1.INTRODUCTION Some forty years ago, most opening supports and reinforcements were designed using empirical rules defining ground loads acting on the supporting structures. This approach is still popular and interest in it has been renewed by the use of rock mass classification systems (Barton et al. 1974, Bieniawski, 1974,1976,1989). Correlations between rock mass conditions and the type of su...

In this research, the effects of torque tightening on the stress distribution in double lap simple bolted and hybrid (bolted-bonded) joints have been investigated numerically. In order to determine the bolt clamping force value due to tightening torque in simple bolted and hybrid joints, which is necessary in numerical simulation, an experimental approach has been proposed. To do so, two kinds ...

Adequate initial bolt preload is necessary to ensure the strength and stiffness of bolted connections. In this study, an experimental torque control method was used determine relationship between tightening nine Extended Hollo-Bolt (EHB) blind connections Concrete-Filled Steel Hollow Sections (CFSHS). order obtain EHB nut factors, which allow calculate level for any value applied torque, versus...

The influence of the working load on dynamic loading bolt was investigated in our study for two cases flange joints. analytical calculation according to Verein Deutscher Ingenieure (VDI) 2230 recommendation and numerical analysis using finite element method (FEM) were performed a model four-bolt joint. To verify FEM analysis, forces bolts measured during preloading application test rig. Based r...

this research was carried at the university of reading in 1999. the aim was to estimate the effects of 18 hd-1 (long-day, ld) and 12 hd-1 (short-day, sd) light exposure duration of plants before bolting or flowering on time to bolt and flower in two bolting susceptible (bsg, ic1) and bolting resistant (brg, saxon) genotypes of sugar beet. so, two experiments were conducted. the experiments were...

For tunnel-support engineering, the bed separation of surrounding rock has a great influence on support performance bolts. In order to reveal mechanical properties full-grouted prestressed bolt under separation, three typical working conditions single-separation, multi-separation and different positions were set up, theoretical models numerical established. Furthermore, characteristics axial fo...

We examine the thermodynamics of Euclidean dyonic Taub-NUT/Bolt-AdS4 black holes for a variety horizon geometries to understand how gauge field regularity conditions influence thermodynamic relations. find several distinct features that distinguish NUT-charged case from its Reissner-Nordstrom counterpart. For NUT solution, vanishes at and so is ensured. Bolt solution we norm required vanish in ...