Super High-rise Buildings Research Articles

Acoustic wind tunnel experimental study of aerodynamic noise distribution in high-rise buildings

Wind-induced aerodynamic disturbance has become a major noise source affecting residents in super high-rise buildings. To investigate the distribution characteristics of aerodynamic noise on high-rise building surfaces in strong wind conditions and the impact of wind speed and direction, this paper pioneers the application of the acoustic wind tunnel method based on microphone array localization to the experimental study of the surface acoustic pressure field of a high-rise building model, the far-field noise spectrum of which is obtained using the microphone array sensor. The beamforming calculation method was used to obtain the spectrum and localization cloud. By comparing the spectra and cloud diagrams under different process conditions and based on existing building wind pressure reports, it is concluded that: the noise source is always located at the height of the connecting corridor where there is large wind pressure pulsation in the two building models; the aerodynamic noise is more pronounced around building gaps where the airflow is more disturbed and also in the oncoming wind trailing direction where the wind pressure pulsation is more pronounced. An increase in wind speed increased noise source amplitude from 30 dB to 60 dB, and the location of the noise source shifted backwards to the tail of the incoming wind. This paper shows that the acoustic wind tunnel method based on microphone array localization technology can obtain the aerodynamic noise intensity on the surfaces of super high-rise buildings and reasonably predict the location of the sound source. This article puts forward suggestions to reduce noise in high-rise buildings based on experimental results.

Analysis and Reflection on the Green, Low-Carbon, and Energy-Saving Design of the Super High-Rise Building

Shanghai Tower has become a new landmark of Shanghai. In the current trend advocating green building and energy efficiency, considerations of wind loads and thermal characteristics of the perimeter structure of Shanghai Tower are crucial. This paper conducts comparative simulation studies on the wind environment of Shanghai Tower using Ecotect software, and stress analyses and thermal simulations of the perimeter structure using ANSYS software. The study compared three buildings’ surface wind pressure distributions using models with equal-volume and circular cross-sections. We found that the unique exterior design of the Shanghai Tower results in a more regular and uniform distribution of wind pressure on its surface compared to both circular and square planar models, with a lower average wind pressure value. In addition, the stress analysis results indicate significant differences in deformation and stress distribution between the windward and leeward sides. Enhancing the bending moment detection of the peripheral structure and optimizing the layout of detection points are recommended. Thermal simulation results show excessive heat conduction flux in winter conditions, suggesting optimization using passive energy-saving methods such as light-sensitive thermal insulation materials during winter. This research is a reference for designing other super-tall buildings prioritizing low-carbon energy efficiency and structural safety.

Vulnerability analysis of super high-rise building security system based on Bayesian network and digital twin technology

Recent years have seen the increasing need to prevent illegal intrusions in super high-rise buildings. To improve the security system of super high-rise buildings by adding dynamic vulnerability assessments for illegal intrusion risks and rectification plan optimization capabilities, while also to increase its visualization level, a method utilizing digital twin technology and integrating Bayesian networks is proposed. To validate this method, a case study within a prominent super high-rise building in the Central Business District (CBD) of Beijing is conducted, in which the vulnerability analysis results have shown that among all the tertiary parent nodes, the coverage extent of the video surveillance system most significantly influences the vulnerability. By using the comprehensive blind spot analysis function of the established digital twin platform, thoughtful additions and angle adjustments of surveillance cameras have successfully increased the score of the security level from 84 to 90. This has proved that the method proposed in this study can provide decision support for the vulnerability assessment and improvement for the security system of super high-rise buildings.

Seismic behavior of double-cell CFST columns with table tennis racket-shaped cross section

Multicell concrete-filled steel tube (CFST) columns with excellent mechanical performance have been used in super high-rise buildings in recent years. According to the requirements of a 265-m tall building, the double-cell CFST columns with an innovative cross section of table tennis racket were applied. Hence, six columns were designed according to the prototype columns and subjected to low-frequency cyclic loading. The impacts of different shear-span ratios (SSRs), axial load ratios (ALRs), and steel ratios on the seismic behavior were elaborated and clarified. The test results indicated that the seismic performance varied in different loading directions owing to the asymmetric cross section, and the columns performed better in the positive loading direction resulted from earlier and more sufficient confinement of the circular steel tube, which was also reflected by the measured strain development. With SSR deceasing from 2.5 to 1.7, earlier and more severe damage was recorded. The resisting capacity and stiffness were significantly improved at a cost of ductility loss. Increasing ALR from 0.2 to 0.4 brought about more damage and worse deformability. However, a proper increase in axial load was beneficial to the resisting capacity and stiffness, and its influence on the restoration capacity was associated with SSR. Increasing the steel ratio (by 33.36%) could effectively postpone and alleviate the local buckling of steel tube, thereby comprehensively improving the seismic performance. A finite element (FE) analysis of such columns was performed to carry out the damage evolution and parametric study, and provide references for their application in practical engineering.

