Birth Record of Comprehensive Excavation in Hard Rock of Extremely Complex Coal Mines

Since the beginning of this year, Hancheng Mining's Xiayukou Mine has developed a series of measures to ensure excavation and continuity under the guidance of the requirements of "three optimizations and two improvements" and "one lane, one policy". The monthly advance of rock roadway comprehensive excavation has increased from 120 meters at the beginning of the year to 241 meters, setting a record for the highest level of hard rock comprehensive excavation in extremely complex coal mines in Shaanxi Province

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Tree Concepts and Increase Confidence

At the end of 2021, the mine took the opportunity of Hancheng Mining to comprehensively promote the comprehensive excavation construction process. Faced with many challenges such as long underground transportation lines, severe roadway deformation, and poor disaster management conditions, through research and analysis, serious summary, and establishment of the goal of achieving a rock roadway footage of over 200 meters.

In order to comprehensively improve the comprehensive management level, the mine has innovatively proposed the "dual standard" operation concept of "reaching the standard upon commencement and reaching the standard upon operation". It is explicitly required that all projects must meet production preparation standards, standardized construction standards, and safety assessment standards before starting construction. During the engineering operation process, it is necessary to achieve project quality standards. Standardize and maintain compliance. The safety environment meets the standards. Under the guidance of the "dual standard" concept, a safety foundation has been laid for efficient production.

Improve institutional guarantees

In order to promote the orderly progress of various work, The mine has developed the "Production Task Incentive Assessment Method", which links the daily production impact of the production department with the performance salary of the professional department, and links the completion of production tasks with the performance incentive of district team management cadres. The "123" system for emergency response to production impact has been proposed, and the production and business operations have been upgraded. The "Management Measures for Underground Mining Head Opening and Sporadic Engineering Before Construction" has been formulated Before starting work, it is required to inspect the site, determine responsibilities, schedule, assess, and ensure that the work meets the standards. At the same time, we insist on holding monthly excavation special meetings to break down, arrange, and clarify the time nodes for the excavation assessment indicators of the month. We have also established a production task guarantee group for each department and a 1+N guarantee joint group for each political work and operation department, linking the safety management and production tasks of the district team with the performance rewards of the guarantee group, further strengthening the responsibility of each department in the safety production management of the district team.

Firmly grasp technical challenges

This year, the mine has successively invested in equipment such as full rock high-power tunneling machines, tunnel repair machines, anchor rod double arm drilling vehicles, and kilometer directional drilling machines, improving its comprehensive equipment level. It has launched technical breakthroughs from multiple aspects and actively explored the comprehensive mechanization and rapid excavation technology of rock tunnels under complex geological conditions.

In terms of excavation technology, starting from improving the strength of excavation and cutting teeth, and identifying the soft rock layer, the loss of cutting teeth is reduced from 9 per meter to 1 per 3 meters. By preventing water front exploration holes and top and bottom plate rock exploration to explore the layer, tunnels are arranged in the soft rock layer, and the footage is increased from 4 meters to 8 meters, with a maximum of 11 meters. In terms of support, by adjusting the support parameters, the anchor rod spacing is increased from 0.8 meters to 1 meter. The MQT-130/4.0 high-power anchor rod drilling rig is practical, and the number of drilling rigs is also increased; Reasonably use the anchor rod double arm drilling truck to achieve parallel excavation and support operations in stages, reducing the support time by 50 minutes per cycle, and increasing the round plate footage by 25%. In terms of disaster management, a long-distance large-scale hydrogeological exploration process of "kilometer directional drilling advance exploration+direct current method in the hole" has been explored and formed, achieving parallel operations of excavation and disaster management. The effective time of monthly excavation operations has been increased by 3-4 days, and the footage has been increased by about 30 meters. The empty top distance has been optimized from "two excavations and one support" to "three excavations and one support", and the single cycle footage of excavation has been increased by 50%.

A series of measures have been taken with great success, and the tunnel excavation is fast and vigorous. The Xiayukou Mine has achieved an overall level of comprehensive rock tunnel excavation with a single entry of 200 meters, ranking among the advanced levels in China. In the next round, the mine will adhere to the production management concept of "concept led, system guaranteed, talent based, and equipment accelerated", and steadily improve the level of hard rock comprehensive excavation. (Wei Baona Jidong)