Increase In Pore Water Pressure Research Articles

Pervious Concrete Utilized as a Base Slab of Pavement Edge Drains

The drainage base plate is generally made of normal concrete. The application of pervious concrete as base-slab of pavement edge drain will then be possible to infiltrate storm water runoff on the pavement surface that is not infiltrated through the pavement surface. The edge drain does not only accommodate storm water flow, but also transmits water to the ground so that it can restore the ground water level or can be reused through a reservoir in the ground underneath. The effectiveness of the application of pervious concrete as a drainage base plate on silt-clay soils was conducted experimentally. The thickness of the porous concrete slab in the modeling box is 7 cm, laid above 20 cm height of silty clay soil layer. Reference soil conditions as well as contours and cross-sectional characteristics of the edge drain are taken based on the condition of one of the existing drainages in West Bandung. Based on the results of numerical simulations using Geostudio SEEP/W, it can be seen that there is an increase in pore water pressure in the area of the pervious concrete slab and the surrounding soil. The pore water pressure at the bottom of the plate is in the range of 18.64 kPa. Overall, the pore water pressure in the first modeling tends to be higher than in the second modeling. On the third day of testing, the difference in pore water pressure between the two modeling conditions is 27.08%.

Seismic Response of Utility Tunnels with Different Burial Depths at the Non-Homogeneous Liquefiable Site

Damage to underground structures induced by soil liquefaction under cyclic loads such as earthquakes has long been an important issue in underground engineering practice. In this paper, five models are developed using Flac3D software to analyze the effect of burial depth on the force, deformation characteristics, and uplift behavior of utility tunnels in the non-homogeneous site containing a liquefied layer. The cyclic shear property of saturated sand and the increase in pore water pressure during the earthquake are modeled using a cyclic load-volume strain increment model, using Shell-Type structural elements to model underground utility tunnels, and by using plastic hinges to represent the bending moment capacity of member’s joints. Numerical results show that for shallow-buried utility tunnels, increasing the burial depth increases the bending moment, shear force, and deformation of the structure while significantly reducing its uplift. Therefore, for high-strength shallow-buried utility tunnels, appropriate increase in burial depth can improve its seismic safety.

Rheological Behaviors and Damage Mechanism of Asphalt Binder under the Erosion of Dynamic Pore Water Pressure Environment.

Asphalt binder plays an important role in the overall resistance of asphalt mixture to the moisture damage induced by a dynamic pore water pressure environment. This study evaluates the moisture sensitivity of asphalt binder from the perspective of rheological behaviors using the dynamic shear rheometer (DSR) and the bending beam rheometer (BBR) methods at high, medium, and low temperatures. The damage mechanism is further discussed quantitatively based on the Fourier transform infrared spectroscopy (FTIR) method. The results indicate that a longer conditioning duration is beneficial for asphalt binder to recover its adhesion at 60 °C in multiple stress creep recover (MSCR) tests, but the increasing pore water pressure magnitude of 60 psi held an opposite effect in this study. The asphalt binder's fatigue life at 20 °C in linear amplitude sweep (LAS) tests decreased obviously with conditioning duration and environmental severity, but the reducing rate gradually slowed down, while the groups of 50 psi-4000 cycles and 60 psi-4000 cycles held a comparable erosion effect. Both the stiffness and relaxation moduli at -12 °C in the BBR tests exhibited an obvious decreasing trend with conditioning duration and environmental severity. The erosion effect on the asphalt binder was gradually enhanced, but it also exhibited a slightly more viscous performance. Water conditioning induced several obvious characteristic peaks in the FTIR absorbance spectra of the asphalt binder. The functional group indexes presented a trend of non-monotonic change with conditioning duration and environmental severity, which made the asphalt binder show complicated rheological behaviors, such as non-monotonic variations in performance and the abnormal improving effect induced by dynamic pore water pressure conditioning.

STRATA SUBSIDENCE CHARACTERISTICS OF SHIELD TUNNELING IN COASTAL SOFT SOIL AREA

In order to study the subsidence characteristics caused by large diameter shield tunneling in coastal soft soil area, based on the project of North Oujiang shield tunnel in Wenzhou City, the displacement field, seepage field and stress field of surrounding rock during shield tunnel construction process under fluid-solid coupling were analyzed by using finite difference method. The results show that when the shield tunneling passes through the monitoring section of the tunnel, the surrounding rock in a certain range of this section above the tunnel will be uplifted. Shield tail grouting can effectively control the settlement of the ground, and the increasing range of the ground subsidence gradually decreases. With the advance of the shield the pore water pressure increases, and the pore water pressure in the soil layer will rise sharply due to the shield tail grouting. When the shield passes through the monitoring section of the tunnel, the strata stress above the tunnel increases due to uplift extrusion, and the strata stress below the tunnel decreases due to stress releasing. When the grouting at the tail of the shield is completed and gradually moves away from the monitoring section, the stress releasing results in the decrease of the stress in the surrounding stratum and shows a funnel-shaped form.

