Deformation of the main beam of the bridge crane is one of primary breakdown.The pre-stressed method not only restores the main beam of the bridge crane , but alos improves its load-bearing capacity .

• 桥式起重机主梁的下挠变形是桥式起重机的主要故障之一，采用预应力张拉工艺修复，不仅能使主梁下挠得以恢复，而且可以使主梁的承载能力得到提高。