非一致激励下埋地管道地震响应数值模拟及其试验验证

Numerical simulation and experimental validation of seismic response of a buried pipeline under non-uniform excitation

为了研究埋地管道在非一致激励下的地震响应,本文利用已开展的埋地管道非一致激励振动台试验,建立了能考虑埋地管道非一致地震激励和管-土非线性动力相互作用的三维有限元数值模型。该模型采用静-动力耦合分析方法,土体选用Davidenkov非线性本构模型,管-土相互作用采用摩擦接触以考虑管-土的滑移、分离现象,模型边界采用滚轴边界,模型底部地震动输入为振动台试验中主动箱底部加速度传感器测得的加速度时程。分析结果表明:数值模拟计算与振动台试验实测结果在加速度时程、加速度放大系数及沿管道轴向的应变峰值曲线等方面吻合较好,体现出了相似的规律,相互印证了数值模型和振动台试验结果的正确性。

In order to study the seismic response of buried pipeline under non-uniforn excitation,this paper presents a three-dimensional(3D)finite element numerical model based on the shaking table test of a buried pipeline under nonuniform excitation,which considers the nonuniform seismic excitation and pipe-soil nonlinear dynamic interaction of the buried pipeline.The model adopts the static and dynamic coupling analysis method,and Davidenkov nonlinear constitutive model was utilized for the soil analysis.The pipe-soil interaction adopts frictional contact to consider the slip and separation of the pipe and soil.The roller boundary is adopted in the model.The input of the numerical model is the acceleration time history measured at the bottom of the corresponding active box in the shaking table tests.The analysis results show that the numerical simulation results fit well with the measured results of the shaking table tests in terms of the acceleration time history,acceleration amplification coefficient,and strain peak curve along the axial direction of the pipeline,reflecting similar laws,which mutually confirms the correctness of the numerical model and shaking table test results.