【作者】 王满生；

【导师】 胡聿贤； 周锡元；

【作者基本信息】 中国地震局地球物理研究所 ， 固体地球物理学， 2005， 博士

【摘要】 本文全面系统地回顾与总结了关于土-结构动力相互作用的研究方法的历史和现状。土-结构动力相互作用研究的对象重要、研究内容复杂以及研究方法具有多样性,一直受到广泛地关注。本文针对土结构动力相互作用研究中存在的一些问题,比如考虑土-结构动力相互作用的结构自振特性的时域识别、实际地基土集总参数模型的建立、地震作用下桩-土动力接触的模拟等问题进行了详细地研究。研究内容主要有以下四个部分: 第一部分,针对三维浅层场地动力计算问题,给出了一种交错网格四阶差分计算方法,并编制了计算程序,为自由场地三维计算提供了一种新的计算途径。 第二部分,在结构抗震计算中,我们只有知道了结构自振特性,才能对结构进行计算分析。针对结构自振特性的频域识别方法存在的许多缺陷,比如当记录数据从时域转换到频域过程中容易导致数据信息的部分丢失以及传递函数的处理存在较大误差。本文提出了一种引入ARX(Auto-Regressive Exogenous)参数模型进行时域识别的方法,并提供了一种简单有效的方法来确定此模型参数的阶数,并利用实际地震观测资料识别了考虑土-结构动力相互作用后的结构自振特性。 第三部分,现有地基土集总参数模型中的参数都是基于均匀弹性半空间来确定的,而实际土介质是非常复杂,具体表现在不均匀、各向异性、以及非线性,此时,基于弹性半无限地基的集总参数法将不再适用,为了解决这一问题,本文以地基土双自由度集8参数模型为基础,提出了根据现场地震动记录,利用阻尼最小二乘反演模型中的各参数值和利用EKF(Extend Kalman Filter)滤波技术进行状态参数时域非线性估计对模型参数进行识别的两种方法,解决了实际复杂成层地基的简化集总参数模型如何建立的问题。本文还对EKF滤波方法进行了改进,并把改进的EKF方法应用到结构的健康安全监测问题中,给出了一个剪切型结构的层间刚度的识别算例。 第四部分,研究了软弱场地上桩-土-结构的动力相互作用,本文针对目前常用的Goodman接触单元中的一些缺陷,建议了一种改进的Goodman接触单元,编制了Fortran有限元计算程序,利用Seed的等效线性化方法考虑了土层的非线性,并利用此接触单元进行了不同的算例分析。 概括起来,具体的研究内容和取得的研究成果包括: 1.首先对场地的地震动力反应进行了研究。根据三维FDM(Finite Difference Method)研究地震波在自由场地中的传播的理论与方法,编制了浅层场地四阶交错网格三维有限差分地震反应更多还原

【Abstract】 In this thesis, the study methods about SSDI (soil-structure dynamic interaction) are reviewed systemically. The field of SSDI is very important to civil engineering because of its complex study contents and much calculating methods. Though this field has been studied for several tens years, there are still some problems in the SSDI, such as, how to found soil foundation lumped parameters model about actual site, how to simulate the contact problem between soil and pile, how to identify the structural natural oscillation properties after considering soil-structure interaction in time domain, etc. There are four parts in the dissertation for Ph.D.In the first part, a forth-order staggered-grid finite difference approach is used to compute the seismic response of three-dimensional shallow site and the corresponding Fortran computing program is developed. This is a new method to analyze dynamic response of three-dimensional free-field site.In the second part, the identification of structural natural oscillation properties after considering soil-structure dynamic interaction is studied. Most of identification methods is only used in frequency domain in civil engineering now, the identification method in frequency domain will bring much deficiency, such as, some information of data will be lost when the recorded data in time domain is transformed to frequency domain, and the processing of transfer function will bring much errors. In the paper, the ARX (Auto-Regressive Exogenous) parameters model in time domain is used to identify the structural natural oscillation properties based on the seismic recorded data and a simple and effective way is offered to determine the order of ARX model parameters. The structural natural oscillation properties after considering the soil-structure dynamic interaction are identified using the ARX model.In third part, the parameters values of all types of soil foundation lumped parameters models are obtained by basing on uniform elastic half-space site, it may be bring much errors if these lumped parameters model is used to replace the actual soil foundation because the actual soil is heterogeneity, anisotropic and non-linear. In the paper, both damping least square method and modified EKF(Extend Kalman Filter) identification method are offered to resolve the problem how to found lumped parameters model in actual complex soil foundation. The modified EKF identification method can also be used to structure monitoring problems.In the forth part, soil-pile-structure interaction is studied. A modified Goodman contact element is offered in the paper to reduce the deficiency of original Goodman contact element. A finite element program in Fortran is developed and soil non-linear problem is considered using the Seed’s equivalent linearization method. Some different examples are computed using the modified Goodman contact element.In summary, the contents and conclusions of the paper are including:1. The seismic response of free field is studied. The seismic response of one-dimensional site is computed using the second order finite difference method to simulate the earthquake wave propagating in free field. A three-dimensional free-field is analyzed here. The FDM (Finite Difference Method) program in FORTRAN is developed in the paper and the program offer a new way to analyze the free-field site seismic response.2. The identification of structural low order modal shape after considering soil-structure dynamic interaction is studied. The ARX parameters model is used and the identification program in Matlab is developed using the ARX model. Using the program, an actual structural oscillation properties in Alaska is identified according to the actual earthquake records. The identified results are compared with the results obtained in frequency domain. The compared results shows that this identification method has more identification precision and be easy to operate.3. The varied damping least square method is offered in the paper. The parameters of soil foundation two-degree-of-freedom lamped parameter model are identified by using this back analysis method and the corresponding program in FORTRAN is made in the paper.4. A modified EKF (Extend Kalman Filter) method is offered to identify the parameters in soil foundation two-degree-of-freedom lamped parameter model. The identified results obtained by the modified EKF are more credible. A iterative program in Matlab is developed to resolve the problem which the identified results are strongly depended on the original system model values.5. A new contact model of soil-pile interaction is offered in the paper based on the Goodman更多还原