| 地震作用下抗滑桩—预应力锚索框架组合结构受力机制 |
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| 引用本文： | 陈建峰,杜长城,陈思贤,石振明,彭铭.地震作用下抗滑桩—预应力锚索框架组合结构受力机制[J].地球科学,2022,47(12):4362-4372. |
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| 作者姓名： | 陈建峰 杜长城 陈思贤 石振明 彭铭 |
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| 作者单位： | 1.同济大学土木工程学院地下建筑与工程系, 上海 200092 |
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| 基金项目： | 国家重点研发项目2019YFC1509700 |
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| 摘 要： | 为了解抗滑桩—预应力锚索框架组合结构在地震作用下的受力机制，基于四川省东北部某滑坡治理工程，采用MIDAS/GTS有限元程序建立抗滑桩—预应力锚索框架数值模型，利用位移时程曲线法对加固边坡进行稳定安全系数计算，而后输入不同峰值地震加速度（peak ground accelerations，PGA）的Wolong地震波，分析了加固边坡的加速度响应、桩锚结构内力变化以及荷载分担规律.研究结果表明，加固边坡的稳定安全系数满足规范要求，在地震作用下其上部存在潜在浅层滑面，中部和下部存在潜在深层滑面，与静力条件下加固边坡的潜在滑面分布不同，这是加速度高程放大效应所致；随着输入地震波PGA增大，加速度高程放大效应明显加强，且抗滑桩桩身弯矩和剪力增大，但其最大值出现位置不变，桩身正、负弯矩最大值分别位于距桩顶约0.7L和0.4L处，最大正、负剪力分别位于距桩顶约0.9L和0.7L处，实际工程中需注意防范抗滑桩在滑面附近发生破坏；同时随着输入地震波PGA增大，桩锚承担的荷载逐渐增大，但抗滑桩分担的下滑力比例增大，而锚索分担的下滑力比例减小，故实际工程设计中不应固定桩锚荷载分担比例.
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| 关 键 词： | 抗滑桩 预应力锚索 边坡 地震 受力机制 工程地质 |
| 收稿时间： | 2022-06-01 |
Mechanical Mechanism of Slopes Stabilized with Anti-Slide Piles and Prestressed Anchor Cable Frame Beams under Seismic Loading |
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| Abstract: | A numerical model of a landslide stabilized with anti-slide piles and anchor cable frame beams was developed using a three-dimensional finite element program MIDAS/GTS. The factor of safety of the reinforced slope was calculated using the displacement time curve method. The acceleration responses, structural internal forces, and load-sharing rules were analyzed by inputting Wolong seismic waves with different peak ground accelerations(PGA). The results show that the factor of safety of the reinforced slope satisfies the code requirements. A potential shallow slip surface exists in the upper part of the slope, and a potential deep slip surface exists in the middle and lower parts of the slope under the earthquake action. The acceleration of the reinforced slope under seismic loading shows an elevation amplification effect. As the PGA of the input seismic wave increases, the amplification effect is enhanced. The bending moments and shear forces of the anti-slip pile increase when the PGA of the input seismic wave increases. The maximum positive and negative bending moments of the anti-slip pile are located at about 0.7 L(pile length) and 0.4 L from the top of the pile, respectively. The maximum positive and negative shear forces are located at about 0.9 L and 0.7 L from the top of the pile, respectively. When the PGA increases, the load sheared by piles and anchor cables increases gradually. However, the proportion of thrust shared by anti-slip piles increases while the proportion of thrust shared by anchor cables decreases. Thus, the variation of the proportion of thrust shared by anti-slip piles and anchor cables is recommended to be considered in engineering projects. |
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