Abstract:The practice of completed tunnel projects in Chengdu has proved that if the sufficient recognition and attention are not given to lagging settlement, and timely measures are not taken upon discovering anomalies, it will inevitably lead to lagging settlement so as to trigger surface collapse accidents. To address the issue of surface collapse caused by lagging settlement in the strata resulting from shield construction, combined with a case study of shield method construction in the water-rich sandy gravel strata of subway construction in Chengdu, by analyzing the causes of lagging settlement and referring the previous engineering construction experience, the investigation and disposal measures for lagging settlement in water-rich sandy gravel strata are proposed, and are applied in practices, which effectively avoids the ground collapse caused by lagging settlement.
