The　cobble　stratum　is　prone　to　collapse　during　the　shield　driving.　It　is　important　to　understand　the　collapse　behavior　of　cobble　stratum　for　construction　safety　of　the　tunnel.　Taking　Tsinghuayuan　Tunnel　in　Beijing　as　the　background,　a　test　of　shield　tunnelling　in　the　cobble　stratum　is　performed　using　the　model　shield　with　the　diameter　of　280　mm.　A　total　of　5　collapse　pits　occur　on　the　ground　surface　during　the　test　process.　The　settlements　at　the　surface　and　subsurface　are　measured　to　analyze　the　collapse　process　of　the　cobble　stratum,　as　well　as　the　earth　pressure　in　the　region　above　the　tunnel　crown.　The　quadratic　partial　derivative　of　the　settlement　and　earth　pressure　are　used　to　judge　the　collapse　moment　of　the　soil.　The　test　results　show　that　the　collapse　of　the　cobble　stratum　develops　with　a　uniform　speed　from　the　bottom　to　up　with　the　shield　advancing,　and　that　the　collapse　region　extends　to　the　surface　after　the　cutter　head　passes　through　the　center　of　the　collapse　pit　0.5D　∼　1.0D.　Meanwhile,　the　final　earth　pressure　is　much　smaller　than　its　initial　value　only　in　the　region　above　the　tunnel　crown,　indicating　the　collapse　region　concentrating　in　the　position　directly　above　the　crown　in　the　cross-section.　In　addition,　the　shape　of　surface　settlement　trough　changes　significantly　with　the　collapse　development.　Development　curves　of　two　characterization　physical　quantities　of　the　surface　settlement　trough,　i.e.,　the　maximum　settlement　and　width　coefficient,　are　respectively　close　to　the　“S”　shape　and　the　inverse　“S”　shape.　©　2023　Elsevier　Ltd