Research On Codes Based Equivalent Static Wind Loads On High-rises

Wind loading is of great importance to the safety, serviceability and economy of tall buildings. Wind loading is becoming the most considered load instead of earthquake loading with the increase of building height. However, it is difficult to calculate wind induced response direct from wind characteristics, because numerous dynamic analyses involved in calculation is hard for structural engineers to accept. Equivalent Static Wind Loads (ESWL) is then carried out as the bridge between wind engineering and structure design. Equivalent static wind loads means that it will produce the same max response as reality when applying the loads on structures. Structures are now gradually becoming higher, lighter and more flexible. Therefore, wind loads turns into the dominant loads for many structures. It is great useful to optimize structure design and improve efficiency if rational and easy equivalent wind loads method could be proposed and quickly accepted by structural engineers. Equivalent static wind loads on tall buildings earns a lots attention in the field of wind engineering.The great majority of constructions are designed by standard or code. Current code gives winds loads distribution in the form of equivalent static wind loads based on stochastic oscillation theory. According to the past research, current method of calculating mean wind loads and resonant equivalent wind loads is more mature, but method of Background Equivalent Static Wind Loads (BESWL) hasn't been perfect yet The importance of background equivalent wind loads is that, it dominants generally 70% to 80% of tall buildings which are designed by code procedures. Therefore, improvement method of background equivalent wind loads will make engineering design more accurate.According to the points mentioned above, this paper aims to propose an easy and accurate ESWL model for code use. First of all, formulas of background and resonant equivalent wind loads are listed and simplified so that multi integral will not trouble during calculation. Then, based on current research, two new kinds of BESWL methods based on respectively base shear and base moment are proposed and verified. These two new methods are programmed for use and specific discussion is made to compare the applicability to codes of new methods and current methods. Results show that new equivalent methods have enough precision, clear physical meaning and not sensible to resultant response. At last, various methods are applied to calculate wind loads response of skyscrapers. Also the applicability of various methods on skyscrapers is investigated and some new results are gained. These results can be referred to when code for wind loads on high-rises is revised.