Shanghai World Financial Center Research Articles

Field Measurements of Wind-Induced Responses of the Shanghai World Financial Center during Super Typhoon Lekima.

In this paper, the wind-induced responses of the Shanghai World Financial Center (SWFC) under Super Typhoon Lekima are measured using the health monitoring system. Based on the measurements, the characteristics of vibration, including probability density distribution of accelerations, power spectra, and mode shapes are studied. The curve method and the standard deviation method are used to analyze the relationship of the first- and second-order natural frequencies and damping ratios with amplitudes and the mean wind speed. The results show the following: (1) The structural wind-induced responses in the X and Y directions have high consistencies, and the vibration signals exhibit a peak state; moreover, response amplitudes and acceleration signals disperse when the floor height increases. (2) The first- and second-order natural frequencies in the X and Y directions decrease with the increasing amplitudes and are negatively correlated with mean wind speed; the maximum decrease in natural frequency is 5.794%. The first- and second-order damping ratios in the X and Y directions increase with the increasing amplitudes and are positively correlated with the mean wind speed; the maximum increase in damping ratio is 95.7%. (3) The curve method and the standard deviation method are similar in identifying dynamic characteristic parameters, but the discreteness of the natural frequencies obtained by the curve method is lesser. (4) Under excitations of various typhoons, the mode shapes of SWFC are basically the same, and the mode shapes in the X and Y directions increase with the height and have nonlinearity.

Field Measurement Study on Dynamic Characteristics of the Shanghai World Financial Center

It is of great practical importance to study the vibration response characteristics of super high-rise buildings under an earthquake action to provide a basis for seismic design and later maintenance of structures in coastal areas. During this study, the Shanghai World Financial Center (SWFC)’s health monitoring system was utilized to monitor earthquakes of magnitude 6.4 in Taiwan, 6.0 in Japan, 7.2 in the East China Sea, and 4.4 in Jiangsu, in real-time. Through the improved Envelope Random Decrement Technique (E-RDT), the dynamic properties of super high-rise buildings were examined under different earthquake effects in terms of the acceleration power spectrum, natural frequency, damping ratio, and mode shape. The results demonstrated that (1) the vibration responses of the structure in X (East–West) and Y (North–South) directions under four earthquakes were consistent, and with increasing floor height, the discreteness of the amplitude and acceleration signals of vibration responses increased. (2) The first two natural frequencies of the structure in X and Y directions decreased with the increase in amplitude, but the damping ratio increased with the increase in amplitude. The minimum values of the first two natural frequencies are 0.1498 Hz and 0.4312 Hz, respectively, and the maximum values of the first two damping ratios are 0.0086 and 0.0068, respectively. (3) Under different earthquake excitations, the SWFC’s mode shape’s estimates were similar, and their change trends in the X and Y directions were nonlinear as the number of floors increased. The structure was not seriously damaged by the four earthquakes. This study can provide helpful information for the seismic design of super high-rise buildings based on its findings.

Optimization Analysis of Key Technologies of Super High-Rise Buildings with Soft Soil Foundation

The frequency of super high-rise buildings has gradually increased in larger cities. Compared with ordinary buildings, super high-rise buildings involve more difficult technologies of construction. Soft soil foundation is one of the unfavorable foundation types for engineering construction because of its high sensitivity and low bearing capacity. Therefore, the combination of super high-rise buildings and soft soil foundations will greatly increase the insecurity of the project. Although related methods of soft soil treatments have been proposed and optimized in recent years, there is still a lack of targeted construction methods combing for super high-rise buildings, which is of vital significance to improve the safety and efficiency of future construction projects. Based on the case analysis of Jinmao Tower, Shanghai World Financial Center and Shanghai Tower in the Lujiazui zone, this paper summarizes the optimization of key technologies of super high-rise buildings under the background of soft soil foundation. The author hopes to provide a clear reference for future projects by systematically sorting out the construction projects in this typical area.

