Key technologies and equipment of quickly and safely building life support and rescue channel in mine disaster

In case that persons are trapped underground as a result of shaft and roadway damage due to a major disaster accident in a mine, the most effective way of rescue is to construct the rescue channel in a safely and efficient manner. The rescue channel is divided into the underground and ground types. Building a large diameter rescue channel through the collapsed section is the most direct way if underground construction conditions are available. However, if no underground construction conditions are available or it is prone to secondary disasters, it is necessary to drill small diameter rescue holes on the ground quickly and accurately to determine the location and physical condition of the trapped people underground, and deliver the supplies in time. Then, a large diameter relief well should be constructed to ensure that the trapped people can be pulled out of the well with the special rescue equipment. The research covers multiple disciplines in many fields such as mechanical engineering, drilling engineering, electrical engineering, software engineering, hydromechanics, geotechnical mechanics, dynamics, and advanced control technology. Meanwhile, the key technologies and equipment for drilling rescue were developed with the theoretical analysis, numerical simulation, experimental research, type test and engineering demonstration in combination, focusing on the main line of development of construction equipment for rescue channel, development of construction technologies for life support channel, development of construction technologies for large-diameter rescue channel, development of ground lifting rescue equipment, and integration and engineering test of technologies and equipment. Three sets of emergency rescue integrated equipment have been developed. ZMK5550TZJF50/120 rescue truck-mounted drilling rig has the maximum lifting force of 1 200 kN and the maximum torque of 50 000 N·m. The integrated centralized control system of drilling rig and supporting tools was developed, with the single tripping efficiency of 3 min/rig. In terms of XZJ5240JQZ30 rescue lifting vehicle, the communication monitoring and control system based on multi-sensor information fusion was developed, and the maximum rescue depth of the lifting system is 848 m. ZDG1500 downhole large-diameter pipe jacking machine has a diameter of 1 630 mm and the maximum jacking force of 8 541.2 kN. In addition, three construction technologies of mine emergency rescue channel were developed, including the fast and accurate drilling technology of life support hole in complex formation, the accurate, safe and efficient drilling and roadway penetration technology of large-diameter ground relief well, and the rapid construction technology of pipe jacking in underground large-section rescue channel. The first integrated research and engineering tests for the construction of life support hole and large-diameter relief well, as well as rescue lifting, were carried out in the Meihuajing Mine of Ningmei Coal in Ningxia Province. Specifically, a life support hole at a diameter of 215.9 mm and a depth of 670.5 m was constructed in 46.83 h, with a downhole horizontal displacement offset of 0.27 m, satisfying the drilling requirements of 72-hour “golden window” for rescue. A relief well at a diameter of 830 mm and a depth of 654.1 m was drilled with a downhole horizontal displacement of 0.19 m and the media collapsed into the hole about 7.5 m³. Besides, the technology and equipment for rescue lifting was successfully tested in the relief well. Moreover, the test of simulated collapse of pipe jacking drilling project was carried out in the crushing field of Guangdong Foundation Engineering Group Co., Ltd., with a construction length of 102.5 m, a daily footage of 43.92 m and a jacking error of 0.35 m. Further, the relevant results were applied in the emergency rescue of five mine disasters, including Hunan Yuanjiangshan Coal Mine, Shandong Qixiashan Gold Mine and Xinjiang Fengyuan Coal Mine. In general, the three construction technologies of rescue channel and the three sets of rescue equipment developed together form the combined construction technology and equipment system underground and aboveground of mine with independent intelligent property rights, capable of meeting the needs of mine emergency rescue at a depth of 600 m, thus providing technical and equipment support for emergency rescue of mine in China.