Application Study on Active Advanced Support Technology in Deep Roadway under Mine Goaf

Abstract

To solve the problems of the rapid advance of the working face was delayed by complicated working procedure and high labor intensity, and the severe damage of roof bolt (anchor cable) induced by advanced hydraulic support, the deformation characteristics of surrounding rock, and the supporting principle of grouting truss anchor cable were analyzed theoretically by taking the roadway of 3_(down) coal seams 2326# working face in Sanhekou coal mine as the research object; then, the mechanical model of supporting structure of roadway under goaf was established. Based on this model, the optimal supporting scheme was determined, and the active advanced support technology scheme of “advanced grouting truss anchor cable” was proposed to take the place of the existing single pillar. The deformation and failure characteristics of surrounding rock of the working face leading roadway were observed and analyzed on-site. Within the allowable range of reading error, the results showed that the maximum displacement of medium-deep base point and shallow base point of two roadways was 15.2 cm and 10.9 cm, respectively; the pressure value had a more obvious jump increase when the distance between each measuring point and the working face was about 35 m, which means the range is strongly affected by the advance mining, and the area affected by advanced mining was 35 m ahead of the working face. It was observed that the lowest position of roof separation development ranged from 0.71 m to 2.73 m. The separation layer was generally distributed in the range of 0.73 m-2.49 m, and the fracture area was roughly distributed in the range of 0.01 m-0.62 m. Under the condition of overlying goaf, there was a complete stress structure, which can meet the requirements of suspension support.

Gaining Victory in Systems Warfare: China's Perspective on the U.S.-China Military Balance

“…53 Likewise, PLA publications on new operational concepts have highlighted the connection that "fighting spirit" has with problem-solving and adaptability on the modern battlefield-both key elements to system-of-systems-related concepts, such as target-centric warfare and information-firepower warfare. 54 In all cases, these works demonstrate the importance of political work across the board and argue that the role of political work in these "new-type" operations is an essential element of all PLA operational activities.…”

“…During the conflict, a U.S.-led multinational coalition reduced the strength of the world's fourth-largest army by roughly 50 percent in a 38-day air campaign and destroyed 80 percent of the Iraqi C2 network and 90 percent of the Iraqi logistics network. 54 Furthermore, the totality of these air operations substantially reduced the morale, reliability, and, ultimately, the combat effectiveness of Iraqi forces. In follow-on ground operations, the U.S.-led coalition annihilated Iraq's remaining forces in a four-day combined-arms ground campaign that led the PLA to implement a series of experiments to build its own combined-arms capability.…”

“…55 Operation Allied Force in 1999 was yet another highly formative, if largely vicarious, experience for the PLA. 56 Despite the North Atlantic Treaty Organization's (NATO's) overwhelming advantages, this conflict provided 54 Cen Hua et al, eds., A Dictionary of High-Tech War, Beijing: Military Science Press, 1999, pp. 604-605, 608-609.…”

“…53 Similarly, another PLA work on new CONOPs said that "the key points of key annihilation and control warfare are closely related to tactical targets, and they have become concrete representatives of the use of target-centric warfare in the tactical field." 54 The PLA's progress on these new CONOPs appears to be in an early stage as experimentation and training continue across the force. What this body of literature does make clear, however, is that there is an imperative for improving PLA systems warfare capabilities, 51 Wang Yongnan, 2015, p. 1.…”

“…53 Wang Yongnan, 2015, p. 25. 54 Qian Weichao and Yi Xiaoming, Vital Point-Controlled Annihilation Warfare, Beijing: National Defense University Press, 2015, p. 8. namely by further developing its force to be capable of executing these core operational concepts.…”