What’s the typical issues influencing operation performance of HVACs in super high-rise buildings? Field tests and optimization analysis

The HVACs in super high-rise buildings commonly consists of variable air volume (VAV) systems, multistage chilled and cooling water systems, primary-secondary chilled water system in chiller plant, and the chillers combination is much more complex, leading to the significantly higher energy consumption than that of normal buildings. This paper contains field tests and comparative studies on the operation performance of HVACs in two super high-rise buildings and summarized representative issues accounting for the high energy consumption. Field test results showed that the annual energy efficiency of the whole HVAC system, before being commissioned, was only 1.79 and 2.15 in two projects. The HVACs, typically VAV systems, chilled and cooling water systems, all suffered from over-supplying and energy wasting. Besides, the chillers commonly operated with a low partial load ratio (PLR), whose energy performance was much lower than expected. Aiming to dig out the typical issues, analyses were carried out from external, internal factors, and their interconnection. Furthermore, optimization methods were put forward with corrected vital indexes. Results showed that proper control strategies should maintain the VAV system, multistage chilled and cooling water system operating with significant distribution temperature differences, tiny distribution pressure drops, and high energy efficiency, thus achieving energy saving and ensuring space cooling effects. Besides, the control strategies, especially the number control of chillers, were influential during the whole cooling season to ensure the chillers operate with optimal PLR and thus achieve better energy performance.

Strain energy-based uniformity spectrum for elastic deformation control of super high-rise buildings under near-fault pulse-like earthquake excitations

To reasonably control the elastic lateral deformation of super high-rise buildings under near-fault pulse-like ground motions, inspired by a potentially close link between material utilization and normalized strain energy, a novel generalized uniformity spectrum of normalized strain energy (GUSNSE) is proposed via the nonuniform flexural-shear coupled model. With a full understanding of the characteristics of spectral shapes and the influence of shear-flexural stiffness ratios and mass-stiffness nonuniformity, the GUSNSE is fitted by artificial pulses. Utilizing the GUSNSE, a lateral stiffness estimation strategy is developed with the requirement of peak interstory drift ratios (IDRs). The feasibility and effectiveness of the proposed strategy are systematically demonstrated by comparison with not only the original lateral stiffness schemes of three significantly distinct buildings but also those designed for uniform IDRs. The accuracy of the fitted GUSNSE is also validated via the data estimated by four sets of ground motions. The GUSNSE-based strategy is promising as an efficient, reliable, and practical tool for providing lateral stiffness of super high-rise buildings in the preliminary design.

CHARACTERISTICS ANALYSIS FOR HIGH-RISE BUILDINGS DURING TOP-DOWN CONSTRUCTION

New advances in top-down construction are developing with the construction of supertall buildings in China. This study presents a finite element analysis for high-rise structural construction with a top-down method (TDM) considering complex environmental conditions. Based on this analysis model, the forces and the deformation of the diaphragm wall, beams, and soldier piles at various stages of construction are computed. Taking a super high-rise building with a 5-story basement in Nanjing as an example, the reliability and accuracy of the model is verified by comparing the measured and simulated results of displacement and stress values at various locations. The research results reveal the relationship between excavation depth, soil settlement and pile displacement, which is convenient for finding the optimal construction critical surface. It lays a foundation for the study of the critical height of the subsequent construction and facilitates the prediction of the weak link in the process. At present, this project is under construction, so this study has reference value for subsequent construction projects.

Construction Technology of Steel Structures in Large Public Buildings

With the continuous development of the Chinese economy and the rapid development of large public buildings, the application of steel structures in large buildings is gradually increasing. The use of steel structures is crucial for meeting the needs of large-span, super high-rise buildings, rapid construction, and achieving sustainable development of buildings. Therefore, studying and analyzing the construction technology of large-scale building steel structures has important practical significance. This study is based on a library construction project, focusing on the installation of embedded bolts, steel columns, steel beams, and high-strength bolts in the construction of large building steel structures, as well as the technical schemes and construction processes of welding, anti-corrosion coatings, and fireproof coatings. I hope to provide reference and suggestions for actual construction.

