| 小型土石坝加密抗液化离心机振动台试验研究 |
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| 引用本文： | 刘庭伟,李俊超,朱斌,汪玉冰,高玉峰,陈云敏.小型土石坝加密抗液化离心机振动台试验研究[J].岩土力学,2020,41(11):3695-3704. |
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| 作者姓名： | 刘庭伟 李俊超 朱斌 汪玉冰 高玉峰 陈云敏 |
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| 作者单位： | 1. 浙江大学 软弱土与环境土工教育部重点实验室，浙江 杭州 310058；2. 浙江大学 超重力研究中心，浙江 杭州 310058；
3. 河海大学 岩土力学与堤坝工程教育部重点实验室，江苏 南京 210098 |
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| 基金项目： | 国家自然科学基金重点项目（No. 41630638，No. 51808490）；中央高校基本科研业务费专项资金（No. 2018FZA4016）。 |
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| 摘 要： | 地震作用下土石坝液化易导致坝坡失稳滑移等严重后果，加密法是常用的抗液化手段之一。针对坝趾压重与坝壳翻压两种坝身加密加固方法，开展了离心机振动台试验，分析了不同加密型抗液化处理的小型土石坝坝坡地震响应规律。试验结果表明，由于高水头作用下坝坡底部土体软化，未处理坝坡加速度放大系数沿高程先减小后增大，而加密坝坡加速度放大系数沿高程逐渐增大，且坝坡表面处加速度存在表面放大现象。坝趾压重和坝壳翻压提高了坝身有效应力，降低地震产生的超静孔压比，有效防止土体液化。未处理坝坡在峰值加速度为0.24g地震作用下即发生坝趾液化现象，而加密坝坡在峰值加速度为0.24g和0.45g下均未发生液化。未处理坝坡整体侧向位移大，加密处理后，在峰值加速度为0.24g下坝坡整体表现为竖向位移。坝趾压重区坝趾水平位移明显减小，坝壳翻压区坡顶沉降减小了50%。试验结果验证了坝趾压重和坝壳翻压的抗液化效果，为小型土石坝抗震加固设计提供了参考。
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| 关 键 词： | 土石坝 抗液化 离心机振动台 坝趾压重 坝壳翻压 |
| 收稿时间： | 2020-01-09 |
| 修稿时间： | 2020-04-13 |
Centrifuge shaking table modelling test study on
anti-liquefied densification of small earth-rock dam slope |
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| LIU Ting-wei,LI Jun-chao,ZHU Bin,WANG Yu-bing,GAO Yu-feng,CHEN Yun-min.Centrifuge shaking table modelling test study on
anti-liquefied densification of small earth-rock dam slope[J].Rock and Soil Mechanics,2020,41(11):3695-3704. |
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| Authors: | LIU Ting-wei LI Jun-chao ZHU Bin WANG Yu-bing GAO Yu-feng CHEN Yun-min |
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| Institution: | 1. MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China;
2. Center for Hypergravity Experimental and Interdisciplinary Research, Zhejiang University, Hangzhou, Zhejiang 310058, China;
3. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, Jiangsu 210098, China |
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| Abstract: | The liquefaction of small earth-rock dam slope under earthquakes is easy to cause serious consequences, such as instability and sliding of the dam slopes. Densification is one of the most commonly used anti-liquefaction methods. Two centrifuge shaking table tests were carried out to analyze the seismic response of small earth-rock dam slopes using two different densification methods, dam toe weight and dam shell compaction, respectively. The test results show that due to soil soften at the bottom of dam slope under the high water head, the acceleration amplification factor of the untreated dam slope decreased firstly and then increased along the elevation, while the acceleration amplification factor of the densified dam slope gradually increased along the elevation. There is a phenomenon of the surface amplification effect. The dam toe weight and dam shell compaction can increase the effective stress, reduce the excess pore pressure ratio caused by the earthquake, and effectively prevent the occurrence of liquefaction. Liquefaction occurred at the toe of the untreated dam slope under the earthquake peak acceleration of 0.24g, while the densified dam slope did not liquefy under the peak acceleration of 0.24g and 0.45g. The untreated dam slope had globally large lateral displacement, while the densified dam slope had mainly global vertical displacement under the peak acceleration of 0.24g after densification. The horizontal displacement of the dam toe in the dam toe weight area was significantly reduced, and the settlement of the dam slope crest in the dam shell compaction area was reduced by 50%. The test results verify the anti-liquefaction effect of dam toe weight and dam shell compaction, and provide references for seismic strengthening design of small earth-rock dams. |
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| Keywords: | earth-rock dam anti-liquefaction centrifuge shaking table dam toe weight dam shell compaction |
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