Loss-circulation response: the 2-hour plug, reviewed

When pipe jacking hits sudden slurry loss, escaping fluid hollows the ground fast — the response window runs in hours. This is the review of a loss plugged in 2 hours.

Sequence: seal the leak with a rapid-set agent to stop the bleed; re-film the wall with 1:200 PAM-S concentrate to restore protection; backfill with BENT-N thick slurry (10%–12%) to steady pressure; meanwhile step up settlement monitoring to every 2 hours.

Lessons: locate the leak fast — probe multiple points rather than delay; keep plugging agents and protective slurry stocked together; and let settlement data drive the decision to resume. Plugged in 2 hours, resumed in 3 days, no secondary collapse.