| 摘要: |
| 运用有限差分软件FLAC3D，建立某一赋含地下水的顺层岩质边坡三维模型，基于Finn动孔压增长模型，对边坡在地震作用下的加速度响应规律作了流固耦合分析，并就地下水对边坡塑性区分布的影响作了简要分析。数值计算结果表明：含地下水边坡的地震动峰值加速度PGA放大系数和坡顶加速度均大于无水边坡，地下水位升高时，PGA放大系数和坡顶加速度呈波动变化，当边坡土体处于完全饱和状态时，两者均明显增大；坡脚加速度随水位变化也呈波动状态，当边坡土体处于完全饱和状态时，同样明显增大；含地下水边坡的PGA放大系数等值线比不含地下水时的曲线分布更为杂乱，规律性较差，但仍具有明显的加速度垂直放大效应和临空面放大效应；表面风化层的塑性区随水位升高，其拉剪共同作用破坏单元逐渐增加，表面边坡的破坏效应逐渐增大。综合加速度、坡顶位移和塑性区分布来看，地下水对地震作用下顺层岩质边坡的稳定不利。 |
| 关键词: 顺层岩质边坡 地下水 地震作用 动孔压模型 加速度响应 |
| DOI： |
| 分类号:TU 413.6+2 |
| 基金项目:国家自然科学基金资助项目（51579173）；国家科技支撑计划资助项目（2013BAB05B05）；国家重点研发计划（2016YFC0401705） |
|
| Hydromechanical coupling analysis of dynamic response of seepage slope under earthquake |
|
LIANG Chao, ZHANG Jinliang, LIAN Jijian
|
|
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin
|
| Abstract: |
| A 3D model for a rock bedded slope considering groundwater fluctuation is established by the finite difference software FLAC3D. Firstly, the hydromechanical coupling effect is considered on the basis of the dynamic response and a dynamic pore pressure model, and the acceleration response of this seepage slope under the seismic action is studied. Then a brief analysis of the groundwater effects on the distribution of the plastic zones of the slope was made. The numerical simulation results show that the peak ground acceleration (PGA) amplification coefficients and the acceleration of the top of the slope are greater than those of the slope without considering groundwater fluctuation. As the groundwater level rises, the values of PGA amplification coefficients and the slope acceleration of the top of the slope are in the fluctuation conditions. However, when the whole slope is in a saturated state, two parameters mentioned above (i.e., the PGA amplification coefficients and the acceleration of the top of the slope) increase substantially. The acceleration of the toe of the slope also fluctuates as the groundwater level changes and a significant increase also occurs when the whole slope is in the saturated state. Moreover, the PGA amplification coefficient isoline distribution of the seepage slope is more ‘messy’ and has worse regularity than that of the slope without considering groundwater. The contour of the seepage slope still obviously reflects the vertical acceleration amplification effect and free face acceleration amplification effect. In order to analyze the damage conditions of the slope, the distribution of the plastic zones is analyzed. It is found that the plastic zones are mainly distributed in the surface weathered layer. Moreover, the plastic deformations are caused by the tensile shear interaction with the rising of the groundwater level. It proves that the damage effects of the groundwater under the seismic action on the slope increase. Comprehensive analysis of the acceleration response, the displacement of the slope top and the distribution of the plastic zones show that the groundwater is unfavorable to the seismic stability of the bedding rock slope. |
| Key words: rock bedded slope groundwater earthquake dynamic pore pressure model acceleration response |
