PIPE JACKING CONSTRUCTION METHOD FOR CROSSING MIXED GRAVEL LAYER AND SANDSTONE LAYER

The invention provides a pipe jacking construction method for crossing a mixed gravel layer and a sandstone layer, a working well and a receiving well are respectively arranged at the starting and the ending point) of the 5 pipe jacking construction; installing a jacking equipment in the working well and debugging it; after pushing the pipe jacking machine into the soil through the jacking machine, installing a pipe joint behind the pipe jacking machine to make the pipe jacking machine continue to push a certain distance towards the soil, and then placing the next pipe joint to make the 10 pipe jacking machine continue to push along the pipe j acking construction route; when the pipe j acking machine pushes forward in the mixed gravel layer, increasingthe injection amount ofthixotropic mud, and continuously replenishing the slurry to maintain the pressure balance of the earth bunker on the excavation surface; when the pipe jacking machine pushes forward 15 in the sandstone layer, it guides the pipe jacking machine to correct the deviation through tracking measurement. The jacking scheme is adjusted according to different geology, so that the pipe jacking machine has enough mud in the mixed gravel layer to reduce the jacking resistance, and the jacking machine joints are continuously grouted in the sandstone layer to 20 reduce the resistance, and the deviation is corrected through the jacking curve to avoid the deviation of the jacking pipeline.