Discussion on Construction Technology and Welding Deformation of High-Rise Steel Frame Structure

Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.

Quantitative investigation on collapse margin of steel high-rise buildings subjected to extremely severe earthquakes

Reponses of structures subjected to severe earthquakes sometimes significantly surpass what was considered in the design.It is important to investigate the failure mechanism and collapse margin of structures beyond design,especially for high-rise buildings.In this study,steel high-rise buildings using either square concrete-filled-tube（CFT） columns or steel tube columns are designed.A detailed three-dimensional（3 D） structural model is developed to analyze the seismic behavior of a steel high-rise towards a complete collapse.The effectiveness is verified by both component tests and a full-scale shaking table test.The collapse margin,which is defined as the ratio of PGA between the collapse level to the design major earthquake level（Level 2）,is quantified by a series of numerical simulations using incremental dynamic analyses（IDA）.The baseline building using CFT columns collapsed with a weak first story mechanism and presented a collapse margin ranging from 10 to 20.The significant variation in the collapse margin was caused by the different characteristics of the input ground motions.The building using equivalent steel columns collapsed earlier due to the significant shortening of the locally buckled columns,exhibiting only 57% of the collapse margin of the baseline building.The influence of reducing the height of the first story was quite significant.The shortened first story not only enlarged the collapse margin by 20%,but also changed the collapse mode.

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 be strengthened 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.

Research on ETABS Steel Tower atop Building Structural System

Equipping steel tower atop building structural system at the top of high-rise buildings is applied increasingly. However, the earthquake disasters indicate that under seismic effect, the tower on the roof reacts strongly to the earthquake, and the gazebo is damaged greatly under the condition that major structure has no earthquake damage. Based on analyzing the characteristics and application methods of ETABS software, for engineering projects, the paper uses ETABS software and simplified calculation method to calculate and make comparison analysis on steel tower atop building structure. The analysis results indicate that the method established in the paper has higher accuracy, which can meet the engineering requirements.

Seismic assessment of nature-inspired hexagrid lateral load-resisting system

This paper provides a general perspective of the seismic performance of a nature-inspired,honey-comb grid structural system,known as a hexagrid,under near-field ground motions.Seismic performance of this skeleton is then compared to that of a bundled-tube,as a conventional and efficient load-resisting system in order to provide a better perception of the seismic behavior of a hexagrid skeleton.Two 20-story buildings with bundled-tube and hexagrid skeleton were studied.Nonlinear behavior of the structures was investigated through 3-D finite element computer models and nonlinear time history analyses by subjecting the models to seven three-component records of scaled near-field ground motions.Distribution of peak inter story drift and corner beam-column joint rotations were calculated and compared.Results indicated that by replacing the exterior columns of the bundled-tube system with inclined beam-column elements of nature-inspired hexagons,lateral stiffness of the building increased and it would tolerate less deformations before global dynamic instability is reached.The presence of inclined columns in the hexagrid skeleton helped to concentrate local nonlinearities in ring beams rather than exterior columns.