Abstract:

The settlement, deformation and concrete structure crack, may occur to the gallery due to the high construction risk and irrational construction of the shallowcovered largespan loess tunnel. In this paper, in order to satisfy the requirements of the baggagededicated gallery and to control the settlement, 3D numerical simulation method is used to analyze the settlement caused by new tunnel crossing underneath baggagededicated gallery of the airport. In addition, some effective measures, such as strengthening the monitoring and using effective technologies (including excavation step by step, advance support by means of largediameter pipe roof and grout backfilling behind primary support and secondary lining) have been adopted to minimize the settlement of the baggagededicated gallery. The settlement of the gallery floor is limited to about 3 mm, which guarantees the safety of the baggagededicated gallery.

Key words: largespan loess tunnel, crossing underneath baggagededicated gallery, shallowcover mining method, 3D numerical simulation, settlement analysis, doubleside heading, large pipe roof, backfill grouting