Evaluation On Environment Vibrating And Aseismic Safety Of Board High-rise Residential Building

In order to satisfy the requirements for the good ventilation and the good natural lighting,many board high-rise residential buildings with 12 – 18 stories have been constructed in large cities(e.g.Shanghai and Shenzhen)in China.In spite that the requirements of local aseismic design code is stratified,if the vibration of the foundation due to the large equipments with low frequency nearby is amplified,the pseudo-resonance is possibly caused due to the similarity among the frequency of the equipments near the buildings,the predominant frequency of thick soft-clay foundation and the natural vibration frequency of the buildings.Consequently,the comfortability even the safety for resisting vibration of the structure is affected.In the last decade,several events of swaying buildings occurred in Shanghai and complaints were submitted by the local residents.Currently,the countermeasures contain: the restrictions on the night working of equipments with strong vibration,the removal of factory and the construction of vibration isolation systems in the foundation of the affected building.However,the effect of countermeasures is limited as no countermeasures are directly on the vibration mitigation of the affected building itself.Therefore,in the researches of vibration mitigation,it is meaningful to study the countermeasures on the affected building itself.In this thesis,the main contents and conclusions are as follows:(1)The concept and characteristics of high-rise residential buildings with 12 – 18 stories are introduced.The significance of the researches on the evaluation of the aseismatic design and the vibration are addressed.The current researches on the aseismatic design and the vibration mitigation are introduced.Finally,the contents of this research are briefly introduced.(2)In the case study,the environmental vibration test results on a residential building with a thick soft-clay foundation in Shanghai are reported.The characteristics are briefly summarized.A qualitative evaluation,on the feasibility of three types of countermeasures for decreasing the environmental vibration of the high-rise residential buildings,is performed.(3)Numerical calculations are conducted on a high-rise residential building of in Shanghai.The natural vibration period,the torsion and the displacement of the building are calculated assuming the building is one-packed structure or two-packed structures respectively.By comparing the calculation results,the assessments for earthquake-resistance of the two types of structures are performed.In addition,based on the evaluation on the dynamic time history,the dynamic analysis is performed for the two types of structures by using a seismic wave as an input.(4)Comprehensively considering the interference on the residents,the investment and the feasibility of the construction,the reinforcement method by using connections between the walls of two separated structures is more effective than that by using ring beams in the comparison of dynamic response.The connections can effectively decrease the vibration of the structure by decreasing the natural vibration period,the pseudo-resonance of the whole construction and the foundation,and the amplification of dynamic response with height.The research results can provide a reference for the design of the countermeasures for the vibration of high-rise residential buildings with 12 – 18 stories.The research results are meaningful in engineering practice in the mitigation of negative effects of environmental vibration on the comfortability of the residents.