| The rapid progress of urbanization and the construction of high-rise buildings have created many problems,such as the deterioration of urban environment and the absence of public space.These problems have to be addressed in the development process.The utilization of roof of high-rise building podiums provides new ideas for the development of high-rise buildings.By offering suspended spaces,the rational use of roof space of podiums may save land resources,increase urban green space and cool down the unfriendly thermal environment created by tall buildings.Based on the ecological design concepts,this paper explores the formation mechanism of the roof thermal environment of high-rise building podiums,aiming to provide a reference for the roof space design of podiums.Firstly,the author investigated the status of high-rise buildings in Xiamen,analyzed the basic design requirements such as relevant normative design and thermal environment space design,and summarized the spatial features of high-rise building podiums in Xiamen,including the general layout and the architectural forms.Then,the author established preliminary case models for the selection of the empirical objects and the simulation of operating conditions.Secondly,the author obtained the representative thermal environment data of podium roof space through on-site measurement.The experimental objects were two typical roof spaces of high-rise building podiums in Xiamen.They were measured during the daytime.The author performed multiple linear regression analysis on temperature distribution in different areas in combination with multiple thermal environment design parameters such as sky view factor(SVF),profile height to width ratio(H/W),plan transparent rate(L/C)and height(H)of the podium roof,and established a positive correlation between the temperature of podium roof and the sky view factor,and a negative correlation between the temperature and the plan transparent rate and the height.Finally,the author used the Phoenics software to simulate the typical cases in different seasons.The summer simulation results are basically consistent with the measured results.In summer,the temperature of the ground measuring point is higher than the air temperature inside the podium roof space,and in winter,it is lower than the air temperature inside the podium roof space.In different seasons,podium roof space can provide a more suitable outdoor thermal environment than aboveground space.Based on the above-mentioned foundation,the author discussed the internal connection between the spatial features of the roof of high-rise building podium and the thermal environment,numerically simulated the factors affecting the thermal environment in the spatial features through orthogonal combination,and established that the spatial factors affecting the roof of podium can be listed by the following order: height of podium roof > orientation of roof opening > sky view factor.The author found out the best combination of influencing factors and optimized the thermal environment of the typical cases through integrated equilibrium analysis.Through investigation,onsite measurement and numerical simulation of the roof space thermal environment of high-rise building podiums,this paper studied the influence scope of spatial features on the thermal environment of podium roof,and established optimal combination of the spatial features of podium roof and improvement strategy based on the thermal environment. |
