Super High-rise Buildings Research Articles

Experimental study on seismic performance of super high-rise building with topology optimized diagonal mega frame

Diagrid system has received increasing attention by designers and researchers of high-rise building. In this paper, an innovative super high-rise diagonal mega frame-core tube structure adopting topology optimization for two-dimensional diagrid mesh and shape optimization for three-dimensional outline was introduced. Different from traditional diagrid structures, eight corner columns and a number of corner beams were used in the external diagrid frame, leading to unique spatial working capacity. In order to assess and study the seismic performance of this innovative structure, a series of shaking table tests on a 1/35 scaled model were conducted. Three earthquake waves and three seismic intensity levels were considered during the tests and the external diagrid frame tube showed strong lateral stiffness while severe tensile damage occurred at the bottom of corner columns under maximum considered earthquakes. Then repair work of the test model was initiated and second part of shake table test was conducted which covered the same loading steps of the first part test and more loading steps of two higher seismic levels. Based on a large amount of test data recorded, the acceleration response, displacement response, strain response, seismic fragility and hysteretic energy dissipation of this structure were analyzed. This structure performed satisfactory seismic performance and collapse resistance capacity without obvious whiplash effect and weak story. Corner columns became the key components due to their tremendous axial forces and welding connections of corner columns became the comparatively weak parts in this system, which need be carefully concerned in practical project.

Influence of outrigger truss system on the seismic fragility of super high-rise braced mega frame-core tube structure

The braced mega frame-core tube (BMFCT) structure is an efficient seismic structural system for super high-rise buildings of over 500 m high. The outrigger truss (OT) system has become a commonly adopted design option for the super high-rise BMFCT structure, however, its influence on the seismic performance is not clear. In this study, the seismic responses and collapse risks of the 590-m-high BMFCT structures with and without OT system were analyzed. An efficient elasto-plastic modeling method was introduced to establish the accurate FE models. Based on the incremental dynamic analysis-based (IDA) fragility analysis, the deformation responses, energy dissipations, collapse risks and collapse resistance capacities, etc. were researched. The results indicate the average top displacements under earthquakes of ‘one-degree-higher’ rare intensities are reduced by the OT from 1286.51 mm to 1348.31 mm by 4.6%. The OT system can effectively limit the story drift ratios of the BMFCT under earthquakes with the lower intensity. With the increasing seismic intensity, the OT presents an unfavorable effect on the lateral deformations. The OT system increases the proportion of damping energy dissipation from 68.28% to 70.24%, and decreases that of plastic deformation energy dissipation from 20.74% to 20.12%, both by less than 2%. The OT system causes the slope of IDA curves to rise first and then fall, which is the opposite of that without OT. The OT system is detrimental to the structural collapse resistance capacity, reducing the collapse margin ratio from 8.46 to 7.41 by about 14%. The OT's function can effectively reduce the cross-sectional dimensions of main components and ensure the architectural functionality and view-transparency. In the seismic design of BMFCT structures, the OT system should be given more attention, especially in the earthquakes stronger than rare intensity, and recommended to be designed to meet the basic structural stiffness requirement and not to provide excessive lateral stiffness resistance.

Towards the automated virtual trial assembly of large and complex steel members using terrestrial laser scanning and BIM

Virtual Trial Assembly (VTA) is proposed as an alternative to physical trial assembly that can significantly reduce cost and time requirements. Existing studies on VTA can be categorized as total station and camera-based methods or Terrestrial Laser Scanning (TLS)-based methods. The real coordinate measurement procedure in existing total station and camera-based VTA methods is inefficient and complex because many targets have to be manually installed at assembly points and because different members require different installation schemes. Existing TLS-based VTA methods involve significant human intervention because assembly point extraction and assembly simulation are achieved with commercial software. In addition, geometric quality inspection is not performed in TLS-based VTA methods, although the basis for VTA is the dimensional quality compliance of the components. Therefore, this study presents an automated approach to perform VTA for large and complex steel members based on TLS, and Building Information Modeling (BIM) is utilized to provide as-designed geometric data. Specifically, an automated method is presented to extract assembly points. An internal point removal method is proposed for a BIM model to improve the accuracy of fine registration. A geometric quality inspection method is developed for bending and torsional deviation inspection. The proposed approach is found to be reliable through its application to a practical super high-rise building.

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.

