To study the mechanical effects of the arch cover method in the construction of large-span underground subway station with upper soft and lower hard excavation, taking the construction of Southeast Mountain Station on Dalian Metro Line 4 as the research background, a research method adjoining numerical simulation and on-site monitoring was adopted. MIDAS-GTS/NX finite element software was used to study deformation and stability of surrounding rock and contrastive analysis with on-site measured data. The research results indicate that surface subsidence shows a decreasing trend from the centerline of the station to both sides, and the affected region is about twice the excavation skip distance of the station. The variant and stress of country rock have apparent symmetrical characteristics, the surrounding rock of the arch is mainly caused by settlement, while the high side wall is mainly uplift, the arch spans invades towards the tunnel clearance, the large arch foot invades towards the surrounding rock; the von mises stress of the country rock is under compression, and there is a phenomenon of concentration of stresses at the closed angle of the arch foot; the location of the plastic region of the country rock change continuously with the build of the depot, and ultimately funnel into the high side walls. The verification of surface settlement is predicted using the Peck formula, and the feasibility of using the arch cover method for construction in upper soft and lower hard strata is verified, which provides a reference for similar practical projects.
LIWencong.On surface settlement during subway station construction using the center drift excavation method[J].Modern Tunnelling Technology,2018,55(2):189-193.
LIUJiazhu, SUNLichao, ZHANGZhuang,et al.Study on mechanical effect of PBA method in metro station[J].Chinese Journal of Underground Space and Engineering2018,14():240-247, 307.
YUANLong, HEWenshe.Study on the application of double-side heading method in the construction of shallow and large section loess tunnel[J].Chinese Journal of Underground Space and Engineering,2022,18():289-295.
LIYihua, ZHUKangkang, LIMingyu,et al.Surface deformation laws of silty clay strata induced by pipe roofing and cross diaphragm:a case study of a passageway project at portal of Zhongzhou avenue station on Zhengzhou metro line 3[J].Tunnel Construction,2022,42(12):2148-2156.
LIUWeining, SHENYanfeng, LUOFurong,et al.Prediction and analysis of effects during construction of subway station(on Fu-Ba line in Beijing) on environment[J].China Civil Engineering Journal,2000,33(4):47-50.
ZHONGGuo.Arch-cover method:a new subsurface excavation construction for metro stations[J]Urban Mass Transit,2012,15(8):145-148.
[17]
LEIM F, ZHAOC Y, JIAC J,et al.Study on the geological adaptability of the arch cover method for shallow-buried large-span metro stations[J].Tunnelling and Underground Space Technology,2023,132:104897.
WEIZhiyuan, FENGJimeng, YULongping.Study on the mechanical behavior of the the double-layer arch cover initial support during the construction of subway stations by arch-cover method[J].Modern Tunnelling Technology,2022,59(3):265-274.
[20]
LIUX R, LIUY Q, QUW B,et al.Internal force calculation and supporting parameters sensitivity analysis of side piles in the subway station excavated by Pile-Beam-Arch method[J].Tunnelling and Underground Space Technology,2016,56:186-201.
GONGXudong.Deformation pattern and control of Qingdao metro station adopting primary arch cover construction method in upper soft and lower hard stratum[J].Urban Mass Transit2021,24(6):109-114.
[23]
SHANGY L, DUS J, HANT Y,et al.Case study on deformation control of upper-soft and lower-hard large span tunnel station using combined control technology and monitoring demonstration[J].Sains Malaysiana,2017,46(11):2091-2099.
KONGChao, GAOXinqiang, YAOYong,et al.The deformation and mechanical properties of surrounding rock of primary support arch-cover construction method in upper-soft and lower-hard stratum[J].Chinese Journal of Rock Mechanics and Engineering,2020,39():2634-2644.
[26]
LIUX R, LIUY Q, YANGZ P,et al.Numerical analysis on the mechanical performance of supporting structures and ground settlement characteristics in construction process of subway station built by Pile-Beam-Arch method[J].KSCE Journal of Civil Engineering,2017,21(5):1690-1705.
[27]
GUOX P, JIANGA N.Study on applicability of double layer superimposed primary support arch cover method for large-span station in upper soft and lower hard stratum[J].KSCE Journal of Civil Engineering,2022,26(3):1407-1418.
[28]
WANGJ B, HUOQ, SONGZ P,et al.Study on adaptability of primary support arch cover method for large-span embedded tunnels in the upper-soft lower-hard stratum[J].Advances in Mechanical Engineering,2019,11(1):1-15.
YINXiaoliang.Comparative selection of large-span metro station underground-excavated construction method under diabase intrusion into granite formation condition[J].Urban Mass Transit,2023,26(7):159-164.
ZHANGZilong, JIANGAnnan, YUHai,et al.Analysis of the mechanical response in the construction of large-span mined metro stations by the arch-cover method[J].Modern Tunnelling Technology,2021,58(3):139-146.