Performance of Slurry Shield Tunnelling in Mixed Strata Based on Field Measurement and Numerical Simulation

Cui, Jian; Xu, Wanghao; Fang, Yong; Tao, Liming; He, Chuan

doi:10.1155/2020/6785260

Cited by 9 publications

(3 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, scholars have conducted field experiments, theoretical analyses, and numerical simulations to analyze the grouting pressure distribution and pressure dissipation process that determine the regularity of grout diffusion ( 13 – 15 ). Yang et al adopted the Shanghai Yangtze River tunnel as the research object, established the relationship between the stability and early strength of the tunnel, and developed longitudinal and lateral calculation models ( 16 ).…”

Section: Literature Reviewmentioning

confidence: 99%

Optimization of the Grout Mix Ratio and Simulation Test of Shield Tail Grouting Similarities in a Water-Rich Fine Sand Layer

Song,

Li,

Wang

et al. 2023

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

When shield tunneling is performed in water-rich silt and fine sand strata, the grout becomes runny when diluted by groundwater. After dilution, the filling effect of the grout is not significant, and the level of surface settlement is very high. In this study, based on bidding section 04 of Tianjin Metro Line 11, traditional grouting materials were selected to conduct response surface method (RSM) tests. The purposes of the RSM analysis were to analyze the interactions between materials and their influences on grout performance and to optimize the grout mix ratio. Various admixtures were compared to assess the effects of different admixtures and compositions on the dispersion resistance and flow performance of the grout. Finally, a shield synchronous grouting test system was developed, and a similar indoor grouting simulation test was performed to analyze the influences of the different admixtures on the filling effects and to determine a reasonable grout mix ratio. The following three results were obtained. (1) The RSM was suitable for grout performance prediction and grout mix ratio optimization, and hydroxyethyl cellulose could improve the grout performance and increase the bond performance between the cementing material and aggregate. (2) Admixture incorporation enhancement could improve the grout utilization rate and increase the diffusion distance at the top of the tunnel, which would be conducive to filling the gap at the tail end of the shield. (3) The optimal preparation scheme of grout in water-rich fine sand formations included a water–binder ratio of 0.72, cement–sand ratio of 0.80, fly ash content of 5%, bentonite content of 14.94%, and admixture content of 0.8%–0.9%

show abstract

Section: Literature Reviewmentioning

confidence: 99%

Optimization of the Grout Mix Ratio and Simulation Test of Shield Tail Grouting Similarities in a Water-Rich Fine Sand Layer

Song,

Li,

Wang

et al. 2023

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

show abstract

“…It has unique advantages in material elastic-plastic analysis, large deformation analysis, and simulation of construction processes. Some scholars have already used FLAC3D to analyze the stability of tunnels in the sand-cobble mixed strata and obtained good results (Zhang et al, 2019;Cui et al, 2020;Di et al, 2023).…”

Section: Introductionmentioning

confidence: 99%

Stability analysis of tunnel in sandy cobble strata under different pre-reinforcement techniques

Zhao

Xue³

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

Excavating tunnels in sandy cobble strata carries a high risk of ground collapse caused by instability of the tunnel face. In order to prevent instability at the tunnel face during excavation, this paper focuses on studying the effects of various pre-reinforcement method on the stability of tunnel in the sand-cobble strata. Firstly, pre-reinforcement projects suitable for these tunnels are proposed. Then, using FLAC3D to established numerical models, then simulate the excavation process under six different working conditions: non-reinforced, pre-reinforcement with advance small pipes, pre-reinforcement with pipe-roof, pre-reinforcement with GFRP bolts, pre-reinforcement with advance small pipes and GFRP bolts, and pre-reinforcement with pipe-roof and GFRP blots. The displacement and stress fields of the soil behind and in front of the tunnel face under each condition are obtained. The results show that the use of GFRP bolts for pre-reinforcement can effectively control the deformation of the surrounding rock in front and behind the tunnel face, and pre-reinforcement with advance small pipes or pipe-roof can reduce the settlement of the tunnel crown. Pre-reinforcement by the combination of GFRP bolts with advance small pipes or pipe-roof can better ensure the stability of the tunnel during the excavation process.

show abstract

“…Shield tunneling has many advantages, such as high efficiency of mechanized construction and a small effect on the underground pipeline, pile foundation, ground deformation and ground traffic. Therefore, this method is often considered the best choice for subway tunnel construction (Liu et al, 2020;Lv et al, 2020;Yang et al, 2020;Cui et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Influence of grouting pressure volatility on additional response of adjacent pile foundation in shield construction

Zhang¹,

Li²,

Zhang³

et al. 2022

Journal of Theoretical and Applied Mechanics

View full text Add to dashboard Cite

Soil parameters along the heading direction are subjected to spatial variability during shield construction, so grouting pressure requires constant adjustment to ensure ground stress stability. This causes grouting pressure to fluctuate around the design pressure/curve. Therefore, the influence of the grouting pressure volatility on the adjacent loaded-pile foundation should be considered in shield tunneling. In this study, a refined numerical simulation of the shield construction process is conducted using the Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D) software. A total of 300 groups of grouting pressure parameters with a skewed normal distribution are input into the numerical model. Then, the influence of the construction parameter uncertainty on the adjacent loaded-pile foundation is analyzed. Finally, the back analysis method is conducted based on the monitored data to evaluate how the construction process affects the pile foundation. The calculation results are compared with those of the traditional finite element method. The results indicate that in the tunneling process, the grouting pressure fluctuation greatly affects the additional bending moment of the adjacent pile foundation. Under the influence of the grouting pressure, the additional axial force and additional bending moment of the pile foundation also follow the skewed normal distribution. The back analysis results of the pile foundation are greater than those of the typical numerical method by about 60% 100%, that is using the back analysis calculation results to evaluate the pile foundation additional response can reduce the risk.

show abstract

Performance of Slurry Shield Tunnelling in Mixed Strata Based on Field Measurement and Numerical Simulation

Cited by 9 publications

References 32 publications

Optimization of the Grout Mix Ratio and Simulation Test of Shield Tail Grouting Similarities in a Water-Rich Fine Sand Layer

Optimization of the Grout Mix Ratio and Simulation Test of Shield Tail Grouting Similarities in a Water-Rich Fine Sand Layer

Stability analysis of tunnel in sandy cobble strata under different pre-reinforcement techniques

Influence of grouting pressure volatility on additional response of adjacent pile foundation in shield construction

Contact Info

Product

Resources

About