In the paper the roof of a tank storaged liquid is simplyfied as an end of a fixed shear beam with lumped mass. According to the principle of variants the intrinsic vibration type was found by the Heizi method,and the distribution of dynamic liquid pressure is calculated by the seismic spectrum theory.

Based on both the pseudo excitation approach and the Kanai Tajimi and Clough Penzien Spectrums, the acceleration transfer function for the structure with MTMD are formulated. The explicit expression for the acceleration dynamic magnification factor of the structure with MTMD, denoted by ADMF, is then derived.

Based on both the pseudo_excitation approach and the Kanai_Tajimi and Clough_Penzien Spectrums,the transfer function and corresponding dynamic magnification factor(DMF) for the structure with MTMD are formulated.

The results show that absolute values of P-wave spectral ratio slop are all more than 0.030 for the earthquake doublets with one event occurring 7 months before the Yao′an M_L6.5 earthquake and the other occurring outside that period,significantly higher then the earthquake doublets preceding the Yao′an earthquake by more than 7 months.

4. Earthquake response is part of the dynamic performance of the support system. This paper studied the systems earth quake response by inputting the earthquake wave into ANSYS according to the standard waves, and the influence of the earthquake on the support system is studied.

3. Transient and spectrum analysis of 4# pier was carried out on the base of the numerical simulation of underwater blasting. The rules of pier's displacement, velocity, acceleration and stress response were deduced. The relationship of blasting response with explosive mass and site properties was also analyzed.

Each building model has been subjected to a set of site-specific seismic spectrum compatible ground motion records, and the response has been determined using the proposed method and the general method for MDOF systems.

In considering the seismic spectrum, one of the methods to incorporate irregularity of fault motion statistically is to introduce the concept of coherency of fracture.

In a classic paper,Aki (1967) investigated the scaling law of seismic spectrum on the basis of a statistical model in which an exponentially decaying function is fitted to the autocorrelation function of the dislocation velocity.

We show that an analytical function of dislocation velocity gives the same autocorrelation function and the same seismic spectrum as those ofAki's model.

In conclusion, it is important to check the seismic spectrum to ensure that the assumed source model does not deviate too far from the desired one.

Estimation of seismic spectral acceleration in Peninsular India

As for the seismic spectral analysis, the frequency sampling was set to 15 samples per decade.

For Virginia, the area with the highest seismic spectral accelerations is the southwestern part of the state, where Bristol is located.

The dynamical analysis gives the harmonic forced and the seismic spectral responses.

Does any relation between microtremors and ground motion induced by the earthquake exist? And what is the relation like? There are different answers by different researches The Songpan earthquake in 1976 suppolied, the chance to discuss this problem. From the investigation of we come to the following conclusions: (1)Both the acceleration and the maximum amplitude of Fourier spectrum of gr, ound surface motion induced dy earth quake increase with the earthquake magnitude increasing; and both the amplitude of...

Does any relation between microtremors and ground motion induced by the earthquake exist? And what is the relation like? There are different answers by different researches The Songpan earthquake in 1976 suppolied, the chance to discuss this problem. From the investigation of we come to the following conclusions: (1)Both the acceleration and the maximum amplitude of Fourier spectrum of gr, ound surface motion induced dy earth quake increase with the earthquake magnitude increasing; and both the amplitude of microtremors and its Fourier spectra increase with the altitude of observation site and the thickness of alluvial stratum increasing. (2) The amplitude of microtremors and the surface motion induced by different series of earthquake in the same site appears to have certain direction. (3)The characteristics of the Fourier spectra of the same series of earthquake are exactly alike. (4)The old style wooden house of one storey does not affect the spectrum of microtremors, but the site condition obviously affects the Fourier spectrum of the microtremors of the wooden house.

In this paper the mode shapes and seismic response of a jack-up drilling rig are analysed. The structure of the jack-up is idealized as an assemblage composed of 3-D beam elements. The legs in the assemblage are considered as beams by means of the equivalent legs. The seismic spectrum curve in Reference [1] is used for calculating the seismic response. First, the lowest 5 eigenfrequencies and modes of the jack-up are solved, then the maximum displacement and stress responses are calculated by the spectrum analysis...

In this paper the mode shapes and seismic response of a jack-up drilling rig are analysed. The structure of the jack-up is idealized as an assemblage composed of 3-D beam elements. The legs in the assemblage are considered as beams by means of the equivalent legs. The seismic spectrum curve in Reference [1] is used for calculating the seismic response. First, the lowest 5 eigenfrequencies and modes of the jack-up are solved, then the maximum displacement and stress responses are calculated by the spectrum analysis method based on mode superposition method, and finally the results for both types of supports, in the water depth of 30m and 50m aregiven and compared.

In the paper the roof of a tank storaged liquid is simplyfied as an end of a fixed shear beam with lumped mass. According to the principle of variants the intrinsic vibration type was found by the Heizi method,and the distribution of dynamic liquid pressure is calculated by the seismic spectrum theory. The results show that the mass of tank roof gives less effect on the distribution and magnitude of dynamic liquid pressure.