单排水平冻结工程温度场数值模拟

Numerical Simulation of Temperature Field for Single Row Pipes Horizontal Freezing Engineering

该文以广州地铁某客运站折返线暗挖法施工隧道为例,研究了单排水平冻结工程温度场、冻结壁的交圈时间、冻结壁的厚度以及影响冻结效果的因素,包括冻结管数量与间距、原始地温和冻结管外壁温度。研究表明,冻结壁内任意点的温度是各冻结管共同作用的结果,冻结管数量越多,冻结效果越好,但温度主要受临近的3个冻结管影响。按盐水冷媒的通常温度冻结,冻结壁厚度难以超过3m;冻结管间距越小,冻结效果越好。按盐水冷媒的通常温度冻结,能使冻结壁交圈的冻结管间距不能超过2m;原始地温越高,冻结时间越长;冻结管外壁温度越低,冻结效果越好,冻结管外壁温度不宜高于-20℃。

The thesis is based on a constructed tunnel of back-turning line in a passenger station of Guangzhou subway,which is adopted by tunneling method.It studied temperature field of single row horizontal freezing pipes,cross-lap time of freezing wall,the thickness of freezing wall and the factors of influencing freezing effect,such as the quantity of freezing pipes and the distance between neighboring pipes,the original ground temperature and the temperature of freezing pipe outer surface.The study shows that the temperature of any point inside freezing wall is influenced interactively by all freezing pipes,and the more the quantity of freezing pipes are,the better the effect of freezing will be,but the temperature is mainly affected by three neighboring freezing pipes.If it is froze by normal temperature of salt water,the freezing wall thickness can not exceed 3m.If interval of neighboring freezing pipes is smaller,it will get better freezing effect.If it is froze by normal temperature with salt water,the interval of neighboring freezing pipes cannot beyond 2m.The higher the original ground temperature is,the freezing time will be longer.The lower the temperature of freezing pipe outer surface is,the freezing effect will be better,and the temperature of freezing pipe outer surface should not be higher than-20℃.