This program states that First Emperor did not have human sacrifices placed in his tomb, but it would be more accurate to add "that we know of." While the terracotta army and other environs have been excavated and examined, the tomb itself has never been entered for two reasons. First, ancient histories report that it is full of Raiders of the Lost Ark (1981) style booby traps. Second, even if there are no booby traps, it is most likely too fragile to withstand being excavated. So it's possible that there are human sacrifices within it, which would certainly suit the character of First Emperor, who indulged in mass murder like a hobby.