Building Structural Design Innovation and Code Development

In recent years, Some new structural systems and design difficulties of high-rise and super high-rise buildings were emerged in Shenzhen, such as forced displacement and non-forced displacement, story lateral stiffness calculation method, frame-core wall structures with partial perimeter frame beams missing, super high-rise structure with great height-width ratio, high-rise less shear walls in one direction structure, conjoined tower structures, high-rise structure with inclined column, mega structure with belt truss, rare earthquake design method etc. The emergence and solution of these problems reflect the innovation of the structural design of high-rise buildings. Meanwhile, Structural design has encountered many difficulties and new problems. The solutions to these problems sometimes conflict with the current Chinese code, or there are no relevant provisions in the Chinese code. The current Chinese code is the basis for designing of high-rise buildings, which is the crystallization of the wisdom of previous generations, but the emergence of various new types of building structures has brought about numerous difficulties in structural design. Therefore, during the design process, it is necessary to conduct research, innovation, supplementation, and development of the current code. In view of this situation, this paper combines the previous engineering practical experience and introduces some structural design points of complex super high-rise buildings located in Shenzhen. It is for designers' reference, which also provides content for the revision of the specification.

Research on Key Problems and Optimization Based on Structural Design of Super High-rise Buildings

At present, complex super high-rise buildings and super high-rise buildings are emerging all over China, but there are still many problems to be solved in the design of super high-rise structures. For example, the wind pressure and earthquake risk of high-rise buildings, fire safety issues and personnel evacuation issues, earthquake will produce greater inertia force and bending force in high-rise buildings, wind load and wind pressure effect will be more significant, these are the parts that need to be carefully considered to ensure the safety and stability of the building structure. Therefore, it is necessary to analyze and optimize the problem of high-rise buildings. Taking a super high-rise building in Luohu District of Shenzhen City as an example, this paper analyzes the basic structure of super high-rise building, analyzes the key problems of structural design, and discusses the optimization method. This paper puts forward the optimization design method of building structure for seismic problem of super high-rise building structure, puts forward the solution to wind resistance problem, and puts forward the optimization layout method of building fire protection.

Full-scale experimental simulation of the stack effect pressure acting on an elevator door system in a high-rise building

The pressure-bearing performance of an elevator system under the stack effect in a super high-rise building is usually difficult to simulate directly in a laboratory environment due to the difficulty in fully meeting the similarity requirements. In this paper, a new full-scale experimental device for simulating stack pressure was designed in a large boundary layer wind tunnel laboratory, which was based on using wind pressure to simulate the action of thermal pressure on an elevator door system. By employing this approach, the pressure-bearing performances of an elevator door system under different levels of wind pressure of the static and dynamic conditions were systematically investigated, and the malfunction of the elevator door system due to the strong stack effect was successfully simulated. The critical pressure threshold of the elevator door system, which was difficult to evaluate accurately in previous studies, was then measured and it was approximately equal to 150 Pa. Meanwhile, the pressure-bearing state of the elevator door system was numerically simulated and compared with the wind tunnel experiment results. The study shows that the simulation employing the dynamic mesh model can accurately reflect the force characteristics of an elevator lobby door during its physical process of opening and closing. Finally, based on the experimental simulation results, the pressure-bearing thresholds of the elevator door systems of several typical high-rise buildings were estimated, and the reasonability of the full-scale simulation was finally verified by comparisons with field measurement data.

Seismic performance and flexural strength prediction of high-strength bar reinforced UHPFRC walls under high axial load ratio

A new-type shear wall built with high-strength reinforcement and ultra-high performance fiber reinforced concrete (UHPFRC) is proposed in this paper, aiming to solve the problem of too large cross-section size of bottom shear wall members of high-rise and super high-rise buildings. Four UHPFRC wall specimens built with high-strength reinforcement were tested under cyclic loading to examine the influence of the parameters of fiber volume fractions (0 vs. 1.5% vs. 2.5%) and the spaces of horizontal distribution reinforcing bars (150 mm vs. 300 mm) on the seismic performance. In addition, a calculation method of flexural strength of UHPFRC shear wall is established. The research results show that: the UHPC wall specimen without fibers failed in the axial compression brittle mode, and the UHPFRC wall specimens with fibers failed in flexure-dominated ductile mode. The bridging effect of steel fibers at the cracks kept the integrity of the UHPFRC. The drift ratio capacities of the UHPFRC wall specimens under high axial compression ratio of 0.5 were 3.56%. Increasing the fiber volume fractions can improve the strength, initial stiffness, and cumulative energy consumption of the wall specimens, reduce the damage degree of the UHPFRC at the toes of the wall specimens, and can also reduce the reinforcement ratio of horizontal reinforcement without influence on the seismic performance. The proposed method of flexural strength of UHPFC walls shows reasonable prediction accuracy.