Dynamic performance evaluation of a 492 m super high-rise building with active tuned mass dampers during four consecutive landfall typhoons within a month

Field measurement is the most reliable and intuitive method to assess the wind effects of super high-rise buildings. However, due to the different inherent characteristics of each typhoon, the observations may be different or even contradictory. Therefore, there is a need to conduct further analysis on the wind effects during typhoons to reveal more general results. In this study, wind-induced acceleration responses collected by the structural health monitoring system installed atop the Shanghai World Financial Center (SWFC) during the landfall of four consecutive typhoons (Ampil, Jongdari, Yagi and Rumbia) within a month are systematically investigated. The first five-order modal directions are determined based on the spectral method. The envelope random decrement technique is adopted to identify the natural frequencies and damping ratios, and the amplitude dependencies and time-varying characteristics of the structural dynamic properties are also analyzed. Furthermore, the control performance of active tuned mass damper (ATMD) system during typhoons is discussed. Finally, the serviceability of the skyscraper during typhoons is assessed, and the global damage evaluation is performed. The results show that the natural frequencies decrease with increasing amplitude and present V-shaped variation trends with time. The damping ratios almost increase with increasing amplitudes but do not show any noticeable variation trend with time. The time-varying environmental conditions may have considerable effects on the modal parameters, and those effects may be superimposed in a short time. The ATMD system can effectively mitigate wind-induced vibrations. The occupant comfort is satisfactory, and no evident structural damage is detected during typhoons.

A Review of Key Technologies Development of Super High‐Rise Building Construction in China

Super high‐rise building is a typical architectural form of urban modernization, and it is also the trend of urban architectural development. This paper reviews the development history of super high‐rise buildings in China combined with the engineering practice of representative super high‐rise buildings since the 1980s, such as the Shanghai Center, Shanghai Oriental Pearl Tower, Jinmao Tower, Shanghai World Financial Center, Canton Tower, and Shanghai Tower. The development process of the key technologies of super high‐rise projects from the aspects of several technologies, such as soft soil pile foundation and foundation pit technology, concrete structure construction technology, integral formwork equipment technology, and steel structure comprehensive installation technology, is also elaborated. At the same time, the Shanghai Tower is selected as a typical case to share the innovative technology of China’s tallest building. Finally, prospects for development of super high‐rise construction technology are presented.

Research on Wind Load Calculation Based on Identical Guarantee Rate Method

Wind load on building surface is one of the main loads for structural design; scholars in this field have put forward some methods to calculate wind load, such as Simiu method and Kasperski method. Based on the basic theory of probability and the systematic analysis of the surrounding environment and turbulence, a random variable model for calculating wind load is established. According to the model, through the analysis of the relationship between guarantee rate and wind load, a numerical calculation method to calculate wind load is proposed based on extreme value analysis and polynomial fitting theory. To verify the performance of the algorithm, wind tunnel experiments were carried out to obtain a large number of first-hand measured data of high-rise building (Shanghai World Financial Center). Based on the measured data, the algorithm is simulated, and calculated results are analyzed, including wind pressure distribution on building and probability distribution of fluctuating wind pressure of some measuring points. The validity and accuracy of the proposed model and algorithm are verified by the comparative analysis and theoretical analysis of the calculation results.

Evolutionary Spectra Estimation of a Nonstationary Process Based on a Single Sample

This paper proposes a novel method for estimating the evolutionary power spectral density (EPSD) of a nonstationary process based on a single sample. In the proposed method, a sample of a nonstationary process is decomposed into several components with a new binomial fitting decomposition (BFD). The EPSD of each component can be estimated using a newly proposed time-varying standard deviation estimation method and short-time Thomson multiple-window spectrum estimation method. The EPSD of the analyzed nonstationary sample is obtained by combining the EPSDs of all components. Via a comprehensive numerical study, the applicability of the proposed EPSD estimation method (for estimating the EPSD of a nonstationary process) is analyzed and compared with those by the Priestley method and wavelet-based method. The numerical results indicate that the estimated EPSD by the proposed method is more consistent with the corresponding theoretical one than those by the other two methods. Finally, the EPSDs of Storm Ampil, measured atop the Shanghai World Financial Center, are analyzed by the proposed method.

