Variation of Pore Water Pressure in Tailing Sand under Dynamic Loading

Abstract

Intense vibration affects the pore water pressure in a tailing dam, with the tendency to induce dam liquefaction. In this study, experiments were performed wherein model tailing dams were completely liquefied by sustained horizontal dynamic loading to determine the effects of the vibration frequency, vibration amplitude, and tailing density on the pore water pressure. The results revealed four stages in the increase of the tailing pore water pressure under dynamic loading, namely, a slow increase, a rapid increase, inducement of structural failure, and inducement of complete liquefaction. A lower frequency and smaller amplitude of the vibration were found to increase the time required to achieve a given pore water pressure in dense tailings. Under the effect of these three factors-vibration frequency and amplitude and tailing density-the tailing liquefaction time varied nonlinearly with the height from the base of the tailing dam, with an initial decrease followed by an increase. The pore pressure that induced structural failure also gradually decreased with increasing height. The increase in the tailing pore pressure could be described by an S-shaped model. A complementary multivariate nonlinear equation was also derived for predicting the tailing pore water pressure under dynamic loading.

Review of Research on Physical and Mechanical Properties and Engineering Application of Metal Tailings

“…Uniaxial compression test and triaxial shear laboratory are used to study the stability of tailings dams. The stability of tailings dams is also affected by the following factors such as permeability, capillary water, dry and wet cycles [29]. Unify these parameters into a model to describe the stability of tailings dams is one of the directions.…”

“…The discriminant method of seismic liquefaction is obtained by considering several different working conditions and analysing the results of two-dimensional seismic response analysis of tailing dam [30]. Based on the relationship between the anti-liquefaction degree and the pore pressure ratio, a simplified calculation formula for the excess pore pressure on the tailings dam is proposed [31], the calculation indicates that the area near the water's edge of the upstream slope is the easiest area to liquefy, followed by the initial dam. The length of the dry beach has a great influence on the seismic liquefaction stability of the tailings dam.…”

High Embankment Dam Stability Analysis Using Artificial Neural Networks

“…The pore water pressure response is fundamental for dam stability since its increase results in shear strength reduction, and can cause dam instability [6].…”

Experimental Investigation on the Behavior of Gravelly Sand Reinforced with Geogrid under Cyclic Loading

“…Sharma and Maheshwari [21] conducted cyclic triaxial tests on sands with different degrees of saturation and found that the damping ratio of saturated sand is greater than that of dry sand and partially saturated sand. Jin et al [22] studied the relative density on the dynamic pore pressure of tailing sand. It is believed that, for dense tailing sand, the growth rate of dynamic pore pressure decreases with the loading frequency and amplitude.…”