Construction Simulation and Monitoring of the Jacking Steel Truss and Main Column of a Super High-Rise Building

To ensure that the steel truss used in a super high-rise building in Xi’an remains in a safe and reliable state during the construction and jacking process, the jacking steel truss and the main column are studied. A finite element model of the steel truss and the main column is established by using finite element software. The stress values of the steel truss and the main column under various working conditions are simulated, and the stress and perpendicularity of the key points of the structure are monitored via the stress monitoring system under different working conditions. Through the monitoring system, the data on the operation of the steel truss are collected, and the monitoring data are compared with the finite element simulation data to ensure the safe operation of the steel truss. The results indicate that the inclination angle of the main column is easily disturbed by the external environment. The main column is inclined in two directions, but it does not exceed 0.3°, indicating good verticality. The stress monitoring values are generally close to the simulated values. The peak values of the stress at the measuring points during the construction stage are the same as the results obtained from the field test, and the error between the measured maximum stress value and the simulated value is controlled within 10%. In general, the simulated values are in good agreement with the measured values.

A damage-oriented ground motion intensity for degrading super high-rise buildings

To explicitly identify the influence of different seismic damages on the correlation between ground motion intensity measure (IM) and demand measure (DM), with a specific concern of super high-rise buildings, a novel damage-integrated spectral acceleration-based combination-type IM is developed for degrading systems. With the integration of seismic damage measure, inelastic displacement spectrum, and design acceleration spectrum, the prototype of the IM is theoretically derived for single-degree-of-freedom systems with a Q-type hysteretic model. The high-mode effect is reflected by an optimal number of lower modes combined with corresponding modal damage. To estimate the optimal number of modes while maximizing the case-independency of DM predictions, the dynamic properties of concerned damaged and undamaged structures are estimated with the collaboration of the modified flexure-shear model (FSM-MS), and further utilized to establish the regression expression with a large number of near-field and far-field ground motions. The performance of the proposed IM is systematically demonstrated via a case study on two super high-rise buildings, along with other selected IMs.

Optimizing safe evacuation using pathfinder: emergency strategies in high-rise and super high-rise complex buildings in the new administrative capital

ABSTRACT Recently, the Egyptian government has sought to create new urban spots. The New Administrative Capital was one of those new urban extensions. Architects and urban designers tended to vertical expansion in planning this city as a result of the high cost of the land. Accordingly, high-rise and super-high-rise buildings have been relied upon in the architectural design of the buildings. This study aims to evaluate the achievement of safe occupants’ evacuation in case of fire for two high-rise and one super high-rise complex buildings based on a set of variables. Staircase design, the use of elevators, and the provision of refuge areas were evaluated, through simulating seven scenarios using Pathfinder software. The simulation results comprised an assessment of average stairs traffic jams, the occupant load density on emergency stairs, and the required safe evacuation time (RSET) for each scenario. It was concluded from the study that staircase design has a significant impact on (RSET) time. As well as, evacuation using elevators or relaying on refuge areas as auxiliary means with the emergency stairs may be safer for these types of buildings. Finally, the study provided technical requirements for using refuge areas and elevators in emergency evacuation in high-rise and super high-rise buildings.

Wind Effects of Super High-Rise Buildings in the Pearl River Delta of China Based on 10-Year Full-Scale Measurements

Wind Effects of Super High-Rise Buildings in the Pearl River Delta of China Based on 10-Year Full-Scale Measurements

Retracted: Simulation Study on the Influence of Fire Partition on Curtain Wall Temperature in Super High-Rise Buildings in China

Retracted: Simulation Study on the Influence of Fire Partition on Curtain Wall Temperature in Super High-Rise Buildings in China

Pressure deviation monitoring and early warning in large integrated tower crane support system for super high-rise buildings

In super high-rise buildings, the integration of large tower cranes with climbing platforms can enhance the construction efficiency. However, this integration mode significantly increases the load on the tower crane support system (TCSS). Current low-precision manual construction methods can lead to uneven pressures at the support points, potentially causing structural damage and serious accidents. This study proposes a method for monitoring, providing warnings, and optimizing deviations in TCSS pressure to ensure safe and controlled operations. Large-load sensors have been developed to monitor the pressure on TCSS in super-high-rise building projects. The pressure tests revealed that the uneven load distributions at the support points differed significantly from the simulation results. The safety of large integrated construction equipment can be ensured by considering the uneven distribution coefficients of the support pressure and improving the design accuracy of the support points.

Research Progress on Dynamic Characteristic Monitoring Methods of Super High-Rise Buildings

Research Progress on Dynamic Characteristic Monitoring Methods of Super High-Rise Buildings

Static and Dynamic Deformation Monitoring of Super High-Rise Buildings During the Construction Stage

Static and Dynamic Deformation Monitoring of Super High-Rise Buildings During the Construction Stage