A DEM-based study of the disturbance in dry sandy ground caused by EPB shield tunneling

Chamber earth pressure is one of the significant parameters during the Earth Pressure Balance (EPB) shield construction processing. The soil arching effect is existence when the tunnel depth is enough. It is significant to consider the influence of arching effect to analyze the pressure in soil chamber in shield tunneling. In this paper, the influence of arching effect is considered to calculate the chamber earth pressure. Firstly, the soil is supposed as loose media, and the necessary buried depth of producing arching affects is deduced according to the loose media theory. Then, based on the characteristic of proper arching axis, the equation and the height of proper arch are obtained. At last, the calculation formula of minimum chamber earth pressure of EPB shield tunnel is deduced which can consider the effect of arching effect.

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Control Parameters of EPB Shield Tunneling in Weathered Granite Ground and Below Existing Tunnels

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.3572 ◽

2011 ◽

Vol 243-249 ◽

pp. 3572-3581

Author(s):

Xing Gao Li ◽

Da Jun Yuan ◽

Hao Hu

Keyword(s):

Collaborative Work ◽

Earth Pressure ◽

Measured Data ◽

Second Phase ◽

Control Parameters ◽

Shield Tunneling ◽

Weathered Granite ◽

The Earth ◽

Epb Shield ◽

Advance Speed

The choice of reasonable parameters of EPB shield tunneling in weathered granite ground is of great importance to reduce tunneling-induced effects on existing tunnels. Combined with the practice of the EPB shield tunneling below existing interval tunnels from Kexueguan station to Dajuyuan station of Shenzhen metro line No.1, the method of design and regulation of main parameters including the earth pressure in excavation chamber, the ground conditioning, the volume of the discharged soil, the grouting control and the advance speed, of the EPB shield tunneling are studied. The practice of the below-crossing shows in the weathered granite ground, it is reasonable that the earth pressure in excavation chamber is taken as 0.15-0.2 mpa, and that FER, FIR and CF of foam are taken as 8-15, 30-50% and 3-5% respectively, and that the amount of synchronization grouting is 8-10 m3 per ring along with the injecting pressure of 0.3-0.4 mpa, and that the second phase injection is employed to control the further settlement of existing tunnels when necessary, and that the advance speed is taken as 8-10 mm/min, and as steady as possible. Meanwhile, adjustments according measured data must be performed when necessary. Moreover, the real-time monitoring and a collaborative-work environment among the Parties involved in project are also very crucial to facilitate the risk management of the below-crossing.

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EPB Shield Tunneling in Mixed Face Conditions

Journal of Geotechnical Engineering ◽

10.1061/(asce)0733-9410(1993)119:10(1640) ◽

1993 ◽

Vol 119 (10) ◽

pp. 1640-1656 ◽

Cited By ~ 11

Author(s):

G. Wayne Clough ◽

Eric Leca

Keyword(s):

Shield Tunneling ◽

Epb Shield

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