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http://dx.doi.org/10.9711/KTAJ.2022.24.6.699

Pillar stability in very near-twin tunnels  

Kim, Donggyou (Korea Institute of Civil Engineering and Building Technology)
Koh, Sungyil (SEOHA Engineering and Construction)
Lee, Jeongyong (Sambo Engineering Co., Ltd.)
Lee, Chulhee (Korea Institute of Civil Engineering and Building Technology)
Publication Information
Journal of Korean Tunnelling and Underground Space Association / v.24, no.6, 2022 , pp. 699-714 More about this Journal
Abstract
The objective of this study is to suggest a safe and economical pillar reinforcement method when very near-twin tunnels with a minimum interval of 1 m passes through a soft zone such as weathered soil or weathered rock. A standard cross-sectional view of a two-lane road tunnel was applied to suggest a pillar reinforcement method for the very near-twin tunnels. The thickness of the pillar was 1 m. The ground condition around the tunnel was weathered soil or weathered rock. There were four reinforcement methods for pillar stability evaluation. These were rock bolt reinforcement, pre-stressed steel strand reinforcement, horizontal steel pipe grouting reinforcement, horizontal steel pipe grouting + prestressed steel strand reinforcement. When the ground condition was weathered soil, only the pillar reinforced the horizontal steel pipe grouting + prestressed steel strand did not failed. When the ground condition was weathered rock, there were no failure of the pillar reinforced the horizontal steel pipe grouting or the horizontal steel pipe grouting + prestressed steel strand. It is considered that the horizontal steel pipe grouting reinforcement played a role in increasing the stability of the upper part of the pillar by supporting the upper load applied to the upper part of the pillar.
Keywords
Very near-twin tunnels; Pillar; Horizontal steel-pipe reinforcement; Numerical analysis;
Citations & Related Records
Times Cited By KSCI : 10  (Citation Analysis)
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