  How eruption can recur from a confined magnetic structure is discussed based
on the {\it Solar Dynamics Observatory} (SDO) observations of the NOAA active
region 11444, which produced three eruptions within 1.5 hours on March 27,
2012. The active region had the positive polarity magnetic fields in the center
surrounded by the negative polarity fields around. Since such a distribution of
magnetic polarity tends to form a dome-like magnetic fan structure confined
over the active region, the multiple eruptions was puzzling. Our investigation
reveals that this event exhibits several properties distinct from other
eruptions associated with magnetic fan structures: (i) a long filament
encircling the active region was present before the eruptions; (ii) expansion
of the open-closed boundary of the field lines after each eruption suggestive
of the growing fan-dome structure, and (iii) the ribbons inside the closed
magnetic polarity inversion line evolving in response to the expanding
open-closed boundary. It thus appears that in spite of multiple eruptions the
fan-dome structure remained undamaged, and the closing back field lines after
each eruption rather reinforced the fan-dome structure. We argue that the
multiple eruptions could occur in this active region in spite of its confined
magnetic structure because the filament encircling the active region was
adequate for slipping through the magnetic separatrix to minimize the damage to
its overlying fan-dome structure. The result of this study provides a new
insight into the productivity of eruptions from a confined magnetic structure.
