This paper presents an experimental study on circular stirrup-confined concrete specimens under uniaxial and monotonic load. The effects of stirrup volume ratio, stirrup yield strength and concrete strength on damage evolution of stirrup-confined concrete were investigated. The experimental results showed that the strength and ductility of concrete are improved by appropriate arrangement of the...

The effect of a blasting vibration from an excavating tunnel on adjacent excavated is great importance for the stability and security twin tunnels. Due to relatively small distance between face concrete lining tunnel, impact could be significant should considered in practical project. In order control scales during excavation one minimize one, research based field-blasting tests performed tunne...

There are several methods for analysing the behaviour of underground structures under different loading conditions. Most of these methods have many simplifications; therefore, in some cases, the results are too conservative and a very high safety factor, usually of more than 2 is needed. On the other hand, for stability analysis and the designing of support systems, these methods consider segme...