The simplified procedures for evaluation of the earthquake-induced displacement in earth and rockfill dams are widely used in practice. These methods are simple, inexpensive, and substantially less time consuming as compared to the complicated stress–deformation approaches. They are especially recommended to be used as a screening tool, to identify embankments with marginal factor of safety, assuming that these methods always give conservative estimates of settlements. However, recent studies show that application of these methods may not be conservative in some cases, especially when the tuning ratio of a dam is within a certain range. In this paper, the fundamental theory behind the simplified methods is critically reviewed. A case in which the results of the simplified methods are reportedly nonconservative is investigated in detail and possible reasons are discussed. The reliability of the simplified methods is examined here based on the existing thresholds proposed in the literature and accounting for the embankment geometry and type, and for the seismic activity characterization, and a practical framework is proposed accordingly. The effectiveness of this framework is evaluated in the study of seismic behaviour of a rockfill dam where all simplified procedures failed to predict the order of deformation experienced by the dam under a recent earthquake event.

This paper presents a bounding surface plasticity model that can be used to simulate complex monotonic and cyclic loading paths.A new mapping rule that only uses the last stress reversal point is introduced to describe the stress-strain behavior of granular soils during loading and unloading. This mapping rule is easy to implement and is suitable for highly erratic cyclic loading conditions, e.g., those induced by earth-quake or traffic loading. The application and performance of the model are demonstrated using the results of experimental tests with various stress paths conducted under both monotonic and cyclic loading conditions. The study shows the efficiency of the new mapping rule in cap-turing the characteristic features of the behavior of granular soils under various loading paths. Abstract: This paper presents a bounding surface plasticity model that can be used to 5 simulate complex monotonic and cyclic loading paths. A new mapping rule which only uses 6 the last stress reversal point is introduced to describe the stress-strain behaviour of granular 7 soils during loading and unloading. This mapping rule is easy to implement and is suitable for 8 highly erratic cyclic loading condition, e.g. those induced by earthquake or traffic loading. 9The application and performance of the model is demonstrated using the results of 10 experimental tests with various stress paths conducted under both monotonic and cyclic 11 loading conditions. The study shows the efficiency of the new mapping rule in capturing the 12 characteristic features of the behaviour of granular soils under various loading paths. 13

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Application of advanced bounding surface plasticity model in static and seismic analyses of Zipingpu Dam AbstractThe strong ground motion of the Wenchuan earthquake that hit the Zipingpu Dam in China in 2008 has provided an excellent benchmark to study the behaviour of large modern rockfill dams subjected to seismic loading. The performance of the dam during construction and prior to and after the earthquake loading has been recorded with good accuracy, and provides a reliable database to examine the reliability of available constitutive models and numerical methods in predicting the static and dynamic behaviour of embankment dams. In this paper, an advanced bounding surface plasticity model has been used in a series of numerical analyses to study the static and dynamic behaviour of Zipingpu Dam. The model can take into account particle breakage that may occur in monotonic and cyclic loading of rockfill materials. The material parameters required for the model are calibrated based on the results of available monotonic and cyclic triaxial tests. In the numerical procedure, the staged construction of the dam and the subsequent impounding of the reservoir are simulated, followed by dynamic loading. At each stage, the results of the numerical analysis are compared with in situ monitoring records of the dam. The results of the numerical simulation and the displacements measured after the earthquake are also compared with those estimated by two simplified engineering procedures that are routinely used in practice. The effectiveness and applicability of the simplified procedures to such a large dam subjected to an earthquake with a long duration is also discussed. procedures to such a large dam subjected to an earthquake with a long duration is also discussed.

This paper presents an analytical solution and numerical simulation of vacuum consolidation beneath a circular loading area (e.g. circular oil tanks or silos). The discrete system of vertical drains is substituted by continuous concentric rings of equivalent drain walls. The effectiveness of the vacuum as distributed along the drain length and the well resistance of the drains are considered. A rigorous solution of radial drainage towards cylindrical drain walls is presented and compared to numerical FEM predictions. The model is then successfully adopted to analyse the vacuum consolidation of a circular embankment in the Ballina field testing facility in Australia. Disciplines Engineering | Science and Technology Studies