Deformation Response and Safety Evaluation of Buildings Affected by Subway-Station Construction

Table 9

Safety evaluation of building-deformation response during foundation-pit excavation and corresponding grade description.

Safety level evaluation	Basis of evaluation		Description of basis	Description of the safety degree
	Sj	Lj
Level III	2∼3	5∼9	Both the safety evaluation index and the safety grade of the scheme are high	The safety reserve of the foundation-pit design scheme is larger or the surrounding environment deformation is less affected by the excavation of the foundation pit
Level II	2∼3	1∼5	The safety evaluation index is higher, but the safety grade of the scheme is lower	The safety reserve of the foundation-pit design scheme is small or the surrounding environment deformation is less affected by the foundation-pit excavation
	1∼2	5∼9	The safety level of the scheme is higher, but the safety evaluatioxn index is lower	The design of the foundation pit has a high safety reserve or the surrounding environment or the deformation of the surrounding environment is greatly affected by the excavation of the foundation pit
Level I	1∼2	1∼5	Both the safety evaluation index and the safety grade of the scheme are lower	The safety reserve of the foundation-pit design is lower or the surrounding environment or the deformation of the surrounding environment is greatly affected by the excavation of the foundation pit