STUDY ON SPALLING PHENOMENON OF PILE-DRIVING WITH HAMMER IN SOFT SOIL
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摘要: 在软基中打桩时,软土层对桩的阻力很小。当桩锤以一定速度夯击桩头,桩身便传播着应力波,此类压缩波在桩尖近似自由面处反射后成为反向拉伸波,压缩、拉伸波干涉的结果往往在桩尖上部形成一个相当高的拉应力区,这会导致桩底端附近层裂(断裂)。基于一维应力波理论,采用有限差分法,对此进行了初步探讨,得出了一些有益的结论,供工程应用参考。Abstract: The resistance from soft soil layers is smaller while piling in soft foundation.The stress wave will propagate along pile body when the pile head is stricken by hammer with a certain velocity.And it will turn into tensile waves when reflected at the bottom of pile.Thus,one tensile stress region on pile body will appear near pile bottom because of intervention between the incident waves and the reflect waves,which can cause pile to be fractured or spalled.Based on one dimensional wave theory,the primary discussion on this phenomenon is done with finite difference method,and some benefit conclusions and suggestions are obtained.In a way,they have definite reference value for engineers.
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Key words:
- pile /
- spalling /
- stress wave /
- hydrodynamic-elastic-plastic model
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