TRUCK OPERATOR ATTEMPTED TO DUMP HIS LOAD WHILE SITTING ON AN UNEVEN GRADE ON THE STOCKPILE. AS HE RAISED THE TRUCK BED THE TRUCK TIPPED OVER ONTO ITS RIGHT SIDE. THE OPERATOR, WHO WAS WEARING SEATBELT, WAS UNHARMED BUT COMPLAINED OF A SORE NECK. HE WAS GIVEN PAIN MEDICATION AND PLACED ON LIGHT DUTY FOR ONE DAY BY THE ER PHYSICIAN.