Abstract:

Shield is often jammed during tunneling, which has adverse impact on construction schedule, security and environment. The causes of cutterhead jamming, shield body jamming and shield tail jamming are analyzed; and then corresponding releasing technologies are summarized by cases study. The classification characteristics of shield jamming are summarized as shield cutterhead covered by grout, insufficient excavation contour of tunnel face caused by marginal cutters wear and obstacles in front of cutterhead.

Key words: shield, jamming, jamming releasing, cutterhead, shield body, shield tail