Abstract
The investigation shows that Longxi Tunnel, across a fault zone, was severely damaged during the 2008 Wenchuan earthquake, China. In this paper, the dynamic time history analysis method is used to study the seismic response characteristics of Longxi Tunnel and the aseismic effect of seismic measures. The interfaces of the fault are simulated by bonded interfaces. The results show that high earthquake intensity, high in situ stress, and fault zone are the main reasons for damage of Longxi Tunnel. The inconsistent motion response between the normal surrounding rocks and surrounding rocks within the fault zone resulted in the damage of Longxi Tunnel, and the maximum displacement difference reaches 50 cm. With the seismic measure by setting shake absorb layer and seismic joints, the tunnel has better performance: the maximum peak internal force of the tunnel structure is reduced by about 26% and the acceleration is reduced by 30%. Seismic measures should not only be considered within fault zones but also extend to adjacent surrounding rocks. In this study, the fault seismic measures of Longxi Tunnel should be no less than 4.0 times the tunnel diameter.
Highlights
Tunnels are deemed to perform much better than surface structures during earthquakes [1,2,3,4,5], and their seismic capacities improve with the increase of embedment depths [6, 7]
In the dynamic time history analysis, the objectives are to study the earthquake damage characteristics of Longxi Tunnel during the Wenchuan earthquake and the anti-shock effects of seismic measures, including shock absorption layer and seismic joints. e main seismic response information is measured in the monitoring points
Numerical modeling is performed to investigate the seismic responses of Longxi Tunnel crossing a fault zone during the 2008 Wenchuan earthquake
Summary
Tunnels are deemed to perform much better than surface structures during earthquakes [1,2,3,4,5], and their seismic capacities improve with the increase of embedment depths [6, 7]. Wang et al [23] investigated and preliminarily analyzed the seismic damage of highway tunnels in Wenchuan earthquake-stricken areas, including Longxi Tunnel. Lai et al [24] conducted a seismic investigation on 52 tunnels after the 2008 Wenchuan earthquake. Chen and Shen [29] studied the isolation layer which was one of the countermeasures to enhance seismic safety of tunnels Li and He [30] pointed out that different seismic measures were suitable for different tunnel working conditions based on the shaking table test and damage investigations after the 2008 Wenchuan earthquake. Numerical modeling was conducted to investigate the seismic response of Longxi Tunnel during the 2008 Wenchuan earthquake. Two seismic measures are examined, including shake absorb layers and seismic joints. e major objectives of this study were (1) to investigate the influence areas of seismic responses of tunnel due to fault and (2) to explore the effects of seismic measures on seismic response of Longxi Tunnel
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
