Research And Application Of Support For Broken Rock Mass In Self - Propelled Iron Mine

With the increasing development of mining engineering, in the tunneling process due to the growing branch nurse undeserved and cause the accident, although domestic and foreign scholars have paid a lot of effort, but due to the complexity of engineering rock mass, there is still no a unified theory can be a good fit for rock support.In Yunnan Province since iron ore 1530 middle fractured rock mass as the background, through the theoretical research, field investigation, experimental study, numerical simulation, etc. in Yunnan since iron ore 1530 middle rock supporting scheme is studied, the main work as follows:(1) the integrity of the rock mass in the middle section of the Yunnan iron mine and the structural condition of the 1530 middle section of the mine were investigated in the field. Using the RMR rock stability classification, our country the stability of engineering rock mass classification of Yunnan iron 1530 middle rock of stability classification of rock mass, and ultimately determine the Yunnan iron 1530 middle rock rock â…£, relatively hard rock, rock is broken to fractured.(2) through in Yunnan since iron ore 1530 middle rock site sampling, samples processed into test specimens, and the test specimen uniaxial compression, splitting, acoustic emission testing. Analysis rock in the test process of mechanical properties and acoustic emission characteristics. Finally, the mechanical properties of lime rock are average uniaxial compressive strength is 72MPa, and the average tensile strength is 6MPa. Limestone is the acoustic emission characteristics for total AE number, AE number of ringing AE cumulative energy in the initial stage of rapid growth, the limestone inside, outside the pores, more broken cracks. Of the cumulative number of AE AE cumulative number of rings AE cumulative energy at the later stage of the loading appear rapid growth. The results showed that plastic deformation until the destruction of the limestone.(3) according to the ratio, laboratory pouring and curing of concrete test block to determine the concrete mixing, and through uniaxial compression tests of 1%,2%, two kind of steel fibers with different proportions at 7d,14d, the uniaxial compressive strength of 28d three maintenance cycle and plain concrete 7d,14d, the uniaxial compressive strength of 28d three maintenance period compared to analysis with different proportions of steel fiber in 7d, 14d,28d three curing period of concrete strength variation.(4) by referring to the rock failure theory, earth pressure theory, supporting theory and the supporting method related theory. Finally, using the theory of new Austrian tunneling method, the combined support theory, deformation theory of ground pressure, dispersion theory of ground pressure of Yunnan iron 1530 middle using advanced small pipe grouting support, steel fiber spray concrete and anchor combined support. Combined support operations as the maximum distance between the tunnel operation uses 38 manufacturing workers, dig a branch, a day digging footage cycle, the general forward tunneling 4 meters, according to the field experience, soft rock supporting roof control distance is generally not more than 40 m,1530 middle limestone is a hard rock, do not belong to soft rock, so the roof control away from 20 meters (i.e. the second time permanent support from the heading section can not be more than 20 meters) is the latest in steel fiber shotcrete temporary supporting the 5 days to carry out the second times of steel fiber shotcrete support, local pressure is large, large deformation of parts of the stell yieldable support support support.(5) using MIDAS numerical simulation software to model the part of the middle part of Yunnan self walking iron mine 1530, the driving simulation, support simulation, simulation analysis of the supporting effect.