Immersed tube tunnels are usually placed on soft soil layers in cross-sea tunnelling engineering.Owing to the influence of stratum conditions and slope design,the longitudinal distribution of substratum layers is gene...Immersed tube tunnels are usually placed on soft soil layers in cross-sea tunnelling engineering.Owing to the influence of stratum conditions and slope design,the longitudinal distribution of substratum layers is generally uneven.Thus,the inhomogeneous deformation of the element-joint becomes the key factor in the failure of the immersed tube tun-nel.Therefore,a corresponding calculation method for joint deformation is needed to explore the deformation law of immersed tube tunnels.By constructing a three-section immersed tube tunnel analysis model(TTM),the relationship between the two types of deformation of the immersed tube tunnel structure in a longitudinal nonuniform soft soil foundation is described,and the deformation characteristics of the immersed structure under different boundaries are discussed.Based on the mechanical behaviour of the joint and foundation,according to the Timoshenko beam on the Vlasov two-parameter foundation(VTM),considering the tidal cyclic load during the operation and maintenance period,an example analysis is given.Moreover,the deformation characteristics and development trend of the immersed tube tunnel under the influence of different soil layers are discussed.The obtained results have a certain guiding significance for the deformation calculation of immersed tube tunnels.展开更多
To determine the appropriate soft foundation treatment for a river-crossing tunnel, freezing reinforcement design and technology were introduced based on the channel tunnel design and construction practice. Through fi...To determine the appropriate soft foundation treatment for a river-crossing tunnel, freezing reinforcement design and technology were introduced based on the channel tunnel design and construction practice. Through finite element analysis and engineering practices, two rows of horizontal perforated freezing pipes were designed and installed on both sides of a passage for tunnel rein- forcement, which produced the thickness and strength of frozen crust that satisfied the design requirements. These information are valuable for guiding the design and construction of river-crossing tunnels in coastal areas.展开更多
基金The work was financially supported by the Natural Science Foundation of Guangdong Province,China(Grant No.2022A1515011200)the State Key Laboratory for Geo-Mechanics and Deep Underground Engineering of China University of Mining&Technology(Grant No.SKLGDUEK2005)the Science and Technology Planning Project of Guangdong Province of China(Grant No.STKJ2021129).
文摘Immersed tube tunnels are usually placed on soft soil layers in cross-sea tunnelling engineering.Owing to the influence of stratum conditions and slope design,the longitudinal distribution of substratum layers is generally uneven.Thus,the inhomogeneous deformation of the element-joint becomes the key factor in the failure of the immersed tube tun-nel.Therefore,a corresponding calculation method for joint deformation is needed to explore the deformation law of immersed tube tunnels.By constructing a three-section immersed tube tunnel analysis model(TTM),the relationship between the two types of deformation of the immersed tube tunnel structure in a longitudinal nonuniform soft soil foundation is described,and the deformation characteristics of the immersed structure under different boundaries are discussed.Based on the mechanical behaviour of the joint and foundation,according to the Timoshenko beam on the Vlasov two-parameter foundation(VTM),considering the tidal cyclic load during the operation and maintenance period,an example analysis is given.Moreover,the deformation characteristics and development trend of the immersed tube tunnel under the influence of different soil layers are discussed.The obtained results have a certain guiding significance for the deformation calculation of immersed tube tunnels.
文摘To determine the appropriate soft foundation treatment for a river-crossing tunnel, freezing reinforcement design and technology were introduced based on the channel tunnel design and construction practice. Through finite element analysis and engineering practices, two rows of horizontal perforated freezing pipes were designed and installed on both sides of a passage for tunnel rein- forcement, which produced the thickness and strength of frozen crust that satisfied the design requirements. These information are valuable for guiding the design and construction of river-crossing tunnels in coastal areas.
