外文翻譯--由隧道排水引起的地面反應(yīng)曲線(xiàn)-全文預(yù)覽
【正文】 es in the elastic region under dry condition (Timoshenko and Goodier, 1969). For the seepage condition, Stern (1969) suggests effective stresses in the elasticregion with consideration of the seepage force as follows: Where C,A and B are constants defined by the boundary conditions. (12) and (13) can be solved by using the boundary conditions σrei′ =0 at r=r0,σrei′ =0 at r=R0 and σθei′ =0 at r=R0 Here, subscript i represents the term related to seepage. Consequently, the radial and tangential effective stresses with consideration of the seepage forces in the elastic region can be obtained by the superposition of both of solutions as follows: (16) is derived from (14) and (15) and the MohrCoulomb yield criterion at the stress state in the elastic region. Finally, at the interface between the plastic and elastic regions, r=re, the radial stress calculated in the plastic region must be identical to that in the elastic region. Consequently, (10) should be equal to (16) since the radial stress should be continuous over the boundary. The radius of the plastic zone, re, can be derived as follows: Theoretical solution for displacement The radial displacement for a circular tunnel can be worked out based on the elastoplastic theory. The strains in the plastic region are posed of elastic and plastic strains, and are expressed as Eqn. (18) and (19), respectively. The superscripts e and p represent the elastic and plastic parts, respectively. By considering pressive strains and radially inward displacements to be positive, the relationship between strain and displacement at any point in a soilmass can be written as follows: The plastic strain can be represented by using the plastic flow rule. When the volume expansion effect is important in plastic strain, generally the nonassociated flow rule is valid。 Carter (eds), pp. 15031508. Sharan, . (2020). Elasticbrittleplastic analysis of circular openings in HoekBrown media. International J. of Rock Mechanics and Mining Sciences, Vol. 40:817824. Shin, ., Potts, . and Zdravkovic, L. (2020). The effect of porewater pressure on NATM tunnel lingings in deposed granite soil. Canadian Geotechnical J., Vol. 42: 15851599. Shin, ., Lee, . and Shin, . (2020). Seepaeinduced Stress due to Tunnelling under Drainage Condition., Canadian Geotechnical J., (Submitted). Stille, H., Holmberg, M. and Nord, G. (1989), Support of Weak Rock with Grouted Bolts and Shotcrete, International J. of Rock Mechanics and Mining Sciences amp。 this result means that there is no ground water when the cover depth of the tunnel, C , is 10 times the diameter of the tunnel, D .This is due to the fact that even if the effective overburden pressure can be decreased by the arching effect during tunnel excavation, seepage forces still remain CONCLUSIONS The flow of groundwater has a significant effect on the radial displacement of a tunnel wall. While the effective overburden pressure is reduced slightly by the arching effect during tunnel excavation, seepage forces still remain. Therefore, the presence of groundwater induces larger radial displacements of the tunnel wall than those in the case of dry condition. ACKNOWLEDGMENTS This paper was supported by the Underground Space Con
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