【作者】 王莉莉；

【导师】 孙建刚；

【作者基本信息】 大庆石油学院 ， 防灾减灾工程及防护工程， 2003， 硕士

【摘要】 我国拥有幅员辽阔的冻土地区，在世界四大冻土国家中位居第三。其中季节性冻土面积为514万平方公里，约占国土面积的54％。冻土场地的土体从未冻结状态过渡到冻结状态或反向循环，土体的物理力学性质将发生巨大变化，各种强度指标大幅度提高或衰减。1986年黑龙江省德都地区在同一地点于春夏不同时间先后发生两次5.0级以上地震，其震害特征截然相反。我国东北，华北及西北大部分地区冻融层厚度大于1.5m，烈度在7度以上。通过研究季节性冻土地基的冻害机理及其地震动特性从而可以把震害损失减小到最低程度，为提高储罐的抗震性能提供科学的理论依据。因此研究季节性冻土场地的地震动特性具有一定的理论指导和工程实践应用意义。 因此，本论文以季节性冻土场地上的储罐为研究对象，主要完成了以下研究内容： 第一章确定季节性冻土场地的地震动参数及其特性，总结了泊桑比、动剪切模量和阻尼比从非冻结期过渡到冻结期的变化特征。 第二章建立了适用于工程实际的简化力学模型并确定了该模型的运动方程和控制方程，给出了该模型的基底剪力和弯矩的计算公式。 第三章研究了八种季节性冻土场地上储罐的地震响应，将冻结期场地上储罐的地震响应与非冻结期场地上储罐的地震响应进行了对比分析，结果表明季节性冻土层的存在影响着储罐的地震反应特性。 第四章研究季节性冻土场地上储罐抗震设计的反应谱设计方法，并将此方法所的结果与第三章数值分析的结果进行了对比，证实了所给方法的有效性。 通过上述内容的研究可以达到以下的成果和具体的使用价值： 1．研究季节性冻土场地的地震动特性，从而为季节性冻土场地上储罐的抗震设计提供理论的依据。 2．建立工程实际计算所需的科学的理论方法。更多还原

【Abstract】 Our country have the far-flung frozen earth territory, it is the third in the four countries that have the broadest frozen earth area. There are 5.14 million sq.km seasonally frozen ground in our country, it is about 54% of the country. The soil of the frozen ground transit from un-frost state to frost state or on the reverse cycle, property of the soil will occur a great transformation and the strength target will increase or decrease dramatically. The same place of Dedu region in Heilongjiang province happened twice earthquakes over 5 grade in the spring and summer in 1986 ,the seismic damages were polarity. The thickness of the frost-thaw layer in the northeast, northchina and the most area in the northwest exceed 1.5m, the intensity exceed 7 degree. Trough the investigation of freeze damages mechanism and dynamic characteristics, the seismic damages can be decreased to the lowest degree and the theory gist can be provided for improving the earthquake resist character of the tanks. So the investigation on seismic response of liquid storage tanks on seasonally frozen ground has a great significance in theory and engineering practice.So this paper takes the tanks on seasonally frozen ground as study object to complete the investigations as follow:Chapter 1:To ascertain earthquake parameters of the seasonally frozen ground and the characteristic ofthese parameters and sum up the changing character of the Poisson ratio , shear modulus and dampratio that change from un-frost state to frost state.Chapter 2:To ascertain the predigest mechanics model and math model that same with the engineeringpractice .ascertain the movement and the control equation and give the calculating formula of shearingforce and bending moment on tanks’ base.Chapter 3:To study the seismic response of the tanks on 8 seasonally frozen grounds and compare theseismic response of the tanks on the un-frozen ground with the seismic response of the tanks on thefrozen ground., then prove that the existence of the seasonally frozen ground affect the seismicresponse characteristic of the tanks.Chapter 4: To study the theory analysis method of the seismic response of the tanks on the seasonallyfrozen ground and compare the results of this method with the results of numerical analysis of chapter3 to approve the validity of this method.Through the study, we can get the results and practical values as follow:1. Provide the theory analysis basis for earthquake resist design of the tanks on the seasonally frozen ground;2. Establish the science theory method for the engineering practical computation;更多还原