scholarly journals Study on Effect of Rainfall on Earth Pressure of Shield Tunnel in Expansive Soil Stratum

2018 ◽  
Author(s):  
Feng Chao ◽  
Zaifeng Yao ◽  
Xiaohong Guo
Keyword(s):  
Expansive Soil ◽  
Earth Pressure ◽  
Shield Tunnel ◽  
Soil Stratum

The Influence of Earth Pressure Balanced Shield Tunnel Underpassing Coastal Water Body on Stratum Deformation

2019 ◽  
Vol 83 (sp1) ◽  
pp. 237 ◽  
Author(s):  
Caixia Guo ◽  
Xiaoming Guan ◽  
Leilei Shi ◽  
Shengyuan Qiu
Keyword(s):  
Coastal Water ◽  
Water Body ◽  
Earth Pressure ◽  
Shield Tunnel ◽  
Stratum Deformation

Method of Calculating Chamber Earth Pressure of EPB Shield

2014 ◽  
Vol 886 ◽  
pp. 426-431 ◽  
Author(s):  
Bo Liang ◽  
Jing Cao ◽  
Hai Xing Yang ◽  
Zu De Ding ◽  
Hui Ming Zhao
Keyword(s):  
Limit Equilibrium ◽  
Earth Pressure ◽  
Relative Displacement ◽  
Shield Tunnel ◽  
Limit States ◽  
Relationship Of ◽  
The Relationship ◽  
Epb Shield ◽  
Selection Of ◽  
Construction Practice

In order to calculate earth pressure in working chamber, three calculation modes which corresponding to status of elastic balanced, active limit equilibrium and passive limit equilibrium of the soil on the excavation face was built. The relationship of relative displacement between the soil in the chamber and the soil on the excavation face of shallow EPB shield tunnel was analyzed based on Rankines earth pressure theory. The threshold of chamber earth pressure values which correspond to the limit states of subsidence and upheaval were deduced and the reasonable range of the values were obtained. Combined with a shield tunnel construction practice, the theoretical and measured values are compared. The results show that the theoretical equations are valid and can provide a theoretical approach for the selection of chamber earth pressure.

Research on Chamber Earth Pressure of EPB Shield Considering Soil Arching Effect

2014 ◽  
Vol 1065-1069 ◽  
pp. 373-377
Author(s):  
Jing Cao ◽  
Hai Xing Yang ◽  
Bo Liang ◽  
Hai Ming Liu
Keyword(s):  
Earth Pressure ◽  
Shield Tunnel ◽  
Pressure Balance ◽  
Soil Arching ◽  
Shield Tunneling ◽  
Arching Effect ◽  
Soil Arching Effect ◽  
Earth Pressure Balance ◽  
Tunnel Depth ◽  
Epb Shield

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.

scholarly journals Deformation Characteristics of Existing Twin Tunnels Induced by Double Shield Undercrossing with Prereinforcement: A Case Study in Hangzhou

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xinjiang Wei ◽  
Mobao Zhang ◽  
Shaojun Ma ◽  
Chang Xia ◽  
Xingwang Liu ◽  
...  
Keyword(s):  
Soft Soil ◽  
Earth Pressure ◽  
Plain Concrete ◽  
Horizontal Displacement ◽  
Shield Tunnel ◽  
Deformation Characteristics ◽  
Pressure Balance ◽  
Concrete Wall ◽  
Shield Tunnelling ◽  
Epb Shield

This paper is based on the case of the earth pressure balance (EPB) shield tunnelling project of the new Metro Line 2 undercrossing the existing Metro Line 1 in the soft soil urban area of Hangzhou. Because the EPB shield must break through a plain concrete wall before undercrossing the existing tunnels, the pipe roof prereinforcement was adopted to stabilize the soil between the existing tunnels and the new shield tunnel. The deformation characteristics of the existing tunnels in the process of double shield undercrossing were discussed. According to the variation of shield position, the settlement development could be divided into three stages: shield approaching subsidence, shield crossing heave, and shield leaving subsidence. The horizontal displacement shows a back and forth variation characteristic consistent with the direction of shield tunnelling. At the junction of tunnel and station, the shield undercrossing caused considerable differential settlement between the existing tunnel and the station. The construction of pipe roof prereinforcement will lead to the presettlement of the existing tunnels. The settlement of the existing tunnels caused by the attitude deviation of pipe roof and grouting disturbance should be reduced in reasonable ranges. In addition, the maximum longitudinal settlement of the existing tunnel during the shield second undercrossing was also discussed. It was considered that the influence of wall breaking is greater than the sequence of shield undercrossing. The driving parameters of shield tunnelling should be optimized before the second crossing.

Analysis of the Calculation Method of Active Earth Pressure of Unsaturated Expansive Soil

2012 ◽  
Vol 594-597 ◽  
pp. 180-185
Author(s):  
Jia Shan Zhang
Keyword(s):  
Calculation Method ◽  
Expansive Soil ◽  
Earth Pressure ◽  
Swelling Pressure ◽  
Active Earth Pressure ◽  
Calculation Formula ◽  
Retaining Structure ◽  
Derivation Process ◽  
Sliding Soil ◽  
Unsaturated Expansive Soil

The properties of unsaturated expansive soil were analyzed, and the shortcomings of present methods which are explored to calculate the active earth pressure of unsaturated expansive soil on the retaining structure were discussed. Based on Coulomb’s earth pressure theory, a calculation formula of active earth pressure of unsaturated expansive soil was proposed taking into account of the swelling pressure parameters according to the condition of static equilibrium of sliding soil. The formula has simple composition and derivation process, is convenient for application, and the example shows that this method is reasonable.

scholarly journals LONG TERM PREDICTION OF VERTICAL EARTH PRESSURE LOADING ON A SHIELD TUNNEL IN SOFT CLAY GROUND

2017 ◽  
Vol 73 (3) ◽  
pp. I_75-I_84
Author(s):  
Shigeaki OKA ◽  
Yoshihiro ITO ◽  
Ayaka YOKOTA ◽  
Jin SAITO ◽  
Shunsuke KANEKO ◽  
...  
Keyword(s):  
Soft Clay ◽  
Earth Pressure ◽  
Shield Tunnel ◽  
Pressure Loading ◽  
Term Prediction ◽  
Clay Ground ◽  
Long Term Prediction ◽  
Vertical Earth Pressure
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