Ground Convergence Curve

a$)$ Five different types of support $($early installed mechanically anchored rock bolts; lately installed mechanically anchored rock bolts; $75$ mm thick shotcrete; steel sets with shotcrete and tiebar between the steel sets; and steel sets without shotcrete and with tiebar between the steel sets$)$ in conjunction with the ground convergence curves for the roof, sidewall and floor of a tunnel are illustrated on Figure $1$ below.

With references to these curves, identify to the best of your judgment which support types belong to which numbers in Figure $1$ and explain your rationale.

$(5$ marks$)$

i$)$ For the ground convergence curves, provide $5$ bulletin points highlighting the characteristics of the curves with respect to location, displacement, stiffness or yielding.

$(10$ marks$)$

ii$)$ Regarding the support types you have identified above, discuss the strengths and weaknesses of each support type in terms of time of installation, stiffness, displacement, and equilibrium.

$(10$ marks$)$