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A Preliminary study on the seismic conceptual design

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Earthquake Engineering and Engineering Vibration 2014年第S1期13卷 183-188页

作者： Zhao Zhen xie lili Institute of Engineering Mechanics China Earthquake Administration Key Laboratory of Earthquake Engineering and Engineering Vibration China Earthquake Administration School of Civil Engineering Harbin Institute of Technology

The seismic conceptual design is an essential part of seismic design codes. It points out that the term 'seismic conceptual design' should imply three aspects,i.e.,the given concept itself,the specific provisions related to the given concept and the designing following the provisions. Seismic conceptual design can be classified into two categories: the strict or traditional seismic conceptual design and the generalized seismic conceptual design. The authors are trying to define for both conceptual designs their connotations and study their characteristics,in particular,the differences between them. Authors emphasize that both conceptual designs sound very close,however,their differences are apparent. The strict conceptual designs are usually worked out directly from engineering practice and/or lessons learnt from earthquake damage,while the generalized conceptual designs are resulted in a series of visions aiming to realize the general objectives of the seismic codes. The strict conceptual designs,(traditional conceptual designs) are indispensable elements of seismic codes in assuring designed structures safer and the generalized conceptual designs are playing key roles in directing to a more advanced and effective seismic codes.

关键词： Conceptual design Earthquakes

On civil engineering disasters and their mitigation

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Earthquake Engineering and Engineering Vibration 2018年第1期17卷 1-10页

作者： xie lili Qu Zhe Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration

Civil engineering works such as buildings and infrastructure are the carriers of human civilization. They are, however, also the origins of various types of disasters, which are referred to in this paper as civil engineering disasters. This paper presents the concept of civil engineering disasters, their characteristics, classification, causes, and mitigation technologies. Civil engineering disasters are caused primarily by civil engineering defects, which are usually attributed to improper selection of construction site, hazard assessment, design and construction, occupancy, and maintenance. From this viewpoint, many so-called natural disasters such as earthquakes, strong winds, floods, landslides, and debris flows are substantially due to civil engineering defects rather than the actual natural hazards. Civil engineering disasters occur frequently and globally and are the most closely related to human beings among all disasters. This paper emphasizes that such disasters can be mitigated mainly through civil engineering measures, and outlines the related objectives and scientific and technological challenges.

关键词： disaster hazard civil engineering disaster earthquake

Attenuation of peak ground accelerations from the great Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2009年第2期8卷 179-188页

作者： Wang Dong xie lili Institute of Engineering Mechanics China Earthquake Administration Harbin 150080 China School of Civil Engineering and Architecture Harbin Institute of Technology Harbin 150090 China

Over 800 accelerograms recorded by 272 ground-level stations during the Wenchuan earthquake are used to analyze the influence of rupture distance, local site conditions and azimuth on peak ground accelerations （PGAs）. To achieve a better understanding of the characteristics of ground motions, the spatial distributions of the EW, NS and UD components of PGAs are obtained. Comparisons between the EW and NS components, the fault-normal and fault-parallel components, and the vertical and horizontal components of PGAs are performed, and the regression formula of the vertical-to-horizontal ratio of PGAs is developed. The attenuation relationship of peak horizontal accelerations （PHAs） is compared with several contemporary attenuation relationships. In addition, an analysis of residuals is conducted to identify the potential effects of rupture distance, azimuth and site conditions on the observed values of PHAs. The analysis focuses on medium-hard soil site conditions, as they provided most of the data used in this study.

关键词： Wenchuan earthquake peak ground acceleration (PGA) attenuation rupture distance azimuth

Effect of seismic super-shear rupture on the directivity of ground motion acceleration

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Earthquake Engineering and Engineering Vibration 2013年第4期12卷 519-527页

作者： Hu Jinjun xie lili Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration School of Civil Engineering and Architecture Harbin Institute of Technology

The effect of seismic super-shear rupture on the directivity of ground motions using simulated accelerations of a vertical strike-slip fault model is the topic of this study. The discrete wave number/finite element method was adopted to calculate the ground motion in the horizontal layered half space. An analysis of peak ground acceleration （PGA） indicates that similar to the sub-shear situation, directivity also exists in the super-shear situation. However, there are some differences as tbllows：（1） The PGA of the fault-normal component decreases with super-shear velocity, and the areas that were significantly affected by directivity in the PGA field changed from a cone-shaped region in the forward direction in a sub-shear situation to a limited near-fault region in a super-shear situation. （2） The PGA of the fault-parallel and vertical component is not as sensitive as the fault-normal component to the increasing super-shear velocity. （3） The PGA of the fault-normal component is not always greater than the fault-parallel component when the rupture velocity exceeds the shear wave velocity.

关键词： ground motion directivity rupture velocity super-shear rupture peak ground acceleration

Identifi cation of model structure parameters via combination of AFMM and ARX from seismic response data

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Earthquake Engineering and Engineering Vibration 2014年第3期13卷 411-423页

作者： Gong Maosheng Sun Jing xie lili Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering Mechanics CEA Institute of Civil Engineering Heilongjiang University

To identify the model structure parameters in shaking table tests from seismic response, especially from time- varying response records, this paper presents a new methodology by combining the online recursive Adaptive Forgetting through Multiple Models （AFMM） and offtine Auto-Regression with eXogenous variables （ARX） model. First, the AFMM is employed to detect whether the response of model structure is time-invariant or time-varying when subjected to strong motions. Second, if the response is time-invariant, the modal parameters are identified from the entire response record, such as the acceleration time-history using the ARX model. If the response is time-varying, the acceleration record is divided into three segments according to the accurate time-varying points detected by AFMM, and parameters are identified by only using the tail segment data, which is time-invariant and suited for analysis by the ARX model. Finally, the changes in dynamic properties due to various strong motions are obtained using the presented methodology. The feasibility and advantages of the method are demonstrated by identifying the modal parameters of a 12-story reinforced concrete （RC） frame structure in a shaking table test.

