Key technologies of emergency response and large diameter borehole for mine surface rescue

Objective Large diameter lifesaving holes have been successfully applied multiple times in emergency rescue operations of surface mining drilling. However, there are still shortcomings in rapid deployment and cross-regional rescue, and the technological adaptability of large diameter lifesaving holes in coping with complex strata is insufficient. Methods From the perspective of emergency rescue as a whole, focusing on rescue efficiency, key technologies such as enhancing response capabilities and adapting drilling techniques for complex strata were summarized. An emergency response process for surface mining drilling rescue was constructed, specifying improvements in contingency plan activation, response actions, and response speed. Hierarchical cross-regional rescue mobilization mechanisms and pre-drilling technical support response mechanisms were established. The drilling process characteristics of loose strata and bedrock layers for large diameter lifesaving holes were analyzed, proposing solutions for construction challenges in complex strata such as fragmentation and high water inflow, and identifying typical issues in rescue enhancement processes. Results and Conclusions The study demonstrates that: (1) A scientific emergency response mechanism for surface mining drilling rescue is one of the important ways to improve rescue efficiency, by adopting hierarchical cross-regional rescue mobilization mechanisms and pre-drilling technical support response mechanisms, emergency response efficiency can be effectively increased by 2.3 times. (2) An efficient well construction solution for large diameter lifesaving holes under complex strata conditions has been developed and applied in the experimental project of Jiuding Mountain Mine in Jining, achieving a final hole depth of 403.2 m, a hole diameter of 580 mm, and an average mechanical drilling speed of 2.5 m/h. The total time from emergency response to rescue enhancement was reduced to 311.95 hours, improving overall rescue timeliness by 47%. (3) In terms of rescue timeliness, efficiency improvements in the rescue preparation phase are superior to those in the implementation phase, and enhancing emergency response capabilities is more achievable. Therefore, mining rescue teams should focus on improving emergency preparedness and rapid response capabilities, even when drilling techniques and equipment enhancements are limited. The research results meet the emergency rescue needs of mines shallower than 400 m, provide guidance for mining rescue teams to establish emergency response mechanisms, offer references for the construction design of large diameter lifesaving holes, and have significant guiding implications for emergency rescue in surface mining drilling.