Study on Design Method of Mega-Structure Linked with the Ground

2011 ◽  
Vol 243-249 ◽  
pp. 1288-1295
Author(s):  
Tao Lan ◽  
Ji Ping Hao ◽  
Si Yuan Zhao ◽  
Xiao An Wang
Keyword(s):  
Design Method ◽  
Time History ◽  
Dead Weight ◽  
Structure Comparison ◽  
Vibration Period ◽  
Analysis And Design ◽  
History Analysis ◽  
Steel Truss ◽  
Control Load ◽  
Steel Trusses

Based on the research of Life Ring in Shen Fu, the basic criteria for structural design of the unconventional rigid mega-structure linked with the ground are proposed in this paper. Through the structure comparison and selection, the space steel truss is used as the optimal structure form. After static analysis and time-history analysis by FEM, it is found that the control load case is the combination of dead weight and wind load. Because of its long vibration period, the structure is not sensitive during an earthquake. The key design of the structure is the selection of foundation form, a mixed-foundation made of steel trusses with piles is proposed in this paper. The steel truss is used as a bridge which transmits forces between superstructure and foundation. At last, the pile foundation is classified by the loading mechanism, the analysis and design of key joints in the mixed-foundation is proposed.

Research on Seismic Performance Objectives of High-Rise Diagrid Tube Structures

2010 ◽  
Vol 163-167 ◽  
pp. 1100-1106
Author(s):  
Jun Teng ◽  
Wei Liang Guo ◽  
Bai Sheng Rong ◽  
Zuo Hua Li ◽  
Zhi Jun Dong
Keyword(s):  
Seismic Performance ◽  
Design Method ◽  
Time History ◽  
Lateral Stiffness ◽  
Related Factors ◽  
Concrete Core ◽  
Core Tube ◽  
Plastic Energy ◽  
High Rise ◽  
History Analysis

Diagrid tube structures have advantages on constructing high-rise buildings for its great lateral stiffness, but its seismic design methodology researches are limited. The two-stage design method in Chinese code is not specific enough for the seismic fortification objectives of this kind of structures. It is necessary to propose some specific seismic performance objectives for the key components. Typical CFST diagrid tube-concrete core tube structures are studied by dynamic elastic-plastic time-history analysis using Perform-3D program. The structure plasticity developing process is summarized and the distribution characteristics of seismic fortification lines between tubes are discussed. The influences of main structure lateral stiffness related factors on the plasticity developing process are researched. The key components of structure lateral stiffness and plastic energy dissipation are studied. The seismic performance objectives of the key components are proposed for the three-level seismic fortification objectives.

Vibration Analysis of Bridge Structure under Moving Train Load and Earthquake Action

2014 ◽  
Vol 501-504 ◽  
pp. 1266-1269 ◽  
Author(s):  
Bei Bei Fan ◽  
Yuan Zhang ◽  
Dong Hua Ruan
Keyword(s):  
Dynamic Response ◽  
Time History ◽  
Dynamic Effect ◽  
Bridge Structure ◽  
Steel Truss Bridge ◽  
History Analysis ◽  
Steel Truss ◽  
Earthquake Action ◽  
Truss Bridge ◽  
Moving Train

In this paper, vibration of a steel truss bridge under moving train and earthquake action is analyzed. The following conclusions are drawn by modal analysis and time-history analysis. 1) Lateral dynamic response of this structure is more obvious under earthquake action and lateral dynamic effect of train running load; 2) seismic response in the directions different from train load is small, and dynamic response becomes larger obviously when they are considered together.

North Torrey Pines Bridge Seismic Retrofit: Part II, Structural Analysis and Design

2015 ◽  
Vol 31 (4) ◽  
pp. 2211-2233 ◽  
Author(s):  
Nathan S. Johnson ◽  
Mark L. Creveling ◽  
Keith J. Gazaway
Keyword(s):  
Precast Concrete ◽  
Time History ◽  
Rehabilitation Program ◽  
Nonlinear Time History Analysis ◽  
Deep Foundations ◽  
Analysis And Design ◽  
History Analysis ◽  
Support Excitation ◽  
Nonlinear Time History ◽  
Structural Irregularities

The historic North Torrey Pines Road Bridge in Del Mar, California, is a 15-span precast concrete tee-girder structure built in 1933. The bridge has been classified as structurally and seismically deficient and functionally obsolete, with a sufficiency rating of 19 out of 100. Through the Caltrans Retrofit and FHWA Rehabilitation Program, the structure was to be rehabilitated or replaced for improved sufficiency and to satisfy seismic life safety. The combination of complex site geology, its deteriorated state, structural irregularities, site constraints, and the requirement to preserve its historic designation presented a challenging task. The solution was a performance-based methodology, more complex than typically applied in California, which led to a unique multifaceted retrofit and rehabilitation approach. Design and analysis included detailed inelastic static analysis, secant spectral methods, and nonlinear time-history analysis with multi-support excitation. The resulting solution included ground remediation, substructure strengthening, stiffness decoupling, a replacement superstructure, and new abutments on deep foundations.

