| 可液化场地微型桩地震响应特性研究 |
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| 引用本文： | 汪明武,赵奎元,朱其坤,徐新宇.可液化场地微型桩地震响应特性研究[J].岩土力学,2016,37(6):1543-1549. |
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| 作者姓名： | 汪明武 赵奎元 朱其坤 徐新宇 |
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| 作者单位： | 合肥工业大学 土木与水利工程学院，安徽 合肥 230009 |
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| 基金项目： | 国家自然科学基金项目（No.41172274）。 |
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| 摘 要： | 可液化场地微型桩的地震响应分析是确保工程安全和优化抗震设计的前提。应用动态离心机试验和三维有效应力数值分析方法，研究了微型单桩桩台的侧向变形和加速度、不同埋深桩身弯矩、可液化场地的加速度及超孔隙水压力等响应特征。首先开展了相对密实度为57%饱和土层、输入波是频率为1 Hz和峰值加速度为1.516 m/s2正弦波的微型桩40 g动态地震响应离心机试验，进而应用基于多重剪切机构塑性模型和液化前缘状态面概念的三维有效应力分析方法，反演了试验结果，并进行了对比分析，结果表明，数值模拟与离心机试验结果吻合，液化场地特性控制着建于其中微型桩的地震响应特征，微型桩桩台的水平变形和残余变形可达78、30 mm，桩身最大弯矩和最大残余弯矩呈现向桩身底部迁移特点，同时表明，基于动态土工离心机试验和数值分析相结合的研究方法，分析可液化场地微型桩地震响应特性是有效可行的，研究结论为可液化场地微型桩的抗震设计提供了可靠的依据和参考。
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| 关 键 词： | 液化 离心机试验 有效应力 地震响应 微型桩 |
| 收稿时间： | 2014-08-20 |
Seismic responses of a micropile in liquefiable soils |
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| WANG Ming-wu,ZHAO Kui-yuan,ZHU Qi-kun,XU Xin-yu.Seismic responses of a micropile in liquefiable soils[J].Rock and Soil Mechanics,2016,37(6):1543-1549. |
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| Authors: | WANG Ming-wu ZHAO Kui-yuan ZHU Qi-kun XU Xin-yu |
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| Institution: | School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, Anhui 230009, China |
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| Abstract: | Seismic response of micropiles in a liquefiable soil is one of the key components that must be addressed in aseismic design. In this paper, the seismic responses of a micropile in liquefiable soils, including lateral displacement and acceleration, moment distribution and pore water pressure, are analyzed based on dynamic centrifuge testing and three-dimensional effective stress analysis. A dynamic centrifuge test is performed on a saturated sandy soil of a 57% relative density, using an input excitation of a sine form with a peak shaking amplitude of 1.516 m/s2 and 1 Hz frequency under a 40g condition. A numerical simulation is conducted to investigate the distributions and variations of lateral deformation and acceleration at the pile cap, the bending moments of the pile at different buried depths, the acceleration and excess pore water pressure in the liquefiable soil. An inversion analysis is performed on the experimental results based on the three-dimensional effective stress method and the concepts of multiple shear mechanism plastic model and state surface of liquefaction front. Comparison between the physical and numerical models indicates that the computed results agree well with the measurements of the centrifuge test, and that the dynamic response of the micropile is controlled by the field condition of the liquefiable site. It is also indicated that the maximum amounts of the lateral deformation and residual deformation at the pile top are 78 mm and 30 mm respectively. The largest bending moment and residual bending moment of the micropile occur at deeper buried depths. It is shown that the seismic response of micropiles in liquefiable soil can be effectively analyzed by combining the centrifuge test and numerical simulation. |
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| Keywords: | liquefaction centrifuge test effective stress seismic response micropile |
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