Shaking table tests on the intersection of cross passage and twin tunnels

• Published in: Soil dynamics and earthquake engineering (1984) Vol. 124; pp. 136 - 150
• Main Authors: Zhang, Jinghua, Yuan, Yong, Bao, Zhen, Yu, Haitao, Bilotta, Emilio
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01-09-2019; Elsevier BV
• Subjects: Acceleration; Cross-passage intersection; Deformation; Deformation mechanisms; Dynamic responses; Earthquakes; Environmental risk; Linings; Seismic action; Seismic activity; Seismic engineering; Seismic response; Shake table tests; Shaking table tests; Tunnels; Twin tunnels; White noise; Dynamic responses; Twin tunnels; Shaking table tests; Cross-passage intersection; Seismic action
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2019.05.035

The abrupt structural change at the intersection of cross passage and twin tunnels is a potential risk when earthquakes strike. This paper addresses the seismic responses of the cross-passage intersection by shaking table tests. Test data from six cases are presented, where white noise and synthetic earthquake motions are adopted. Discrepant responses between the cross passage and the twin tunnels are described by acceleration data. The extent of discrepancy is quantified statistically. Influence of this discrepancy is evaluated in two directions: dynamic strains of the linings in the transverse direction and circumferential-joint extensions in the longitudinal direction. Since the earthquake-induced dynamic strains are relatively small, they are considered as an insignificant factor. However, there are considerable circumferential-joint extensions near the cross passage. Two simplified models are proposed to estimate the joint extensions in a pseudo-static way. Each model is corresponding to a unique pattern of longitudinal deformation caused by the discrepant responses of the intersection. Test results are compared with analytical results.
•Discrepant responses between the cross passage and the tunnels are described.•Circumferential-joint extensions are greatly raised near the cross passage.•Simplified models are proposed to estimate circumferential-joint extensions.