A circular tunnel is located $2,000m$ below surface near a fault plane which strikes parallel to

tunnel axis $($refer to Figure $2).$ The k ratio, density of rock and the gravitational acceleration

are $0\mathrm{.}5,2700k\frac{g}{m^3}$ and $9\mathrm{.}81\frac{m}{s^2}$ respectively. Assume plane strain condition.

Determine whether failure will take place at point $A$ if the strength of fault is defined by:

Cohesion: $100$kPa

Friction angle: $30$