通过对一起塔机倾覆事故的现场勘查与综合分析,总结出事故原因为未调整好塔机起重臂与平衡臂之间的平衡,顶升外套架滚轮处与标准节接触受力不均匀,导致顶升外套架上部偏斜,吊架引进轮的损坏致使顶升标准节就位困难,外力撬动打破整体平衡造成整体失稳,以及作业人员违规操作,对比提出预防事故发生的建议。 Through a site investigation and comprehensive analysis of a crane overturning accident, it is concluded that the cause of the accident is that the balance between the boom crane and the balance arm of the tower crane is not adjusted, and the contact force between the jacking wheel of the jacking tower crane and the standard knuckle is uneven. As a result, the upper part of the jacking jacket is deflected. The damage of the hanger introducing wheel causes the lifting of the standard knuckle to be difficult to position. The external force leverages to break the overall balance and causes the overall instability as well as the irregular operation by the operator. The suggestions for preventing accidental accidents are proposed.