Variation Of Pore Water Pressure Research Articles

Design and Development of an In-Flight Actuator for Modeling Dynamic Compaction in a Geotechnical Centrifuge

Abstract The objective of this article is to present the design details and performance of an in-flight actuator for simulating dynamic compaction (DC) at enhanced gravities in a geotechnical centrifuge. The developed actuator is equipped with an automatized lifting and dropping mechanism to induce repeated impacts on the soil surface at high gravities, with prototype energies varying from 50 to 400 t-m. In addition, the developed actuator encompasses a wide range of tamper shapes, tamper diameter, and mass coupled with variable drop heights during centrifuge testing, thereby simulating both low-energy impacts and high-energy DC processes adopted in the field. The various components and working mechanism of the developed actuator are discussed, with particular emphasis on measures taken for ensuring vertical alignment of tamper and for minimizing Coriolis acceleration generated during flight. In this article, the results of four calibration tests and four centrifuge model tests of DC on a typical loose granular deposit are discussed, conducted in a 4.5-m radius large beam centrifuge facility available at IIT Bombay, India. The calibration results indicate that the impact frequency can be regulated remotely by controlling the motor voltage to enable monitoring of pore water pressure build-up in saturated soils during impact and its subsequent dissipation. The average time interval between successive impacts, in this case, is observed to be uniform and approximately 1.4–2.3 min in prototype dimensions. Further, the analysis of data captured by pore water pressure transducers and accelerometers, coupled with GeoPIV-based image analysis, was employed to demonstrate the effectiveness of DC in granular soils using the developed actuator for various tamper energies and saturation levels. The results are interpreted in terms of pore water pressure variations during impacts, crater formations, surface settlements, induced ground velocities and peak accelerations, and increases in relative density of the soil after DC.

Numerical-probabilistic modeling of the liquefaction-induced free fields settlement

Liquefaction is a phenomenon through which saturated sandy soil loses its shear strength and turns into a liquefied state. One of the most detrimental consequences of liquefaction is the reconsolidation volumetric settlements after the earthquakes, which is due to the dissipation of excess pore pressure caused by earthquakes. Severe floods can follow these settlements in free fields such as grounds close to the sea or rivers. Several researchers studied this phenomenon using data obtained from experiments in the lab or observations in the fields. Previous works were mainly based on a limited number of experimental observations and considered loadings and boundary conditions that were different from reality in the field. In actual field cases, loading does not occur in fully undrained conditions, and earthquake excitations do not comply with load application limitations on the laboratory samples. Accurate simulation of liquefaction-induced settlement phenomenon requires using fully coupled hydro-mechanical numerical analysis. In the current study, a Numerical-Probabilistic framework is proposed to estimate the liquefaction-induced settlement of the fully saturated sandy layers in the free field subjected to earthquake excitations. A fully coupled (u-P) formulation is employed to analyze soil deformations and pore water pressure variations in order to assess the soil volumetric strains and settlement. The main advantage of the current work is considering the probabilistic nature of the phenomenon and providing insight into the prediction uncertainties. Additionally, it uses a comprehensive database obtained from extensive numerical analyses. Based on the obtained settlements from the numerical analyses, a new method is proposed that predicts the post-earthquake settlement using the Bayesian linear regression method. The proposed method predicts the free field liquefaction-induced settlement in a confidence interval with high accuracy, which is validated by comparing the current work results with the observed liquefaction-induced settlements in the field case studies.

Lime-cement columns with PVDs for embankment on soft consolidating soil

The effectiveness of providing lime-cement (LC) columns along with Prefabricated Vertical Drains (PVDs) on the stability of embankment constructed on soft consolidation soil is investigated. Providing LC columns or PVDs separately or combining LC columns with PVDs is compared. Two-dimensional plane strain finite element method is used for the analysis. The parameters considered for the study are the variation of settlement and excess pore water pressure at various time intervals during the consolidation of foundation soil. From this study, it is concluded that, LC columns along with PVDs are the most effective technique compared to providing LC columns or PVDs separately to reduce both the displacement and excess pore water pressure for the embankment constructed on soft consolidating soil.

