High-rise Buildings In China Research Articles

Time-dependent responses and modeling of circular steel tube confined reinforced concrete (STCRC) accounting for partial exposure condition

Circular steel tube confined reinforced concrete (STCRC) columns are becoming increasingly popular in high-rise buildings in China due to their high compressive strength, excellent seismic performance, and high fire resistance. However, the time-dependent behavior has not been well studied for these columns. The time-dependent behavior of STCRC columns is particular, due to the longitudinally partial exposure condition for the concrete core, which is different from either fully exposed members or fully sealed ones. To investigate this difference, long-term experiments with a test duration of 1465 days were conducted on partially exposed circular STCRC columns and the test results were compared against those from fully exposed and fully sealed specimens. With the partial exposure condition accounted for by modifying the notional size h0 of the concrete core, a mathematical expression was then theoretically developed and benchmarked against the test data. Investigation shows that: (1) significant differences exist in the time-dependent deformation between partially exposed, fully exposed, and fully sealed columns; (2) with the modified notional size (defined as the longest path length for the water diffusion), the EC2 model can well predict the time-dependent deformation of partially exposed circular STCRC columns, with a maximum deviation of 7.6 %. The Mean Stress (MS) method is suggested for the conceptual design to achieve safer results.

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

Probable Evidence of Aerosol Transmission of SARS-COV-2 in a COVID-19 Outbreak of a High-Rise Building.

Although it is well established that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be transmitted through aerosols, the mode of long-range aerosol transmission in high-rise buildings remains unclear. In this study, we analyzed an outbreak of coronavirus disease 2019 (COVID-19) that occurred in a high-rise building in China. Our objective was to investigate the plausibility of aerosol transmission of SARS-CoV-2 by testing relevant environmental variables and measuring the dispersion of a tracer gas in the drainage system of the building. The outbreak involved 7 infected families, of which 6 were from vertically aligned flats on different floors. Environmenìtal data revealed that 3 families' bathrooms were contaminated by SARS-CoV-2. In our tracer experiment, we injected tracer gas (CO2) into the dry floor drains and into water-filled toilets in the index case' s bathroom. Our findings showed that the gas could travel through vertical pipes by the dry floor drains, but not through the water of the toilets. This indicates that dry floor drains might facilitate the transmission of viral aerosols through the sewage system. On the basis of circumstantial evidence, long-range aerosol transmission may have contributed to the community outbreak of COVID-19 in this high-rise building. The vertical transmission of diseases through aerosols in high-rise buildings demands urgent attention.

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.

Investigation on the Performance of Partial Penetration Welds in Multicell Concrete Filled Steel Tubes

This paper presents an experimental and analytical investigation on the performance of partial penetration welds used to adjoin steel plates in irregular shaped multicell concrete filled steel tubes. The experimental program of this study is designed based on an actual implementation of such members as mega columns in a super high rise building in China. A total of six specimens are designed with different plate arrangements for the purpose of testing the performance of the partial penetration welds at different locations of the specimen. The designed specimens are tested under different load procedures and directions; this is achieved by placing them in vertical and slantwise manners between two loading plates which impose monotonic and cyclic actions. The failure conditions of each of the tested specimens are presented and discussed in detail and are based on the conclusions drawn from the experimental observations; the partial penetration weld at the corner of the tested specimens is found to be the most vulnerable. To facilitate large scale analysis, a finite element model constructed by the finite element analysis program ABAQUS is verified against experimental results. The evaluation of the stress at the partial penetration welded corner is carried out following an empirical procedure, which is adopted due to the complexity of the problem domain. The adopted procedure consists of two steps: the first one is to initially evaluate the stress based on an existing method in the literature, and the second one is to fit the results of the initial evaluation with the finite element model results based on parametric and regression analysis. After performing regression analysis, a formula to predict the weld stress is concluded, and the results of the proposed equation are found to be satisfactory when compared with the finite element model results.

The innovative structural systems at the heart of China’s surge in super high-rise structures

There is a surge in the construction of super high-rise buildings in China. Bin Wang of Sichuan University outlines the various innovative structural systems being used, in particular the universal adoption of steel plate–reinforced concrete composite walls.

