A hollow bar soil nail wall is used as a temporary soil retention struc-

ture. The retained soil and its properties are shown in Figure 7.61. The

following design parameters are also selected for this project:

Pullout factor of safety, FSp = 2.0

Global factor of safety, FSG = 1.4

Nail horizontal spacing, SH = 1.5 m

Nail vertical spacing, SV = 1.5 m

Nail inclination = 15 degrees

Drillhole diameter, DDH = 200 mm

Ultimate pullout resistance, qu = 120 kN∕m²

Determine:

(1) The preliminary nail length and maximum design nail tensile force

to satisfy the global stability.

(2) The factor of safety against sliding.

(3) The factor of safety against the heaving of the foundation soil.