Experimental Study on the Sand of Bandar-e Anzali Using Shaking Table

Due to the economic and tourist importance of Bandar-e Anzali coastal zone and also the high seismic risk in this area, this article provides an experimental seismic study using shaking table test on the sandy soil of Bandar-e Anzali. Modeling the laboratory conditions and applying seismic forces were carried out using a transparent tank on a shaking. Additionally, digital instrumentations of horizontal displacement transducers, pore water pressure gauge and data entry device via computer were used. In this study, data collection was conducted by creating saturated samples with relative densities of 20%, 30% and 50% and accelerations of 0.15 g, 0.3 g and 0.53 g and the variation of pore water pressure, horizontal displacement and settlements were measured. The results indicate the high effect of input acceleration on the occurrence of liquefaction and amount of the settlements, especially in low relative density. The effect of higher density on reducing the liquefaction potential and settlement is also significant.

Grain Configuration Effect on Pore Water Pressure in Debris Flow

The generation and development of excess pore water pressure directly affects the grain interaction in debris flow, which can significantly reduce the friction strength and promote the movement of debris flow. It has been found that coarse grains favor the increase in excess pore water pressure, but the effect due to grain configuration is missing in studies. In order to study the influence of grain configuration, field investigations and laboratory tests were carried out for two typical cases, i.e., flow with coarse grains evenly mixed (case I) and flow with coarse grains floating on the surface (case II). The results show that case II generates much higher excess pore water pressure than case I. The variation of relative excess pore water pressure (Ur) with time (t) satisfies the power function relationship: Ur = mt–n. Case II often has a smaller n value, meaning a low dissipation rate of excess pore water pressure. This study is helpful for a better understanding of granular effects in debris flow.

Resonance vibration approach in soil densification: laboratory experiences and numerical simulation

This paper describes the improvement effect and mechanism of strengthening a liquefied sand foundation using the cross-vibration wing resonance method, through an indoor model test and numerical simulation. The results obtained from the model test showed that a vertical drainage tube was formed during vibration compaction, and finally a crater with a depth of 40 mm and a radius of 150 mm was formed with sloping sides. The sand layer obtained a good improvement effect after resonance vibration, especially in the middle-lower sand deposit. The variation in excess pore water pressure showed different behavior in three stages of the vibration process, and the value after treatment was less than before with a decrease of 18.81%. The vibration energy in the horizontal direction gradually decreased to zero, however the absorption of vibration energy of the soil presented obvious nonuniformity along the depth direction. The results of the numerical simulation were similar to the model test results, including the scope and variation of pore water pressure, and the ground settlement after treatment.

Influence of Water Retention Curves Model Fitting Parameters on Unsaturated Seepage Modeling of Fly Ashes and Pond Ashes

Water retention curves (WRC) and its fitting parameters are important inputs for conducting unsaturated seepage modeling study in any geotechnical and geo-environmental problems. This study investigated the effect of variation in WRC model fitting parameters on unsaturated seepage modeling behavior for different types of fly ashes and pond ash. A transient seepage analysis was carried out in a one-dimensional cylindrical column using a finite element method-based software SEEP/W, under a specified total head (H) boundary condition. The variation in pore water pressure (PWP) and volumetric water content (VWC) with time was studied for different conditions. It was found that both PWP and VWC variation with time got affected when WRC model fitting parameters of different fly ashes were used. The influence of suction measurement range on unsaturated seepage modeling result was also found to be considerable. It was established from this study that variation in PWP with time for different fly ashes was mainly due to the variation in the WRC model fitting parameters since the saturated hydraulic conductivity (ksat) value of all the fly ashes was comparable. Further, the sensitivity of Fredlund and Xing (Can Geotech J 31(3): 521–532, 1994) model parameters was studied in detail based on their standard deviations. The study showed that sensitivity on seepage modeling results drastically reduces beyond 20% variation from the reference mean value.

Experimental study of the evolution of pore water pressure and total stresses during and after the deposition of slurried backfill

