论文部分内容阅读
在西部白垩系地层煤矿立井冻结法凿井施工过程中,通过分析2个代表性水平层位温度的现场监测数据,得到了冻结凿井期间外壁及冻结壁温度变化的基本规律。研究表明:外壁浇筑后即出现温度迅速增长阶段,两监测层位在1.5 d内温度上升幅度最大可达68.4℃,且粗粒砂岩受水化热影响的温度上升速率大于细粒砂岩;大量水化热使两监测水平保持了较长的正温养护时间,对外壁混凝土早期强度增长有利;同时,释放的水化热使冻结壁出现大范围升温以至局部融化(融化深度达305 mm),对冻结壁的强度造成不利影响。通过分析和探讨水化热对井壁及冻结壁的影响规律,对西部白垩系地层井筒冻结工法设计与施工具有重要意义。
During the construction of the mine shaft freezing shaft method in the western Cretaceous strata, the basic laws of the temperature variation between the outer wall and the frozen wall during freezing shaft sinking were obtained by analyzing the field monitoring data of two representative horizontal layer positions. The results show that the rapid temperature increase occurs after the external wall is poured. The maximum temperature rise of the two monitoring beds can reach 68.4 ℃ in 1.5 days, and the temperature rise rate of coarse sandstone affected by hydration heat is higher than that of fine sandstone. The heat treatment kept the two monitoring levels for a longer positive temperature curing time, which was beneficial to the early strength growth of concrete in the outer wall. Meanwhile, the released hydration heat caused a wide range of temperature increase and partial melting of the frozen wall (melting depth of 305 mm) The strength of the frozen wall is adversely affected. Through analyzing and discussing the influence law of hydration heat on the borehole walls and frozen walls, it is of great significance to design and construct the wellbore freezing method in the Cretaceous strata in western China.