Deformation monitoring and analysis of the thermal expansion of high-rise buildings in Shanghai Lujiazui using tomography-based persistent scatterer interferometry

We utilize a tomography-based persistent scatterer interferometric synthetic aperture radar (Tomo-PSInSAR) approach for monitoring the deformation performance and analysis of the thermal expansion of 33 high-rise buildings in Shanghai Lujiazui. For the purpose of this study, we use 31 stripmap acquisitions from TerraSAR-X missions spanning from December 2009 to February 2013. Considering that thermal expansion, concrete creep, and shrinkage are three long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude) are estimated simultaneously. Additionally, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen in the study area. The thermal amplitude map demonstrates that the derived thermal amplitude of the buildings is highly related to the building height due to the upward accumulative effect of thermal expansion. The deformation velocity map reveals that the Shanghai World Financial Center is subject to a great deal of deformation during the newly built period due to concrete creep and shrinkage effects, which are height-dependent downward movements. In addition, the deformation rates caused by concrete creep and shrinkage are largest at the beginning and gradually decrease, finally achieving a steady state as time goes to infinity. In contrast, the deformation velocity map shows that the Jin Mao Tower is almost stable during this period. We observe a negative correlation between deformation characteristics and the time of completion of high-rise buildings, inferring that the newly built concrete buildings are more sensitive to concrete creep and shrinkage effects than the older concrete buildings. Our study emphasizes the potential of the Tomo-PSInSAR solution for monitoring the deformation performance and analysis of the thermal expansion of high-rise buildings.

Field Measurements of Dynamic Properties of a Supertall Building during Construction of an Adjacent Supertall Building

AbstractField measurements of wind speeds, wind directions and acceleration responses on top of the Shanghai World Financial Center building (SWFC), which is 492 m high, were obtained from 2011 to ...

Estimation of peak factor and gust factor of nonstationary wind speed

This paper proposes a new method for estimating the peak factor and gust factor of nonstationary wind. In this method, the probability density function (PDF) of the largest value of a nonstationary wind speed is fitted using the PDF of the largest value of an equivalent stationary wind speed; subsequently the mean wind speed and standard deviation of the equivalent stationary wind speed, which are respectively defined as equivalent mean wind speed and equivalent standard deviation, are used to normalize the largest value of the nonstationary wind speed to calculate its gust factor and peak factor. The proposed method can be utilized in the field measurement of nonstationary wind speed to obtain peak factor and gust factor which might be applicable for predicting the largest value of a new nonstationary wind speed only using its time-varying mean wind speed and time-varying standard deviation. The applicability of the proposed method is verified using numerical simulation and wind speed data of three typhoons, which were measured atop the Shanghai World Financial Center (SWFC) at a height of 497 m. The three typhoons’ peak factor and gust factor estimated by the proposed method are also analyzed in this study.

Design and performance of the piled raft foundation for Shanghai World Financial Center

Design and performance of the piled raft foundation for Shanghai World Financial Center

Are the “A’s” in AAI Anachronistic? An Imaginary Interview with Bert Foer

We conducted this interview with Bert Foer in 2014, at the time of his retirement from the presidency of AAI.1 Our interview was held in AAI’s beautiful offices overlooking the Department of Justice, the Federal Trade Commission, the Congress, the White House, various federal regulatory agencies (including the FCC and FERC), and, in the distance, the offices of the fifty-five state government antitrust enforcers. Farther in the distance are the Berlaymont building, the Shanghai World Financial Center, and the Taj Mahal.