关键词： parameter identification time-varying response model structure shaking table test

Effect of seawater on incident plane P and SV waves at ocean bottom and engineering characteristics of offshore ground motion records off the coast of southern California, USA

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Earthquake Engineering and Engineering Vibration 2014年第2期13卷 181-194页

作者： Diao Hongqi Hu Jinjun xie lili Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration College of Earth Science University of Chinese Academy of Sciences School of Civil Engineering and Architecture Harbin Institute of Technology

The effect of seawater on vertical ground motions is studied via a theoretical method and then actual offshore ground motion records are analyzed using a statistical method. A theoretical analysis of the effect of seawater on incident plane P and SV waves at ocean bottom indicate that on one hand, the affected frequency range of vertical ground motions is prominent due to P wave resonance in the water layer if the impedance ratio between the seawater and the underlying medium is large, but it is greatly suppressed if the impedance ratio is small; on the other hand, for the ocean bottom interface model selected herein, vertical ground motions consisting of mostly P waves are more easily affected by seawater than those dominated by SV waves. The statistical analysis of engineering parameters of offshore ground motion records indicate that:(1) Under the infl uence of softer surface soil at the seafl oor, both horizontal and vertical spectral accelerations of offshore motions are exaggerated at long period components, which leads to the peak spectral values moving to a longer period.(2) The spectral ratios(V/H) of offshore ground motions are much smaller than onshore ground motions near the P wave resonant frequencies in the water layer; and as the period becomes larger, the effect of seawater becomes smaller, which leads to a similar V/H at intermediate periods(near 2 s). These results are consistent with the conclusions of Boore and Smith(1999), but the V/H of offshore motion may be smaller than the onshore ground motions at longer periods(more than 5 s).

关键词： offshore ground motion seawater P and SV waves vertical ground motions spectral ratio

A fiber-section model based Timoshenko beam element using shear-bending interdependent shape function

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Earthquake Engineering and Engineering Vibration 2013年第3期12卷 421-432页

作者： Li Ning Li Zhongxian xie lili School of Civil Engineering Tianjin University/Key Laboratory of Coast Civil Structure Safety Ministry of Education Institute of Engineering Mechanics China Earthquake Administration

A fiber-section model based Timoshenko beam element is proposed in this study that is founded on the nonlinear analysis of frame elements considering axial, flexural, and shear deformations. This model is achieved using a shear-bending interdependent formulation （SBIF）. The shape function of the element is derived from the exact solution of the homogeneous form of the equilibrium equation for the Timoshenko deformation *** proposed element is free from shear-locking. The sectional fiber model is constituted with a multi-axial plasticity material model, which is used to simulate the coupled shear-axial nonlinear behavior of each fiber. By imposing deformation compatibility conditions among the fibers, the sectional and elemental resisting forces are calculated. Since the SBIF shape functions are interactive with the shear-corrector factor for different shapes of sections, an iterative procedure is introduced in the nonlinear state determination of the proposed Timoshenko element. In addition, the proposed model tackles the geometric nonlinear problem by adopting a corotational coordinate transformation approach. The derivation procedure of the corotational algorithm of the SBIF Timoshenko element for nonlinear geometrical analysis is presented. Numerical examples confirm that the SBIF Timoshenko element with a fiber-section model has the same accuracy and robustness as the flexibility-based formulation. Finally, the SBIF Timoshenko element is extended and demonstratedin a three-dimensional numerical example.

关键词： Timoshenko beam shear-flexure coupled effect shear-bending interdependent formulation nonlineargeometric analysis finite element

Response spectra for nuclear structures on rock sites considering the near-fault directivity effect

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 357-365页

作者： Xu Longjun Yang Shengchao xie lili Department of Civil Engineering Harbin Institute of Technology at Weihai Weihai 264209 China CCCC Highway and Bridge Consultants Co. Ltd. Beijing 100029 China

Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.

关键词： near-fault ground motion directivity response spectrum rock site nuclear design

Consecutive combined response spectrum

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Earthquake Engineering and Engineering Vibration 2014年第4期13卷 623-636页

作者： Xu Longjun Zhao Guochen Liu Qingyang xie Yujian xie lili Department of Civil Engineering Harbin Institute of Technology at Weihai Institute of Engineering Mechanics China Earthquake Administration

Appropriate estimates of earthquake response spectrum are essential for design of new structures, or seismic safety evaluation of existing structures. This paper presents an alternative procedure to construct design spectrum from a combined normalized response spectrum （NRSc） which is obtained from pseudo-velocity spectrum with the ordinate scaled by different peak ground amplitudes （PGA, PGV, PGD） in different period regions. And a consecutive function./（/） used to normalize the ordinates is defined. Based on a comprehensive study of 220 strong ground motions recorded during recent eleven large worldwide earthquakes, the features of the NRSc are discussed and compared with the traditional normalized acceleration, velocity and displacement response spectra （NRSA, NRSv, NRSD）. And the relationships between ground amplitudes are evaluated by using a weighted mean method instead of the arithmetic mean. Then the NRSc is used to define the design spectrum with given peak ground amplitudes. At last, the smooth spectrum is compared with those derived by the former approaches, and the accuracy of the proposed spectrum is tested through an analysis of the dispersion of ground motion response spectra.

关键词： ground motion response spectrum normalized response spectrum consecutive combined response spectrum design spectrum