A　set　of　test　system　of　ground　settlement　caused　by　damage　of　pipelines　in　water-rich　sand　layers　is　designed.　For　11　kinds　of　soil　samples　with　frame　diameter　d90　of　1.45~8.45　mm　under　6　kinds　of　permeability　ratio　drops　and　full　flow　velocity　of　pipelines,　the　laws　of　ground　settlement　induced　by　seepage　erosion　of　soil　mass　are　studied.　On　this　basis,　a　prediction　model　for　ground　settlement　induced　by　damage　of　underground　pipelines　is　proposed.　The　results　show:　(1)　Whether　the　pipeline　damage　will　induce　settlement　in　the　water-rich　sand　layers　is　mainly　determined　by　the　soil　skeleton　particle　size　d90,　the　diameter　D　of　the　damaged　mouth　and　the　thickness　span　ratio　hS/D.　The　maximum　value　of　the　soil　skeleton　particle　size　d90　that　causes　the　settlement　should　meet　both　the　conditions　of　the　diameter　D　of　the　damaged　mouth　and　the　thickness　span　ratio　hs/D,　and　take　the　smaller　value　of　the　two.　(2)　In　the　water-rich　sand　layers,　the　area　of　pipeline　damage-induced　settlement　is　circular　in　plane　and　inverted　triangle　in　section,　and　the　slope　angle　is　close　to　the　saturated　internal　friction　angle　of　soils.　The　top　radius　and　settlement　depth　of　settlement　area　increase　with　the　increase　of　full　flow　velocity　u　and　permeability　ratio　drop　hw/hs,　and　decrease　with　the　increase　of　thickness　span　ratio　hs/D.　(3)　Based　on　the　Manning＇s　formula,　the　prediction　formulas　for　settlement　radius　and　settlement　depth　are　deduced,　and　are　consistent　with　the　test　results　in　law　and　close　to　the　test　results　in　numerical　value.　They　can　be　used　to　predict　the　settlement　caused　by　damage　of　pipelines　in　water-rich　sand　layers.　©　2021,　Editorial　Office　of　Chinese　Journal　of　Geotechnical　Engineering.　All　right　reserved.