In this paper,a three-dimensional numerical model was established to study the development and distribution of the temperature field of the frozen soil curtain wall of Yushan Park Station －Suzhou Leyuan Station of Suzhou Subway.The optimized design scheme was also proposed for comparison analysis.It was mainly concluded that the weakest place of the entire connected aisle was at x=－10.7m,in which a small row of frozen tubes can be embedded to enhance the freezing effect;cooling laws of path 1,path 3 and path 5 are similar,which means the excavation area temperature is much higher than the temperature of frozen soil curtain area.The temperature of each analysis point was gradually reduced with the passage of time,and it was more difficult to excavate close to the frozen tube when the soil was in much lower temperature and higher strength.The cooling laws of the path 2 and path 4 were similar,which means the temperature of each analysis point is kept at around 18 ℃,and the temperature gradually decreases with the passage of time.The distance between the curves and the temperature decrement was approximately equal in every 5 days.The temperature of the soil in the upper tunnel was higher than that in the lower tunnel.It was shown that the dropping temperature along the X－axis(ie,vertical)was similar,and the dropping temperature along the Y－axis(ie,the transverse direction)was similar.The optimizing program to set the level of freezing tube could reduce the difficulty of the construction and cost savings.The results can provide technical reference for future similar engineering design.%本文结合苏州地铁玉山公园站-苏州乐园站区间联络通道冻结加固工程,建立三维数值模型对该工程冻土帷幕温度场发展与分布规律展开研究,同时提出优化设计方案并进行对比分析.主要得出:整个联络通道最薄弱的地方是x=-10.7 m处土体,可在该部位打设一小排冻结管来增强冻结效果;路径1、路径3和路径5降温规律相似,即开挖区温度比冻土帷幕区温度高很多,随着时间推移,各个分析点的温度逐渐降低,且离冻结管越近,土体温度越低,其强度越高,越难开挖.路径2和路径4降温规律相似,即各分析点温度基本保持在原始地温18℃左右,随着时间的推移,温度逐渐降低;每隔5 d,曲线之间间距大致相等,降温幅度大致相等,靠上行线隧道端口土体温度较靠下行隧道端口土体温度高.可知沿着X轴方向(即纵向)降温规律相似,沿着Y轴方向(即横向)降温规律相似;采取优化方案将冻结管水平打设,可降低施工难度及节约成本.所得结果可为今后类似工程设计提供技术参考依据.
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