燕山水库坝基顺河向断层带特征及渗透稳定性分析

Characteristic and Seepage Stability Analysis of Faulted Zone along River in Yanshan Reservoir Dam Foundation

在研究断层带物质组成的基础上,通过现场双钻孔管涌试验、参数敏感性分析取得了准确可靠的计算参数,并采用有限元数值法对不同工况进行分析计算求得了断层破碎带及影响带的允许渗透比降。计算结果表明,未做防渗工程时,断层破碎带与影响带风化安山岩渗透变形可能性不明显,在校核洪水位作用下坝后溢出处及坝基水平渗流段内第四系松散层均可能产生渗透变形,提出了防渗措施。工程实践检验该防渗方案合理、效果明显,为工程设计提供了可靠的计算参数及科学依据。可供类似工程借鉴。

Based on studying the matter component of faulted zone, the accurate and reliable calculating parameters were gotten through borehole dual piping experiment and parameter sensibility analysis, and the seepage gradients of fault zone and influence zone were calculated by analyzing different working condition in finite element methods. The results indicated seepage deformation probability of effloresced andesites in fault zone and influence zone was not obvious before seepage prevention works, however, exceptional flood level may cause seepage deformation on the spillover position behind the dam and the loose bed of the quaternary system in horizontal percolation part of dam foundation, therefore leakage protection measures were proposed. Engineering practice proves the anti-seepage plan is reasonable and effective, and provides reliable calculating parameters and scientific basis for engineering design for reference.