Srivastava, Lok Priya
Analysis of a rock bolt-reinforced tunnel with equivalent mechanical properties - Vol.52(4), Aug - New York Springer 2022 - 815-834p.
After the excavation of a tunnel, generally, rock bolts are used as primary support. Installation of rock bolts considerably reduces the further deformation in the rock mass around the tunnel boundary. Bolts provide additional support to mass and therefore mass becomes stiffer, rigid, and stronger. The theory of rock bolts–rock mass interaction is quite complex and contains numerous factors. The complex interaction between mass and bolts leads to complex theoretical analysis, and sometimes, it is very difficult to find out the solutions. Hence, to rectify this, the continuum model of numerical analysis is used which is simple and convenient. Rock mass and rock bolts are two distinct materials, and their mechanical properties are much different from each other. In continuum analysis, generally, they are modelled separately, i.e. different mechanical properties are assigned to rock mass and rock bolt. As the whole mass is treated as equivalent continua, separate modelling of the bolt and the rock mass may give misleading results. Proper interaction between mass and bolts may not develop due to the non-existence of joints in the continuum model. Hence, if, in the continuum model, rock and bolt to be modelled together with equivalent mechanical properties, the result would be different. The present research work deals with continuum analysis of a rock bolt-reinforced tunnel in which equivalent mechanical properties of bolt and rock are used. Equivalent mechanical properties were worked out from the laboratory investigations conducted on the specimens of natural jointed rock and rock bolt. The equivalent continuum model of a rock bolt-reinforced tunnel was developed, analyzed, and compared with the conventional continuum model. The result suggested that if rock bolts are taken as an integral part of the rock mass and modelled as an equivalent continua, the result would be more rational and reliable.
Civil Engineering
Analysis of a rock bolt-reinforced tunnel with equivalent mechanical properties - Vol.52(4), Aug - New York Springer 2022 - 815-834p.
After the excavation of a tunnel, generally, rock bolts are used as primary support. Installation of rock bolts considerably reduces the further deformation in the rock mass around the tunnel boundary. Bolts provide additional support to mass and therefore mass becomes stiffer, rigid, and stronger. The theory of rock bolts–rock mass interaction is quite complex and contains numerous factors. The complex interaction between mass and bolts leads to complex theoretical analysis, and sometimes, it is very difficult to find out the solutions. Hence, to rectify this, the continuum model of numerical analysis is used which is simple and convenient. Rock mass and rock bolts are two distinct materials, and their mechanical properties are much different from each other. In continuum analysis, generally, they are modelled separately, i.e. different mechanical properties are assigned to rock mass and rock bolt. As the whole mass is treated as equivalent continua, separate modelling of the bolt and the rock mass may give misleading results. Proper interaction between mass and bolts may not develop due to the non-existence of joints in the continuum model. Hence, if, in the continuum model, rock and bolt to be modelled together with equivalent mechanical properties, the result would be different. The present research work deals with continuum analysis of a rock bolt-reinforced tunnel in which equivalent mechanical properties of bolt and rock are used. Equivalent mechanical properties were worked out from the laboratory investigations conducted on the specimens of natural jointed rock and rock bolt. The equivalent continuum model of a rock bolt-reinforced tunnel was developed, analyzed, and compared with the conventional continuum model. The result suggested that if rock bolts are taken as an integral part of the rock mass and modelled as an equivalent continua, the result would be more rational and reliable.
Civil Engineering