Ground surface settlements due to construction of closely-spaced twin tunnels with different geometric arrangements

摘要: Abstract This paper examines the ground surface settlement profiles due to construction of closely-spaced twin tunnels using shallow tunnelling method. In concerned zone, where twin-tunnelling was performed in stacked and offset arrangements, settlements total 18 cross-sections were continually recorded during construction. To cater for different conditions partial face, full face forepoling reinforcement schemes adopted. The troughs three typical sections are reported illustrated. induced by each fitted Gaussian function. parameters that characterize tunnels, such as maximum settlement, percentage loss, trough width empirical parameter presented compared.