Deformation of compensated piled raft foundations with deep embedment in super‐tall buildings of Shanghai

SummaryThis paper presents a synergetic approach based on a statistical‐empirical method, conservation of energy method and superstructure‐foundation interaction theory, and this paper aims to estimate the deformation level of a compensated piled raft foundation. The advantages and main characteristics of such a compensated piled raft foundation are described, and a history of the heave, recompression deformation and final settlement data measurements is provided. Case studies of four super‐tall buildings, the 88‐story Jinmao Building, 66‐story Henglong Plaza, 101‐story Shanghai World Financial Center and 121‐story Shanghai Center Tower in Shanghai, all of which are engineering projects that the second author participated in, are provided to illustrate the effectiveness of different calculations for heave, recompression deformation and final settlement. This study demonstrates that the deformation process can be reasonably projected for a piled raft foundation with deep embedment in Shanghai using superstructure‐foundation interaction methods, statistical‐empirical formulas and a method based on the conservation of energy. The coefficients in the statistical‐empirical method are also further optimized. This deformation estimation considering compensation for deep embedment unloading is reasonable and can be used to avoid excessively conservative designs, and the synergetic approach is applicable to any compensated piled raft foundation with deep embedment in Shanghai. Copyright © 2014 John Wiley & Sons, Ltd.

Field Measurement of Wind Speeds and Wind-Induced Responses atop the Shanghai World Financial Center under Normal Climate Conditions

Field measurement data on wind velocities and wind-induced acceleration responses at the top of the 492 m high Shanghai World Financial Center (SWFC) under normal climate conditions are studied. Characteristics of the mean wind speeds and turbulence intensities, gust factors, power spectral densities, and turbulence integral scales of the fluctuating wind speed are analyzed in different observation time intervals. Power spectral densities of wind-induced acceleration are also investigated. The basic natural frequencies and structural damping ratios of the building are identified based on Hilbert-Huang transform method and random decrement method. The field measurement results of wind-induced responses of the SWFC are finally compared with those from the corresponding high-frequency force balance wind tunnel test study.

超高速・大容量・超高行程対応エレベーターの最新技術(特別企画(4):最もホットな最新技術)

Toshiba Elevator and Building Systems Corporation has developed four ultra-high-speed, large-capacity elevators, as well as two elevators accommodating up to 27 passengers along the longest running path of 464.4m in Japan. These elevators were installed in the newly constructed freestanding broadcasting tower, TOKYO SKYTREE^[○!R], which started operation in May 2012. We have developed advanced technologies for elevators with larger capacity and longer traveling distance based on our proprietary technologies acquired through the development of the world's fastest elevator for TAIPEI101, super-high-speed elevator for China's highest Shanghai World Financial Center, and so on. In order to realize a safe and comfortable ride, we have also applied new safety and earthquake-resistance regulations prescribed in the Building Standards Act and related laws and regulations to the design of elevator systems, including unintended car movement protection(UCMP).

Cover Picture: Structural Concrete 4/2012

AbstractThe Shanghai Skyline shows some remarkable tower structures, all of them within the top list of tall structures worldwide. The Jin Mao Tower (left) is an 88‐story landmark sky scraper, containing offices and a hotel. It was the tallest building in China and the fifth tallest in the world by roof height until it was surpassed in September 2007 by the neigh bouring Shanghai World Financial Center (middle, see pp. 236–247). The Shanghai Tower (right), a 128‐story building located next to these two buildings and now under construction, will be even taller. (Photo: Geert De Schutter)

Field Measurement of Wind Characteristics of Typhoon Muifa on the Shanghai World Financial Center

Field measurement is considered to be the most reliable method to obtain wind characteristics of typhoon, and it is of essential value of further understanding of wind-resistant design of super tall buildings. In this paper, the wind data were recorded atop the Shanghai World Financial Center (SWFC) with a height of 494 m during the whole course of Typhoon Muifa on August 6–8 in 2011. Detailed analysis of the field data is conducted to investigate the characteristics of the typhoon-generated wind including the mean wind speed and direction, turbulence intensities, gust factors, peak factors, turbulence integral length scales, and spectra of fluctuating wind speed. A comparative study between the measured wind characteristics and those previously obtained in the literature is also carried out. It is found that the average values of turbulence intensities, gust factors, and turbulence integral length scales under the condition of Typhoon Muifa are higher than those under monsoon condition atop the SWFC, and Von Karman spectra are suitable to describe of the turbulent kinetic energy distribution at Lujiazui of the Pudong district in Shanghai.

