冻结管断管原因及冻结温度场数值计算分析

The numerical simulation of freezing temperature field and the reasons of freezing pipes broken

杨村煤矿副井安全顺利通过井筒掘砌的薄弱环节深厚粘土层位,但出现了多根冻结管断裂现象。该粘土层导热性能差,冻土发展速度慢,冻土强度低,同时,施工过程中掘砌段高大,井帮暴露时间长,从而引起较大的井帮位移和底鼓量,是造成冻结管断裂的主要原因。根据冻结管的实际偏斜位置,同时考虑冻结管断管影响,建立有限元计算模型,计算分析了该层位的冻结温度场分布情况,井帮温度为-10^-13℃之间,井帮温度数值计算结果与实测结果相差-0.7~0.4℃,表明数值计算结果是可靠的,可为淮南矿区深厚粘土层冻结设计和施工提供参考。

Auxiliary shaft in Yangcun mine has safely passed the deep clay layers, while several freezing pipes are broken. A main reason is the large displacements in well and bottom hole, which caused by the low strength frozen clay layer with bad heatconducting property and slow freezing speed, and an other reason is digging too fast during the construction progress. Here builds FEM model on the basis of the real site of freezing pipes and consider the impacts of broken pipes. And the paper analyzes the freezing temperature field by numerical simulation. The numerical results show that the wells temper atures are between-10℃ and-13℃ and similar with the real results. The numerical results are relia ble. That can be used as the reference for the design and construction of freezing deep clay layer in Huainan mine area.