| Our country has vast territory and large population. But the regional resource allocation is very uneven. The development of the transportation construction become the first target. Tunnel construction will inevitably through the coal-bearing strata. The geological situation of coal-bearing strata is so complex that makes unstable coal seam became the serious trouble of tunnel construction. At present, the study of coal tunnel surrounding rock stability is less in our country. The span, traffic speed and the road level of coal tunnel is more advanced than coal mine’s. The construction specifications can not reference from each other. So the study of coal tunnel surrounding rock stability has practical significance and engineering application value. This thesis is based on the actual project as the research background. After analysis of coal tunnel surrounding rock properties. I using the finite element software Midas GTS NX to numerical value simulate the coal seam surrounding rock stability. The main work is as follows:1. Combining with the current problems in rock tunnel construction. This thesis expounds the common analysis methods for rock stability research. And the coal tunnel construction measure has carried on the induction and collation.2. By using the finite element software Midas GTS NX to select the appropriate geotechnical model. And simulating the stability of surrounding rock under different working conditions in the case of the actual project. Than analyzing the negative impact of the groundwater seepage of rock mass stability. The result illustrate that the stability of no seepage rock is better than seepage rock. Coal seam tunnel rock stability becomes the worst when the seepage surface is located in the vault and hance.3.Simulating different dip angle of coal seam in the coal tunnel excavation. Considering that horizontal coal seam makes the coal tunnel became the worst instability. The stress mainly concentrated near the roof and waist of the tunnel. The slope of coal seam stress in the sidewall is significantly higher than the inverse slope of coal seam’s.4. Comparing the working date from different attitude of rock in coal tunnel. Believing that tunnel coal-bearing section stress often is concentrated and deformative. So the strong support measures should be made in the construction. When coal seam is located in the tunnel vault, the surrounding rock stability is most unstable. The rock from the top of tunnel appear easily roof caving, rock sluffing or even collapse. The preliminary support need be done in the construction. To further ensure the stability of surrounding rock. Setting up a arch, if appearing any seepage of groundwater, drainage seepage control measures is needed.5. Simulating the stability of surrounding rock in the case of different thickness of coal seam. Finding some conclusions by comparing the result. When the coal seam is on the above of tunnel step line. With the increasing thickness of coal seam, surrounding rock stability is reduced. When the coal seam is in the below of tunnel step line. With the increasing thickness of coal seam, surrounding rock stability is increased. Surrounding rock stress near the inverted arch is minimum affected. It illustrate the importance of making inverted arch. The surrounding rock stability of blew step line in the tunnel is better than the above step line. In order to ensure the smooth progress of construction. Construction design need to pay attention to enhance the strength of anchor and primary support.Eventually, by means of the comparison and analysis of the stability of surrounding rock. Summarizing some laws of surrounding rock stability. And giving some optimization measures for the actual engineering of surrounding rock supporting in. |
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