Question

The sketch shows a triangular rock mass (ABC) resting on a joint plane (AC) inclined at 35° with the horizontal. A rockbolt having an inclination of 25° with the horizontal is used to stabilize the slope. If the bolt tension (T) is 110 kN, the absolute value of shear force along the joint plane induced by the bolt tension is \(\underline{\hspace{1cm}}\) kN. 

Hint:

When calculating shear force along a joint plane, use the bolt tension and the sine of the inclination angle of the joint plane.

Answer 1

Correct Answer: 55

The shear force \( F \) induced along the joint plane is related to the bolt tension by:
\[ F = T \cdot \sin(\theta) \] where:
- \( T \) is the bolt tension, and
- \( \theta \) is the angle of inclination of the joint plane, which is 35°.
Thus, the shear force is: \[ F = 110 \cdot \sin(35^\circ) = 110 \cdot 0.5736 \approx 55 \, \text{kN} \]