PORTAL FRAME FOR TRENCH BOX STACK

摘要

A portal frame attached to the open end of a trench box structure and assembling and rigidifying the stacked plural boxes forming the smooth wall sides of the consequent trench box whereby side sections or panels of trench boxes are stackably adjustable as to depth of trench served and the portal span provides maximum clearance for the pipe and including thrust plates in the portal frame for transmitting thrust from the boxes and into the portal frame.