Exploration Of Structural Design Principle and Construction Technology Application for Super High-Rise Buildings

With the rapid development of super-high-rise buildings, the popularity rate becomes higher and higher. People's requirements for the stability and practicability of their buildings are also increasing. At the same time, the design principle of super-high rise building structure is constantly improved and developed. The various construction methods of super-high rise building make the structure of high-rise building more stable. It can meet more construction needs and further improve the appearance of the building. At the same time, the construction process is improved. The application of construction technology and construction optimization are laying a foundation for the development of super high-rise buildings. This paper focuses on the summary of structural design principles of super-high-rise buildings and the introduction of construction technology and optimization. At the same time, it discusses the construction process of the main structure of the building, as well as the different processes and different theoretical schemes before and during the construction. In this way, the super-high rise building structure is systematically improved and summarized, which will lay a foundation for future research and development.

Structural Design and Analysis of a Super-High Building in Nanjing, China

This study analyzes a high-rise building with B-level height (i.e., a total height of 146.5 m) and a shear wall structure. Since the project contains many plane irregularities (including 1a torsional irregularity, 1b eccentric arrangement, and 2a plane convex irregularity), it should be treated as a super high-rise building. This study introduces the main characteristics and overrun conditions of the project and describes the structural design of the foundation and the basement, upper structural layout, force conditions under frequent, fortified, and rare earthquake actions, and structural performance-based objectives in detail. The following measures can be adopted to address the overrun problem. First, the floor at the thin waist of the structure was thickened to 150 mm and reinforced in the bilayer and bidirectional patterns, with a reinforcement ratio of no less than 0.25%. The damage condition on the floors under a great earthquake was analyzed. The vertical components at the waist were reinforced to constrain the extension of the edge components toward the top. Second, the structure’s peripheral stiffness was strengthened to enhance the anti-torsional performance and minimize the adverse effects on torsional irregularities. Third, using two software programs, the performance-based envelope design under medium earthquake action and dynamic elastoplastic analysis under great earthquake action were analyzed to ensure structural safety. Fourth, the edge components were constrained for the shear wall columns with axial-to-compressive stress strength ratios exceeding 0.3. For the overall structure and critical parts, force conditions under frequent, fortified, and rare earthquake conditions were calculated and examined with the SATWE, MIDAS GEN, and SAUSAGE software packages. The calculation results revealed that the structure shows favorable anti-seismic performance, with an overall anti-seismic C-level and a safe and reliable structure. The structural design method introduced in this article can promote the sustainable development of structural design.

Optimization Strategy of Rolling Mill Hydraulic Roll Gap Control System Based on Improved Particle Swarm PID Algorithm

Medium and heavy plates are important strategic materials, which are widely used in many fields, such as large ships, weapons and armor, large bridges, and super high-rise buildings. However, the traditional control technology cannot meet the high-precision control requirements of the roll gap of the thick plate mill, resulting in errors in the thickness of the medium and heavy plate, thereby reducing the quality of the product. In response to this problem, this paper takes the 5500 mm thick plate production line as the research background, and establishes the model of the rolling mill plate thickness automatic control system, using the Ziegler-Nichol response curve method (Z-N), particle swarm optimization (PSO) algorithm and linear weight particle swarm optimization (LWPSO) algorithm, respectively, optimizes the parameter setting of the PID controller of the system, and uses OPC UA communication technology to realize the online semi-physical simulation of Siemens S7-1500 series PLC (Siemens, Munich, Germany) and MATLAB R2018b (The MathWorks, Natick, Massachusetts, United States). Comparative studies show that when the same roll gap displacement step signal is given, the overshoot of the system response using the LWPSO algorithm is reduced by 14.26% and 10.18% compared with the Z-N algorithm and the PSO algorithm, and the peak time is advanced by 0.31 s and 0.05 s. The stabilization time is reduced by 3.71 s and 4.31 s, which effectively improves the control accuracy and speed of the system and has stronger anti-interference ability. It has certain engineering reference and application value.

Research Progress of SHM System for Super High-Rise Buildings Based on Wireless Sensor Network and Cloud Platform

In recent years, the number of super high-rise buildings is increasing due to the rapid development of economy and construction technology. It is important to evaluate the health condition of super high-rise buildings to make them operate safely. However, conventional structural health monitoring (SHM) system requires a great number of wires to connect the sensors, power sources, and the data acquisition equipment, which is an extremely difficult process to plan the layout of all wires. Hence, one of the usually used compromising approaches is to limit the number of sensors to reduce the usage of wires. Recently, wireless sensor networks and cloud platform have been widely used in SHM system for super high-rise buildings because of their convenient installation, low maintenance cost, and flexible deployment. This paper presents a comprehensive review of the existing SHM system for super high-rise buildings based on wireless sensor network and cloud platform, which usually consists of sensing network subsystem, data acquisition subsystem, data transmission subsystem, and condition evaluation subsystem. This paper also reviews the crucial techniques and typical examples of SHM system used for famous super high-rise buildings. In addition, the existing difficulties in wireless sensor network and cloud platform based SHM system for super high-rise buildings and the future research directions are discussed and summarized.

