| With the rapid development of urban under ground traffic construction in our country,the construction of two or more shield tunnels has been gradually developed.The interaction between the new tunnels and the existing tunnels has become an important problem in construction,but the relevant theoretical research is still lagging behind the engineering practice,there is no relevant clear standard.Therefore,it is of great theoretical and engineering application to study the mutual influence of the two-line parallel shield tunnel.In this paper,the following work is carried out:First,based on the Mindlin solution of elasticity mechanics and considering the influence of the incision pressure of the shield machine during the excavation of the shield tunnel and the effect of the friction softening effect between the shield and the surrounding soil,the amended calculation method of the additional stress field near the surrounding soil of the existing tunnels can be used to calculate the internal forces generated by the construction of the existing tunnels due to the construction of the new tunnels.Secondly,based on the finite difference software FLAC 3D,the three-dim ensional numerical analysis of the construction section of the two-line parallel shield tunnel between the Lvcu Station and Chengshigua ngchang Station of Xiamen Metro Line 1 is carried out,which gives the force and deformations of the soil and the lining when the left tunnel was com pleted and the influence of the new shield tunnel on the displacement of the existing tunnel lining and the surrounding soil during the excavation.Finally,based on the principle of stiffness correction method,the ground subsidence prediction formula of double-line parallel shield tunnel excavation is modified accordingly,and the modified double-line Peck Formula,which can provide a reference for the settlement prediction of the two-line parallel shield tunnel excavation. |
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