Knowledge base

# Code-check of bolts and preloaded bolts according to Hong Kong Code

Preloaded bolts are checked for shear slip capacity and combination of tension and shear.

### Shear capacity

Shear capacity of preloaded bolts is determined according to Cl. 9.3.6.2 as:

\[ P_{SL} = 0.9 \cdot K_s \cdot \mu \cdot P_0 \]

where:

- \(K_s\) – hole coefficient taken as
- for standard holes \(K_s = 1.0\)
- for oversized holes \(K_s = 0.85\)
- for slotted holes \(K_s = 0.7\)

- \(\mu\) – slip factor between connected parts from Table 9.7; editable in Code setup
- \(P_0\) – minimum proof loads of bolts specified in relevant international or local standards

### Combined tension and shear

Combined tension and shear is checked according to Cl. 9.3.8.2 as:

\[ \frac{F_s}{P_{SL}}+\frac{F_{tot}}{0.9\cdot P_0} \le 1.0 \]

where:

- \(F_s\) – shear force in a bolt
- \(P_{SL}\) – slip resistance of a preloaded bolt
- \(F_{tot}\) – total applied tension in the bolt including the prying force
- \(P_0\) – specified minimum proof load of a preloaded bolt