Performance-based seismic analysis and design of code-exceeding tall buildings in Mainland China

Design codes provide the minimum requirements for the design of code-compliant structures to ensure the safety of the life and property. As for code-exceeding buildings, the requirements for design are not sufficient and the approval of such structures is vague. In mainland China in recent years, a large number of code-exceeding tall buildings, whether their heights exceed the limit for the respective structure type or the extent of irregularity is violated, have been constructed. Performance-based seismic design (PBSD) approach has been highly recommended and become necessary to demonstrate the performance of code-exceeding tall buildings at least equivalent to code intent of safety. This paper proposes the general methodologies of performance-based seismic analysis and design of code-exceeding tall buildings in Mainland China. The PBSD approach proposed here includes selection of performance objectives, determination of design philosophy, establishment of design criteria for structural components and systems consistent with the desirable and transparent performance objectives, and seismic performance analysis and evaluation through extensive numerical analysis or further experimental study if necessary. The seismic analysis and design of 101-story Shanghai World Financial Center Tower is introduced as a typical engineering example where the PBSD approach is followed. The example demonstrates that the PBSD approach is an appropriate way to control efficiently the seismic damage on the structure and ensure the predictable and safe performance.

Vibration control using ATMD and site measurements on the Shanghai World Financial Center Tower

The Shanghai World Financial Center Tower is the tallest landmark building in mainland China, with a height of 492 m. In order to mitigate wind-induced vibration, a set of two identical damping devices was installed at the 90th floor. The damping devices are active tuned mass dampers: under wind loading, the active control feature is enabled, while the active control feature becomes disabled under earthquake conditions, and the damping devices function as passive tuned mass dampers. The dynamic parameters of the damping devices, structural analysis results and field measurement results under different vibration scenarios are presented in this paper. The analysis and field measurement results show that the damping devices performed well and had the following characteristics: they increased the damping ratio up to eight times in field measurements and reduced the wind acceleration response up to 60% when wind speed is below the designed value in the analysis. Copyright © 2012 John Wiley & Sons, Ltd.

Experimental study on an ultra high-rise building evacuation in China

With the development of modern cities, more and more ultra high-rise buildings have been built. Emergency evacuation of such buildings becomes one of the major concerns for building designers, building occupants and governments, especially after the disaster of 9/11. In this study we designed three experiments to investigate the process of ultra high-rise building evacuation. The experiments were performed in Shanghai World Financial Center, which is about 470m tall. In the first experiment, the evacuation of a single pedestrian from the top floor to the first floor was performed. Movement characteristics such as mean speed and the time needed for evacuation were analyzed. In the second experiment, the mass evacuation process was captured by video cameras and the data were extracted out manually. The evacuees were distributed initially on floors 12–17, and were asked to evacuate through a staircase onto the refuge floor. On the refuge floor, i.e. the 6th floor, the evacuees were required to transit into another staircase to keep moving down to the ground floor. The characteristic space–time curves for each evacuee were extracted and analyzed. Parameters such as the mean speed and the evacuation time, as well as the characteristic of the transit process from one staircase to another were investigated. We at last mimicked and discussed the process of lift evacuation for an ultra high-rise building in the 3rd experiment. Evacuees located on the 41st and 65th floor were asked to move downward by stairs until they came to the refuge floors, where they would evacuate to the ground floor by lifts. The time characteristic of the mixed evacuation strategy was discussed. The basic data obtained from the experiments are useful for building designers and can be used to validate and refine ultra high-rise building evacuation models.