摘要
土体对埋置海底管线的约束特性是决定管线稳定性的重要因素。采用PFC离散元分析和物理模型试验相结合的方法研究了不同埋深条件下管线的抗拔特性,分析了砂土在管线模型上拔过程中的流动机制。研究结果表明:数值分析和模型试验结果吻合较好;通过对比模型试验和数值模拟,发现两者的抗拔力-位移关系演化趋势是极其相似的,都呈现明显的三阶段特征,即:抗拔力发展阶段、抗拔力软化阶段、抗拔力软化后的稳定阶段,同时结合PIV技术和数值分析中对增量位移场的提取,分别从宏观上和微观上分析了在单调荷载作用下管线周围砂土的流动机制。
The uplift resistance provided by surrounding soil is one of the key factors when predicting the stability of pipelines buried in sand .Here ,the uplift resistance behavior of pipelines buried in sand was investigated by PFC discrete element numerical simulations and physical model tests .PIV technology was used to obtain the flow mechanism of sand in the uplift process .The results indicate that the numerical results agree well with the experimental data .Comparing the result of the model test with that of the numerical simulation ,it is found that the uplift resistance-displacement curves of the above are very similar ,i .e .the uplift resistance increases rapidly in the initial uplift process until reaching a peak value ,then reduces gradually due to the strain softening of sand ,and finally reaches to a steady phase .In the meantime , the soil flow mechanism were analyzed macroscopically and microscopically based on PIV technology and built-in program of PFC2D .
出处
《水利与建筑工程学报》
2015年第5期156-160,189,共6页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金(51209033)
辽宁省自然科学基金(2013020154)
中央高校基本科研业务费(DUT15LK36)
