含滑床软弱带的水中填土坝抗震加固措施研究  

Study on seismic reinforcement measures for sluicing-siltation earth dams with sliding bed weak zone

作　　者：赵小东 王建[1] 刘敬文 ZHAO Xiaodong;WANG Jian;LIU Jingwen(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《人民长江》2023年第3期148-153,共6页Yangtze River

摘　　要：发生过坝面滑坡的早期土坝,坝坡内存在相对软弱层,为解决含滑床软弱带的水中填土坝抗震问题,以某水中填土坝为例,通过数值计算对比分析了不同坝坡加固措施的抗震稳定效果。结果表明:由于震时受到地震动孔压的影响,滑床软弱带有效应力降低,部分穿过软弱带的滑弧不满足抗滑稳定要求。通过对比振冲碎石桩与水泥搅拌桩组合方案以及岸抛抛石压重与水泥搅拌桩组合方案,发现两种加固方案均能有效降低动孔压,提高抗液化能力,但后者对提高含软弱带的坝坡稳定效果不佳,主要原因在于部分区域抛石量集中、滑床软弱带地震惯性力增大,最终不利于坝坡稳定;而前者能明显降低坝体动孔压,减小液化范围,提高滑床软弱带的密实度和强度,可以达到较好的抗滑效果。Some earth dams built in the early stage have experienced dam surface landslide,and there is a relatively weak layer in the dam slopes.To address the seismic problems of earth dam with sliding bed weak zones,taking a sluicing-siltation earth dam as an example to analyze the seismic and stability effects of different reinforcement measurements based on numerical calculation.Results indicate that due to the influence of seismic pore pressure during the earthquake,the effective stress of the weak zone of the sliding bed was reduced,and some of the sliding arcs passing through the weak zone do not meet the requirements of anti-sliding stability.By comparing the combination scheme of vibro-replacement gravel pile-cement mixing pile,and the combination scheme of bank riprap weight-cement mixing pile,it is found that both the two reinforcement schemes can effectively reduce the dynamic pore pressure and improve the anti-liquefaction ability,but the latter has poor effect on improving stability of dam slope with weak zone.The main reason is that the amounts of riprap in some areas are concentrated,and the seismic inertia force of weak zone in sliding bed is increased,which is not conducive to the dam slope stability.The former scheme can significantly reduce the dynamic pore pressure of the dam,reduce the liquefaction range,improve the compactness and strength of the weak zone,thus achieving better anti-sliding effect.

关 键 词：水中填土坝 抗震加固 软弱带 动力分析 地震动孔压 

分 类 号：TV641[水利工程—水利水电工程]