The new dystopian thriller “Divergent” defied the recent trend of young-adult book adaptations faltering on the big screen, topping the weekend box office with an estimated $56-million opening.

Allegiant Part 1 will keep that date, with Part 2 to follow on March 24, 2017. Both films will be produced separately. Divergent has quickly made a box office star of Woodley, who will reprise her ...