DEVELOPMENT OF DAMPED BRACED TUBE SYSTEM AND APPLICATION TO ACTUAL PROJECT

A new vibration control system, Damped braced tube system, is developed for adopting on super high-rise buildings in central Tokyo. This system consists of tube frame using elastic braces and damped slit where a portion of braces are replaced by dampers. Damped slit acting as link beam of coupled shear wall system can dissipate seismic energy very efficiently and contribute to succeeding to meet higher seismic criteria. This paper describes system outline and efficiency through numerical analysis of actual high-rise project expected to be one of the tallest towers in central Tokyo.

Wind-Induced Responses and Wind Loads on a Super High-Rise Building with Various Cross-Sections and High Side Ratio—A Case Study

With the development of construction technology and material, more and more super high-rise buildings will be constructed in the future. In a specific metropolitan area, super high-rise building with various cross-section and high side ratio have to been designed and constructed due to the size limitation of construction site. This kind of building is also very prone to wind excitations. In this research, wind tunnel tests for a practical case of this kind of building with surrounding buildings were carried out in atmospheric boundary wind tunnel. Equivalent static wind loads (ESWLs), wind-induced responses and wind load distribution on the building were analyzed. In particular, the base overturning moment along the axis with weak lateral stiffness were investigated for bearing capacity limit state design of the building. The results demonstrate that the maximum value of wind-induced base overturning moments and acceleration responses appears at 60° or 330° wind directions instead of the orthogonal wind direction, and the aerodynamic interference of surrounding buildings affects the wind pressure distribution on facades of the building. These results and conclusion may be helpful to wind-resistant design of super high-rise buildings with high side ratio.

Determination of pressure difference coefficient of shuttle elevator doors in super high-rise buildings under stack effect

The stack-induced airflow of super high-rise buildings in winter results in obvious indoor environmental problems at the shuttle elevator shaft. Strong pressure difference can cause malfunction of elevators. The estimation of pressure differences at the shuttle elevator doors under different building layout and climate conditions is still a challenge to obtain in engineering application. Considering the difficulties of measuring and simulating the air leakage characteristics of various components, a dimensionless metric, the Pressure Difference Coefficient of Elevator Doors, Cele, is defined according to the theory of pressure distribution in buildings. First, the accuracy of the index calculation results was verified in an elevator test tower. The hand-calculated method to predict the pressure differences at the shuttle elevator doors is convenient and reliable when compared with measurement and simulation. Then, two influence factors on Cele, floor plan and flow exponents are discussed. The determination method of recommended Cele is proposed by analyzing with different building partition layers. The recommended values are given under different shaft heights and temperature difference. Moreover, the novel method and metric were applied in an actual building to determine the number and air tightness of partition layers under the target conditions. This paper provides an evaluation reference for the convenient and effective design of elevator type selection and building layout of super high-rise buildings under stack effect.

Effects of corner modifications on wind-induced responses of super high-rise buildings by wind tunnel tests based on a novel low-damping elastic test model

Corner modification is a useful aerodynamic countermeasure to reduce wind-induced responses of super high-rise buildings. In this paper, the effects of corner modifications on wind-induced responses of super-tall buildings with square section were carefully studied by using wind tunnel tests based on a low-damping elastic test model, from which the aeroelastic effect can be taken into account. First, an elastic test model of a 452-m-high building with low damping was designed and manufactured. In this test model, a core beam with a cross-shaped section was adopted to provide the essential stiffness. Four types of coats with different corners, including right-angle, recessed, chamfered and rounded, were specially designed to conveniently change the configurations of the elastic test model. Second, the frequency and damping ratio of the elastic test model were identified experimentally. The measured frequencies of the test model are in good agreement with the target frequencies, and a very low damping ratio of 0.3% and 0.5% were achieved. Third, a series of wind tunnel tests on the elastic test models were carried out to measure the wind-induced responses of the buildings with different corner modifications, including the accelerations at the top, the base shears and moments at the bottom. The results show that the three types of corner modifications, including recessed, chamfered and rounded corners, all play an important role in reducing the cross-wind and along-wind responses. It seems that the optimized parameters for the recessed, chamfered and rounded corners are respectively 3%, 7.5% and 10% from the viewpoints of both the peak and RMS base moments. 15.3%, 23.4% and 18.9% of the maximum peak base moment in the cross-wind direction can be reduced by the optimized parameters of the recessed, chamfered and rounded corners, respectively. The values in the along-wind direction (RMy) are 15.2%, 22.3% and 21.1%, respectively. As for the acceleration at the top, the RMS acceleration of the building with the three types of corners can all be significantly reduced up to 90% for wind attack angle of α = 15°, 30° and 45°.