Mining backfill is increasingly used in underground mines to fill stopes. Its successful application depends on the stability of barricades built to retain the backfill in stopes. The design of barricades requires a good estimation of pore water pressure (PWP) and total stresses during and after the deposition. On this regard, a large number of works have been published on analytical and numerical solutions. There are however very few experimental results with simultaneous measurements of PWP as well as horizontal and vertical total stresses that can be used to validate or calibrate the analytical and numerical solutions. For a specific project, field measurements are interesting in terms of representativeness to field conditions, but the results are very difficult to be correctly interpreted because the treated problem can involve a large number of uncertainties and the obtained results are due to combined effects of several influencing factors. Laboratory tests with simplified and well-controlled conditions are thus preferred. Until now, however, the most previous laboratory tests were conducted with dry backfill or with a tailings slurry instantaneously poured in a confining structure without simultaneous measurements of PWP as well as horizontal and vertical total stresses. Studies on the effects of filling rate and solid content of backfill on the variation of PWP and total stresses during the filling operation are absent. To fill these gaps, a series of column backfilling tests were conducted with simultaneous measurements of PWP as well as vertical and horizontal total stresses during and after the deposition of slurried backfill. When the filling rate is high, the test results showed that the PWP, horizontal and vertical total stresses increase at the same rate and equal to the iso-geostatic overburden pressure during the deposition of backfill slurry. Their peak values appear at the end of deposition. The backfill thus behaves like a liquid with little generation of effective stresses during the deposition. High filling rate and/or high solid content lead to high PWP and horizontal total stresses at the end of deposition. When the filling rate is small, the PWP and total stresses exhibit also peak values at the end of filling operation, but the vertical total stress at the center can continue increasing with time after the end of deposition due to the suspended sensor and occurrence of a phenomenon known as stress shielding effect. The results also showed that the settlement of settled backfill after the end of slurry deposition can generally exhibits a fast evolution rate stage, followed by a slow evolution rate stage. The duration of the fast evolution rate stage and the final settlement of the settled backfill increase as the solid content decreases. The final settlement after the end of slurry deposition is related to the solid content, not to the filling rate.

Effect of Rainfall Pattern and Crack on the Stability of a Red Bed Slope: A Case Study in Yunnan Province

Red bed slopes in the southwest of China are associated with a grant number of geological hazards, such as landslides, mud‐rock flows, and rock blocks falling, which are vital problems in geotechnical engineering. The damage can be induced or triggered due to a series of human and environmental activities, such as excavation, concentrated or long‐term rainfall, earthquake, and fluctuation of groundwater level. According to the field observations and geological exploration results, a small‐scale landslide was observed on January 10, 2016, after excavation along XiaoMo highway in Yunnan Province. A numerical model in actual size using GeoStudio software based on this typical red bed engineering slope was established in this study. Back analyses and laboratory tests were used to obtain the mechanical parameters of the geomaterial inside the slope. The historic rainfall data of Mengla County from July to September in 2016 was utilized as the flux boundary in analyzing the seepage variation features and the stability of the engineering slope in the rainy season. One major tension crack was set in the shallow region of the silty clay according to the geology survey to perform the disturbance of excavation on the geomorphology of the slope. Attempts were made to establish the anisotropic permeability of the crack induced by the complex fillings, and differences in the hydraulic response between the cracking and completed slope during the rainfall process were discussed. The result shows that the factor of safety of the slope without crack before the rainfall is 1.076, and the slope is considered in the state of the critical limit equilibrium, which is in accordance with the previous state of the slope under real conditions. The pore water pressure variations of the monitor points in the shallow region of the completed slope present close compliance with the rainfall intensity subjected to different rainfall patterns, which also controls the distribution of the plastic zone in the slope after rainfall. The comparisons in the seepage field and plastic zone between the cracking and completed slope reveal that the crack can shorten the infiltration path effectively, and the higher the permeability coefficient in the vertical direction is, the larger the pore water pressure increasing zone is and the higher the underground water level is, which should be paid more attention in highway constructions.

The alterations of critical pore water pressure and micro-cracking morphology with near-wellbore fractures in hydraulic fracturing of shale reservoirs

The crack initiation and propagation in a laminated shale formation have been widely investigated, but the alterations of critical pore water pressure (including fracture initiation pressure and breakdown pressure) and the micro-cracking morphology with near-wellbore fracture geometry are still unclear. This paper numerically investigates the alterations of critical pore water pressure and the morphology of the hydraulic fractures in shale formation with different near-wellbore fractures. First, a hydro-fracturing model is developed for a laminated shale formation within the framework of PFC2D. Then, this model is validated with the Blanton’s criterion, pressure history and fracture geometry. Finally, the effects of length, shape, and symmetry properties of near-wellbore fractures on the critical pore water pressure and micro-cracking morphology are comparatively investigated. The critical pore water pressure, micro-cracking morphology, aperture and permeability, and the fractal dimension of hydraulic fractures are quantitatively analyzed at three initial near-wellbore fractures. Simulation results indicate that the length and the distribution of near-wellbore fracture branches play a crucial role in pore water pressure variation and micro-crack propagation during hydraulic fracturing. The critical pore water pressure is sensitive to the initial near-wellbore fracture length especially when the initial fracture length exceeds a critical fracture length. The shape of initial near-wellbore fracture could change the distribution of micro cracks and induce large pore water pressure. The symmetrical radial fracture (θ=0°) more likely causes a hydraulic fracture with high permeability while the X-shape fracture (θ=30°) contributes greatly to the complexity of the fracture network and stimulated reservoir volume. These findings on the pore water pressure variation and the micro-cracking morphology are helpful in the optimization design of hydraulic fracturing treatment.