Cyclic Behaviour of Uniform Sand in Drained and Undrained Conditions at Low Confining Stress in Small-Scale Landslide Model

Earthquakes are one of the main landslide-triggering factors. Earthquakes induce cyclic shear stresses and strains in soil and raise pore water pressure, degrading soil strength towards slope failure. Slopes on which shallow landslides can form due to geological conditions are most susceptible to such failures, mainly because of low confining stress. Effective confining stress has a significant role on soil response during static and cyclic loading. Under low confining stress, soil exhibits dilatant behaviour and can degrade rapidly under cyclic loading. This paper presents the results of undrained and drained cyclic triaxial tests on uniform sandy soil material used for modelling small-scale shallow landslides under 1g conditions. Based on the scaling laws for a model in 1g conditions, the frequencies of straining amplitudes for strain-controlled cyclic triaxial tests were defined. Undrained and drained cyclic triaxial tests on the type of sand used in small-scale landslide models were performed. The sandy samples had been previously consolidated at low confining stress corresponding to the values present in the shallow landslides used as the prototype. The influences of loading frequency and low confining stress on sand behaviour were investigated, and simple models for pore pressure build-up and volumetric strain on sand behaviour were proposed. These simple models can be used to estimate increasing pore water pressure and volumetric strain due to cyclic loading at low confining stress for frequencies lower than 1 Hz. The proposed models show good correlation with the data obtained in the laboratory test.

Forward calculation of displacement fields with multilayered unsaturated highway system induced by falling weight deflectometer using dynamic response method

A new dynamic forward model of a multilayered highway structure, which considers the unsaturated characteristics of subgrade soil, is established in this paper to assess the dynamic response induced by the falling weight deflectometer (FWD) load. The Laplace-Hankel transform and dynamic stiffness matrix method are employed to solve the governing equations of the unsaturated soil layer. Combined with the global stiffness matrix and boundary conditions, analytical solutions of the entire system can be derived in the transform domain. A numerical integration method is utilized to perform the Laplace-Hankel inverse transform to obtain time-domain solutions. An analysis of the effects of saturation on the stress, displacement, and pore water pressure is presented. It is revealed that the effect of saturation of unsaturated subgrade soil on vertical stress is negligible, whereas vertical displacement and pore water pressure increase significantly with increasing saturation. Additionally, the vertical displacement response on the pavement surface is sensitive to subgrade deterioration and variations in material properties. Moreover, subgrade deterioration can be reflected in the variation in vertical displacement at approximately 1.2 m from the load center for the studied road structure. The proposed model, which is more realistic and reasonable, can provide a theoretical basis for the back-calculation of the elastic modulus of multilayered highway systems.

Mechanical and microscopic properties of soil according to the rate of increase in pore water pressure

Increases in pore water pressure affect the effective stress state of loess soil, resulting in deformation and even soil erosion. However, it is still unclear how the mechanical behaviours and microstructures of soil are influenced by the rate of increase in pore water pressure (RIPWP). To better understand the mechanical failure process and properties of soil under different RIPWPs, a series of constant-shear drained (CSD) triaxial tests were carried out on Q2 loess (silt loam, a loose aeolian deposit) in the South Jingyang Platform of China. Further, scanning electron microscopy (SEM) tests were conducted on the samples before and after the triaxial tests to observe the microscopic characteristics of the soil, and reveal the microscopic mechanism of liquefaction failure in soil under CSD triaxial tests. The results showed that the failure process was divided into two stages of 1) stable creep and 2) sharply unstable deformation. In the second stage, rapid-slow strain development was observed at relatively low RIPWPs. With increases in RIPWP, the critical pore pressure ratio u/σc increased within the range of 0.48–0.66. Microscopic analysis of the samples after shearing found clay particles filling the pores and obvious aggregation structures. In addition, macropores and mesopores were transformed into micropores. With increases in RIPWP, the orientations of particles and pores increased and the abundance and fractal dimension of pores decreased. In conclusion, the microscopic mechanism of soil instability under CSD triaxial testing was as follows. Increases in pore water pressure led to the dispersion of fine particles, weakening of cementation, and the rotation and recombination of coarse particles within the soil. In addition, the clay particles rolled, slipped and filled into pore throats, resulting in the blockage of seepage channels and, correspondingly, rapid increases in local pore water pressure. Finally, the loess liquefied due to a sudden collapse of its structure under the effect of long-term high pore water pressure. These results can provide a theoretical guidance for soil management and slope instability prevention.