Voice broadcast based on 5G sensor in urban fire emergency system application

With the rapid development of 5G sensors, the development of low cost, low power consumption, and miniaturization is also constantly progressing, and 5G sensor networks have achieved great development. Node positioning technology is an important support for 5G sensors, so it has been a hot research direction in recent years. This article has carried on the basic discussion to the speech broadcasting technology, and introduced the speech broadcasting coding in many aspects, including the development history, the current situation and the compression coding algorithm. This article has launched a basic analysis and discussion on the voice broadcast algorithm, such as its basic principles and classification. In order to minimize the property losses and casualties caused by urban fires and improve the efficiency and success rate of urban fire emergency systems, it is necessary to be able to query fire information in a timely and effective manner and formulate emergency protection. As we all know, China’s current economic development is in a period of steady improvement, and the process of urbanization is gradually accelerating, especially the number of high-rise and super high-rise buildings has increased significantly. Therefore, once a city fire occurs, it will not only cause huge losses of property, but also may cause a large number of casualties. Although the current fire protection system in Chinese cities is relatively complete, there are still some problems that have not been resolved in actual work, such as insufficient technical equipment and insufficient response speed in some areas due to economic constraints. Therefore, it is very necessary to establish an efficient urban fire emergency information system, not only to be able to query fire information in a timely and effective manner, but also to be able to formulate emergency support plans for specific actual situations.

The Influence of Chamfered and Rounded Corners on Vortex-Induced Vibration of Super-Tall Buildings

In order to study the influence of chamfered and rounded corners on vortex-induced vibration of super-tall buildings, a series of multi-degree-of-freedom (MDOF, in short) aeroelastic models were made, including chamfered-corner models with chamfer ratios of 0%, 2.5%, 5.0%, 7.5%, and 12.5%, and rounded-corner models with rounded ratios of 0%, 12.5%, 15%, and 17.5%. The crosswind displacement response of each aeroelastic model was measured by a laser displacement meter in a wind tunnel. The test results indicate that the crosswind displacement response is significantly reduced when the chamfer ratio increases to 5% or the rounded ratio increases to 12.5%; in particular, the vortex-induced vibration (VIV, in short) response can be reduced by more than 60%, which indicates that the chamfered corner and rounded corner play a good role in restraining the VIV of super high-rise buildings. When the reduced wind speed is small, the reduction of the crosswind response of chamfered and rounded models is mainly caused by the reduction of wind load; when the reduced wind speed approaches the VIV wind speed, the negative aerodynamic damping phenomenon of the model with a proper chamfer ratio and rounded ratio disappears, which shows that the VIV is suppressed not only because the cut corner reduces the wind load but also because the cut corner weakens the aeroelastic effect. Generally speaking, a chamfer ratio of about 7.5% and rounded ratio of about 15% can achieve a good reduction effect on the VIV of super high-rise buildings.

Dynamic response evaluation of the Shanghai Tower in along- and across-wind directions during super typhoon Lekima

The dynamic responses of the Shanghai Tower (ST) under Typhoon Lekima in 2019 were evaluated in the along- and across-wind directions based on SHM data. Compared to most similar studies that focus on two main axes of the buildings, this study focused on such dynamic responses in the along- and across-wind directions; these processes were also widely discussed regarding wind tunnel tests. The results of dynamic responses in wind directions were compared to those in the main axes of buildings. The vibration amplitudes in the along- and across-wind directions were closer than those in the two main axes. The relationship between acceleration amplitudes and reduced wind speeds showed a significant effect of the vortex shedding. Additionally, time-varying frequency spectra were used to discuss the modal contribution of the vibration signal. The fundamental frequencies and damping ratios were identified using the SSI method, and correlation analyses were carried out. The relationship between the identified damping ratios and the reduced wind speeds exhibits different aerodynamic effects in the along- and across-wind directions. Comparison of the data showed that dynamic response evaluation in the along- and across-wind directions was more suitable to analyze the wind-resistant performances of super high-rise buildings. All results can aid in understanding the characteristics of these interactions as well as perfect the wind-resistant design of super high-rise buildings.

