复杂地基下某混凝土纵向围堰深层滑动稳定分析

Analysis of the Stability against Sliding in Deep and Complicated Foundation of a Longitudinal Concrete Cofferdam

针对某水电站的复杂地质条件,对不同工况下的围堰建基面的深层抗滑稳定问题进行了计算分析,采用刚体极限平衡法中剩余推力法、被动抗力法以及等安全系数法,计算岩体在不同滑出角时的安全系数,并对围堰的安全储备进行评价;针对现有方案围堰断面较大的特点,比较了在堰基设置混凝土抗滑桩方案及不抽排方案,分析得出类似岩体的最危险滑出角,比选得出合理的围堰断面体型以及抽排防渗系统。

Due to the complicated foundation condition of a hydropower station,the stability of the longitudinal concrete cofferdam against sliding in deep foundation is of great importance for its construction and operation. Thus,three rigidbody limit equilibrium analysis methods,including the residual thrust method,the passive resistance method and the equal safety factor method,are adopted to investigate and evaluate the stability of the cofferdam under different working conditions. In view of the fact that the original cofferdam section design is rather big,several improvement schemes are studied and compared,such as the installation of stabilizing piles under the cofferdam base and the arrangement of seepage water pumping and drainage system. Finally,the reasonable cofferdam section and the seepage water pumping and drainage system are determined.