Full-scale Monitoring Of Wind-induced Response Of High-rise Building

At present, the wind engineering study on the wind-induced vibration of super high-risebuildings is mainly used by the wind tunnel test.Measured as a very important basic andlong-term work,but the research work and achievements are insufficient and the comparisonwith wind tunnel test is proved to be scarce. Damping ratio as the control parameter ofdynamic response of the structure, its value has a decisive role on the wind-induced vibrationcontrol, the existing literature shows that: the structure response amplitude has a greatinfluence on the structural damping ratio, which shows a nonlinear relationship, however theclassical dynamic equation of the structure-damping ratio as a constant.therefore, the studyon the relationship between structure response amplitude and structural damping ratio is ofgreat significance to the wind engineering.This article is mainly study on the analog signaldamping ratio, the field measurement and the wind-induced response of high-rise buildingand the wind tunnel test etc.1.After get RDT decay curve by using a series of initial thresholds, the relationshipbetween damping ratio getting by outer envelope curve fitting signal with the initialthresholds shows nonlinear. Too big or too small initial threshold to get the damping ratioerrors lager,too small initial threshold to get the damping ratio also Present largediscreteness.Different random signals, Damping ratio trends are inconsistent with the initialthreshold. Take double the RMS as the initial threshold to get the damping ratio closest to thedefault value; Using four-parameter fit long RDT signal attenuation modal parameters ofstructure, the frequency values consistent with default values. Damping ratio in the bigamplitude error is very small, but the errors and discreteness larger in the small amplitude;The same signal attenuation by the outer envelope fitting damping ratio and the average valueof four parameter fitting damping are the same in the big amplitude,also the errors anddiscreteness larger in the small amplitude,but the trend is the same.2.In shen zhen zhuo yue huang gang century center under the condition of differenttyphoon implementation uninterrupted monitoring show that: The structure comfort meet regulatory requirements; The measured structure inherent frequency is less than the generalfinite element model frequency; The four-parameter fit and power spectrum to get the firsttwo frequencies of the structure value was about0.80Hz,0.220Hz; The first2order modaldamping ratios were about0.8%,0.9%obtained by the outer envelope and four-parametersfitting, and the structure modal damping ratio under the condition of typhoon did not showincreased with the increasing trend of acceleration amplitude. damping ratio geting byenvironmental motivation showed a larger volatility and error.3.The shen zhen zhuo yue huang gang century center rigid body model’s high frequencybase balance test show that: in the10year return period, the structure’s peak acceleration isabout18mg, meeting the requirements of specification;From the first order generalized forcepower spectrum, the reduced frequency of structure is close to Strouhal number0.1, thevortex shedding frequency is close to the natural frequency, resonance response big, So thereshows a large acceleration and the base moment value in the180degree direction angle. Themeasured frequency and the finite element model building analysis show that the measuredfrequency response is less than the finite element model of frequency response, because,inthe actual structure, non load bearing components increases the stiffness of the structure, thefinite element model period should be reduced. Actual wind field environment measuredacceleration response and the rigid body model added speed response to the correspondingwind field environment, there is a big gap in the first place and to LiuFeng field basic windspeed, wind direction and structure of the actual response corresponding to wind speed, winddirection, not necessarily accurate, the scale effect of wind tunnel tests may also cause isn’tconsistent with the measured results, at the same time, structural modal dampingidentification method may lead to biased results.