Single excavation face method for super-large-span bifurcated tunnels

Tan, Zhiying; Zhou, Zhenliang; Kong, Heng; Zhao, Bojian; Zhao, Jinpeng

doi:10.1680/jgeen.20.00222

Cited by 5 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pilots and steps are adopted to excavate cross-passage (Tan et al, 2021;Xu et al, 2021). Temporary bottom sealing is done when the shaft is excavated to 1.5 m below the inverted arch of Frontiers in Earth Science frontiersin.org each pilot.…”

Section: Cross-passagementioning

confidence: 99%

“…The excavation of a three-layer guide tunnel to five-layer guide tunnel has little influence on the surface. Figure 12 instantaneous The reason for this is that the deep hole grouting (pressure 0.5-0.8 MPa) is carried out before the t crosspassage is excavated, which makes the surface uplift (Zhang et al, 2018a;Zhao et al, 2021). When the guide hole of the first layer of the cross-passage is excavated through the existing line (that is, step 1), the settlement value of the DB-08-01 monitoring point is −4.56 mm, accounting for about 76.305% of the total settlement.…”

Section: Surface Subsidence Curvementioning

confidence: 99%

See 1 more Smart Citation

Tunneling construction technology of shafts and cross-passages under strictly controlling deformation of the existing railway

Liu

Xu²,

Li³

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

Underground construction will have more or less adverse effects on adjacent existing buildings with more and more existing buildings above ground. However, this situation has only been reported by a small number of researchers. In view of this, this article takes the existing airport line shaft and horizontal passage project in the western suburb of Beijing Metro Line 12 as the background to study the impact of the construction of subway station and shaft passage on the adjacent existing railway. Based on the above project reality, under the action of pavement load, the effects of different parameters (the distance between the surface measuring point and the middle line of the transverse passage and the substep of construction loading sup step) on the surface settlement and track deformation of the shaft and cross-passage through the existing railway are studied by numerical analysis method. The calculation results show that the construction method of shaft and cross passage is reasonable. The comprehensive reinforcement measures of subgrade, rail and hole are effective, effectively controlling the deformation of subgrade and rail within the standard value (surface settlement ≤60 mm, rail deformation ≤6 mm). In addition, the numerical simulation data can better represent the actual situation as a whole.

show abstract

Section: Cross-passagementioning

confidence: 99%

Section: Surface Subsidence Curvementioning

confidence: 99%

Tunneling construction technology of shafts and cross-passages under strictly controlling deformation of the existing railway

Liu

Xu²,

Li³

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…Due to the late start of single-hole four-lane highway tunnels, research in the field of tunnel engineering on large-span highway tunnels mainly focuses on single-hole threelane highway tunnels and double-track railway tunnels [8][9][10], while there are limited studies on single-hole four-lane super large-span highway tunnels. Previous research on large-span highway tunnels has mainly focused on construction methods [11,12], support parameters [13][14][15], and stability control of surrounding rock [16][17][18] during construction. Nevertheless, there has been less attention paid to the stress properties of the secondary lining of large-span highway tunnels, and related research has mainly focused on load effects.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Behavior of Secondary Lining in Super Large-Span Tunnels Considering Temperature Effects

Dong,

Luo,

Chen

et al. 2024

Symmetry

View full text Add to dashboard Cite

Temperature stress has a significant impact on the structural stress of (super) large-span tunnel lining, which can easily lead to structural fatigue damage and premature cracking. With the increasing scale and quantity of super large-span tunnels, the issue of temperature stress in secondary lining has attracted widespread attention. Previous studies have paid little attention to the influence of temperature stress on the structural internal forces of ordinary small–medium-span tunnels, but this influence cannot be ignored for super large-span tunnels. We take the Letuan Tunnel (a double-hole eight-lane tunnel) of the Binzhou-Laiwu expressway renovation and expansion project in Shandong Province as a case study and analyze the mechanical response of the secondary lining through on-site measurement. Moreover, a numerical simulation was conducted to evaluate the effects of self-weight and temperature stress on the secondary lining of the case tunnel. The results indicate that: the stress of the secondary lining concrete and steel bars is greatly affected by seasonal temperature changes. The compressive stress of the concrete and steel bars is significantly greater in summer than in winter, and the tensile stress is greater in winter than in summer. Furthermore, multiple measurement points have shown a phenomenon of transition between tensile and compressive stress states. The stress of concrete and steel bars fluctuates periodically with a sine function over time, with a fluctuation period of one year. The structural stress increases with the increase of summer temperature and decreases with the decrease of winter temperature. The fluctuation amplitude of stress in the inner side of the lining concrete and steel bars is greater than that on the outer side. Among them, the stress amplitudes of the inner and outer sides of the concrete are between 0.77–1.75 MPa and 0.44–1.07 MPa, respectively, and the stress amplitudes of the inner and outer steel bars are between 5–31 MPa and 7–13 MPa, respectively. The safety factors in summer are lower than those in winter. The minimum safety factors for secondary lining in summer and winter are 3.4 and 4.6, respectively, which can meet the safety requirements for service. The average axial forces of the secondary lining under the coupling effects of self-weight and temperature in winter and summer are 528 MPa and 563 MPa, respectively, which are significantly greater than the combined axial forces under their individual effects. The bending moment distribution of the secondary lining at the tunnel vault, inverted arch, wall spring and other positions under the coupling effect of self-weight and temperature is different from or even opposite to the bending moment superposition result under the two individual actions. The achieved results reveal that the influence of temperature stress on the service performance of the lining structure cannot be ignored, and the research results can provide useful reference for similar tunnels and related studies.

show abstract

Mechanical responses of a shallow-buried super-large-section tunnel in weak surrounding rock: A case study in Guizhou

Zhao¹,

Tan²,

Yu³

et al. 2023

Tunnelling and Underground Space Technology

View full text Add to dashboard Cite

Single excavation face method for super-large-span bifurcated tunnels

Cited by 5 publications

References 11 publications

Tunneling construction technology of shafts and cross-passages under strictly controlling deformation of the existing railway

Tunneling construction technology of shafts and cross-passages under strictly controlling deformation of the existing railway

Mechanical Behavior of Secondary Lining in Super Large-Span Tunnels Considering Temperature Effects

Mechanical responses of a shallow-buried super-large-section tunnel in weak surrounding rock: A case study in Guizhou

Contact Info

Product

Resources

About