富水砂卵石地层中长距离掘进（Long distance excavation in water rich sandy cobble stratum）.docVIP

富水砂卵石地层中长距离掘进（Long distance excavation in water rich sandy cobble stratum） Shield long distance excavation in high strength in sand and gravel will result in the following situations: affected by sand pebble soil and high permeability, easy to form a muck impermeable plastic flow and cannot establish the earth pressure balance mechanism, or the earth pressure is not stable, caused by surface subsidence occurred; when the soil is not good. When the screw conveyor is prone to spewing, not only lead to the earth pressure loss, but also because of bad effects of mucking excavation progress cutter, cutter; cutting the pebble soil inhomogeneity and impact, easy to produce abnormal damage, cutter, cutter and spiral conveying machine wear will be more serious. The shield machine good sealing and abrasion resistance, good slag soil and slag discharge capacity based on the key of shield tunneling construction is how to ensure the stability of the excavation face, long distance smoothly, this is the difficulty of this project. The main countermeasures are as follows: The shield machine in addition to basic functions, is also equipped with other devices in the sandy gravel system: mud, polymer foam, strong; equipped with sufficient cutter torque and engine thrust; cutter opening rate and the diameter of the screw conveyer through particle size below 300mm pebbles; the same tool base, soft and hard rock cutter interchangeable, can realize the back loading; with perfect barometric pressure maintaining function, with advance reinforcement formation function; cutter, cutter and screw conveyor has good abrasion resistance; double screw conveyor has good anti spewing ability; cutter main bearings, articulated system has good sealing function. In front of the foam cutter, setting the appropriate parameters, increase the lubrication of a full range of the cutter, cutter and muck (bubble spread to the entire panel after full expansion, at the same time in the chamber) add appropriate wa