Influence of Underpinning Pile Drilling Construction on the Bearing Behavior of Existing Loaded Foundation Piles: Case Study

Table 2

Effect of borehole diameter on the end resistance of the existing foundation pile.

Diameter (m)	0.26	0.28	0.30	0.32	0.34
Rd	0.9701	0.9675	0.9650	0.9626	0.9601
Decreasing percentage	—	−0.3	−0.5	−0.8	−1.0