Research on the cuttings discharge in air cushion chamber of slurry shield based on CFD-DEM coupling method--颗粒学报PARTICUOLOGY

Wang, H., Ding, W., Yang, W., Wang, C., Yu, W., & Wang, Z. (2024). Research on the cuttings discharge in air cushion chamber of slurry shield based on CFD-DEM coupling method. Particuology, 91, 88-105. https://doi.org/10.1016/j.partic.2024.02.008

Research on the cuttings discharge in air cushion chamber of slurry shield based on CFD-DEM coupling method

Han Wang^a, Wantao Ding^a *, Weimin Yang^a *, Chengzhen Wang^b, Wenduan Yu^b, Zhicheng Wang^b

a School of Qilu Transportation, Shandong University, Jinan, 250002, China
b China Railway 14th Bureau Group Co., Ltd, Jinan, 250101, China

10.1016/j.partic.2024.02.008

Volume 91, August 2024, Pages 88-105

Received 29 November 2023, Revised 16 January 2024, Accepted 27 February 2024, Available online 15 March 2024, Version of Record 21 March 2024.

E-mail: dingwantao@sdu.edu.cn; weimin.yang@sdu.edu.cn

Highlights

• A numerical model completely reflecting cuttings discharge process is established based on CFD-DEM coupling method.

• Effects of various factors on cuttings discharge are investigated.

• Reasons for the effects of each factor are analyzed.

• Relevant suggestions for practical engineering are provided.

Abstract

The rapid discharge of cuttings from the air cushion chamber is crucial for the construction safety and excavation efficiency of the slurry shield. Previous studies have mainly focused on the transport characteristics of cuttings in the slurry discharge pipe, while the complete process of cuttings entering the slurry discharge pipe from the air cushion chamber until they are discharged was often overlooked. Based on the CFD-DEM coupling method and combined with actual engineering, this paper established a numerical model that can more completely reflect the cuttings discharge process during slurry shield tunneling, and the effects of the slurry velocity at slurry gate and scouring pipes, inclination angle of slurry discharge pipe, cuttings diameter and shape coefficient were investigated by analyzing the variation in the mass flow rate, mass of discharged cuttings, and discharged ratio. The results revealed that increasing the slurry velocity can promote the discharge of cuttings. To keep the discharged rate at a high level, it is recommended that the slurry velocity at the slurry gate should be greater than 0.15 m/s. Reducing the inclination angle of the discharge pipe is conducive to the rapid discharge of cuttings. Cuttings with large diameter or small shape coefficient are more prone to accumulate in the air cushion chamber and cause clogging risk. The research results not only help to improve engineers' understanding of cuttings discharge in slurry shield, but also provide practical guidance for formulating relevant construction measures.

Graphical abstract

Keywords

Slurry shield; CFD-DEM coupling method; Cuttings discharge; Air cushion chamber; Slurry discharge pipe

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