东北两座已建大坝的安全复核与评价

Safety check and evaluaion of two existing gravity dams in northeast China

东北太平哨和云峰砼重力坝已分别运行十余年和二十余年，需进行安全检查与评价．本文首先介绍了现场动力试验和自振特性及地震动应力分析结果．对云峰宽缝重力坝进行了抗滑稳定复核，静力和温度应力计算，并研究了基础岩石裂缝、扬压力、上游库区水压力及材料弹模对应力状态的影响。

The anti-seismic study of Taipingshao and Yunfeng dam is first introduced. The excitating method of setting off explosive in reservoir is used to measure the dam natural frequencies, which are in good agreement with the calculation results. The dynamic stresses under earthquake are calculated, which show that the dynamic strength could be satisfied. The check of sliding stability and static stress analysis of Yunfeng dam are carried out. Cracking may occur in the downstream face of the dam under the minimum temperature condition. After considering the crack in foundation rock, the stresses are redistributed and the tensile stresses at the foot of the dam disappear. The effects of uplift, water pressure on foundation in reservoir and medulus of elasticity of materials are also studied.