Study On The Comfort Of Concrete Floor Under The Loads Of Pedestrian

With the development of our country's economy and society and the improvement of people's living standard,people more and more demanding for the housing conditions on the basis of improving the quality of life,and the issue of the floor comfort is more and more concerned.People who engaged in different activities in the building,have different requirement for the floor comfort under the impact of pedestrian load on the floor.For doctors and people who work on some higher sensitivity jobs,they are more stringent for the comfort requirement,while for the people who dining in restaurant in which a noisy environment,they have the lower vibration comfort requirement.The concrete floor will generate an impact response under the influence of the walking impact force,and this impact response also influents on the people who being on the floor to easily make them feel uncomfortable.Currently,the methods of designing structure comfort at home and abroad can be summarized as the following three: annoyance rate method,frequency limitation method and acceleration limitation method.According to the existing research results at home and abroad,we combine with the specific requirements of the assessment criteria for comfort to carry on the theoretically analysis of the structure of concrete floor and discuss the effects of the concrete floor thickNess and length-width ratio,etc.on the impact of pedestrian load response in this paper.And we carry through the related simulations by the finite element software ANSYS.The research results are as follows:(1)Floor self-vibration frequency increases with the thickNess increases.The self-vibration frequency and the thickNess are shown in linearly variation.However,floor self-vibration frequency decreases with the width increases.The self-vibration frequency variation obviously changes with the variation of floor length L when the floor with the random length L between 4 and 16 m.The variation rate of the self-vibration frequency tends to be moderate when the length is more than 16 m.When the floor length is less than 4m,the variation of the length-width ratio has a great influence on the self-vibration frequency and the self-vibration frequency is lower for the floor with a longer span.(2)The floor maximum acceleration response decreases with the thickNess increases,but is independent of the path.Floor weight also increases with the thickNess increases.However,the instantaneous response acceleration is related to the path when the variation of the length-width ratio is not 1.When the span is small,the instantaneous acceleration response is larger.The instantaneous response acceleration figures are similar when the length-width ratio is the same.(3)of floor slab size natural frequencies,vibration has influence,the weight of the aspect ratio decreasing speed and acceleration response is reduced,production floor slab thickNess increasing floor base frequency almost in a straight line.Floor size change has some impact on the floor vibration comfort,but in the practical engineering need combined with stiffness,damping ratio and the quality,column plate connection mode,as well as on the pedestrian step load factors in comprehensive analysis.