Bailey main beam combination form

From the perspective of stress, the combination of Bailey's main girder should be multi-row type as far as possible to make the structure stable when hoisting, and can be hoisted in place by a large-tonnage crane. However, the cost of the crane is high in this case, and it is generally only used when the construction period is very tight and the crane time is limited. Most of the construction sites adopt this method. During the day, the Bailey hoisting unit is assembled on the ground, and the Bailey hoisting unit is transported to the site for group hoisting or overall hoisting at night. The crane cost is very high.

From an economic point of view, the combination of Bailey's main beams should be single-row or double-row as far as possible, and small-tonnage cranes should be used to hoist them in stages. In this case, the crane cost is low, and it is generally used when the lifting capacity is limited. For example, there are only two towers in the landscape structure construction site, and the lifting capacity of a single tower is 23kN (30m). The construction period is tight and the site is narrow. Only single-row lifting units can be used. After the lifting units are in place, the horizontal connection operation will be carried out.