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以南京地铁二号线逸仙桥车站盾构出洞水平杯型冻结加固实例为工程背景,建立有限元温度场计算模型,对冻结壁交圈时间及其底部冻结壁厚度的发展规律进行了研究。结果表明:冻结条件相同时,较低的地层初始温度、盐水温度、潜热、热容量和较大的冻结管直径、导热系数对应较短的交圈时间、较低的地层温度与较大的短管底部冻结壁厚度;各因素取值范围内,短管交圈时间为7～17d,冻结40d时,短管底部冻结壁厚度可达30～77cm,该“保护层”厚度有效确保了拔除板块区冻结管后杯型冻结壁整体稳定性。
Taking the horizontal cup-type freezing reinforcement of the shield tunnel in Yixianqiao Station of Nanjing Metro Line 2 as an example, the calculation model of the temperature field in the finite element is established, and the law of development of the intercalation time of the frozen wall and the thickness of the frozen wall at the bottom is studied . The results show that the initial formation temperature, brine temperature, latent heat, heat capacity and larger diameter of frozen tube, thermal conductivity correspond to shorter lap time when the freezing conditions are the same, and the lower formation temperature is corresponding to the larger short tube The thickness of the frozen wall at the bottom of the short tube; within the range of various factors, the short tube cross-lap time is 7 ~ 17d, the frozen wall thickness at the bottom of the short tube reaches 30 ~ 77cm after freezing for 40d, which effectively ensures the removal The overall stability of the cup - shaped frozen wall after the freezing zone of the block area.