Ground motion

The peak of all the curves represent the condition of resonance that occurs when the system or equipment frequency ny, is a little higher than of the ground motions o> or is slightly less than 1. Curve 1 represents a system that is undamped, fig(a) of 14.22 Higher the level of damping, lower will be the amplifications, hi < h < ha-... 

United States, where most recorded earthquake data are in MM intensity units, there are two approaches for determining the attenuation of ground motion. Method 1 is an intensity-atte ition... 

Failure frequencies of structures, equipment, and piping are related to their acceleration which is related to the ground-motion of the plant s foundation (e.g., the peak ground acceleration). For PSA, it is useful to present the seismic hazard at the site as a family of hazard curves with different nonexceedence-probability levels (Figure 5.1-3). By selecting various values of the peak ground acceleration, the acceleration and forces on the plant components may be obtained as described in the following. 

The natural frequency, co associated with the mode shape that exhibits a large displacement of the pump is compared with the fundamental frequency, of the wall. If co is much less than ru, then the dynamic interaction between the wall and the loop may be neglected, but the kinematic constraint on the pump imposed by the lateral bracing is retained. If nearly equals nr , the wall and steam supply systems are dynamically coupled. In which case it may be sufficient to model the wall as a one-mass system such that the fundamental frequency, Wo is retained. The mathematical model of the piping systems should be capable of revealing the response to the anticipated ground motion (dominantly translational). The mathematics necessary to analyze the damped spring mass. system become quite formidable, and the reader is referred to Berkowitz (1969),... 

The fragility analysis evaluates the conditional fraction of failure of plant structures and equipment as a function of ground motion. The seismically initiated failure of plant components is expressed in terms spectral acceleration at 5.0 Hz which is between the fundamental frequency of the... 

Perkins, D. M. et al., 1980, Probabilistic Estimates of Maximum Seismic Horizontal Ground Motion on Rock in The Pacific Northwest and the Adjacent Outer Continental Shelf, U.S. Geological Survey No.80-471. 

Work by the USBuMines in ground motion transmission (Ref 2) produced two particularly significant results for the typical charge weights and distances found in surface blasting 1) the constant m is equal to one-half of the constant n the power law equation then has only two unknowns and assumes the following form ... 

Damage Lavals from Ground Vibration as a Function of Peak Particle Velocity of Ground Motion Naar Structures (from Ref 4)... 

Multiple Threat Cratering Experiment. Vol II. Ground Motion in Rock , AFWL-TR-67-8-Vol 2, Air Force Weapons Lab, Kirtland AFB, NM (1967) 44) E.A. Nawrocki et al, Theoretical... 

Makris, N. Roussus, Y.S. 2000. Rocking response of rigid blocks under near-source ground motions. Geotechnigues 50 (3) pp. 242 -262. 

The procedures outlined in this chapter are static-force procedures, which assume that the entire seismic force due to ground motion is applied instantaneously. This assumption is conserv ative but greatly simplifies the calculation procedure. In reality earth quakes are time-dependent events and the full force is not realized instantaneously. The UBC allows, and in some cases requires, that a dynamic analysis be performed in lieu of the static force method. Although much more sophisticated, often the seismic loadings are retluced significantly. 

Seed, H.B., and Idriss, I.M. 1982. Ground motions and soU liquefaction during earthquakes. Monograph series. Earthquake Engineering Research Institute, Berkeley, CA. 

Using the quantified uncertainty obtained from Bayesian methods, there are two important types of applications. The first category is robust reliability analysis. Under severe earthquake excitations, buildings and bridges may exhibit significant nonlinear behavior. With a stochastic representation of the anticipated ground motions [96,130,237], one important reliability problem is to determine the first passage probability of some response quantities of interest in a... 

Application to Model Updating with Unmeasured Earthquake Ground Motion... 

Figure 4.11 Ten-story shear building subjected to earthquake ground motion...

Analysis with Strong Ground Motion Measurements 6.5.3.1 Description of the Database... 

Shi, S. and Shen, J. Study on ground motion attenuation relation in Shanghai and its adjacent region. Earthquake Research in China 18(2) (2004), 105-113. 

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