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| Experimental Research on the Site Monitoring of Double Lining Structure in Shield Tunnel |
| YANG Jun - sheng 1，XIAO Xiao - wen 1 , ZHANG Cong 1 , ZOU Zhi - lin2, ZHANG Xue - min1, LIANG Kui - sheng3, LIU Hong - zhen3 |
| (1. Central South University，Changsha，Hunan 410075, China；2. Beijing Urban Construction Group Co. Ltd，Beijing 100085 , China;3. China Railway Tunnel Stock Co. Ltd , Zhengzhou，Henan 450000 , China) |
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Abstract Abstract: Research purposes: To explore the stress characteristics of double lining in undersea shield tunnel，taking undersea water - intaking shield tunnel of Taishan Nuclear Power Plant as background， this paper makes the field monitoring of double lining structure force， and based on field test data， proposes a method which can accurately calculate the undersea shield tunnel design load of soft soil layers. Research conclusions: 1 ) Monitoring results show that large cross section slurry pressurized balance shield and new lining construction method have many advantages such as quick construction and high quality. (2) Secondary lining of water - in taking shield tunnel mainly withstand internal water pressure, tunnel surrounding rock pressure is mainly borne by the segment. Segmental lining external water and soil pressure is affected by construction and formation conditions significantly. During construction, the earth pressure exists three periods like acceleration, deceleration and acceleration stabilized, and acceleration is the most critical period; soil pressure of stable period showed the next big small shape in whole , pressure distribution of measuring points is uneven distribution. Water seepage pressure distribution is consistent with the tunnel region , but affected by tunnel surrounding rock strata , water pressure distribution also has a certain randomness. The impact of secondary lining concrete solidification shrinkage weakens with time by the impact of second lining weight , the contact pressure between the double lining of vault is smaller , and arch foot is larger. (3) When the depth ≤1. 7D , vertical earth pressure =1.31 x rh , horizontal earth pressure = 1.65 xλrh ； When the depth of 1.7D < H≤2. 2D , vertical earth pressure =0.39 x rh , horizontal earth pressure = 1.35 xλrh ； When the depth H >2. 2D , vertical earth pressure =0. 63 x rh , horizontal earth pressure = 0. 61 x λrh. (4) The research results can provide guidance for the design and construction of undersea shield tunnel linings.
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Received: 19 November 2015
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2016, Vol. 33 