Liquefaction resistance behaviours of gravel steel slag

Due to the continuous scarcity of sand and gravel under environmental protection policies, a new geo-backfill material with the good liquefaction resistance is urgently needed. Steel slag is a kind of industrial solid waste. The aged eight-month steel slag usually could be used as backfill material. It is important to investigate the liquefaction resistance behaviours of steel slag. According to the soil classification method, the waste steel slag is also divided into gravel steel slag, coarse steel slag and fine steel slag. Dynamic triaxial tests were carried out to investigate the liquefaction resistance of gravel steel slag in the paper by considering the effects of consolidation stress ratio, loading frequency, confining pressure and gravel-size particle contents. The variations of pore water pressure and cyclic shear resistance were analysed. The calculation model of pore water pressure of saturated sand proposed by Seed and Finn could be applied to analyse the dynamic pore water pressure development of gravel steel slag. Compared with conventional soils, the cyclic liquefaction resistance of gravel steel slag is better than that of fine sand, gravel soil, sand-gravel soils and sand pebbles. Gravel steel slag can be used to replace some conventional cohesionless soils as a geo-backfill material.

The Effect of Lightweight Expanded Clay Aggregate on the Mitigation of Liquefaction in Shaking Table

Non-conventional materials are often applied to dissipate the energy of dynamic loads and mitigate liquefaction. In this study, the effect of Lightweight Expanded Clay Aggregate (LECA) on the mitigation of liquefaction was examined using shaking table tests. LECA, a common lightweight material, was added to saturated sand in a range of 0–20% to study the variation of excess pore water pressure (EPWP) generation, as well as the acceleration response of the soil. Based on the obtained results, the addition of 5% and 10% LECA to saturated sand resulted in a significant decrease in the generation of EPWP, while higher LECA content led to an increase in the generation of EPWP. The mechanisms behind such behaviors contradict the effects of increasing the damping of the soil mixture and reducing the effective initial stress as a function of overall mixture density. Adding 5 and 10% LECA reduces EPWP because aggregates accelerate the dissipation of EPWP during and after vibration. As the percentage of LECA increases by 15% and 20%, excess pore pressure ratio increases. The cause of this may be the reduction of effective initial stress leading to reduced soil density in higher-LECA contents. 10% LECA is presented as the threshold for changing the liquefaction behavior of sand-LECA mixtures. This study concludes that adding LECA to sand samples increases the rate of dissipation of EPWP, but also leads to a significant decrease in initial effective stress.

Experimental study on the mechanical properties of Guiyang red clay considering the meso micro damage mechanism and stress path

This study investigated the macroscopic physical and mechanical properties of Guiyang red clay during surcharge loading, lateral excavation and lateral unloading with axial loading, and clarified the failure mechanism of microstructure before and after shear under different stress paths of CTC, RTC and TC. Consolidated undrained triaxial shear permeability, SEM scanning, XRF fluorescence spectrum analysis and XRD diffraction tests were conducted to simulate the actual engineering conditions. The stress–strain curve, shear strength, pore water pressure variation rule and macroscopic failure mode of soil samples under different stress paths were analysed. In addition, Image Pro Plus 6.0 and PCAS were used to study the relationship between the macro mechanical properties and micro microstructure failure under different stress paths. The stress–strain curves from CTC, RTC and TC in CU tests were different, with the peak values of shear stress under the three stress paths being P-increasing, equal P-path and P-decreasing path. Moreover, the internal friction angle and cohesion of the increasing P path were higher than those of equal P path and decreasing P path, hence, the influence of stress paths on the cohesion is greater than that of internal friction angle. The pore water pressure is strongly dependent on the stress path, and the variation characteristics of pore water pressure are consistent with the change in the law of the stress–strain curve. Under the same confining pressure in the P-increasing path, the shear failure zone runs through the whole soil sample, and the shear failure zone is significant, whereas under the condition of the P-reducing path, the shear failure angle of soil sample is about 65°, 55° and 45°, and in the equal P path, the soil sample is dominated by the confining pressure, with no obvious microcrack on the surface of the soil sample. The difference is that the distribution of pores in the path of increasing P and equal P is directional, and the anisotropy rate is small, while the distribution of pores in soil samples with shear failure and before shear is random and the anisotropy rate is high.

