Authorities say the accident happened near Grand Avenue at about 10:15 a.m. Caltrans crews had been working on the side of the road, cleaning trash off the freeway.
The big rig driver was trapped inside his vehicle and had to be extricated by a rescue team. The truck driver and seven other people were taken to area hospitals in unknown condition.
Four eastbound lanes were shut down, causing a major traffic back-up in the area.
The cause of the accident has not yet been determined.