Pengaruh Tinggi Muka Air Terhadap Deformasi Tanah Terlikuefaksi

Liquefaction occurs in saturated loose sandy soils that experience an increase in pore water pressure due to the propagation of earthquake waves to the ground surface. This phenomenon raises various questions such as how the groundwater level can affect the occurrence of liquefaction events at different earthquake strengths. The purpose of this study was to determine the effect of groundwater level on liquefaction-prone soils at different seismic peak acceleration values and the effect of relative density (Dr) values on liquefaction-prone soils with variations in groundwater level and earthquake acceleration. In this study, a sample of Jono Oge sand soil was used from the occurrence of liquefaction that met the gradation criteria. The soil was separated through the #8 sieve and retained #100. The modeling technique is carried out with several variables such as the ratio of groundwater level (Hw/Hs) of 25%, 50%, 75%, and 90%, relative density (Dr) 30%-40% and 40%-50%, and at different peak accelerations of 0.3g and 0.4g. The modeling test uses a sieve shaker for earthquake vibrations.. The results of the study show that the difference in groundwater level affects the subsidence of liquefied soil where the settlement will be accure greater in the ratio of the groundwater level (Hw/Hs) and the peak acceleration is greater and vice versa, the difference in relative density (Dr) also affects the magnitude of the the settlement where the lower the Dr value for Hw/Hs and the greater the peak acceleration, the greater the settlement will be occure.

Investigation of Dynamic Compaction and Vibro-compaction to Mitigate Liquefaction: A Case Study

Liquefaction is one of the phenomena that can be triggered by an earthquake. Earthquake causes an increase in pore-water pressure in soil, reducing soil’s effective stress to zero or near-zero. In this state, the soil loses its strength and behaves like a liquid. This is known as liquefaction. When soil loses its strength, so it also loses its bearing capacity, causing damage or failure to structures. The soil type that is most prone to liquefaction is loose saturated fine sand. Such soil can be found in many of coastal areas in Indonesia. Indonesia is also one of the most earthquake prone countries in the world, hence liquefaction is one of the natural hazards that Indonesia has to face. Earthquake cannot be prevented, and its occurrence cannot be accurately predicted. Fortunately, liquefaction can be prevented by doing soil improvement to increase the sand density. The two most commonly used ground improvement techniques to increase sand density is dynamic-compaction and vibro-compaction. A case study from Aceh province, where both ground improvement techniques were used, is presented in this paper to compare the performance of dynamic compaction and vibro-compaction.

An Assessment of Landslides along Mountain Forest Roads: Bamenda Ring Road Segment through Bafut and Befang Forests on the Cameroon Volcanic Line.

Purpose: Landslides cause distress in communities worldwide, disrupt socio-economic activities and cause damage to roads infrastructure. The purpose of this study was to undertake a comprehensive assessment of the recurrent landslide events along the Bamenda Ring Road (BRR) segment through the Bafut and Bafang mountain forests in the North West Region of Cameroon, located along the Cameroon Volcanic Line (CVL).
 Methodology: Topographic and geologic map studies, foot-borne surveys, hydro-meteorological data analysis and soil permeability tests were employed to the study. Results at the time of this study reveal 35 new slide scarps in Bafut and 16 along the Befang forests.
 Findings: The topography culminates between 670-1300 m altitude, while more than 50% of the slopes in the study area are convex, the rest are convexo-linear, concave, while a few of them are linear. Natural slope gradients vary from 35-600, while prevalent number of slides occur on sub-vertical road-cut embankments. The slides are classified as small volume, short distance-travelled shallow translational than rotational debris flows. Base rocks of the study zone are essentially coarse-grained leucocratic granites with quartz, feldspars, biotite and muscovite minerals which appear liable to weathering. Meanwhile, residual soil samples are permeable, have increased pore water pressure and has a high liquefaction tendency due to its high clay content. The absence of recent or historic earthquakes suggests that causative factors of landslides could be linked to steep gradients, lithology, deep weathering profiles, considerable affinity for water of the weathered materials and prolonged rainy seasons. As such we highlight the contribution of the landslide hazard with the direct risk based on the extensive deterioration of the road characterized by multiple road defects and reduced socio-economic activities and the indirect risk linked to difficulties in the movement of goods and persons and management of resources.
 Recommendations: This study recommend present officials to improve on their documentation and skills in monitoring rainfall and landslide hazard and manage disaster emergency; sensitize the population on landslide hazard and associated risk. There is need for government to establish a road authority for the management of landslide hazard, disaster relief and the land inside and outside the road.

