Influence of grouting on rehabilitation of an over-deformed operating shield tunnel lining in soft clay

Liu, Zisheng; Wang, Rulu; Zhang, Dong Ming

doi:10.1007/s11440-018-0696-8

Cited by 70 publications

(15 citation statements)

References 27 publications

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“…In the mainland China, a light-disturbance grouting technique has been extensively adopted to control or reduce the transverse deformation of shield tunnels [3]. Unlike traditional structural reinforcement methods such as steel plate bonding [4], which solely enhance the structural stiffness and bearing capacity without addressing deformation, the grouting technique exerts additional stresses on both sides of the tunnel, effectively mitigating deformation and achieving the intended rehabilitation objectives.…”

Section: Introductionmentioning

confidence: 99%

New indices of the recovery effect of the large deformation shield tunnel based on a light-disturbance grouting model test

Ye,

Zhang,

Zhang

et al. 2024

IOP Conf. Ser.: Earth Environ. Sci.

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The sudden surface surcharge is a key disturbance that causes excess transverse deformation of the existing shield tunnel underneath. The light-disturbance grouting technique, which is applied on two sides of a tunnel spring-line, is an effective way to control or even recover the large tunnel structural deformation. Based on the 1g model test of grouting for the shield tunnel in the sand layer using the Shanghai Metro shield tunnel as a prototype, a numerical model is established based on the FLAC3D software. Meanwhile, the numerical simulation method of simulating grouting involves the application of the virtual expansion stress. The grouting transfer efficiency and recovery bias are proposed in this paper and used as the evaluation indexes of the recovery effect of light-disturbance grouting on the shield tunnel. The findings indicate that irrespective of various overloading modes and symmetrical single-row grouting, the transfer efficiency remains approximately 12%, which may potentially serve as a optimization index for determining the number of grouting rows. Moreover, the observed disparity in recovery bias within tunnels experiencing asymmetric deformation underscores the significance of joint behavior, emphasizing the necessity for closer monitoring during grouting procedures.

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Section: Introductionmentioning

confidence: 99%

New indices of the recovery effect of the large deformation shield tunnel based on a light-disturbance grouting model test

Ye,

Zhang,

Zhang

et al. 2024

IOP Conf. Ser.: Earth Environ. Sci.

View full text Add to dashboard Cite

show abstract

“…Shield tunneling is selected for its minimal environmental impact and is the preferred method for metro construction in soft ground regions like Shanghai (Zhang et al, 2019). The soft ground conditions in such areas are typically marked by high water content, porosity, compressibility, low shear strength, and sensitivity (Yin and Chang, 2009;Tan and Li, 2011).…”

Section: Introductionmentioning

confidence: 99%

Responses of metro shield tunnels to an adjacent deep excavation in Shanghai soft ground

Fang,

Jia,

Xie

2024

IOP Conf. Ser.: Earth Environ. Sci.

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Deformation in metro shield tunnels is a consequence of conducting adjacent deep excavations. Accordingly, this research examines the response of existing metro shield tunnels in Shanghai’s soft ground to nearby deep excavations, focusing on how tunnel deformation correlates with the distance to the excavation. Utilizing actual measurement data from metro shield tunnels located 12-45 m from an 11.5-24.1-m-deep excavation, the study initiates with a project overview before analyzing the deformation data of the metro tunnels. This analysis includes the settlement and transverse convergence of both upward and downward lines. Furthermore, by integrating the settlement history curve and settlement increment ratio statistics, the study explores the deformation of the metro tunnels across different construction stages of the adjacent excavation. Additionally, the effect of the distance to the excavation on metro tunnel deformation is discussed, considering identical excavation depths, supporting stiffness, construction levels, and soil conditions. This investigation aims to provide insights applicable to similar cases and inform future research.

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“…The external strengthening method involves strengthen the tunnel lining structure by grouting outside the tunnel. This method effectively reduces the lateral deformation of the tunnel and solves the problem of water leakage of tunnel segments and has been applied in Shenzhen and Shanghai subway tunnels [3,4]. However, the process of this method is complex, and there are many uncertainties in construction.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigations of a Tunnel Lining Segment Strengthened by In Situ Spraying Mortar

Wang

Zeng

et al. 2022

Applied Sciences

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After long-term operation, tunnel lining segments encounter various problems. Aiming at these problems, in this paper, we present a method of strengthening tunnel lining segments by in situ spraying mortar. An experimental study of the in situ spraying mortar was carried out to determine the compressive strength, flexural strength and interface properties (splitting tensile strength and shear strength) between concrete and H-70 mortar. The experimental results show that the mechanical properties of H-70 mortar are less dependent on the curing humidity than ordinary concrete under standard curing conditions, the 7-day compressive strength of H-70 is 55 MPa, which is 61% of the 28-day compressive strength. This shows that H-70 has high early strength and is very suitable for rapid reinforcement. The interface roughness has a significant effect on the splitting tensile strength, and it can be increased by chiseling to improve the bearing capacity of the strengthened structure. A full-scale loading experiment was carried out on the segment strengthened by in situ spraying mortar. The loading process, failure mode and ultimate bearing capacity of the strengthened structure were analyzed by full-scale loading experiment. The research shows that the ultimate bearing capacity of the tunnel segment strengthened by in situ spraying mortar increased significantly. The ultimate bearing capacity of the strengthened structure is 10% higher than that of the unstrengthened structure. The advantages and disadvantages of in the situ spraying-mortar strengthening method are analyzed in comparison with the internal-tension steel-ring strengthening method.

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Influence of grouting on rehabilitation of an over-deformed operating shield tunnel lining in soft clay

Cited by 70 publications

References 27 publications

New indices of the recovery effect of the large deformation shield tunnel based on a light-disturbance grouting model test

New indices of the recovery effect of the large deformation shield tunnel based on a light-disturbance grouting model test

Responses of metro shield tunnels to an adjacent deep excavation in Shanghai soft ground

Experimental Investigations of a Tunnel Lining Segment Strengthened by In Situ Spraying Mortar

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