Finite Element Analysis on 3D Freezing Temperature Field in Metro Cross Passage Construction

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• 作者：Haiqing Song ; ^{haiqingsong80@hotmail.com} ; Haibing Cai ; Zhishu Yao ; Chuanxin Rong ; Xiaojian Wang
• 关键词：Cross passage ; Artificial ground freezing ; 3D freezing temperature field ; Finite element analysis
• 刊名：Procedia Engineering
• 出版年：2016
• 出版时间：2016
• 年：2016
• 卷：165
• 期：Complete
• 页码：528-539
• 全文大小：1627 K
• 卷排序：165

文摘

Artificial ground freezing has been widely practiced in construction of metro cross passage in soft ground. The ground freezing process creats a frozen mass of improved compressive strength and impermeability, which will make the ground safely stand by itself at the point of excavation and prevent cave-ins from happening. With this technique, freeze pipes are arranged like stretchers of a half opened umbrella from two ends of the cross passage. Usually finite element analysis on transient temperature field of frozen soil can simulate propagation process of frozen wall (frozen barrier) before construction and evaluate rationality of freeze pipes arrangement. Usually finite element analysis on temperature field has been mostly simplified to the plane problem, which is difficult to simulate the actual situation because freeze pipes are not horizontal parallel along the cross passage. In this article, for one cross passage in Shanghai Metro Line No. 13, taking into account the initial conditions and boundary conditions, such as such as ground temperature, ground surface convection and latent heat of phase change, a 3D finite element numerical model is presented for the temperature field evolution. The modeling yields a detailed distribution pattern for freezing temperature field. The results are compared with the in-situ monitoring soil temperature changes, which verify the reliability of finite element numerical analysis.