Abstract
A pile driver is a large construction machine used for ground improvement and foundation work. In recent years, there have been some reports of accidents in which the machine overturned. An investigation revealed that overturning accidents often occur while the machine is relocating to another pile. In this study, to clarify the mechanism which makes the pile driver unstable when it is self-propelled, real-scale experiments were performed. The behavior of the pile driver was measured by putting three-axis accelerometers in three places: the upper part and lower part of the leader, and the crawler base. The experiments were conducted under two conditions, straight and curved, on flat, firm ground. As a result, it was discovered that the pile driver was subject to long periodic shaking during self-propelling. The degree of shaking in response to acceleration on the curved course was large, and it was clarified that turning makes the machine unstable.