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

The poor fire resistance characteristic of super high-rise curtain wall makes the curtain wall design one of the main approaches to improve its capacity for prevention and control over fire and smoke spread. The propagation of smoke leads to the increase in the temperature of the curtain wall on the upper and lower floors of the fire floor and consequently leads to glass fracture and other serious consequences. Current codes have control over fire resistance performance and size of fire partition materials but do not include requirements on the position of curtain walls on floors. By changing the position of fire partition in curtain walls, the paper carries out three comparative simulation experiments on two forms of fire partition: spandrel and fire prevention cornice. Besides, PyroSim is used to calculate the comparative simulation of fire and smoke spread and obtain the data on temperature variation nephogram and monitoring points in the center line of glass curtain walls during different fire scenarios, so as to discuss the influence of different positions of spandrels and fire canopy on fire hazard and smoke. This study finds out the following: fire canopy can better prevent the longitudinal spread of fire smoke than spandrels. The fire canopy above spandrels can reduce the flue-gas temperature. The higher the spandrels above floors, the faster the temperature of the central lines of glass curtain walls above fire floors reduced. However, the higher the spandrels above floors, the more uneven the distributions of high-temperature regions and low-temperature regions, thus leading to the increase in horizontal temperature differences of glass panels. This research conclusion can be taken as a reference for fire protection design of super high-rise glass curtain wall.

Field measurement and coupled simulation for the shuttle elevator shaft cooling system in super high-rise buildings

The stack effect in super high-rise buildings causes various negative problems in winter. The shuttle elevator shafts are the main vertical movement route and also the most vulnerable area suffered from the stack effect in super high-rise building. The elevator shaft cooling countermeasure is proved a suitable application under the operation condition. In this paper, the mitigation effect of the shuttle elevator shaft cooling countermeasure is investigated by field measurements and coupled numerical simulation in a typical super high-rise building in China. Field test was carried out under the stack dominated condition and hybrid dominated condition which mechanical ventilation system is applied. A coupled multi-zone and CFD model is built to simulate the shuttle elevator shaft cooling system in a super high-rise building based on the driven forces and air flow directions during stack phenomenon. The accuracy of this coupled model is verified by the comparison between the measurement and simulation results. The driving forces of stack effect through the shuttle elevator shaft, the optimization of the shuttle elevator shaft cooling configuration and the determination of mechanical air volume under different outdoor temperatures are investigated through the coupled simulation method. This study demonstrates that it is important to design the shaft cooling system in super high-rise buildings to ensure the safe and normal use of the shuttle elevators.

Possible SARS-CoV-2 Transmission by Fecal Aerosol in High-Rise Building in China

In 2003, fecal aerosol transmission was suspected in an outbreak of severe acute respiratory syndrome (SARS) in a high-rise complex in Hong Kong (NEJM

Analysis of the influence of pile foundation settlement of high-rise buildings on surrounding buildings

In order to explore the impact of pile sinking on surrounding buildings in existing high-rise buildings, in this study, the influence of pile foundation settlement on surrounding buildings of existing high-rise buildings is studied and analyzed by building models. Firstly, the theory of pile-soil interaction is introduced. The theoretical calculation of pile foundation settlement is simplified by existing theory and practical engineering calculation, and the settlement value of surrounding buildings is calculated. Then, the simulated experimental area model is established. Finally, the influence of pile foundation settlement on the surrounding buildings with and without raft in foundation is explored. The results show that under the condition of pile diameter and other conditions being the same, with the increase of pile length, the pile foundation settlement of existing high-rise buildings has less and less influence on the surrounding buildings. When the pile length increases to 22 m, the pile foundation settlement of existing high-rise buildings has little impact on the surrounding buildings; at the same time, under the same pile length, the settlement of pile foundation of existing high-rise buildings without raft has less influence on the surrounding buildings than that of pile foundation with raft. This study is of guiding significance to the construction of buildings around high-rise buildings in China.

