Random forest-based predictors for driving forces of earth pressure balance (EPB) shield tunnel boring machine (TBM)

2022 ◽  
Vol 122 ◽  
pp. 104373
Author(s):  
Xiangxun Kong ◽  
Xianzhang Ling ◽  
Liang Tang ◽  
Wenchong Tang ◽  
Yifan Zhang
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shisen Zhao ◽  
Shuchen Li ◽  
Zeen Wan ◽  
Manling Wang

When a slurry shield tunnel boring machine (TBM) encounters sticky ground during tunneling, mud cakes often occur on the cutter head due to the high stickiness of soil. The mud cakes caused several negative issues, such as high torque demand, advancement rate reduction, and additional costs. Existing studies have largely focused on Earth pressure balance TBMs; research on formation and mitigation measures of mud cakes in slurry shield TBMs is limited. Therefore, this study proposes the addition of dispersant to the slurry to prevent mud cakes during the tunneling of slurry shield TBMs by reducing stickiness of excavated clay. The basic properties of slurry were measured experimentally, and the effectiveness of dispersant in reducing the potential for mud cakes was investigated through mixing tests and viscosity experiments. A statistical analysis of the data was performed to determine relationships between slurry properties and material behaviors. The results showed that the slurry with dispersant had a lower viscosity and formed filter cakes more quickly, thereby meeting the performance requirements of a supporting fluid for slurry shield TBMs. Further, dispersant effectively reduced the empirical stickiness ratio and suspension viscosity. Therefore, a slurry with an appropriate dispersant content could effectively reduce the potential for mud cake formation.


Author(s):  
Kabir Nagrecha ◽  
Luis Fisher ◽  
Michael Mooney ◽  
Tonatiuh Rodriguez-Nikl ◽  
Mehran Mazari ◽  
...  

The earth pressure balance tunnel boring machine (TBM) is advanced excavation machinery used to efficiently drill through subsurface ground layers while placing precast concrete tunnel segments. They have become prevalent in tunneling projects because of their adaptability, speed, and safety. Optimal usage of these machines requires information and data about the soil of the worksite that the TBM is drilling through. This paper proposes the utilization of artificial intelligence and machine learning, particularly recurrent neural networks, to predict the operational parameters of the TBM. The proposed model utilizes only performance data from excavation segments before the location of the machine as well as its current operating parameters to predict the as-encountered parameters. The proposed method is evaluated on a dataset collected during a tunneling project in North America. The results demonstrate that the model is effective in predicting operation parameters. To address the potential issue of gathering sufficient data to retrain the model, the possibility of transferring the trained model from one tunnel to another is tested. The results suggest that the model is capable of performing accurately with minimal or even no re-training.


2014 ◽  
Vol 1065-1069 ◽  
pp. 373-377
Author(s):  
Jing Cao ◽  
Hai Xing Yang ◽  
Bo Liang ◽  
Hai Ming Liu

Chamber earth pressure is one of the significant parameters during the Earth Pressure Balance (EPB) shield construction processing. The soil arching effect is existence when the tunnel depth is enough. It is significant to consider the influence of arching effect to analyze the pressure in soil chamber in shield tunneling. In this paper, the influence of arching effect is considered to calculate the chamber earth pressure. Firstly, the soil is supposed as loose media, and the necessary buried depth of producing arching affects is deduced according to the loose media theory. Then, based on the characteristic of proper arching axis, the equation and the height of proper arch are obtained. At last, the calculation formula of minimum chamber earth pressure of EPB shield tunnel is deduced which can consider the effect of arching effect.


2001 ◽  
Vol 7 (1) ◽  
pp. 3-11
Author(s):  
Christoph Michael Goss

Abstract The objective of this paper is to provide insight to the application of state-of-the-art ground modification technology for Earth Pressure Balance (EPB) soft ground tunneling. The paper reflects data from a wide array of sources including conference proceedings, trade journal articles, manufacturer publications, books and personal experience. The paper first introduces the concept of soft ground tunneling and then discusses the Earth Pressure Balance Tunnel Boring Machine method. The bulk of the paper is spent discussing ground-conditioning agents, particularly foam. Use of, quantities, theory behind them, environmental impact, lab testing, and effects of foams are described. The paper concludes with a brief case study of the Sheppard Subway Twin Tunnels in Toronto, Canada. Attached to the paper is a comprehensive literature search on EPB tunneling, particularly with regards to foam use.


2011 ◽  
Vol 346 ◽  
pp. 364-371 ◽  
Author(s):  
Xu Chen ◽  
Zhu Feng Shao ◽  
Xiao Qiang Tang ◽  
Ping Fa Feng

Referring to the Earth Pressure Balance (EPB) shield with the diameter of 6.25m, a new experiment station of EPB shield is proposed, which is loaded with mechanical structure instead of traditional soil box. The structure of the experiment model is designed for the performance analysis of the EPB shield. The mechanical loading device, which is called the soil simulator, can simulate different geological environments. The soil simulator is capable of realizing three work states, such as earth balance pressure, earth under pressure, and earth over pressure. By adopting virtual prototype technology, parametric model of the shield station is established and the co-simulation scheme is determined. Besides, the kinematic analysis as well as variation principles between the displacement and driving forces of the propulsion system are obtained, which build the foundation for optimization design and control of the shield prototype.


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