Relationship between critical seismic acceleration coefficient and static factor of safety of 3D slopes

Many analytical methods have been adopted to estimate the slope stability by providing various stability numbers,e.g.static safety of factor(static FoS)or the critical seismic acceleration coefficient,while little attention has been given to the relationship between the slope stability numbers and the critical seismic acceleration coefficient.This study aims to investigate the relationship between the static FoS and the critical seismic acceleration coefficient of soil slopes in the framework of the upper-bound limit analysis.Based on the 3D rotational failure mechanism,the critical seismic acceleration coefficient using the pseudo-static method and the static FoS using the strength reduction technique are first determined.Then,the relationship between the static FoS and the critical seismic acceleration coefficient is presented under considering the slope angleβ,the frictional angleφ,and the dimensionless coefficients B/H and c/γH.Finally,a fitting formula between the static FoS and the critical seismic acceleration coefficient is proposed and validated by analytical and numerical results.

Study on Critical Slowing Down Phenomenon before the Two Medium-strong Earthquakes in Xinjiang

We study the critical slowing down phenomenon in deformation and groundwater observations before the Nilka-Gongliu MS6. 0 earthquake on November 1, 2011 and Xinyuan-Hejing M S6. 6 earthquake on June 30,2012. Firstly,we remove the annual variation and tendency change of basic data by means of wavelet transform analysis.Secondly,we calculate the autocorrelation coefficients and variance of the critical slowing down phenomenon. Lastly,we try to verify the critical slowing down phenomenon before an earthquake. The result indicates that there was obvious critical slowing down of the records at different stations before earthquakes.

Effect of surfactant type on interfacial area and liquid mass transfer for CO_2 absorption in a bubble column

The effect of different surfactants(n-octyltrimethylammonium bromide(OTABr),sodium dodecyl benzene sulfonate(SDBS) and Tween 80) with different critical micelle concentrations(CMC) on the CO_2 absorption into aqueous solutions in a bubble column is analyzed in the present work.The presence of these surfactants increased the gas-liquid interfacial area,and decreased the liquid phase mass transfer coefficient,but with significant different extent.The results indicated that the CMC can be a key parameter affecting the mass transfer of CO_2 absorption into a dilute aqueous solution of a surfactant.Sardeing's model was used to fit the experimental data successfully by re-correlating the parameters.

Bifurcations of a discrete-time SIR epidemic model with logistic growth of the susceptible individuals

This study focuses on the stability and local bifurcations of a discrete-time SIR epidemic model with logistic growth of the susceptible individuals analytically,and numerically.The analytical results are obtained using thenormal form technique and numerical results are obtained using the numerical continuation method.For this model,a number of bifurcations are studied,including the transcritical(pitchfork)and fip bifurcations,the Neimark-Sacker(NS)bifurcations,and the strong resonance bifurcations.We especially determine the dynamical behaviors of the model for higher iterations up to fourth-order.Numerical simulation is employed to present a closed invariant curve emerging about an NS point,and its breaking down to several closed invariant curves and eventuality giving rise to a chaotic strange attractor by increasing the bifurcation parameter.