With　the　continuous　development　of　the　underground　road　construction　in　various　cities　in　China,　accidents　including　damage　or　even　collapse　of　the　surrounding　structures　can　often　happen　due　to　the　underground　excavation.　Therefore,　it　is　very　importannt　to　predict　reasonably　the　ground　settlement　for　the　protection　of　ground　buildings　and　structures.　We　combine　the　ground　settlement　velocity　coefficiennt　with　the　three-dimensional　imaging　method,　and　establish　a　new　calculation　method　for　the　tunnel　surface　settlement　considering　the　time　effect.　We　take　a　subway　tunnel　in　Shenzhen　as　an　example,　and　demonstrate　the　rationality　of　the　method　by　comparing　it　with　the　on-site　monitorinng　data.　This　method　is　then　used　to　further　analyze　the　variation　of　the　ground　lateral　and　longitudinal　settlement　with　time　during　the　tunnel　shutdown,　and　the　time　dependencies　of　the　ground　settlement　and　the　settlement　velocity　are　studied　through　a　parameter　analysis.　The　results　show　that　the　ground　settlement　and　the　maximum　slope　of　the　longitudinal　settlement　increase　gradually　with　the　increase　of　shutdown　time　and　eventually　tend　to　be　stable.　The　maximum　ground　settlement　velocity　increases　following　a　logarithmic　function　with　the　increase　of　the　excavation　speed　and　the　settlement　velocity　coefficient.　In　contrast,　the　final　ground　settlement　is　less　affected　by　those　two　factors.　The　final　ground　settlement　and　the　maximum　ground　settlement　velocity　both　increase　linearly　with　the　increase　of　the　ground　loss.　The　time　at　which　the　ground　settlement　velocity　reaches　its　maximum　has　nothing　to　do　with　the　amount　of　the　ground　loss.