The seismic performance of one-third scale double units three-storey tunnel form reinforced concrete building tied up with foundation beam tested under in-plane lateral cyclic loading are performed and analysed in this paper. This building is designed according to BS 8110, constructed in heavy structural laboratory and tested under in-plane lateral cyclic loading using displacement control method. The specimen is tested on a strong floor starting from 0.01% drift until 1.25% drift with an increment of 0.25% drift. From visual observation, the initial crack starts at +0.25% drift with more cracks observed at +1.0% drift. The ultimate lateral strength is reached at +1.25% drift and the experiemental work is stopped at this drift due to the danger of collapsing the tunnel form RC building. Based on the experimental hysteresis loops, the ultimate in-plane lateral strength is 93kN, maximum displacement ductility (  ) is 2.5, average elastic stiffness is 6.11kN/mm, average secant stiffness is 2.94 kN/mm and equivalent viscous damping (EVD) for the first cycle is 15% and second cycle is 6%. It can be concluded that this type of building will survive in a low to moderate earthquake but will collapse in a strong or severe earthquake due to the existence of a plastic hinge zone at wall-foundation interfaces.

Dynamic response of dams under earthquake loading depends on their foundation stiffness. Additional hydrodynamic pressures are generated not only by the ground motions but also due to the dynamic response of the dam to the ground motions. The magnitude and distribution of hydrodynamic pressures vary and these effect the deformation of dam which in turn influences the pressure. This paper aims at investigating the effect of dam–foundation interaction on the dynamic response and consequent development of hydrodynamic pressure on dam face using dynamic centrifuge modelling technique. From a series of centrifuge tests it was found that the inclusion of a flexible foundation significantly reduces the dynamic response of the dam. Significant correlation was also observed between the dynamic response of dams and the hydrodynamic pressures developed on their faces. Comparisons with theoretical hydrodynamic pressures show that Westergaard's equation gives a conservative estimation of hydrodynamic pressures during most nonresonant vibrations. Comparison with Chopra's method revealed that it severely underpredicts hydrodynamic pressures for low reservoir depths. However, it yields a reasonably good approximation of the hydrodynamic pressures for higher depth of reservoirs during nonresonant vibration.

Dynamic response of dams is significantly influenced by foundation stiffness and dam-foundation interaction. This in turn, significantly effects the generation of hydrodynamic pressures on upstream face of a concrete dam due to inertia of reservoir water. This paper aims at investigating the dynamic response of dams on soil foundation using dynamic centrifuge modelling technique. From a series of centrifuge tests performed on model dams with varying stiffness and foundation conditions, significant co-relation was observed between the dynamic response of dams and the hydrodynamic pressures developed on their upstream faces. The vertical bearing pressures exerted by the concrete dam during shaking were measured using miniature earth pressure cells. These reveal the dynamic changes of earth pressures and changes in rocking behaviour of the concrete dam as the earthquake loading progresses. Pore water pressures were measured below the dam and in the free-field below the reservoir. Analysis of this data provides insights into the cyclic shear stresses and strains generated below concrete dams during earthquakes. In addition, the sliding and rocking movement of the dam and its settlement into the soil below are discussed.

During earthquakes, hydrodynamic pressures are generated by the impounded reservoir on the dam face. The magnitude and distribution of the hydrodynamic pressures vary with factors such as frequency and intensity of earthquake-induced ground motion, depth of impounded reservoir, stiffness of dam and geological conditions. It is difficult to obtain experimental data on hydrodynamic pressures from the field owing to uncertainties associated with earthquake loading. This paper aims at using dynamic centrifuge modelling to measure hydrodynamic pressures behind both relatively stiff and flexible model dams. Comparisons of the experimental data with theoretical hydrodynamic pressures show that Westergaard's equation gives a conservative estimation of hydrodynamic pressures. Comparison with Chopra's method revealed that it underpredicts hydrodynamic pressures for low reservoir depths but gives reasonably good predictions for higher depths of reservoir. It is concluded that dynamic centrifuge modelling may be an effective experimental method to estimate the hydrodynamic pressures acting on a dam.