An overturned tractor trailer shutdown the northbound lanes of the Pennsylvania Turnpike at the Lansdale Interchange on the Northeast Extension Friday afternoon.   It happened where an on ramp merges with the highway.   There were no injuries but the mishap backed up the toll road for more than ten miles   Motorists got around the bottleneck by using Routes 663 and 309 to reach the turnpike at the Quakertown Interchange north of the accident scene.