Analysis Of The Aspect Ratio And Shear-to-weight Ratio Of High-rise Buildings

In order to make the city’s tense construction land fully function,to protect people’s basic living needs and leisure and entertainment requirements,the height and structure of the building are constantly being refreshed,and now the over-limit high-rise buildings have to be designed to be "high and thin".The fa?ade shape makes the seismic design more difficult.A long with the increase in height,the problem of high-altitude ratio and shear-to-weight ratio of high-rise buildings is serious,which makes people have to question the safety of the building itself.Therefore,this paper focuses on the theoretical research and finite element comparison analysis of the aspect ratio and shear-to-weight ratio of over-limit high-rise buildings.The main research contents and results are as follows:(1)The finite element software Midas Gen was used to establish a reinforced concrete shear wall structure system for the analysis of problems: the basic model A(aspect ratio 5.81),and the model was used for elastic calculation analysis by Midas Gen and SATWE,and the calculation results were compared.Analysis,the results obtained by the two softwares are not much different,indicating that the model selected in the paper is reliable.(2)The calculation of the aspect ratio has been studied and analyzed.The plane irregularity irregularity model is used to calculate it by various calculationmethods,which shows that the equivalent width calculation method considering the plane stiffness factor is better than the minimum width and weighted average width calculation method.It is suggested that the equivalent width calculation method can be used as an aspect ratio calculation index in the structural design stage.(3)In order to study the effect of the P-△effect on the building of the high aspect ratio,by increasing the number of layers on the basis of the original model A,different aspect ratio models B(aspect ratio 5.81),C(aspect ratio 6.54),and D(aspect ratio 7.26),E(aspect ratio 7.99),F(aspect ratio 8.72).Through software calculation and analysis,it can be seen that the models E and F need to consider the effect.The models E and F are considered and considered without considering the effect,and the calculated inter-layer displacement angle,floor displacement,floor shear force and internal force of some components are compared and analyzed.In each case,the calculated indicators differ by less than 5%,and can be ignored.(4)In order to study the influence of the aspect ratio of high-rise buildings on the anti-overturning performance of the structure,the calculation of the models A,B,C,D,E,F is frther carried out.As the aspect ratio increases continuously,the structural overturning moment and the anti-overturning moment are continuously increased.Large,but the anti-overturning safety factor is continuously decreasing.When the aspect ratio reaches 8.0,it is necessary to carry out anti-overturning check and calculation of high-rise buildings to takemeasures to ensure the building’s ability to resist overturning.(5)Insufficient tension in the shear wall is a common phenomenon in high-altitude and over-limit high-rise buildings.An effective measure to solve this problem is to arrange steel in the wall.On the basis of the original model A,the model A1 is established.The software does not yield the mid-earthquake calculation.It can be seen that the partial wall of the individual floor of the A1 model is insufficiently stretched,and the steel needs to be arranged;on the basis of A1,the number of layers of the structure is changed.Model B1(aspect ratio:7.99)and C1(aspect ratio 8.72),respectively,for B1 and C1,the mid-seismic unyielding calculations show that with the increase of the aspect ratio,the shear strength of the shear wall is not serious enough,C1 Most of the wall limbs on most floors of the model require steel profiles to meet the tensile properties of the wall.After the tensile stress exceeds the limit of A1,B1 and C1,the tensile strength of the mid-seismic shear wall is improved.However,the statistics of the wall-section steel of the first part of the three models can be known.The aspect ratio is constantly increasing.In order to ensure the tensile strength of the wall,the amount of steel is very large.The steel of the wall of the C1 model is 25 times higher than that of the A1 model.If you continue to increase the height of the structure,you must pay a huge economic cost,otherwise you should consider the use of different structural systems(such as steel reinforced concrete composite structure,cylinder structure)to replace the reinforced concrete structural system.In order to ensure the safety of the structure and thecomprehensive economic benefits,it is considered that the aspect ratio of the reinforced concrete high-rise building structure should be controlled within 8.0.(6)The shear-to-weight ratio of large-aspect-ratio buildings often does not meet the requirements of the specification.Models under different site categories are established by model A and analyzed separately.Under the Ⅰ and Ⅱ site categories with better site conditions,the shear-to-weight ratio does not meet the specification limit.Under the Ⅲ and Ⅳ site categories with poor site conditions,the shear-to-weight ratio can easily meet the specification limit,indicating that the specification is about the minimum shear.The weight ratio rule does not take into account the impact of the site category.Elastic time-history analysis was carried out on the models under the Ⅰ and Ⅱ site categories.The calculated interlayer displacement angles of the obtained structures were not exceeded,and the floor shear force and stiffness were uniform and continuous.The model shear weight ratio under the Ⅰ and Ⅱ site categories was overrun,but the structural safety performance is good,there is no need to change the structure of the structure to make the shear weight ratio of the structure meet the specification requirements.