Dynamic Response Characteristics of the Structures under Excavation by High-Efficiency Blasting in the Urban Ultradeep Foundation Pit

Table 1

Parameters for blasting.

Position		Bench height (m)	Hole spacing (m)	Row spacing (m)	Overdrilling depth (m)	Borehole diameter (mm)	Length of stemming (m)	Single-hole charge (kg)
Distance from supporting pile	>20 m	4.0	3.0	2.5	0.5	90	2.9	8
	15–20 m	3.5	3.0	2.5	0.5	90	2.8	6