Numerical Analysis of Instability Mechanism of a High Slope under Excavation Unloading and Rainfall

High slope simulation analysis is an essential means of slope engineering design, construction, and operation management. It is necessary to master slope dynamics, ensure slope safety, analyze slope instability mechanisms, and carry out slope stability early warning and prediction. This paper, aiming at the landslide phenomenon of the high slope on the left bank of a reservoir project, considering the influence of stratum lithology, fault, excavation unloading, rainfall, and water storage, establishes a refined finite element model that reflects the internal structure of the slope. The fluid-solid coupling numerical simulation analysis of the high slope is carried out. Based on this, the failure mechanism of the slope under excavation unloading and heavy rainfall is explained. The application of an engineering example shows that under the combined action of excavation unloading and rainfall infiltration, the in-plane saturation of the structure formed at fault at the trailing edge of the excavation slope surface increases, the pore water pressure increases, and the shear strain concentration area appears at the internal structural surface of the slope. The shear strain concentration area extends along the structural surface to the front and rear edges of the slope, resulting in landslide damage.

Millimeter slope ratcheting from multitemporal SAR interferometry with a correction of coastal tropospheric delay: A case study in Hong Kong

Tropospheric delays (TDs) limit the accurate detection of slow slope motion using interferometric synthetic aperture radar (InSAR), especially in subtropical coastal regions prone to frequent changes in humidity. Although TDs can be estimated through external weather data, their spatiotemporal resolution and data availability are greatly limited, which is not applicable for individual slopes. This paper presents new TD correction methods for slopes with both small dimensions and small elevation changes. We simultaneously estimated and eliminated the TD signal from a line-of-sight (LOS) time series through a blind source separation (i.e., independent component analysis). The stratified TD sources were isolated according to a spatially elevation-linked and temporally periodic independent-component (IC), which was determined via a correlation test and power spectrum analysis. Hence, the TD was corrected without the use of any external weather products/meteorological data and had unprecedented spatiotemporal details equivalent to the synthetic aperture radar (SAR) images. The proposed method was verified using CosmoSkyMed (CSK) and Sentinel-1 (SNT-1) images covering a slope in Tai O, Lantau Island, Hong Kong, and validated using a series of geodetic, meteorological, and hydrological data. Up to 3–4-cm relative TDs were measured in the LOS directions of CSK and SNT-1. The relative TD exhibited a slower increment rate than the slope elevation and was largely affected by specific air conditions (e.g., temperature and humidity) on the SAR image-acquisition days. The analysis of InSAR data yielded reasonably good estimates of millimeter-scale downslope slips (due to increases in pore-water pressure in the wet season) and upslope rebound (due to soil shrinkage in the dry season). It was found that soil swelling and shrinkage of the slope (also known as seasonal ratcheting) and the reclamation were likely regulated by rainfall and sea levels, respectively. Although the slope motion in Tai O was determined to be small (i.e., seasonal variations of 10 mm), the TD correction reduced the root-mean-square error by 42.3%, such that InSAR time-series measurements with millimeter-level accuracy (potentially 1–3 mm) were obtained.

Experimental study of permeability evolution in modified desulfurization gypsum under complete stress–strain process

In the context of low-carbon economy and sustainable development, industrial by-products are being gradually converted into green building materials. The effect of groundwater on the properties of modified desulfurization gypsum must be examined to increase its application in shotcrete supporting structures in underground engineering. In this study, triaxial compression tests with permeability measurements were carried out for modified desulfurization gypsum by simulating underground engineering conditions. The peak strength, permeability-deformation curves, and permeability-stress curves were obtained. The results showed that an increase in pore water pressure promoted internal crack propagation and enhanced the connectivity between cracks. This decreased the specimen strength and increased the initial permeability. As axial deformation and circumferential deformation increased, the variation in the permeability showed five stages: decline, gradual rise, rapid rise, rapid decline, and gradual decline. The permeability was more sensitive to circumferential deformation compared to axial deformation. The critical impermeability strength and abrupt permeability were defined according to the permeability-stress curves. These parameters can be used to evaluate the seepage problems in shotcrete supporting structures in underground engineering.

