Research on the direct damage-based seismic design method of RC frame structures

Based on the existing research, this paper presents an innovative methodology to realize direct damage-based seismic design for RC frame structures by mobilizing ESDOF theory and the damage-based strength reduction factor（RD factor）. A design example is then followed to verify this method.

Discussion on seismic design of high-rise building structure in China

With the rapid development of China＇s economy, the modernization drive and the process of urbanization continue to advance, land for urban construction is becoming more and tenser and land prices are rising steadily, there are more and more high-rise buildings, its density is also increasing. With the increasing number trend of high-rise building development, anti-seismic building requirement as an important part of architectural design is worthy of our exploration and study. Seismic resistance has become an important subject of engineering design. This paper will discuss the technical principle of seismic design in building structure design, so as to optimize the seismic design of high-rise building structure better.

An improved pseudo-static method for seismic resistant design of underground structures

This paper describes a commonly used pseudo-static method in seismic resistant design of the cross section of underground structures. Based on dynamic theory and the vibration characteristics of underground structures, the sources of errors when using this method are analyzed. The traditional seismic motion loading approach is replaced by a method in which a one-dimensional soil layer response stress is differentiated and then converted into seismic live loads. To validate the improved method, a comparison of analytical results is conducted for internal forces under earthquake shaking of a typical shallow embedded box-shaped subway station structure using four methods： the response displacement method, finite element response acceleration method, the finite element dynamic analysis method and the improved pseudo-static calculation method. It is shown that the improved finite element pseudo-static method proposed in this paper provides an effective tool for the seismic design of underground structures. The evaluation yields results close to those obtained by the finite element dynamic analysis method, and shows that the improved finite element pseudo-static method provides a higher degree of precision.

Optimal design and effectiveness evaluation for inerter-based devices on mitigating seismic responses of base isolated structures

The optimal design and effectiveness of three control systems,tuned viscous mass damper(TVMD),tuned inerter damper(TID)and tuned mass damper(TMD),on mitigating the seismic responses of base isolated structures,were systematically studied.First,the seismic responses of the base isolated structure with each control system under white noise excitation were obtained.Then,the structural parameter optimizations of the TVMD,TID and TMD were conducted by using three different objectives.The results show that the three control systems were all effective in minimizing the root mean square value of seismic responses,including the base shear of the BIS,the absolute acceleration of structural SDOF,and the relative displacement between the base isolation floor and the foundation.Finally,considering the superstructure as a structural MDOF,a series of time history analyses were performed to investigate the effectiveness and activation sensitivity of the three control systems under far field and near fault seismic excitations.The results show that the effectiveness of TID and TMD with optimized parameters on mitigating the seismic responses of base isolated structures increased as the mass ratio increases,and the effectiveness of TID was always better than TMD with the same mass ratio.The TVMD with a lower mass ratio was more efficient in reducing the seismic response than the TID and TMD.Furthermore,the TVMD,when compared with TMD and TID,had better activation sensitivity and a smaller stroke.

Highway bridge seismic design:summary of FHWA/MCEER project on seismic vulnerability of new highway construction

The Federal Highway Administration (FHWA) sponsored a large,multi-year project conducted by the Multidisciplinary Center for Earthquake Engineering Research (MCEER) titled'Seismic Vulnerability of New Highway Construction'(MCEER Project 112),which was completed in 1998.MCEER coordinated the work of many researchers,who performed studies on the seismic design and vulnerability analysis of highway bridges,tunnels,and retaining structures. Extensive research was conducted to provide revisions and improvements to current design and detailing approaches and national design specifications for highway bridges.The program included both analytical and experimental studies,and addressed seismic hazard exposure and ground motion input for the U.S.highway system;foundation design and soil behavior: structural importance,analysis,and response:structural design issues and details;and structural design criteria.

Research on Seismic Design of High-Rise Buildings Based on Framed-Shear Structural System

Under the rapidly advancing economic trends,people’s requirements for the functionality and architectural artistry of high-rise structures are constantly increasing,and in order to meet such modern requirements,it is necessary to diversify the functions of high-rise buildings and complicate the building form.At present,the main structural systems of high-rise buildings are:frame structure,shear wall structure,frame shear structure,and tube structure.Different structural systems determine the size of the load-bearing capacity,lateral stiffness,and seismic performance,as well as the amount of material used and the cost.This project is mainly concerned with the seismic design of frame shear structural systems,which are widely used today.

Structural Design Optimization of a Vertical Axis Wind Turbine for Seismic Qualification and Lightweight

Recently, there is a growing interest in seismic qualification of ridges, buildings and mechanical equipment worldwide due to increase of accidents caused by earthquake. Severe earthquake can bring serious problems in the wind turbines and eventually lead to an interruption to their electric power supply. To overcome and prevent these undesirable problems, structural design optimization of a small vertical axis wind turbine has performed, in this study, for seismic qualification and lightweight by using a Genetic Algorithm (GA) subject to some design constraints such as the maximum stress limit, maximum deformation limit, and seismic acceleration gain limit. Also, the structural design optimizations were conducted for the four different initial design variable sets to confirm robustness of the optimization algorithm used. As a result, all the optimization results for the 4 different initial designs showed good agreement with each other properly. Thus the structural design optimization of a small vertical-axis wind turbine could be successfully accomplished.