Excess pore water pressure caused by the installation of jet grouting columns in clay

Abstract The injection of large volumes of pressurized water and grout into the subsoil during jet grouting generates a sudden increase in excess pore water pressure. This study proposes a theoretical approach to evaluate the variation in excess pore water pressure caused by the installation of a jet grouting column in clay, accounting for the chronological sequence of construction. The jet grouting column installation is simulated through the undrained expansion of a series of spherical cavities. Partial dissipation during the construction process is considered due to the gradual installation of the grouting columns. The relationship between the ultimate cavity radius (au) and the radius of the jet grouting column (rc) is established to represent the influences of both jetting parameters and soil properties on the generated excess pore water pressure. The proposed model is validated using two case studies, one conducted in Singapore marine clay and the other in Shanghai soft clay.

Field Test of Excess Pore Water Pressure at Pile-Soil Interface Caused by PHC Pipe Pile Penetration Based on Silicon Piezoresistive Sensor.

Prestressed high-strength concrete (PHC) pipe pile with the static press-in method has been widely used in recent years. The generation and dissipation of excess pore water pressure at the pile–soil interface during pile jacking have an important influence on the pile’s mechanical characteristics and bearing capacity. In addition, this can cause uncontrolled concrete damage. Monitoring the change in excess pore water pressure at the pile–soil interface during pile jacking is a plan that many researchers hope to implement. In this paper, field tests of two full-footjacked piles were carried out in a viscous soil foundation, the laws of generation and dissipation of excess pore water pressure at the pile–soil interface during pile jacking were monitored in real time, and the laws of variation in excess pore water pressure at the pile–soil interface with the burial depth and time were analyzed. As can be seen from the test results, the excess pore water pressure at the pile–soil interface increased to the peak and then began to decline, but the excess pore water pressure after the decline was still relatively large. Test pile S1 decreased from 201.4 to 86.3 kPa, while test pile S2 decreased from 374.1 to 114.3 kPa after pile jacking. The excess pore water pressure at the pile–soil interface rose first at the initial stage of consolidation and dissipated only after the hydraulic gradient between the pile–soil interface and the soil surrounding the pile disappeared. The dissipation degree of excess pore water pressure reached about 75–85%. The excess pore water pressure at the pile–soil interface increased with the increase in buried depth and finally tended to stabilize.

Assessment of post-failure evolution of a large earthflow through field monitoring and numerical modelling

The analysis of the residual hazard existing after the emergency phases generated by the activation or reactivation of landslides is rarely taken into account in a proper manner. However, the assessment of landslide post-failure evolution should represent a key factor to control potential landslide reactivations and prevent new landslide-induced damages. This paper presents the results of a long-term field monitoring activity performed in the years after the emergency phase of the Montaguto (Italy) earthflow reactivation occurred in 2010 as well as the results of 2-D and 3-D numerical analyses aimed at interpreting the post-emergency landslide behaviour. The results of the numerical simulations, which agree well with the in situ monitoring data, allow to define a conceptual model of the earthflow behaviour that is related to the pore water pressure variations resulting from the drained or undrained processes occurring in the landslide body. The study proposed confirms a general reduction of the landslide activity, as well as allows to detect the factors that control the residual activity existing in a specific area of the landslide and to infer possible critical scenarios for landslide reactivations.

Machine learning for pore-water pressure time-series prediction: Application of recurrent neural networks