Unsaturated Hydraulic Conductivity Estimation—A Case Study Modelling the Soil-Atmospheric Boundary Interaction

Pore water pressure changes due to soil-atmospheric boundary interaction can significantly influence soil behaviour and can negatively affect the safety and stability of geotechnical structures. For example, prolonged rainfall events can lead to increased pore water pressure and lower strength; repeated cycles of pore water pressure changes can lead to degradation of strength. These effects are likely to become more severe in the future due to climate change in many parts of the world. To analyse the behaviour of soil subjected to atmospheric boundary interactions, several parameters are needed, and hydraulic conductivity is one of the more important and is difficult to determine. Hydraulic conductivity deduced from laboratory tests are often different from those from the field tests, sometimes by orders of magnitude. The problem becomes even more complicated when the soil state is unsaturated, where the hydraulic conductivity varies with the soil’s state of saturation. In this paper, a relatively simple alternative approach is presented for the estimation of the hydraulic conductivity of unsaturated soils. The method involved a systematic re-analysis of observed pore water pressure response in the field. Using a finite element software, the soil-atmospheric boundary interaction and related saturated/unsaturated seepage of an instrumented slope have been analysed, and results are compared with field measurements. The numerical model could capture the development of suction, positive pore water pressure and changes in water content with reasonable accuracy and demonstrated the usefulness of the hydraulic conductivity estimation method discussed in this paper.

Evaluation of the Slope Stability of Pile-Supported Wharves Using the Centrifuge Model Test and Limit Equilibrium Analysis

During earthquake, liquefaction can cause slope failure that can significantly affect the behavior of the structure. Therefore, the slope stability must be appropriately evaluated considering the liquefaction. This study evaluated the slope stability according to the increase in the excess pore water pressure (<i>r</i><sub>u</sub>) using the centrifuge model experiment and limit equilibrium analysis, and investigated the stabilizing effect of piles against sliding during earthquake. The results indicated that the increase in <i>r</i><sub>u</sub> directly affected the reduction in the safety factor in the saturated sand model, and the decrease rate of the safety factor mainly depended on the <i>r</i><sub>u</sub> than whether or not piles are installed. Therefore, the analysis must be performed considering the <i>r</i><sub>u</sub> in evaluating the slope stability where liquefaction occurs.

Effect of Water on Mechanical Properties and Fracture Evolution of Fissured Sandstone under Uniaxial Compression: Insights from Experimental Investigation

Abstract Preexisting discontinuities and the water affect the fracture evolution process as well as the rock stability the most extensively. To ensure operational safety, the effects of water on the mechanical properties of fissured rock masses must be understood well. In this study, a series of uniaxial compressive tests is conducted on both dry and saturated fissured specimens with varying fissure angles. Real-time acoustic emission and digital image correlation are applied to monitor the fracture evolution process. The failure mode is investigated by identifying the types of cracks present in the ultimate failure forms of the fissured specimens. The results indicate that (1) the saturated and dry specimens exhibit significantly different strengths and stiffnesses, wherein the saturated specimens exhibit weaker strength by 25.64%–32.59% and a lower elastic modulus by 20.30%–29.22%. (2) The fissure angle and water jointly control the failure mode of fissured sandstone. (3) The observed fracture evolution processes can be classified into six distinct stages to facilitate the understanding of rock failure mechanisms. (4) The presence of water accelerates the nucleation of microcracks at the tips of the prefabricated fissures, enlarges the range of microcrack coalescence, and facilitates the emergence of unstable cracks owing to an increase in pore water pressure and a decrease in the friction resistance of crack surfaces.

Mechanical properties of sandstone under hydro-mechanical coupling

Abstract Study of mechanical properties of rock under hydro-mechanical coupling. The MTS815 rock mechanics system is used to perform triaxial compression tests of water-saturated sandstones under different confining pressures and pore water pressures. The results show that the peak deviation stress and its corresponding axial strain, residual deviation stress, initial deviation stress of dilation and deformation modulus of water-saturated sandstone are related to pore water pressure and confining pressure. They decrease with the increase of pore water pressure and increase with the increase of confining pressure. Poisson’s ratio and angle of rupture of water-saturated sandstone increase with pore water pressure. Based on the effective stress principle and Mohr–Coulomb criterion, the effective cohesion and effective residual cohesion of sandstone are 11.49 and 3.13 MPa, respectively, and the effective angle of internal friction and effective residual angle of internal friction are 38.32° and 25.32°, respectively. In addition, according to the variation relationship of sandstone strength, the relative strength criterion of sandstone under hydro-mechanical coupling is established.

