There are three reasons for the instability of anchorage force: (1) the strength of the rock formation is low; the second is that the anchor cable is smooth and no ribs; the third is the stability of the resin anchor. For the above reasons, the following solutions are proposed: (1) Due to the instability of the roof, the anchorage section of the anchor cable is in the lower level of the anchor, the length of the anchor can be designed so that the anchorage section is in the relatively high layer Bit. The range of 4 ~ 8m in the roof is about 28MPa, which is relatively high. Therefore, the length of the cable is changed from 5.3m to 7.3m, and the length of the cable is from 3 to 8m in the fault section. Pull force can reach more than 180kN. (2) In order to increase the bond area between anchor cable and anchoring agent and improve the anchoring force, the anchor anchorage section can be modified by changing the anchorage section of anchor cable to change the anchorage strength. Without increasing the length of the cable under the premise of the 14505 track through the cable anchor section into a "bird cage", the anchoring force can reach 180kN. (3) At present, with the increasing demand for resin anchoring agent in China`s coal industry, there are hundreds of manufacturers of resin anchoring agents, and the quality of resin anchors produced by various manufacturers is obviously different. Therefore, to choose large-scale, strong, with many years of experience in the production and use of manufacturers, and through the underground anchoring force test to determine the amount of resin anchoring agent and anchor specifications, models. The above measures are applied to the underground, which completely solves the problem of unstable anchorage performance of the cable, which improves the success rate of the installation of the anchor cable, reduces the number of drilling and improves the support speed.
(1) When the soft coal crushing strength of the roof coal seam is low, the anchoring force of the anchor cable will decrease obviously, and the anchoring force of the anchor cable is the prerequisite to ensure the support effect. (2) There are many factors that affect the anchoring force of the anchor cable, and it is the most realistic and reliable way to strengthen the anchorage force test in the field to determine the anchor support parameters. (3) Through the analysis of the factors affecting the anchoring force of the anchor cable and the solution, it will provide an important reference for the design and construction of the coal mine anchor cable in the future and hope to attract the attention of the relevant technical personnel and strengthen the attention to the anchoring force design And on-site construction management.