Construction Automation and Robotics for High-Rise Buildings: Development Priorities and Key Challenges

Construction automation and robotics have been researched and developed over the last three decades. Although the practical needs keep rising, the on-site application rate remains limited. Therefore, this study aims to explore the right approach to the future development of robotics for construction and maintenance of high-rise buildings in China and the US by identifying development priorities (DPs) and key challenges (KCs) related to this technology application domain based on the perspectives of both experienced users and prominent experts. Questionnaire surveys were conducted among major construction companies in both countries to compile data on the current state of related practices, needs, and factors affecting the users in implementing construction automation and robotics for high-rise buildings. The survey results of the two countries were analyzed and compared to provide initial information for a subsequent international expert workshop. Thirteen experts in construction robotics research and development (R&D) were in attendance at the workshop in Beijing in November 2018 to discuss DPs and related KCs. Six major DPs and related KCs were identified, and their implications for future development were described. This study identified the top DPs and KCs and also proposed an effective approach for identification by considering both the practical needs and technical and economic feasibility. It is expected not only to be a valuable reference for many countries and regions where high-rise buildings are being developed but also to contribute to the knowledge body of automation and robotics for high-rise buildings.

Cyclic behavior study of high load-bearing capacity steel plate shear wall

Relevant studies into the high load-bearing capacity steel plate shear wall used in the high-rise building are insufficient, especially for steel plate shear walls whose yield load exceeds 3000kN. This paper developed a kind of high load-bearing capacity steel plate shear wall with yield load no less than 3000kN to be applied in the frame-steel plate shear wall structural system which has been utilized in the design and construction of high-rise buildings in China. Low-Yield-Point (LYP) steel was adopted as the shear web plate of the steel plate shear wall. A total of two specimens with same geometric configuration but different loading procedures were designed and tested under the cyclic loading. The stiffness degradation, ductility and energy dissipation characteristics of the LYP steel plate shear wall (LSPSW) were investigated. Furthermore, comparative studies of the cyclic test and FEM analysis were carried out to verify the accuracy of the FE model of the LSPSW and conduct geometrical configuration optimization in the future. The test results indicate that the newly-developed LSPSW has superior ductility and energy dissipation capacity, which confirm that it can be used as an effective lateral force resisting structure system in the future. The yield load and ultimate load of the LSPSW obtained through cyclic tests exceed 3000kN and 5000kN, respectively, which meets the initial design expectation. In addition, numerical analysis results agree well with the test results.

Design and research of elevator control system based on PLC

With the gradual popularization of high-rise buildings in China, the elevator control system has also achieved rapid development, and the relevant design is constantly improving and optimizing. For the elevator system, the advantage of PLC control system is that it can use the elevator control system of PLC, and its later maintenance cost is lower. In this paper, the hardware and software design of the elevator control system based on PLC are tested, and the operation of the implementation process is carried out.

Refinement construction simulation research of BIM technology on pumping concrete

With the gradual increase of pumping construction of medium and high-rise buildings in China, the construction requirements for concrete pumping process are gradually improved. Based on a project in Wuhan, this paper applied BIM technology on the pumping concrete construction process. Through the use of several softwares, the optimization of pumping pipeline layout, simulation of construction schedule, and priority grouping of marked bends was achieved. The details of the concrete construction of concrete pumping using BIMtechnology were shown, providing a reference for the application of BIM technology in the field of pumping concrete.

Prevention and Control Measures for Vertical Spread of Fire along the External Wall of High-rise Buildings

 In the analysis and research of few cases on the characteristics of vertical "burning" and spreading of fire in high-rise buildings in China and overseas, the mechanism of vertical spreading of fire along external wall is caused by hot pressing and wind pressure existing in high-rise buildings. The use of external wall combustible materials and near-window combustible items resulted in the formation of high temperature pyrotechnics and the burning of the external wall. Besides, due to the lack of fire-fighting measurements in high-rise building, it is recommended that the external wall of the high-rise building should be equipped with vertical fire-proof partitioning and non-combustible materials by setting up an automatic fire-fighting water curtain system along the vertical section of the external wall and above the indoor window. Therefore, the automatic sprinkler can be set up to prevent the fire from spreading vertically along the external wall of the building effectively.

