Seismic effects

Hydro projects, dams, bridges, naval equipment and any installations that aie prone to continuous shocks and vibrations also require their primary and secondary systems to have a better design and operational ability to withstand seismic effects or other ground/surface vibrations. No specific tests are presently prescribed for such applications. But response spectra can be established even for such locations and the primary and secondary systems analysed mathematically or laboratory tested. 

In Section 14.6 we have provided a brief account of such disturbances as well as the recommended tests and procedures to verify the suitability of critical enclosures and bus systems for locations that are earthquake-prone. For this the user is required to provide the manufacturer with the intensity of seismic effects at site of the installation in the form of response spectra (RS). (See Section 14.6.)... 

Seismic effects and earthquake engineering is covered in this part to study the behaviour of an object under seismic conditions and its suitability for critical installations. The formation of the earth and movements of tectonic plates that cause earthquakes and volcanic eruptions are described,... 

Monitoring A seismometer can be used to record the amount of blast and shock produced by the detonation. This record of the audio and seismic effects of each disposal detonation can be used to confirm or dispute property damage claims from nearby residents. 

Different geologic conditions can have similar seismic effects. 

Different seismic effects may be caused by similar geologic conditions. 

Unjoh, S., Sugiyama, T., Sakai, J. and Okada, T. Damage of Bridge Structures during Recent Earthquakes and the Effectiveness of Seismic Retrofit, Proc. of the 4(f" Joint Meeting of UJNR Wind and Seismic Effects, pp.1-13. (2008). 

Iwasaki, T., Penzien, J., Clough, R.(1972) Literature Survey-Seismic Effect on... 

The seismic effects are generally considered as pseudo-static forces to be added to the other static forces. A detailed review ofthe literature regarding the computation of passive earth pressure using planar failure, composite failure mechanism and experimental investigations are presented in the following sections. In addition, the review of the literature for the computation of earthquake-induced displacements is also presented. 

Thoenen, J. R., Windes, S. L. (1942). Seismic Effects of Quarry Blasting. Bureau of Mines. Bull, 442, 83. 

Other systems for the reduction of the seismic effect on the structures can be used. These operate by connecting different parts of the structure, for example by braces, to energy dissipators which are capable of absorbing an enormous amount of energy during an earthquake and therefore increasing the damping of the system. They can also be combined with isolators at the base. 

Veletsos, A.S. (1974) Seismic effects in flexible liquid storage tanks . Proceedings of the 5th Word Conference on Earthquake Engineering, Rome. 

The evaluation of seismic effects on the tank wall has been made in terms of both maximum base shear induced by the dynamic pressure and relative impulsive and convective components. 

The major effect detcmiining water level at any one instant, around the UK at least, is the astronomical tide which can be predicted accurately well in advance. Meteorological and seismic effects are not predictable more than, at best, a few days in advance, and even then the predictions are very uncertain. It is these aspects that can pose a risk to the construction works. 

The response of the strengthened model was considerably different from that of the original model. The increased elasticity limit and reduction of displacements at the top were characteristic. Although there was a considerable deterioration in the load-bearing capacity under maximum seismic effect, the complete stability of the model structure was not disturbed due to the presence of ductile elements, while the damage was such that it was repairable. The structure of the strengthened model was in a state of deep nonlinearity, but still far from failure. 

Definition of Seismic Parameters The elaboration of the Study for Seismic Microzoning of the Location of the Cathedral Church in Mostar according to the JUS and EC8 standards by the Republic Hydro-meteorological Institute of Banja Luka, enabled definition of the total seismic hazard at the church location and analysis of the response of the local soil to seismic effects for the purpose of definition of the parameters of the horizontal elastic spectrum of local soil response (Fig. 8.21), the corresponding time histories of acceleration and deformability properties of the soil. 

In the preliminary design stages, seismic effects (in terms of forces and undesired torsional or rocking effects) should be minimized by the appropriate selection of a structural layout applying certain general criteria, such as ... 

The goal of this approach to qualification is to ensure that the as installed items are capable of withstanding the design basis seismic effects without loss of structural integrity, with account taken of anchorage effects and seismic interaction effects (on items and operators). 

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