【作者】 王卉；

【导师】 王铁成；

【作者基本信息】 天津大学 ， 结构工程， 2010， 博士

【摘要】 由于地下管道受周围土体或岩体的约束,一直以来,人们认为它具有良好的抗震性能。然而,根据震害资料显示,国内外历史上发生的多次地震都使地下管道系统遭受到一定程度的震害,它的发生不仅会直接破坏地下管道的正常使用功能,而且还可能引发水、火、爆炸及疾病等严重的次生灾害。为了减少地震作用对地下管道造成的破坏,确保生命线工程的安全和防止次生灾害的产生,开展在地震激励下埋地输流管道的响应研究,为地下管道的动力设计提供必要的理论基础,有着十分重要的意义。以波动理论为基础,采用大圆弧假定和复变函数法,给出地下单排复合管道在平面P波、SV波、SH波入射下的解析解,研究解明了管道参数、场地土类型、管道埋深以及地震波动参数对管道动应力集中的影响规律。针对实际工程中经常遇到相邻结构的动力相互作用问题,研究了地下多管道体系的动力相互作用。给出详细的理论计算过程,分析两种工况情况下入射P波、SV波和SH波对管道之间的动力相互作用的影响机理及作用规律,考虑场地土的变化,揭示不同参数下地震波对地下管道周围绕射和散射的特性。为了更好地揭示管道内的流体对管道受地震波作用的动力响应特点,利用流体中传播的声波方程,建立地下输流管道的流固耦联波函数,给出地下输流管道对平面P波、SV波入射下的波函数动力学方程,针对动应力集中问题分析管道内的流体受波传播振荡的影响规律。研究结果表明:管道内钢衬的厚度对管道的环向动应力集中峰值有很显著的影响,钢衬越薄,动应力集中程度越高;当管道周围的场地土较硬时,管道内的环向动应力集中峰值在入射P波、SV波和SH波的作用下均表现出明显的放大作用,且放大倍数显著,当管道周围的场地土较软时,环向动应力集中程度减弱;各管道之间的环向动力相互作用不仅与管道之间距离有关,还与管道的布置情况有关;管道内的流体影响了管道的径向应力集中分布。更多还原

【Abstract】 Underground pipes are rarely considered to design to withstand the loads applied by earthquake ground motions, mainly because they have been held by surround soil or rock bound. However, the damage of underground pipelines observed in near-field earthquakes of inside and outside indicates that the occurrence of earthquake not only can damage the normal use of the underground pipelines directly, but also may lead to water, fire, explosion and serious diseases such as secondary disasters. In order to reduce conveying fluid pipelines damage caused by the seismic effect and ensure safety of lifeline works to prevent the emergence of secondary disasters, there is a need for improved analysis response of the buried pipelines under seismic wave forces, and has great significance to found theoretical design of underground pipeline to provide the necessary impetus.First of all, based on complex function of the wave theory and the assumption of large arc, the analytical solution of underground composite pipe in single-row under plane P wave, SV wave and SH-wave incidences is given, and the parameters of the pipe, media types, depth of pipe, as well as fluctuate parameters are investigated to explain the influencing rules.For the dynamic interaction problems of adjacent structures are often encountered in practical engineering, underground pipe system on dynamic interaction of each other is researched. A detailed theoretical calculation process is given and impact mechanism and the role of law of two surrounding conditions of pipes under incident P waves, SV waves and SH-waves on dynamic interaction between the pipes are analyzed to reveal the diffraction and scattering characteristics around underground pipes under different parameters of seismic waves.Making use of fluid-borne acoustic wave equation, analytical answer of the dynamic stress concentration to the underground liquid-filled pipe under the plane P wave, SV wave incident is given in order to better reveal the dynamic response characteristics of pipeline on the pipeline within the fluid effect of seismic waves. And the impact rules of fluid oscillation filled in pipe by the wave propagation is analysis.Analytical results show that steel-line thickness has a significant effect on peak dynamic stress concentration of the pipe, The thinner steel liner, a higher level of dynamic stress concentration; the peak values of hoop dynamic stress concentration impacted by the incident P waves, SV waves and SH waves are amplified obviously as the surrounding medium of pipeline is light soft and hoop dynamic stress concentration reduce when the surrounding medium of pipeline is very soft; The dynamic interaction between the pipes not only the distance of adjacent pipes but also has something to do with the layout of pipeline; the liquid filled in pipe impact the distribution of radial stress concentration.更多还原