Seismic design and analysis of nuclear power plant structures

The seismic design and analysis of nuclear power plant (NPP) begin with the seismic hazard assessment and design ground motion development for the site. The following steps are needed for the seismic hazard assessment and design ground motion development:a. the development of regional seismo-tectonic model with seismic source areas within 500 km radius centered to the site;b. the development of strong motion prediction equations; c. logic three development for taking into account uncertainties and seismic hazard quantification;d. the development of uniform hazard response spectra for ground motion at the site;e. simulation of acceleration time histories compatible with uniform hazard response spectra. The following phase two in seismic design of NPP structures is the analysis of structural response for the design ground motion. This second phase of the process consists of the following steps:a. development of structural models of the plant buildings;b. development of the soil model underneath the plant buildings for soilstructure interaction response analysis;c. determination of instructure response spectra for the plant buildings for the equipment response analysis. In the third phase of the seismic design and analysis the equipment is analyzed on the basis of in-structure response spectra. For this purpose the structural models of the mechanical components and piping in the plant are set up. In large 3D-structural models used today the heaviest equipment of the primary coolant circuit is included in the structural model of the reactor building. In the fourth phase the electrical equipment and automation and control equipment are seismically qualified with the aid of the in-structure spectra developed in the phase two using large three-axial shaking tables. For this purpose the smoothed envelope spectra for calculated in-structure spectra are constructed and acceleration time is fitted to these smoothed envelope spectra.

Fiber-Reinforced Polymer Bridge Design in the Netherlands： Architectural Challenges toward Innovative, Sustainable, and Durable Bridges

This paper reviews the use of fiber-reinforced polymers （FRPs） in architectural and structural bridge design in the Netherlands. The challenges and opportunities of this relatively new material, both for the architect and the engineer, are discussed. An inventory of recent structural solutions in FRP is included, followed by a discussion on architectural FRP applications derived from the architectural practice of the author and of other pioneers.

Research and design of the main equipments and structure of Xiangjiaba shiplift

The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.

Seismic behavior assessment for design of integral abutment bridges in Illinois

Integral abutment bridges(IABs)minimize deterioration and degradation of the abutment seats and bearings due to water,dirt,and deicing chemicals by eliminating bearings and expansion joints.Although the continuity between superstructure and abutments in an IAB is beneficial for reducing maintenance costs,it leads to more complex behavior under strength and service loading(temperature and traffic)and extreme loading(earthquake).The coupling of superstructure and substructure behavior necessitates system-level analysis of IABs.Prior seismic IAB studies have typically investigated the behavior of individual IAB components,however a gap of knowledge has developed due to the lack of studies and investigation about the behavior of all IAB components and their interactions with each other in a single analysis model.This study uses nonlinear static and dynamic analyses to investigate and assess the seismic behavior of IABs typical to the state of Illinois.The analyses aim to bridge the gap of knowledge by evaluating IABs as a whole and utilizing the results to indicate potential vulnerabilities in the design and construction of IABs in Illinois during design-level and larger seismic events,which could not be identified by component-level IAB analyses alone.

Uniform-risk-targeted seismic design for collapse safety of building structures

Seismic design should quantitatively evaluate and control the risk of earthquake-induced collapse that a building structure may experience during its design service life. This requires taking into consideration both the collapse resistant capacity of the building and the earthquake ground motion demand. The fundamental concept of uniform-risk-targeted seismic design and its relevant assessment process are presented in this paper. The risks of earthquake-induced collapse for buildings located in three seismic regions with the same prescribed seismic fortification intensity but different actual seismic hazards are analyzed to il- lustrate the engineering significance of uniform-risk-targeted seismic design. The results show that with China＇s current seis- mic design method, the risk of earthquake-induced collapse of buildings varies greatly from site to site. Additional research is needed to further develop and implement the uniform-risk-targeted seismic design aoDroach oronnsed in thi~ nnner

Seismic design or retrofit of buildings with metallic structural fuses by the damage-reduction spectrum

Recently, the structural fuse has become an important issue in the field of earthquake engineering. Due to the trilinearity of the pushover curve of buildings with metallic structural fuses, the mechanism of the structural fuse is investigated through the ductility equation of a single-degree-of-freedom system, and the corresponding damage-reduction spectrum is proposed to design and retrofit buildings. Furthermore, the controlling parameters, the stiffness ratio between the main frame and structural fuse and the ductility factor of the main frame, are parametrically studied, and it is shown that the structural fuse concept can be achieved by specific combinations of the controlling parameters based on the proposed damage-reduction spectrum. Finally, a design example and a retrofit example, variations of real engineering projects after the 2008 Wenchuan earthquake, are provided to demonstrate the effectiveness of the proposed design procedures using buckling restrained braces as the structural fuses.

