连续缓倾软弱结构面控制下的坝基岩体稳定性分析

Stability analysis of a dam foundation rock mass controlled by continuous gentle discontinuities

泄水闸是重力坝的重要组成部分,其基础的稳定性对大坝的正常运营起着关键作用。大藤峡水利枢纽No.29泄水闸坝基岩体内发育有较多的软弱夹层,在大坝蓄水后,泄水闸遭受巨大的水压力,会引起坝基失稳破坏。因此,为了保证工程的安全,需要对其稳定性进行分析。采用无厚度接触摩擦单元Interface来模拟No.29泄水闸坝基岩体中的软弱夹层,利用FLAC 3D对其整体稳定性水平进行了研究。结果表明,当超载系数K P=9.0时,模型内塑性区贯通,最大不平衡力曲线不收敛,坝基岩体发生破坏。这为后期的加固处理提供参考依据。

Sluice is an important part of gravity dam,and stability of its foundation is the key factor for the normal operation of the hydropower station.The soft interlayers and fault are developed in the No.29 sluice foundation of Datengxia Hydropower Station.After reservoir impoundment,the sluice will withstand greater water thrust force,which will cause dam foundation instability.Consequently,further investigating the safety level of the sluice sections is necessary to ensure project safety.In this paper,in order to research the stability of the dam foundation of No.29 sluice,the contract friction element with no thickness is applied to simulate the soft interlayers and faults developed in the dam foundation rock mass.When the overload coefficient K P is equal to 9.0,the results show that the plastic zones in the model runs through and the maximum unbalanced force curve does not converge,which indicates that the dam foundation rock mass is damaged.This can provide a reference for the later reinforcement.