多维多点地震激励下油气长输管道的灾变机理及抗震性能研究

For the Specialty and complexity of long distance oil and gas pipelines in earthquake disaster protection, experiment researchand numerical modeling will be combined into practice. Meanwhile, systematical research will be taken steps into the disaster mechanism and seismic performance of long distance oil and gas pipelines under multi-dimensional and multi-support earthquake excitation. Researchers need to analyze the distribution characteristics of pipeline and transmission features of earthquake to build artificially synthetic model of earthquake excitation, and confirm stray parameter and coherence function of earthquake in various working conditions when setting up the multi-dimensional and multi-support earthquake excitation modeling; Establish the couple model of pipeline with environment and load,and research the mechanism of dynamic disaster of long distance oil and gas pipelines with kinds of complicated conditions and boundary conditions under earthquake excitation. By analyzing geological conditions of pipe in the soil and environment on the influence law of dynamic response of pipeline, the tube - dynamic response analysis of soil nonlinear contact model under multi-dimensional and multi-support earthquake excitation is put forward . Based on the multi-dimensional and multi-support earthquake excitation model and dynamic response analysis model, combined with the typical pipeline model shaking table test, the different laws and characteristics of dynamic response with consistent and multi-dimensional and multi-support earthquake excitation have been researched, it put forward the seismic performance analysis and evaluation theory and the engineering application method of long distance oil and gas pipeline with multi-dimensional and multi-support seismic action, and provide scientific basis for the seismic safety of long distance oil and gas pipeline in our country.

针对油气长输管道地震灾变保护的特殊性和复杂性，采用试验研究和数值模拟相结合的方法，对多维多点地震激励下油气长输管道的灾变机理及抗震性能进行系统研究。分析管道的分布特征及地震动的传播特性，构建人工地震动合成模型，确定各种工况下地震动的随机参数和相干函数，提出多维多点地震激励模型；建立管道所处环境条件与内外部荷载耦合的工况模型，研究地震激励下油气长输管道在各种复杂工况和边界条件下的动力灾变机理，提出相应的动力灾变性能评价理论；分析管道所处土体地质条件及环境对管道动力响应的影响规律，提出多维多点地震激励下管土非线性接触动力响应分析模型；根据提出的多维多点地震激励模型和动力响应分析模型，结合典型管道模型地震模拟振动台阵试验，研究管道在一致和多维多点地震激励下动力响应的不同规律和特征，提出多维多点地震激励下油气长输管道的抗震性能分析和评价理论，为提高我国油气长输管道的抗震安全性提供科学依据。

油气长输管道在我国分布范围广，相当一部分区段位于高地震烈度危险区，且长期处于腐蚀介质侵害及加压运行状态下，运输线路长、经过的场地条件复杂，在地震作用下极易产生震害。本项目采用试验研究和数值模拟相结合的方法，对多维多点地震激励下油气长输管道的灾变机理及抗震性能进行研究。基于地震动的随机性和空间变化相关性，构建了人工地震动合成模型，确定了地震动的随机参数和相干函数，提出了多维多点地震激励模型，编制了多点地震波合成程序；建立了管道所处环境条件与运行内压耦合的工况模型，研究了管道运行状态下的应力监测方法，提出了腐蚀工况下管道的安全预测与评价方法，总结了油气长输管道的的典型缺陷和不同服役状态下的破坏特征，提出了油气管道桥梁跨越结构减震控制的措施，并对其抗震性能进行了分析和研究；基于管-土接触面切向应力和变形的发展，采用接触单元模拟管-土相互作用，基于有限边界模拟连续型土体理论，构建了人工截断模型的接触刚度及阻尼模型，提出了用于管-土相互作用边界条件接触面特征和粘弹性人工边界模型的模拟和设置方法；通过埋地油气管道模型有限元分析和振动台试验，研究了一致地震激励和多维多点地震激励下管道及管周土体力学性能变化规律、管-土振动特性、抗震薄弱环节、变形特征及动力灾变机理，提出了多维多点地震激励下油气长输管道的抗震性能分析和评价方法。项目的研究成果为提高我国油气长输管道在地震作用下的安全可靠性提供了科学的理论和技术依据，具有良好的工程应用前景。