Application of BIM in the Structural Design of Architectural Engineering

Structural design is an important component of architectural engineering.BIM is integrated into structural design to form a complete,linked,and information-based data platform.Therefore,in line with the features of BIM,such as interaction and coordination,information integration,as well as data simulation,this study analyzes the advantages of BIM in architectural structural design,proposes several optimization measures using BIM for architectural structural design,and promotes the rationality of architectural structural design.

Seismic performance analysis and design suggestion for frame buildings with cast-in-place staircases

Many staircases in reinforced concrete （RC） frame structures suffered severe damage during the Wenchuan earthquake. Elastic analyses for 18 RC structure models with and without staircases are conducted and compared to study the influence of the staircase on the stiffness, displacements and internal forces of the structures. To capture the yielding development and damage mechanism of frame structures, elasto-plastic analysis is carried out for one of the 18 models. Based on the features observed in the analyses, a new type of staircase design i.e., isolating them from the master structure to eliminate the effect of K-type struts, is proposed and discussed. It is concluded that the proposed method of staircase isolation is effective and feasible for engineering design, and does not significantly increase the construction cost.

3D Digital Design of Cranes' Structures Based on Hybrid Software Architecture

3D digital design for cranes’ structures based on hybrid software architecture of Client/Server and Browser/Server is introduced in this paper. Based on Pro/ENGINEER platform,3D parametric model family is built to allow generation of feasible configurations of cranes’ structures in Client/Server framework. Taking use of Visual C++,the second exploiting software kit provided by Pro/ENGINEER and ANSYS GUI/APDL modeling patterns,an integration method of 3D CAD and CAE is achieved,which includes regeneration of 3D parametric model,synchronous updating and analysis of FEA model. As in Browser/Server framework,the 3D CAD models of parts,components and the whole structure could also be displayed in the customer’s browser in VRML format.

The Role of Architectural Considerations in Seismic Performance of Buildings： A Case Study in Iran

Experience from recent earthquakes such as Gilan, Zanjan, Bam and Lorestan earthquakes in Iran indicated that the constructed buildings are vulnerable against earthquake. Vulnerability of these structures is due to various reasons such as designing without considering seismic regulations, problems of regulations （design goals）, implementation problems, changing of the building occupancy class, increasing the weight of building stories, adding new stories to the building and changing in architecture of building without considering structural system. So the main objective of this research is to examine the features of building configuration and their effects as for the damages to buildings in past earthquakes. For this purpose, initially four occurred earthquakes in Iran are selected as case study. Then three types of buildings （steel structure, concrete structure and masonry buildings） are analyzed with details. Results showed that the most of damages are occurred in the old steel structures and masonry buildings which their ages are more than 25 years. The study showed that most of the buildings in the study area are steel structure and masonry buildings while concrete structures are infrequent which most of them had no or slight damages. Therefore, the importance and need to enhance the performance of available buildings against earthquake forces by rehabilitating methods would be more important than before. Also results indicated that the decisions related to architectural plan which have significant effect on seismic performance of buildings, can be divided into three categories： configuration of building, restrictive formal architectural plan and dangerous structural components, as these categories are not obstacle of each other, it is possible that each category has an influential effect on others. So organizing the design decisions in this way is very important so as to manage their effects and interdependencies.

Analysis and Research on the Seismic Performance of Adobe Structure

According to the bearing structure, building materials and process, this paper adobe housing will be divided into Adobe bearing wall, brick wall, hybrid bearing housing and bearing timber frame house. Research shows that, different types of housing distribution has regional and age characteristics, seismic performance is different, but there are different seismic safety problems; in order to improve the seismic capacity of rural houses, we need to accelerate the implementation of rural residential earthquake safety project, speed up the reconstruction of the demolition reconstruction and seismic reinforcement work, to carry out research on seismic technology houses, promote rural seismic residential.

The Compatibility of Architectural Presentation and Structural Design

Architectural works,in the material form of buildings,are often perceived as cultural symbols and as works of art.However,today's architects have excessively seeked the artistic expression of building skins,and ignored the architectural aesthetics represented by the structural system as a building skeleton and the elaboration of aesthetics of the architecture itself.Authors of this paper showed the compatibility of architectural presentation and structural design by interpreting the interaction between them,and proposed that a building is a building structure,and the building structure is the building.

Recent progress of seismic research on tall buildings in China Mainland

As a result of rapid economic growth and urbanization in the past two decades,many tall buildings have been constructed in China Mainland,offering researchers and practitioners an excellent opportunity for research and practice in the field of structural engineering. This paper reviews progress by researchers throughout China Mainland on the seismic research of tall buildings,focusing on three major topics that impact the seismic performance of tall buildings. These are:(1) new types of steel-concrete composite structural members such as steel-concrete composite shear walls and columns,(2) earthquake resilient shear wall structures such as shear walls with replaceable structural components,self-centering shear walls and rocking walls,and(3) performance-based seismic design,including seismic performance index,performance level and design method. The paper concludes by presenting future research needs and directions in this field.