桓仁大头坝劈头裂缝的稳定性分析

Analysis of stability of cracks in diamond head of Hengren buttress dam

用断裂力学对单支墩大头坝的劈头裂缝进行稳定性分析。把劈裂缝视为线弹性的１／４半无限体内半椭圆片状裂缝。用有限元法计算出承载而未开裂的坝体在假定缝面上的应力，运用线性叠加原理计算出裂缝在各种荷载作用下的缝端应力强度因于值ＫＩ，并与二维的ＫＩ值作以比较。通过分析，认为该坝急需防渗加固处理。

The study of cracks,in the diamond head of the Hengren buttress dam is made by means of fracture mechanics.The cracks of the diamond head is consi- dered as linear elastic half ellipse shiver cracks in 1/4 half infinite elastic volume.The finite element method is used to determine the stress which is calculated by computer for loading dam but without cracks,and then to put the stress on the assumed cracks.The stress intensity factors near the crack tip are calculated for various kinds of loading actions by using linear summary principle, and compared with 2-dimension.The results of analysis and comparison indicate that the dam must be urgently strengthened.