Construction technology of hydrologic hole in frozen shaft pipe of soft rock stratum in west China
The geological characteristics of thin aquifuge and thick aquifer in the western soft rock stra-tum make it difficult to report the hydrological hole when the shaft is constructed by freezing method.However,hydrologic hole is the main basis to judge the development law of frozen wall and determine the time of shaft excavation.In order to ensure the accurate reporting of hydrologic hole,the annular space mud replacement technology was used to seal the annular space between the casing and the sur-rounding rock of the hydrological hole,so as to ensure the effective between the casing and the forma-tion and avoid the water flow between the upper and lower layers.The feasibility of the technology was verified by engineering practice,which provides a valuable reference for shaft repair freezing engi-neering and similar projects.