Practical prediction method on thaw deformation of soft clay subject to artificial ground freezing based on elaborate centrifuge modeling experiments

2022 ◽  
Vol 122 ◽  
pp. 104352
Author(s):  
Jie Zhou ◽  
Wenqiang Zhao ◽  
Yiqun Tang
Keyword(s):  
Soft Clay ◽  
Prediction Method ◽  
Centrifuge Modeling ◽  
Ground Freezing ◽  
Artificial Ground Freezing

scholarly journals Research on Microstructure of Soft Clay under Various Artificial Ground Freezing Conditions Based on NMR

2021 ◽  
Vol 11 (4) ◽  
pp. 1810
Author(s):  
Bowen Kong ◽  
Shaoheng He ◽  
Tangdai Xia ◽  
Zhi Ding
Keyword(s):  
Pore Size ◽  
Structural Damage ◽  
Soft Clay ◽  
Freezing And Thawing ◽  
Cutoff Value ◽  
Freezing Method ◽  
Ground Freezing ◽  
Artificial Ground Freezing ◽  
Time Gap ◽  
Size Data

Nuclear magnetic resonance (NMR) can help to collect soft clay pore size data. This paper uses NMR to study the effect of freezing duration, the gap time between two freezing actions and thawing temperature on the pore size distribution (PSD) in soft clay. It was found that most of the freezing and thawing progress was completed during the first two hours. A longer time gap between the first and second freezing cycles leads to greater structural damage. An appropriate thawing temperature results in less subsidence induced by the artificial ground freezing (AGF). A new method to distinguish water types for various freezing conditions is proposed. This freezing method to determine the cutoff value could fill the defect in the previous methods.

Effect of Freeze Pipe Eccentricity in Artificial Ground Freezing Applications

2020 ◽  
Author(s):  
Ahmad F. Zueter ◽  
Minghan Xu ◽  
Mahmoud A. Alzoubi ◽  
Agus P. Sasmito
Keyword(s):  
Energy Consumption ◽  
Radiation Heat Transfer ◽  
Conservation Equation ◽  
Underground Mines ◽  
Phase Front ◽  
Two Phase ◽  
Ground Freezing ◽  
Deep Underground ◽  
Artificial Ground Freezing ◽  
Conjugate Model

Abstract Building concentric tubes is one of biggest practical challenges in the construction of freeze-pipes of artificial ground freezing (AGF) applications for deep underground mines. In this study, the influence of tubes eccentricity on phase-front expansion (i.e., expansion of the frozen body) and energy consumption of AGF systems is analyzed. A 1+1D semi-conjugate model that solves two-phase transient energy conservation equation is derived. The model is firstly validated against experimental data and then verified with a fully-conjugate model from the literature. After that, the model is extended to a field scale of typical deep underground mines to study freeze-pipe eccentricity. The results show that an eccentric freeze pipe can reduce the phase-front expansion by around 25%, as compared with a concentric one. Also, the geometrical profile of the phase-front is significantly influenced by the freeze-pipe eccentricity. Furthermore, in the passive zone, where AGF coolants are isolated from the ground to reduce energy consumption, freeze pipe eccentricity can increase the coolant heat gain by 10%. This percentage can increase up to 200% if radiation heat transfer is minimized.

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