Research And Engineering Application Of Two Stage Coupling Grouting Technology In Incompact And Fractured Soft-rock Roadway

Since the 20th century, more and more problems of soft rock engineering occure in the world. With the development of coal mining's depth, the deterioration of roadways surrounding rock condition exist and the problem of supporting and maintaining for incompact and fracture soft-rock roadway becomes more and more conspicuous. Many scholars have done a great deal of successfull researches on the technology of soft rock supporting, and have gained a large number of achievements. But since the multiformity and complexity of properties of soft rock, and so many supporting projects practices failed yet. Whether is it can be solved properly is a key point for coal mining's development in depth and safety in production. So the thorough studying is urgent.Based on lots of measurements and on-the-spot investigation, the characteristics and influence factors of deformation and failure of incompact and fractured soft-rock roadway surrounding rock are summarized systemically in this thesis. Taking larger area surrounding rock as the research object, the mechanism of deformation and failure of incompact and fractured soft-rock roadway is analyzed and the model of inner and outer bearing structure for fractured soft-rock roadway is established. And the stress fields of inner and outer bearing structure is analyzed based on damage theory, and the calculation formulas of radiuses of fragmentation zone and damage zone for incompact and fractured soft-rock roadway are fetched. The influence factors of stability for incompact and fractured soft-rock roadway are simulated using FLAC, such as the intensity of overlying strata, floor strata, the thickness of the soft rock and so on . The technology of two stage coupling grouting is advanced, and the bearing property of inner structure by grouting is analyzed. The failure reasons of the original supporting scheme are analyzed around the engineering practice of the haulage tunnel of easterly -300m level in Shuijingtou Coal Mine of Niumasi Industral Corporation Ltd. And two supporting schemes wich are reinforcing sides and roof and reinforcing inner structure using two stage coupling grouting are put forward. Using FLAC, the differences of the deformation amount and stress distribution of surrounding rock in such supporting conditions as the original supporting scheme, reinforcing sides and roof, and reinforcing inner structure are computed; The result shows that it is more effective to controll the deformation of incompact and fractured soft-rock roadway by reinforcing inner structure using two stage coupling grouting based on optimizing support parameters. The construction technics of two stage coupling grouting is expatiated systemically. The research achievement has been put into the supporting and maintaining of the haulage tunnel of easterly -300m level successfully. The supporting problem has been resolved and vast economic profit and technological effect has been achieved. By the studying and practices of this paper, a new supporting and maintaining method for incompact and fractured soft-rock roadway is offered. It has broad application foreground and the value of practical popularization in engineering fields...