Knowledge of pore-water pressure (PWP) variation is fundamental for slope stability. A precise prediction of PWP is difficult due to complex physical mechanisms and in situ natural variability. To explore the applicability and advantages of recurrent neural networks (RNNs) on PWP prediction, three variants of RNNs, i.e., standard RNN, long short-term memory (LSTM) and gated recurrent unit (GRU) are adopted and compared with a traditional static artificial neural network (ANN), i.e., multi-layer perceptron (MLP). Measurements of rainfall and PWP of representative piezometers from a fully instrumented natural slope in Hong Kong are used to establish the prediction models. The coefficient of determination (R2) and root mean square error (RMSE) are used for model evaluations. The influence of input time series length on the model performance is investigated. The results reveal that MLP can provide acceptable performance but is not robust. The uncertainty bounds of RMSE of the MLP model range from 0.24 ​kPa to 1.12 ​kPa for the selected two piezometers. The standard RNN can perform better but the robustness is slightly affected when there are significant time lags between PWP changes and rainfall. The GRU and LSTM models can provide more precise and robust predictions than the standard RNN. The effects of the hidden layer structure and the dropout technique are investigated. The single-layer GRU is accurate enough for PWP prediction, whereas a double-layer GRU brings extra time cost with little accuracy improvement. The dropout technique is essential to overfitting prevention and improvement of accuracy.

Physical modeling of combined waves and current propagating around a partially embedded monopile in a porous seabed

In this paper, a series of experimental data for wave (current)-induced pore-water pressure around a partially embedded monopile is presented. Unlike the previous studies, the combined action of waves and currents is studied. The partially embedded monopile is considered. The variations of pore-water pressures around the monopile in time and space are investigated by wave flume experiments. The experimental results indicate that the hydrodynamic response and the seabed response caused by the combined action of waves and currents are significantly different from those caused by wave load. When the following current is superimposed on the wave, the wave profile on the lateral side, rather than on the front, of the monopile fluctuates first, and the wave trough of the incident wave becomes small and gentle. Moreover, it was found that the amplitudes of pore-water pressures increase, while the attenuation of pore-water pressures slows down under the large wave energy with a large current. It was further found that the existence of a current has a significant effect on the pore-water pressure at z∕h = -0.3 on the front side and on the pore-water pressure at z∕h = -0.15 on the back side of the monopile. Additionally, the influence of the current on the vertical and horizontal distributions of pore-water pressures is related to the wave height.

Effects of Two-Phase Flow of Water and Air on Shallow Slope Failures Induced by Rainfall: Insights from Slope Stability Assessment at a Regional Scale

Over 160 shallow landslides resulted from heavy rainfall that occurred in 26–27 July 2011 at Umyeon Mountain, Seoul, South Korea. To accurately reflect the fluid flow mechanism in the void spaces of soils, we considered the two-phase flow of water and air for rainfall infiltration analysis using available historical rainfall data, topographic maps, and geotechnical/hydrological properties. Variations in pore water and air pressure from the infiltration analysis are used for slope stability assessment. By comparing the results from numerical models applying single- and two-phase flow models, we observed that air flow changes the rate of increase in pore water pressure, influencing the safety factor on slopes with a low infiltration capacity, where ponding is more likely to occur during heavy rainfall. Finally, several slope failure assessments were conducted to evaluate the usefulness of using the two-phase flow model in forecasting slope stability in conditions of increased rainfall sums. We observed that the two-phase flow model reduces the tendency of over-prediction compared to the single-phase model. The results from the two-phase flow model revealed good agreement with actual landslide events.

Liquefaction Potential Assessment of Brahmaputra Sand Based on Regular and Irregular Excitations Using Stress-Controlled Cyclic Triaxial Test

The response of saturated soil during earthquakes is governed by many factors such as frequency content, strain, stress, excess pore-water pressure and strength variations within the soil mass. This paper highlights the effect of strains on the stiffness modulus and its degradation at the liquefied condition of cohesionless soil. Cyclic triaxial (CT) tests, in stress-controlled manner, were carried out on saturated sandy soil specimens made at different relative density (Dr = 30%–90%) and effective stress (σ′c = 50–200 kPa). The reconstituted specimens were subjected to regular and irregular stress histories. Representative strong motions with varying PGA were chosen, and the corresponding irregular stress histories were used. Additionally, regular stress histories constituted from different cyclic stress amplitudes were also used. The responses of the saturated specimen were obtained in terms of the excess pore-water pressure generation and strain accumulation with elapsed time. In comparison to the standard frequency and duration parameters (namely the predominant period and significant durations), it is observed that the responses are more influenced by Arias intensity and specific energy density of the strong motion. Based on the increase in pore-water pressure, reduction in shear modulus and increase in shear strain within the specimens, the complete manifestation of liquefaction is divided in four zones, namely the no liquefaction zone, quasi-liquefaction zone, zone marking the onset of liquefaction and the completely liquefied zone. The criteria for the onset of liquefaction of Brahmaputra sand involving shear strain, peak ground acceleration and cyclic stress ratio are provided.