A support structure of systematic anchor bolts is a key part in the system of shotcrete-bolt suppcrts

and it is widely used in preliminary bracing of hiqhway tunnel at present. However

there is no effective quantitative way to calculate the role of the systematic anchor bolts for the stability of tunnel structure. Taking a certain expressway tunnel for example

the influence of anchor bolts on safety factors of tunnels under different geological conditions is calculated with FEM strength reduction method. Together with FEM numerical simulating and analysis to various kinds of effects from anchor bolts

conclusions can be drawn as follows. The anchor bolts have little influence on stability of expressway tunnel under much more geological conditions; therefore

it is suggested that experimental verification of canceling the systematic anchor bolts should be carried out gradually if possible

so as to provide more engineering basis for canceling anchor bolts in highway tunnels.