Effect of Width of Geosynthetic Reinforcement within the Granular Cover on the Load Distribution over the Tunnel Lining

Abstract

A realistic estimation of load distribution over the buried structures is necessary for proper analysis of tunnels, culverts and pipes/conduits. Tunnels with linings are often constructed in transportation and hydraulic engineering. For the design of tunnel lining, it is essential to know the load over the lining. Load distribution over the buried structures has been investigated scientifically during the past several decades. The method of investigation includes experimental, numerical and analytical methods. The finite-element models based on some commercial software have been developed for load analyses for design of the tunnel linings and buried structures. The geosynthetic is an effective reinforcement layer to reduce the load over the buried structure. Although some studies have indicated that the geosynthetic layer can reduce the load over the buried structure, but no attempt has been made to determine the optimal width of the geosynthetic reinforcement within the granular cover. Therefore, in this paper, an attempt is made to present effect of width of geosynthetic layer on the load distribution over the tunnel lining. The study has been carried out by developing a numerical model of the problem. The commercial software PLAXIS 2D has been used for numerical modelling. The results have been presented in the form of design charts, mentioning the optimum width of geosynthetic layer, so that they can be used by practising engineers.