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Abstract Lijiachong large-span tunnel is excavated below the existing high-voltage transmission tower，and the risk of tunnel construction is very high. Several possible schemes for tunnel construction and foundation reinforcement of high-voltage transmission tower were presented based on risk analysis；and comparison among tunnel excavation using two-side wall drift heading method after mountain grunting consolidation，tunnel excavation using three bench method with the core of surrounding rock remained after tower foundation were reinforced with H-shaped framed girders，and tunnel excavation using three bench method with the core of surrounding rock remained after tower foundation were underpinned are introduced through a 3D numerical analysis of the interaction between tunnel construction and high-voltage transmission tower. The scheme of using H-shaped framed girders to connect the foundations as a whole is adopted. It is shown that after the pile foundations were connected with H-shaped framed girders，the foundations worked as a whole，tunneling using three bench method with the core of surrounding rock remained became safety. Cumulative settlement and uneven settlement were well controlled，and the forces and deformations of the tower were in the allowable ranges. By reinforcing the tower foundations using the H-shaped framed girders，Lijiachong tunnel safely passed beneath the transmission tower；and good economical and technical results are obtained. The results can provide a reference for similar projects.
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Received: 25 February 2012
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2012, Vol. 31 