A Practical Design Method for Energy Dissipation Structure

2012 ◽  
Vol 204-208 ◽  
pp. 1150-1153
Author(s):  
Min Chen ◽  
Guo Jing He ◽  
Chang Liu
Keyword(s):  
Energy Dissipation ◽  
Design Method ◽  
Damping Ratio ◽  
Time History ◽  
Structure Design ◽  
Frame Structure ◽  
Seismic Region ◽  
History Analysis ◽  
Dissipation Structure ◽  
Supplemental Damping

Energy dissipation structure is favored by designers because the earthquake energy can be dissipated by the dampers, which can avoid or reduce the damage caused by earthquake. However, the energy dissipation structure design is complex and the most domestic designers can not master it easily. In this paper, a simple and practicable design method for viscous damper dissipation structure by using the PKPM design software is proposed based on a 7-storey frame structure in highly seismic region. Firstly, lower half or one degree for the design intensity to design out an uncontrolled structure. Secondly, determine the supplemental damping ratio required for the fortification intensity via modal analysis method of PKPM software, and identify the numbers of the required dampers as well as their corresponding installation positions in line with the methods in the seismic code of China. Finally, the ETABS program is adopted to conduct the time-history analysis of the designed dissipation structure, showing that the proposed method in this paper can produce a satisfied result.

Dynamic Analysis and Design Method Study on the Combined-Boom System of Portal Crane

2012 ◽  
Vol 152-154 ◽  
pp. 1645-1649 ◽  
Author(s):  
Yuan Tao Sun ◽  
Duan Li
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Design Method ◽  
Time History ◽  
Analysis Method ◽  
Drive Power ◽  
Analysis And Design ◽  
Whole Process ◽  
Handling Device ◽  
Portal Crane

As a main handling device the portal crane is widely used in port, railroad, etc.The crane handling procedure is mainly carried out through its combined-boom system luffing or swing .In general, in order to reduce drive power and improve the operational performance, the luffing trajectory should meet the design requirement. At the same time, structure stress should be secured in the whole process of handling the cargo. Recently, to deal with more heaver and further cargo, the portal crane is becoming more large-scale. So that the large-scale components such as jib elastic deformation effect on large displacement motion cannot be ignored longer. In addition to the structure high speed motion in the process of handling also make the structure dynamic behaviors spending more obvious specially in the condition of luffing combined with swing. However, the problem for this dynamic behavior brings about to physical design sometimes has no method to solve according to the conventional analysis algorithm and dynamics method. To reduce the deviation caused by the common analysis, design and analysis method based on the multibody is put forward in this thesis. According to the method, the result on the luffing trajectory and stress-time history are analyzed easily. So that it ensure the efficiency and increase the accuracy of the initial design according to the conventional design and analysis method.

Key Points Analysis for Seismic Design of Super High-Rise Building

2013 ◽  
Vol 423-426 ◽  
pp. 1230-1233
Author(s):  
Ting Yu Mei ◽  
Lang Wu
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Response Spectrum ◽  
Time History ◽  
Stage Design ◽  
High Rise ◽  
High Rise Building ◽  
History Analysis ◽  
Key Points ◽  
And Performance

In recent years, high-rise buildings have developed very rapidly in our country. Because of the particularity of the high-rise building, more strictly technical measures should be taken in seismic design to ensure security. Three level fortifications, two stage design method have been used for seismic design in our country. Combined with the practical, the key points of response spectrum, time history analysis and performance design which related to seismic design of high-rise buildings were analyzed.

scholarly journals Demand-Based Optimal Design of Storage Tank with Inerter System

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Shiming Zhang ◽  
Ruifu Zhang ◽  
Zhipeng Zhao
Keyword(s):  
Optimal Design ◽  
Vibration Control ◽  
Design Method ◽  
Time History ◽  
Simultaneous Reduction ◽  
Liquid Storage ◽  
History Analysis ◽  
Virtual Excitation ◽  
Constraint Method ◽  
Excitation Conditions

A parameter optimal design method for a tank with an inerter system is proposed in this study based on the requirements of tank vibration control to improve the effectiveness and efficiency of vibration control. Moreover, a response indicator and a cost control indicator are selected based on the control targets for liquid storage tanks for simultaneously minimizing the dynamic response and controlling costs. These indicators are reformulated through a random vibration analysis under virtual excitation. The problem is then transformed from a multiobjective optimization problem to a single-objective nonlinear problem using the ε-constraint method, which is consistent with the demand-based method. White noise excitation can be used to design the tank with the inerter system under seismic excitation to simplify the calculation. Subsequently, a MATLAB-based calculation program is compiled, and several optimization cases are examined under different excitation conditions. The effectiveness of the demand-based method is proven through a time history analysis. The results show that specific vibration control requirements can be met at the lowest cost with a simultaneous reduction in base shears and overturning base moments.

