Aseismic Performance And Dynamic Reliability Of A Novel Damped Outrigger System Of Super High-rise Buildings

Recently, the aseismic performance and safety of super high-rise buildings haveincreasingly attracted our attentions. Designing reasonablely an energy dissipation deviceto achieve a predictable performance and not to impact the function as well has become aresearch topic home and broad. The novel energy dissipation system of super high-risebuildings, in which dampers are equipped vertically between the outrigger and perimetercolumns to make full use of motion discrepancy of these two components,copes well withsuch problems and had been successfully applied into actual engineering. For the purposeof further application, it is in urgent need to study deeply their earthquake-resistantperformance and dynamic reliability. Therefore, this paper organizes the research asfollows:(1) The frequency domain responses of the novel damped outrigger system areanalyzed. The installed linear viscous damper coefficient is optimized in terms ofsupplementary damping ratio. As a result of that, the the transfer functions of roofdisplacement, velocity and acceleration are compared to illustrate the vibration reductionmechanism. And the combination method of pseudo excitation and high preciseintegration scheme is also adopted to study the control effectness of time variant responsedeviation under white noise and Kanai-Tajimi, respectively.(2) The dynamic time history response analyses are conducted. Firstly, the suitablestructural models are carefully examined for the novel damped outrigger system after thestudy on dynamic characteristics, story drift angle and story acceleration from fourtraditional uncontrolled ones. Secondly, the control effectiveness of the novel dampedoutrigger system with viscous dampers or buckling restrained brace (BRB) in terms ofstory drift angle and story acceleration responses correspondingly to seven earthquakerecords are compared. Finally, the augment state equations of the structure and groundsurface are formulated according to lyapunov differential equation and Kanai-Tajimiground motion model spectrum, and the results of time variant response deviations matchwell with those of frequency domain analysis with the help of PIM-CSD toolbox.(3) Taking advantage of the powerful tool of probability density evolution method(PEDM), the probability density evolution of interested response values and structuraldynamic reliability are studied. Firstly, the probability density function theory is brieflyintroduced, including the formulation of probability density function equation，numericalimplementation and dynamic reliability calculation based on first passage theory. Thenfive random sources,resulting from earthquake excitation，damper parameters andstructural mass，stiffness and modal damping ratio, are considered respectively, and theproper discrete representative points are chosen from random variables space according to 3σlaw. The equivalent extreme value method (EEVM) is utilized to study structuralextreme value probability density function and system dynamic reliability, and the totalvariation diminishing (TVD) is employed to provide the probability density evolution ofinterested response values.(4) The novel damped outrigger system is applied into a real engineering project.Inorder to control the story drift angle, the locations of damped outriggers and viscousdamper parameters are optimized, and the control effectness are compared with traditionalenergy dissipation scheme.The results indicate that the super high-rise buildings with redundant outriggersdesigning into novel damped outrigger systems can economically improve the aseismicperformance and dynamic reliability with a relatively small amount of dampers. Thus, it isworthwhile to popularize the new energy dissipation system in the future.