Effect of wind and structural parameters on across wind load of super high-rise buildings

Effect of wind and structural parameters on across wind load of super high-rise buildings

Brief Introduction to Properties of Wood and Application of Wood in Architectural Structures

Wood’s existence in earth is much earlier than human beings’ appearance, after thousands of years’ evolution, many kinds of wood are strong enough to support humans’ basic needs. Since the mid-20th century, scientists had made a great progress in chemistry and civil engineering, which made types of materials for architecture become abundant. However, despite of all the advantages that wood has got, the inflammability and mildew are the main reasons that wood cannot be largely used in the super high-rise building or huge building. The passage mainly introduced the excellent architectural properties of wood with detailed data, wood-based structure along with its characteristics and the typical wooden structures worldwide. From the current situation, wood is widely used in the medium and small-scale building for its good properties and well performance on many respects, including the ancient masterpieces. The typical and contemporary wood building structures system have shown the ingenious ideas and connotation within the structure. Furthermore, modified materials based on wood are developed to adapt the higher standards and requirements for architecture. In this way wood shall overcome the disadvantages of inflammability and mildew and other flaws due to congenital defects and acquired defects caused by environment. Finally, the thesis puts forward simple ideas on how to bring the superiority into full play and expects that the adoption of wood-based composite technology for the prospect of wood products in the construction industry.

Research on Technological Innovation of Super High-rise Buildings

As China enters a new era of socialism, the economy is developing at a high speed, and the urban population density is increasing rapidly. The development of cities is facing the problem of land shortage. Therefore, the development of super high-rise buildings has become an inevitable means of urban development and construction. However, the construction of super high-rise buildings is difficult and complicated, and there are many factors need to be considered. If the construction technology, structural design method and materials adopted in the construction process are too old or inappropriate, it will cause unnecessary economic losses and even potential safety hazards. Therefore, it is urgent to summarize and find more novel and appropriate construction methods for super high-rise buildings in China. In this paper. the literature method is used to discuss and explore the structural design, material selection and construction technology of super high-rise buildings. The results summarized can provide references for designers and engineers.

Experimental and analytical investigation of square-shaped concrete-filled steel tube columns

Square-shaped concrete-filled steel tube (CFST) columns inherit the advantages of conventional steel and concrete columns, and have been used in several super high-rise buildings. This paper presents a calculation model for square-shaped CFST columns. Based on the experimental results of a square-shaped CFST column and the application of a super high-rise building, numerical models are established to simulate the force–displacement curves of the CFST column and the stress–strain curves of square steel tubes and stiffeners, which show consistency with the experimental data. Meanwhile, the load-bearing capacity and ductility of CFST columns can be effectively increased by incorporating tensile plates, diaphragms, shear studs, and stiffeners. Considering the steel ratio, axial compression ratio, and concrete strength, nine finite element models are developed to evaluate the ductility and load-bearing capacity of the columns under the reversed-cyclic lateral load. The seismic and wind resistance properties of the structures are analyzed using a CFST column application.

Study on the Seismic Behavior of a Steel Plate–Concrete Composite Shear Wall with a Fishplate Connection

The steel plate–concrete composite shear wall (SPCSW), having been widely applied to several super high-rise buildings, is currently regarded as a new type of lateral load-resisting structure. The SPCSW design does not consider the connection to the surrounding structure, normally envisaged as a buttweld connection, while the fishplate lap connection tends to be applied in construction. To explore the fishplate lap connection to achieve the performance standard of SPCSW, in this paper, an SPCSW with a fishplate connection is modeled using ABAQUS to investigate the hysteretic behavior under constant axial force and horizontal cyclic loads. Through the hysteresis curve and a load–displacement skeleton curve, the effects of fishplate thickness and lap length on its hysteretic behavior are studied. The results show that increasing the fishplate thickness contributes to a slight increase in the bearing capacity and energy dissipation and has little influence on stiffness degradation. When the fishplate thickness is more than half the steel plate thickness, the strength and energy dissipation of an SPCSW with a fishplate connection can reach the level of an SPCSW without a fishplate connection. The bearing capacity and stiffness of the SPCSW increase with the increase in lap length. When the lap length is greater than 50 mm, the strength, stiffness and energy dissipation capacity of an SPCSW with a fishplate connection are superior to those without fishplate connections. Finally, engineering suggestions on fishplate connections are put forward.