Investigation of Structural Behavior of Piles in Liquefiable Cohesionless Soils

Piled foundation design and behaviour under static and dynamic loading (wave motion, earthquake, wind, vibration loadings of machinery) conditions are study subjects that are focus of interest recently in the geotechnical engineering applications. Liquefaction can be described as strength and stiffness loss of a loose, saturated non-cohesive soil under undrained cyclic loading as a result of increasing pore water pressures which reduce effective stress. Large deformations and lateral flow occurring in the layers of liquefied soil during earthquake could lead to strength and stiffness lose which may result with pile buckling and considerably increased earthquake damage on the superstructure. Predicting the bearing capacity and the deformation shape of the piled foundations during the earthquake is essential for the economy and the structural safety of the design. In this study model pile tests are conducted in uniform sandy soil and pile structural capacity is investigated under the effects of relative density and degree of saturation of surrounding soil, and pile embedment depth. Steel rods were used to represent the piles in the model tests. Sand soil was placed in a cylindirical tank at different thicknesses to provide for different pile embedment depths. Soils were compacted at four different compaction level to provide relative densities in the range of 45-80%. Static incremental load has been applied on the upper plate of the pile system in the tests. While the increase in the relative density affects the structural capacity of the piles positively, surrounding soil being saturated has resulted with capacity losses. Experimental results show that there is a consistency between our experimental findings and literature about deformation shape and buckling length of piles in liquified soils.

Determining trigger factors of soil mass failure in a hollow: A study based in the Sichuan Province, China

Soil mass failure disasters are among the most destructive disasters in mountainous areas worldwide, and they continue to receive significant attention in the literature. However, factors that influence soil mass failure in hollows have not been explored via experimental approaches. In this study, we conducted a series of indoor hollow–flume experiments to exhibit how the three factors, namely, initial moisture content, slope angle, and clay content, influence the collapse of soil mass under surface runoff conditions. Our findings revealed that the major processes causing soil mass failure were internal seepage erosion resulting from subsurface runoff, migration of fine particles, development of tension cracks, increase in pore water pressure, and decrease in cohesion. Fluctuations in pore water pressure were characterized by two main trends: (1) an abrupt rise under static liquefaction and (2) a decrease before failure due to dilatancy. The time required for soil mass failure first decreased and then increased with the increase in moisture content. The soil mass with an initial moisture content of ∼12.5% was more critical to the failure. In addition, the time required for soil mass failure decreased with increasing slope angle, revealing a slope angle of 40° to be more prone to failure. The buildup of pore water pressure was found to increase with clay content; soil with a clay content of ∼7.5% required the shortest amount of time to initiate slides. Thus, our results provide a thorough insight into the processes and factors involved in the initiation and development of soil mass failure in hollow areas, which can be used by public agencies to improve monitoring, early warning, and forecasting systems. Notably, our study can help identify risk-prone source areas, and sensors can be installed to monitor potential mass failure locations.

Evaluating Liquefaction Phenomenon Of Silty Sand Using Piezocone Penetration Test (CPTu)

Most investigations into liquefaction have focused on clean sandy soils, with time, evidence has grown that liquefaction is often associated with silty sand material. Sibalaya Village, which suffered the greatest damage from the Palu-Donggala earthquake, is dominated by silty sand material. Related to this issue, an experimental study is conducted in the laboratory to understand the behavior of excess pore pressure and the strength of the saturated silty sand under dynamic loading. The experimental study uses several sets of testing apparatus such as a shake table, chamber, and CPTu. The shake table provides a dynamic load for the soil sample. The chamber allows the field environment to be duplicated in the laboratory. The CPTu measures excess pore pressure and strength of the soil sample. The test results show that liquefaction can occur in silty sand material. However, the fine-grain particles cannot generate the overall pore water pressure in which the pore water pressure ratio can only reach 93% of the initial effective vertical stress. Liquefaction also generates increased pore water pressure and a decrease in soil strength. The increase of dynamic load will result in a shorter liquefaction starting time, and fine content strongly influences the pore water pressure behavior, especially on the rate of pore water pressure dissipation after liquefaction occurs. Therefore, based on this research, it is known that silty sand material can experience liquefaction and can have a longer liquefaction period due to its lower permeability.