With the development of coal industry, deeper coal mining makes roadway excavation get involved into deep and complex mining environment. Traditional excavation methods, like drilling and blasting, is time-consuming, and unsafe for workers in gaseous and complex coal mine strata conditions. New tunnel excavation method, Pipe jacking methods for example, which were originally used in municipal engineering in shallow stratum, are now introduced in coal mining industry for its safety and efficiency. However, the structural characteristics, mechanical behavior and engineering response of the rock mass in deep coal mine stratum are different from those in the shallow strata, and research is still inadequate nowadays. This paper proposed a new jacking direction adjusting and correction formula, and a jacking force calculation formula, cause the adjusting of jacking direction will be more critical compared with its application in shallow strata conditions, which can offer advices for pipe jacking roadway excavation in deep and complex mining environment.
With development of coal industry, coal mining has entered the era of deep mining below 1000m. At present, approximate 6000 km of roadway is excavated every year in China, and the deep roadway accounts for 28%∼30% (Liu, 2013; Tang, 2017). Traditional excavation methods, like drilling and blasting, is time-consuming, and unsafe for workers in gaseous and complex coal mine strata conditions. TBM method is already used in mining roadway construction, but for auxiliary roadway with small cross section, like high drainage roadway, TBM method is heavy and time consuming. Pipe jacking has advantages of small excavation equipment, flexible installation and short auxiliary process time, which is suitable for high drainage roadway construction. However, the structural characteristics, mechanical behavior and engineering response of the rock mass in deep coal mine stratum are different from those in the shallow strata. This paper proposed a new jacking direction adjusting and correction formula, and jacking force calculation formula, cause the adjusting of jacking direction will be more critical compared with its application in shallow strata conditions.
