For this purpose, a new formula for the estimation of the rock load (support pressure) is recommended.
Among the reasons causing big deformation, compared with high in situ stress and soft rock that cannot be changed during the construction, the rock strength loss and rock stiffness decrease can be improved by providing quick and strong support pressure to the rock and keeping the rock dry.
Shotcrete is useful to prevent the rock from weathering and to provide an integrated support pressure to the rock.
The displacement and stress evolution laws of surrounding rock supported by the pressure relief anchor box beam system were researched.
According to the Fenner formulae, the yielding radium, normal stress at the border between the elastic zone and the yielding zone, and tunnel deformation are related to rock properties, overburden, tunnel radium, and support pressure as left.
The results indicate that the effect of the critical plastic softening parameter on the fictitious support pressure, especially for the rock mass with good quality is obvious.
It is an indicator of the self-supporting capacity of the rock mass.This paper aims at solving the fictitious support pressure on a circular tunnel with hydrostatic initial stress field.
For a rock mass with strong dilatancy behaviour, the fictitious support pressure ahead of the tunnel face decreases rapidly.
Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation, stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring site.
Due to its wide-spread acceptance in the field of rock engineering, the Geological Strength Index (GSI) is adopted in support pressure equation.
