Design of Underground Open Space:Model and Dimension

This paper is composed of three parts.The first part brings out the four basic models of underground open space: below-grade concourse,atrium,sunken plaza,and three-dimensional compound.The second part analyzes three typical plans of the underground open space.These three plans are different in types,but as alike as a positive interaction between ground space and underground space.All these plans integrate ground and underground spaces to create much more public spaces,and contribute new places for their home city.The last part gives a summary of the key three design dimensions of underground open space.The three dimensions are horizontal linkage,three-dimensional compound,and self public-upgrade.This paper shows that the underground open space is not only the key joint linking ground space and underground space,but also an active power to integrate them.