摘要
固结排水试验参数是有效应力法计算模型参数,用作总应力法计算时,只适用于心墙内孔压完全消散的情况。实际上心墙在施工期内仍存在较大的孔压,如果采用现有的总应力法计算,由于使用了饱和土固结排水试验模型参数,夸大了心墙水力劈裂的可能性。为此,提出了用非饱和心墙料做固结不排水试验得出总应力法计算模型参数的改进方法。通过对水力劈裂机理的探讨,提出了一种新的水力劈裂判断标准,即用心墙内紧靠上游表面的单元的组合应力与心墙前库水压力进行比较来判定。通过双江口堆石坝非饱和掺砾心墙料的固结不排水试验,进行了总应力法计算及水力劈裂分析,验证了观点的合理性。
As a larger pore pressure is existent during construction,the model parameters obtained from consolidated-drained test for the hydraulic fracturing calculation of core wall are not applicable and the possibility of hydraulic fracturing will be exaggerated when the total stress method is used.The model parameters from non-saturated material consolidated-undrained test are suggested to be used in the hydraulic fracturing calculation with total stress method.Based on mechanism research of hydraulic fracturing,new criterion by comparing the combination stress of core wall element close the upper surface water and the reservoir water pressures is presented for the determination of hydraulic fracturing.The new method was verified by the experiment of Shuangjiangkou rock-fill dam.
出处
《水力发电》
北大核心
2010年第3期51-54,62,共5页
Water Power
基金
河海大学岩土力学与堤坝工程教育部实验室开放基金项目(GH200902)
关键词
水力劈裂
总应力法
防渗心墙
固结不排水试验
hydraulic fracturing
total stress method
core wall
consolidated-undrained test
