STABILITY ANALYSIS OF PORTALS IN TUNNELS

Abstract

At this paper will be reviewed stabilization and rehabilitation of cuts and portals of railway tunnel. Usually, tunnels are performed in rock areas and there is always need from stabilization and temporary protection during performing and its use. Tunnel's cuts are located at the entrances and exits of the and stabilization but as most common method is with galvanized wire mesh, shotcrete and barriers. During every construction works appears changes in some parts of rocks massive and new deformations. In order to avoid appearance of deformations, in slopes anchors need to be installed. Installation of geotechnical anchors is method with drilling, insertion of anchors and injection. In that way the stabilization of the slope is achieved, where anchors help the rock massive to keep his load. Anchors with pulling force transmit the force in health rock mass. Anchors can be used and with other types of protection for better and longer stabilization of slopes. In this paper will be reviewed stabilization of cuts and portals of tunnel in Republic of Croatia, which had need of stabilization. The process consists of making design (schemes) for stabilization, and then checking and verifying the solutions with software analysis and directly on site. The purpose of this paper is to emphasize the importance of stabilization of slopes and of portals too. In Republic of North Macedonia, the use of protective measures is still low, but it should be increased especially in the area of transport infrastructure.