dynamic response of unlined circular tunnels subjected to internal explosion

Dynamic Response Analysis of Fractionally Damped Beams Subjected to External Loads using Homotopy Analysis Method

This paper examines the solution of a damped beam equation whose damping characteristics are well-defined by the fractional derivative (FD). Homotopy Analysis Method (HAM) is applied for calculating the dynamic response (DR). Unit step and unit impulse functions are deliberated for this analysis. Acquired results are illustrated to show the movement of the beam under various sets of parameters ...

Dynamic stress concentration in a hybrid composite laminate subjected to a sudden internal break

In this work, transient dynamic stress concentration in a hybrid composite laminate subjected to a sudden internal crack is examined. It is assumed that all fibers lie in one direction and the applied load acts along direction of fibers. Two types arrangements are considered for the fiber; square and hexagonal arrangement. Using shear lag model, equilibrium equations are deduced and upon proper...

Explosion loads in immersed tunnels February 2009

Seismic Stability of Subsea Tunnels Subjected to Seepage

Strength reduction method and ADINA software are adopted to study the stability of submarine tunnel structures subjected to seepage and earthquake under different seawater depths and overlying rock strata thicknesses. First, the excess pore water pressure in the rock mass is eliminated through consolidation calculation. Second, dynamic time-history analysis is performed by inputting the seismic...

Dynamic Response of Electromagnetic Launcher's Rail Subjected to Cosine Pressure

In order to extend the rail life and improve the firing accuracy, the electromagnetic launcher’s rail can be modeled as a beam on elastic foundation with simply supported beam by moving load. Euler beam theory is applied to build the Mechanical model and the analytical solution of the equation subjected to cosine magnetic pressure is derived in detail, which has successfully avoided the errors ...

Analysis of Circular Reinforced Tunnels by Analytical Approach

This paper addresses the problem of quantifying the mechanical contribution of rockbolts installed systematically around tunnels (regularly spaced around the tunnel) excavated in rock masses. Assuming that the mechanical contribution of grouted rockbolts is that of increasing internal pressure within a broken rock mass, a new procedure for computation of ground response curves for a circular tu...