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| Research on the Ground Settlement Prediction in Shallow Tunnel under Unsymmetrical Pressure Based on Stochastic Medium Theory |
| FU He-lin, LI Jie, WANG Hong-tao, ZHANG Jia-bing, HUANG Zhen |
| (Central South University, Changsha, Hunan 410075, China) |
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Abstract Abstract：Research purposes： The ground loss caused by tunnel excavation in the uneven ground may lead to the settlement or uplift of the ground surface which could further result in the uneven settlement of the stratum and the buildings above. To ensure the safety of the buildings, it is necessary to calculate and analyze the vertical displacement of the ground surface caused by the tunnel excavation. Research conclusions： (1) Based on the stochastic medium theory, this paper demonstrates the feasibility of settlement prediction in the bias terrain, and derives the ground settlement formula of the shallow bias shield tunnel excavation. (2)Through theoretical derivation, the convergence region U′-V′ needed in the formula are fixed. (3) To simplify the calculation, polar coordinates are used to optimize the formula. (4)When the slope gradient is greater than 45 degrees, the rate of displacement is accelerated obviously. And there is a linear relationship between the maximum vertical displacement of the ground and the ratio of the depth to radius of the settlement of excavation unit. (5) When the vertical distance from the tunnel axis to the slope surface is less than 3.5 R, the vertical displacement of the surface is accelerated. The site where the distance is longer than 3.5R is much better for tunnel excavation. (6)The research results can provide a new way for the predicition of surface displacement of shallow tunnel excavation, and provide technical support for surface displacement control.
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Received: 01 August 2017
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2017, Vol. 34 
