105th tunnel is one of the many tunnels of Iranian railways in Lorestan area. This tunnel with about 1500m length is located at green and red marlstones. The height and dip of valley slopes adjacent to northern part of tunnel axis is very high. In other way host rock of tunnel has low strength and durability especially in existence of water. Occurrence of these conditions in addition to erosion of slope toe by Sezar river have caused the slope to be unstable and some landslide movements take place in this area. Mechanism of landslide movement is very complex but sliding and toppling of small masses is most important instabilities. These masses slide and topple from upper parts of the slope due to erosion of lower parts.These instabilities gradually progress toward the tunnel axis. To stabilize the landslide complex and to prevent tunnel damage, some remedial measures have been predicted. This remediation plan is based on the results of site investigations and stability analysis. Stability analyses carried out using different methods of slices (Bishop, Ordinary, Janbu,…) and in different conditions. Results of analyses show that overall instability of slope is impossible but small mass sliding would occur from top of the slope. Finally, following remedial measures is predicted to control of landslide area: 1.Preventing the entrance of surface water into the slide area by providing a drainage system. 2.Filling and tamping all open cracks which could carry water into the materials. 3.Removing groundwater from the materials by help of ditches, horizontal holes,… 4.Establishing an embankment ridge to stabilize and prevent the erosion of slope toe.
Advanced Search
About CIVILICA®
Showing Abstract of Stability analysis of landslide adjacent to 105th Tunnel (Lorestan Railways)
Links
Abstract of the Article
Stability analysis of landslide adjacent to 105th Tunnel (Lorestan Railways)
Abstract: