BIG CALIBER PIPELINE DRILLED THROUGH BY THE DIRECTION DRILL CONDUCES TO THE MAIN ENVIRONMENTAI GEOTECHNICS PROBLEMS

The direction drill technology introduced into our country from the period of 1980 that adopted comprehensively in pipeline drilled through. At the present time, hundreds of rivers had been drilled though successfully by the direction drill technology.Along with the big caliber pipeline be builded, drilling through some special engineering geological and hydrogeolgical conditions may conduce to some environmentai geotechnics questions, for example, collapse sink,land subsidence and piping by the direction drill.In order to dope out the big caliber pipeline drilled through by the direction drill conduces to the main environmental geotechnics questions in the future,the principle is expatiated on this paper.