Seismic Table Test Research Articles

Numerical simulations of seismic and post-seismic behavior of tailings

Several tailings impoundments have failed as a result of earthquakes in the last few decades. A majority of these failures were due to direct seismic loading, tailings liquefaction during shaking, or the post-seismic behavior of the tailings as it relates to the dissipation of excess pore-water pressures that were generated during shaking. Previous work has indicated that the UBCSAND model developed by Byrne et al. in 1995 is capable of simulating the cyclic simple shear testing response of low-plasticity tailings over a range of consolidation stresses and cyclic shear ratios. However, the ability of the model to simulate the dynamic and subsequent behavior of such tailings for other conditions, such those induced by shaking table tests, has not yet been evaluated. In this regard, previous work has shown that the main components of the UBCSAND model cannot realistically simulate some specific responses, including the post-seismic volumetric strains related to excess pore-water pressure dissipation. This paper presents numerical modeling results of the dynamic behavior of tailings from hard rock mines. It introduces a method for simulating their post-seismic behavior by including an updating scheme for the elastic moduli into the UBCSAND model. The results of cyclic simple shear testing, seismic table testing, and complementary experimental relationships were used to calibrate and validate the model with its new component. The simulated response of tailings during cyclic simple shear testing and for a complete seismic table test shows that the proposed approach simulates the experimental observations well. Level-ground, seismically induced liquefaction and post-seismic behavior of a 15 m thick tailings deposit are also simulated, leading to post-liquefaction settlements that are in agreement with empirical relationships.

Experimental and Numerical Simulation Investigation on Dynamic Response of Liquid Storage Tanks under Seismic Excitations

A large-scale earthquake simulation experiment about the unanchored cylindrical steel liquid storage model tanks has been completed. The self-vibration characteristics of the model tanks with liquid inside were investigated based on the experimental data of the acceleration dynamic response. The seismic table test, the analysis methods are designed and conducted, and experimental results of the model tanks were carefully measured. Furthermore, ANSYS finite element software was used to simulate and calculate the low order natural frequency and fundamental frequency of the model tank systems according to the national design standard. The reasons for the existence of consistency and differences between the results obtained from experiments and numerical simulation were discussed.

Dynamic Experimental Investigation on the Fundamental Frequency of Liquid Storage Tanks under Seismic Excitations

A large-scale earthquake simulation experiment about the unanchored cylindrical steel liquid storage model tanks has been completed. The fundamental frequency of the model tank with liquid inside was investigated based on the experimental data of the acceleration dynamic response. The seismic table test, the analysis methods are designed and conducted, and experimental results of the model tank were carefully measured. Furthermore, national design standard was used to calculate the fundamental frequency of the model tank system. The reasons for the existence of consistency and differences between the results obtained from experiments and national design standard were discussed.

Dynamic experimental investigation on the uplift response of liquid storage tanks under seismic excitations with different characteristics

A series of seismic table tests about the large steel cylindrical liquid storage tank models with floating roof were taken in this study. Horizontal and vertical direction seismic excitations were input respectively to the experimental structure system under different working conditions to test and analyze the seismic response behavior. The effects of various factors, such as the liquid surface height, the floating roof, the different wave amplitudes and frequencies, as well as their combined effects on the seismic dynamic response were obtained. The absolute displacement and the uplift response behavior law of the test models were obtained under different conditions. It was concluded that not only uplift value but also the absolute displacement of the tank bottom should be considered. And it should be noticed that a critical input frequency exists during the model response changing with frequency. In addition, important factors in experiment were described systematically in this article, for example, the experimental equipment selection, the experimental method, the tank model design, the laser displacement sensors, the data acquisition, the measurement point layout method, seismic excitation input method and so on. A reliable basis could be provided for theoretical analysis, structural design and computer numerical simulation research through this investigation.