TRUCK DRIVER WAS STOCKPILLING CRUSHED 1/4 INCH BASE MATERIAL. AS HE WAS ATTEMPTING TO DUMP THE 8TH LOAD OF THIS SHIFT THE TRUCK OVER TURNED ONTO IT LEFT SIDE. THE DRIVER WAS PINNED IN THE TRUC K BY THE STEERING WHEEL. LOCAL EMS WAS CONTACTED AND THE DRIVER WAS EXTRICATED WITHIN 25 TO 30 MIN. THE DRIVER DID NOT SUSTAIN INJURIES AS THE RESULT OF THE ACCIDENT.