EXPERIMENT OF SLIDING SUPPORT OF ALUMINUM ALLOY STRUCTRUE FOR SHANGHAI BOTANICAL GARDEN GREENHOUSES

Aluminum alloy single-layer reticulated shell was adopted for the Shanghai Botanical Garden greenhouses.The longest greenhouse was about 200 m,which belonged to overlength structures.So one of the difficulties of structure design was how to reduce the impact of the thermal stress of the structure,especially the linear expansion factor of the aluminum alloy was twice of the steel.It would be not effective to use fixed support except for sliding support.Another feature of the structure was lots of supports,whose boundary were a closed loop.So it was feasible to release the temperature stress only when the friction factor of the support was little enough(0.01).Therefore,a roller rolling-sliding limit spring support was designed,which could satisfy the performance demand according to the experiment and on-site test.