Key Technology of Reverse Excavation at Tunnel Portal. Issue 1 (February 2020)

• Record Type: Journal Article
• Authors: Wang, Yuwen; Hu, Zhao; Xie, Yongli; Wang, Chao; Hua, Kaicheng; Lai, Jinxing; Lai, Hongpeng; Wang, Yaqiong; Yue, Xiabing
• Is Part Of: IOP conference series. Volume 455:Issue 1(2020)
• Publication Date: 2020-02
• Subjects: Tunnel engineering -- tunnel portal -- reverse excavation -- numerical experiment; Earth sciences -- Periodicals; Environmental sciences -- Congresses; Environmental sciences -- Periodicals; 550.5
• DOI: 10.1088/1755-1315/455/1/012158
• Languages: English
• ISSNs: 1755-1307

Abstract

Abstract: Tunnel portal construction is often from the outside to the inside of the mountain. Under special conditions and requirements, it is necessary to construct from the inside to the outside of the mountain. The method is called reverse excavation in tunnel portal. To ensure the construction safety in reverse excavation, the stress and deformation characteristics of both forward excavation methods and reverse excavation methods were studied by numerical analysis. The results show that reverse excavation could not significantly increase the deformation and stress of surrounding rock, and even reduced the influence range of tunnel excavation on the stress and deformation of slope. Reverse excavation could also reduce the damage to the portal environment. When the tunnel was about to be cut through, in order to reduce the stress concentration on the slope, the final excavation length was recommended to being greater than 2.5 m. Reverse excavation was a kind of green construction.