt and fine sand layer can be used as sand source for making synchronous grouting slurry.

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Prediction and analysis of subsidence induced by shield tunnelling in the Madrid Metro extension

Canadian Geotechnical Journal ◽

10.1139/t02-073 ◽

2002 ◽

Vol 39 (6) ◽

pp. 1273-1287 ◽

Cited By ~ 69

Author(s):

Manuel Melis ◽

Luis Medina ◽

José M Rodríguez

Keyword(s):

Earth Pressure ◽

Tunnel Construction ◽

Pressure Balance ◽

Ground Movements ◽

Construction Methods ◽

The Earth ◽

Predictive Methods ◽

Shield Tunnelling ◽

Earth Pressure Balance ◽

Numerical Modelling And Analysis

The development of tunnelling projects under heavily populated cities has been rapidly increasing around the world during the last decades. Since tunnel construction can have disastrous effects on buildings, structures, and utilities near the excavation, construction methods have necessarily to provide maximum safety inside and outside the tunnel. To predict and correct dangerous ground movements due to the tunnelling works, the authors developed a numerical model to simulate the earth pressure balance (EPB) excavation procedure and injection to complement some deficiencies found in previous analytical or empirical subsidence estimating procedures. This model takes into account the full excavation sequence and has been validated by a large amount of monitoring data from the previous Madrid Metro extension. In the present paper, several predictive methods are used to predict the ground movements generated during a new Madrid Metro extension project consisting of 48 km of tunnel (19992003). At the end of the works the results will be compared with data from monitored sections placed in all five cities linked by the extension. Conclusions about the applicability and accuracy of the methods will be established with the aim of helping researchers and engineers in their future projects.Key words: ground movements, monitoring, numerical modelling and analysis, settlement, tunnels.

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