Causes and countermeasures against excessive thrust of shield machine

Mud pressure balanced shield machine is a kind of machinery equipment for pipeline operation. Except forinternal hydraulic and electric failures, all impacts on thrusting of the shield machine may attribute to excessive thrustforce. Taking the M1051 used in Beijiang Shielding Crossing Project as an example, some factors for excessive thrust areinvestigated, inducing falling objects due to human errors, incorrect selection of thrusting mode, sticking in clay layers, isolation of cutterhead in pebble layers, cementing of shield tail in sand layers, and management over V-configuration ofthe shield machine. In addition, solutions in both management and technical aspects are proposed, providing necessaryreferences to the identical or similar shielding operations involving in oil and gas pipelines.