this paper presents the results of engineering geological studies of rock blocks along a road tunnel in nw iran. the tunnel is to cross the western alborz mountain range through 530 m in length with 11.2 m span and 8 m height. eocene tuffs and andesites crop out in whole of the tunnel route. numerical analyses are done using, a 3d stability analysis and visualization program, called unwedge tha...

This paper presents the results of engineering geological studies of rock blocks along a road tunnel in NW Iran. The tunnel is to cross the Western Alborz Mountain Range through 530 m in length with 11.2 m span and 8 m height. Eocene tuffs and andesites crop out in whole of the tunnel route. Numerical analyses are done using, a 3D stability analysis and visualization program, called Unwedge tha...

Dynamic monopolies in graphs have been studied as a model for spreading processes within networks. Together with their dual notion, the generalized degenerate sets, they form the immediate generalization of the classical notions of vertex covers and independent sets in a graph. We present results concerning dynamic monopolies in graphs of given average threshold values extending and generalizin...

Gyárfás et al. and Zaker have proven that the Grundy number of a graph G satisfies Γ(G) ≥ t if and only if G contains an induced subgraph called a t-atom. The family of t-atoms has bounded order and contains a finite number of graphs. In this article, we introduce equivalents of tatoms for b-coloring and partial Grundy coloring. This concept is used to prove that determining if φ(G) ≥ t and ∂Γ(...

The greedy defining sets of graphs were appeared first time in [M. Zaker, Greedy defining sets of graphs, Australas. J. Combin, 2001]. We show that to determine the greedy defining number of bipartite graphs is an NP-complete problem. This result answers affirmatively the problem mentioned in the previous paper. It is also shown that this number for forests can be determined in polynomial time....

nowadays deep excavations are needed for construction of foundation of high rise buildings, providing space for parking and etc. in some cases deep excavations may be constructed in the vicinity of the subway tunnels and causes unpredicted extra displacements and internal forces in tunnel lining of tunnels which were not designed for them and consequently affect serviceability of tunnel. theref...

the construction of underground tunnel plays a more and more important role in the development of big cities. one of the most important problems caused by the construction of the tunnel is that underground excavation will cause large settlement of the ground and buildings. previous studied showed the difference between numerical and experimental results. in this study the case study of niyayesh...

Modern technology has been used to build tunnels in recent years by means of drilling machines (TBM) that were used for civil engineering work in large cities to reduce the harmful effects of spending on the surface of the earth significantly. To build the tunnel, numerical modeling was used on the basis of the finite element method to predict stress behavior during the tunnel construction proc...