Influence of the vent pipe diameter on the discharge capacity of a circuit vent building drainage system

Experiments on different vent pipe diameters (nominal diameters of 100, 75 and 50 mm; DN100, DN75 and DN50, respectively) in a full-scale circuit vent building drainage system were conducted in a 60 -m high structure, and the wastewater discharge capacities as a function of vent pipe diameter were measured. Critical pipe pressures, water seal losses of sanitary fixtures and air flow rates were measured. The ultimate pressure values in pipes on lower floors were larger than those in pipes on higher floors using DN100 and DN75, which was opposite to the results with DN50. A positive correlation between the ultimate pressure values and floor heights, as well as between ultimate pressure values and water seal losses, was found for DN100 and DN75. The maximum discharge flow of the three systems using DN100, DN75 and DN50 vent pipes was 17.0 L/s, 14.0 L/s and 7.5 L/s, respectively. Nevertheless, in China, the maximum wastewater discharge capacity in a circuit vent system adopting a DN100 vent pipe connected to a DN100 drainage stack in tall residential buildings is 11.5 L/s according to the Code for Design of Building Water Supply and Drainage. Thus, the vent pipe diameter DN75 can fully meet the design requirements of drainage systems for high rise buildings in China. The engineering cost associated with material expenses for building drainage systems can be minimised by optimising the size of vent pipe based on required capacity rather than using a single size universally. Practical application: The engineering cost associated with material expenses for building drainage systems can be minimised by optimising the size of vent pipe based on required capacity rather than using a single size universally.

Cradle-to-Site Carbon Emissions Assessment of Prefabricated Rebar Cages for High-Rise Buildings in China

Construction industrialization is growing rapidly and has received significant attention worldwide in recent years. The industrialization of construction results in several benefits, including the promotion of sustainable construction and the development and application of prefabrication techniques. The Prefabricated Rebar Cage (PRC) is an emerging solution applied to high-rise buildings as a replacement of the In-situ Reinforcing Bar (ISRB) construction method. This paper investigates the cradle-to-site carbon emissions of PRC, and compares the results with those of conventional in-situ rebar construction methods for high-rise buildings. The cradle-to-site cycle is divided into three stages, namely, material preparation, transportation, and on-site construction. For the material preparation stage, it is found that CO2 emissions are increased by 3% when using PRC due to the operation of machinery during the prefabrication process. In the transportation stage, CO2 emissions are found to increase by 3.3 times for PRC, as there is more transportation required for PRCs than for conventional construction methods. During the on-site construction stage, the PRC method demonstrates its advantages by reducing CO2 emissions by 44.7%, which is attributed to decreased hoisting frequency and lower mechanical utilization for fewer joining activities. Overall, CO2 emissions can be reduced by 1.24% by adopting the PRC method for high-rise buildings, and it is therefore recommended to adopt PRCs for this purpose. This research studies carbon emissions of PRC and contributes to promoting the sustainable development of prefabricated building techniques.

Study on Steel Bar Construction Technology of Frameshear Wall in High-Rise Buildings

The development of the construction sector is rapidly growing, which induce competition at global level. In order to achieve the current economic development, more high-rise buildings construction projects were commenced without considering importance of the land to human and other living organism. On the other hand, the quality and safety aspect of the engineering technology used must be analyzed carefully and to be the primary aim for engineers to reduce any risk of harm in future. Many of the high-rise buildings in China consist of a frame or skeleton of reinforced concrete wall which need to bestrengthened with shear walls to improve the stability and safety of the structures. According to practical work experience and relevant theoretical knowledge, the researcher introduced the reinforcement construction technology of frame-shear wall for high-rise buildings in depth from aspects like the arrangement of steel bar, construction preparation, steel bar anchorage, precautions to follow for the related work in future.

Technical analysis on deep foundation pit supporting in architectural engineering construction

In recent years, the construction industry shows a rapid development in China. The amount of high-rise buildings continually increases, and in the meanwhile, the technical requirements of construction gradually increase, especially in deep foundation pit support construction technology. At present, there exist a large number of high-rise buildings in China. The working face of foundation engineering is becoming smaller and smaller, while the foundation pit is getting deeper and deeper. In order to ensure the quality of construction projects, the deep foundation pit support construction technology should be continuously improved. This paper analyzes the current status of deep foundation pit support construction, and the past studies and researches about the supporting technology of deep foundation pit. The conclusion of this paper is expected to provide some help for the construction enterprises.

Structural fire engineering for super-high-rise buildings in China

Structural fire engineering is often adopted in large open-plan structures such as airport terminals, railway stations, etc., where the low fire risk can be directly conceived and a structural fire analysis may bring significant savings on structural fire protective coatings. In some recent cases, structural fire engineering approaches have also been applied to landmark high-rise buildings in China. This paper introduces four different examples of such methods with varying motivations, approaches and ultimate design schemes, to provide readers with an insight into the commercial application of structural fire engineering in China.