Construction Accident

A Tractor Trailer Dump Truck overturned to the passenger side while unloading topsoil at a landfill. A portion of the topsoil was stuck in the nose of the trailer. The driver (plaintiff), the raised  the trailer, was injured when the overturn occurred. The driver, not wearing his seatbelt, was thrown against the passenger door when the tractor and trailer overturned.

A typical tractor-trailer dump truck dumping a load.

The cause of the over turning of the tractor-trailer was caused by the uneven and uncompacted soil causing the raised trailer to act as an inverted pendulum.

The photograph shows the tire tracks that the loaded rear tandem trailer wheels make in the  uncompacted surface of the landfill. This would cause the extended trailer to oscillate side to side when the load slides out of the rear of the trailer and pushes the trailer forward.

The results of the calculations show that the forward acceleration of the tractor-trailer, in banging the tailgate to the trailer, caused harmonic motion (inverted pendulum effect) of the raised trailer. This inverted pendulum effect exceeded the static overturning torque and resulted in the tractor-trailer overturning.

The case was settled.

 Last update: 03/14/2016