The Two-Stage Design Method of Isolated Structures Based on New Code for Seismic Design of Buildings

2013 ◽  
Vol 275-277 ◽  
pp. 1243-1249
Author(s):  
Qiang Qiang Zhang ◽  
Wen Pan ◽  
Bai Feng Sun
Keyword(s):  
Base Isolation ◽  
Design Method ◽  
Time History ◽  
Time History Analysis ◽  
Design Stage ◽  
Two Stage ◽  
Stage Design ◽  
Seismic Code ◽  
History Analysis ◽  
Isolation Device

Two-stage design method for base isolation structures includes simplified estimation and time history analysis. Simplified estimation is used in preliminary design stage for estimating the weight and the first period of an isolated structure, the upper structure is simplified as a SDOF system. According to the expected response reduction goals and response spectrum, the first period of the isolated structure, stiffness of isolation device and number of isolation bearing can be induced. Time history analysis is employed in detail design stage, for determination and optimization of isolation device based on current standards. The author has made it realized based on the old Seismic Code. As there are some changes of provision on base isolation analysis in new code, including the value of bearing stiffness and safety factor, etc., the method mentioned above should be updated. Numerical investigation shows that for regular multi-storey frame structures, the difference of the maxium ratio of floor shear between the old and new Seismic Code increase with fortification intensity.

scholarly journals Optimal Design of Mega-Frame Core Wall Structures Equipped with Viscous Damped Outriggers for Human Comfort Performance under Wind Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Yue Yang ◽  
Xin Zhao ◽  
Weixing Shi ◽  
Jiayue Li
Keyword(s):  
Optimal Design ◽  
Design Method ◽  
Time History ◽  
Simplified Model ◽  
Dominant Factor ◽  
Viscous Dampers ◽  
Analysis And Design ◽  
Vibration Prediction ◽  
Optimal Design Method ◽  
Wind Induced Vibration

Megatall and supertall buildings often adopt megastructure systems characterized by secondary structure systems, and the serviceability problem caused by wind-induced vibrations often becomes the dominant factor in the structural design. Because the deformation of a supertall building usually presents bending characteristics, a viscous damped outrigger can reduce the wind-induced vibration of a supertall building with the installation of a small number of viscous dampers. However, time history analysis of the prototype model considering the nonlinear characteristics of viscous dampers is time-consuming, which is not conducive for iterative design optimization. Additionally, the conventional simplified model composed of one cantilever beam cannot be used for the analysis and design of a viscous damped outrigger. In this study, a simplified wind-induced vibration prediction model is proposed based on the mechanical characteristics of megastructures. This simplified model is a plane model that includes both core walls and frames whose member size can be extracted from the original structure. Parametric analysis shows that the simplified model has high acceleration prediction accuracy. An optimal design method combined with the simplified model, which aims to minimize the damped outrigger system cost, is proposed. A 600-m supertall building is presented as a case study. The accuracy and effectiveness of the simplified model and the optimal design method proposed in this study are illustrated. Thus, applying this optimal design method in combination with the simplified model can save significant analysis and design time and is conducive to the application of viscous damped outriggers in practical engineering.

Experimental investigation of prefabricated steel-truss waffle slab under flexural loading

2019 ◽  
Vol 23 (2) ◽  
pp. 263-276
Author(s):  
Qun Xie ◽  
Song Xue ◽  
Zhen-hua Liang ◽  
Ming-qiang Lin
Keyword(s):  
Aspect Ratio ◽  
Shear Failure ◽  
Design Method ◽  
Steel Wire ◽  
Strain Analysis ◽  
Reinforce Concrete ◽  
Wire Mesh ◽  
Steel Truss ◽  
Waffle Slab ◽  
Steel Trusses

A novel type of prefabricated steel-truss waffle slab has been proposed in this article, and compared with traditional waffle slab, there are several typical characteristics of this floor system, including welded steel wire mesh laid in top concrete wythe, orthogonal steel trusses used to reinforce concrete ribs, and foamed concrete blocks filled among the ribs with the purpose of heat insulation and fire resistance. A special template system is adopted for the installation and concrete cast of prefabricated steel-truss waffle slab. All steel segments in prefabricated steel-truss waffle slab are precast and then assembled to form steel system in site. In order to investigate the structural behavior of prefabricated steel-truss waffle slab, two full-scale specimens with different aspect ratio have been experimentally studied under flexural load. The results obtained from the tests have been discussed and analyzed in the context of ultimate flexural load, cracking pattern and failure mode, load–deflection relationship, and load–strain relationship. The experimental results showed that the ultimate load-bearing capacity of prefabricated steel-truss waffle slab has greatly been influenced by the punching shear failure at the rib joints. Three crack types, such as flexural cracks, tensile cracks, and interface cracks, have been exhibited in the final failure of prefabricated steel-truss waffle slab. The deflection development at slab center has presented a four-stage behavior. The significant effect of aspect ratio has also been verified by strain analysis. A computer program has been developed according to the modified structural design method proposed in this article, and the comparison indicated a good agreement between experimental data and theoretical results.

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