Abstract： Based on the underground project attached to the station of Suzhou Rail Transit Line 5, the stability of driving face of the rectangular pipe jacking was investigated. The silo and wedge model was modified, and the effective support pressure was derived based on the limit equilibrium theory. The maximum support pressure was obtained by optimization method, and the parameter analysis was carried out. The results show that the support pressure is decreased with the increasing of soil strength parameter, and it is increased with the increasing of tunnel geometry parameter.The support pressure result obtained by the optimized wedge model is greater than that by the traditional silo model, which is conducive to avoiding construction risks. The actual support pressure (71.00-90.00 kPa) is greater than the theoretical calculation result of 51.36 kPa, which indicates that the support pressure is suitable. The surface collapse or large settlement is presumed to be construction failure or insufficient support force due to unfavorable stratum conditions.
俞淼， 刘维， 史培新， 贾鹏蛟. 浅埋大断面矩形顶管掘进面稳定性及支护压力分析[J]. 江苏大学学报（自然科学版）, 2022, 43(5): 612-620.
YU Miao, LIU Wei, SHI Peixin, JIA Pengjiao. Analysis of stability and support pressure of driving face in shallow buried rectangular pipe jacking with large section[J]. Journal of Jiangsu University(Natural Science Eidtion)
, 2022, 43(5): 612-620.
LIU L W, XUE F T, LIU C L. Threelane superlarge section rectangular pipejacking tunnel underpassing Nanhu Avenue in Jiaxing, China [J]. Tunnel Construction, 2021, 41(9): 1612-1625. (in Chinese)
XU Y J, WEN Z K,YAN L S, et al. Experimental study on soil improvement during construction of EPB rectangular pipe jacking with multicutter[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(2): 288-296. (in Chinese)
［3］
JANCSECZ S, STEINER W. Face support for a large mixshield in heterogeneous ground conditions[C]∥Conference proceedings Institute of Mining and Metallurgy and British Tunneling Society, London: Institute of Mining and Metallurgy and British Tunneling Society, doi：10.1007/978146152646932.
［4］
BROERE W. Tunnel face stability and new CPT applications[D]. Delft: Delft University, 2001.
［5］
ANAGNOSTOU G. The contribution of horizontal arching to tunnel face stability[J]. Geotechnik, 2012, 35(1): 34-44.
XU Y J, LIANG W Z, LIU X M, et al.Soil mass stability at the working face of a rectangular pipejacking tunnel with a large section[J]. Modern Tunnelling Technology, 2017, 54(5): 70-77，85. (in Chinese)
CHENG C, ZHAO W, CHENG C N, et al.Calculation on active limit support pressure of shield tunnel excavation face in dry cohesionless soil[J]. Journal of Northeastern University (Natural Science), 2018, 39(9): 1348-1352. (in Chinese)
［8］
LIN Y, ZHANG D L, QIAN F, et al. Face stability of shallow tunnelling in sandy soil considering unsupported length[J]. Tunnelling and Underground Space Technology，doi：10.1016/j.tust.2020.103445.
［9］
LECA E, DORMIEUX L. Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material[J]. Géotechnique, 1990, 40(4): 581-606.
[10]
LIU W, SHI P X, CHEN L J, et al. Analytical analysis of working face passive stability during shield tunneling in frictional soils[J]. Acta Geotechnica，2020，15： 781-794.
[11]
LIU W, ZHAO Y, SHI P X, et al. Face stability analysis of shielddriven tunnels shallowly buried in dry sand using 1g largescale model tests[J]. Acta Geotechnica,2018，13： 693-705.
[12]
SENENT S, YI C K, JIMENEZ R. An upper bound solution for tunnel face stability analysis considering the free span[J]. Tunnelling and Underground Space Technology, doi：10.1016/j.tust.2020.103515.
LI A, ZHANG D L, SUN Z Y, et al. Analytical solution of limit support pressure at shield tunnel working face in clay layer [J]. Railway Engineering, 2019, 59(4): 71-75. (in Chinese)
ZHOU L M, TIAN W M. Analysis of influencing factors on excavation stability of shield tunnel in sandy soil[J].Journal of Guiyang University (Natural Sciences), 2020, 15(2): 26-32. (in Chinese)
