Liquefaction Evaluation Research Articles

Evaluation of Soil Liquefaction Using SPT Data at Boyolali Regency, Central Java

On 27 May 2006 at 05:54 local time, a major earthquake with a moment magnitude (Mw) of 6.3 occurred in Yogyakarta Province. This earthquake was widespread causing several damages in Yogyakarta Province and Central Java Province. One of the regencies in Central Java Province impacted was Boyolali Regency. This research aims to evaluate soil liquefaction based on the Standard Penetration Tests (SPT) in Boyolali Regency. Evaluation of soil liquefaction was necessary to minimize the damage as a preliminary in determining mitigation methods that can be applied. Besides Mw 6.3 earthquakes, according to SPT Data, several factors that triggered liquefaction were found in this study area such as a shallow groundwater table and the existence of a poorly graded sandy soil layer. The liquefaction was evaluated by comparing the Liquefaction Severity Index (LSI) and the Liquefaction Risk Index (LRI) using the simplified method. Based on the analysis, the result showed that Boyolali Regency had a value of LSI in the range of very low until low severity and a value of LRI in the range of low until the high risk.

Study on Classification Method of Soil Liquefaction Potential Based on Decision Tree

A new method for evaluating the liquefaction probability of saturated soils is presented in this paper. The existing methods are mainly expressed in equation form, and the evaluation process is always complex. Therefore, to address these shortcomings, a new method based on a tabular form is constructed using a hybrid approach combining the logistic equation and decision trees (classification and regression tree and chi-squared automatic interaction detector) based on the shear wave velocity test databases. The effectiveness of the new method was verified by comparing the predicted liquefaction results with actual liquefaction results. The new method improved the accuracy of the liquefaction evaluation method based on shear wave velocity; the classification was correct for more than 75% of the samples. In addition, the importance of the liquefaction factors was considered during the method construction, which ultimately simplified the evaluation process while ensuring accuracy.

8th Ishihara lecture: Holistic evaluation of liquefaction response

Soil liquefaction during earthquakes is a highly dynamic process involving rapid development of excess pore water pressures (EPWP), reduction in soil stiffness and strength, and diffusion of EPWPs through water flow. In addition, the liquefaction response is characterized by strong cross-layer interactions that significantly influence the severity of liquefaction and overall system response of liquefying deposits. To emphasize the importance of dynamic interactions and provide an in-depth understanding of the liquefaction response, a framework for a holistic evaluation of the liquefaction response is presented. Three key aspects of the response are required to be concurrently considered in the holistic evaluation of the liquefaction response: element (soil) response, cross-layer interactions (system response) and intensity of the input motion. The proposed approach is applied to a comprehensive series of nonlinear dynamic analyses (NDAs) of well-documented case history sites from Christchurch, New Zealand, to identify key interaction mechanisms and quantify effects of dynamic interactions on the liquefaction response. As state-of-practice simplified liquefaction evaluation procedures ignore interactions within the deposit, results from simplified analyses substantially differ from those observed in NDA and show significant anomalies in the evolution of the liquefaction response throughout the depth of liquefiable deposits. A systematic approach for an NDA-based improvement of simplified analysis is proposed to incorporate interaction mechanisms and system response effects in simplified liquefaction evaluation procedures.

Liquefaction Evaluation of Microbial Induced Calcium Carbonate Precipitation (MICP) Treated Sands; A Strain Energy Approach

ABSTRACT The present research investigates liquefaction behavior of microbial induced calcium carbonate precipitation (MICP)-treated Nevada sand with different silt content, for the first time in terms of dissipated strain energy. The obtained results indicated that normalized liquefaction capacity energy for MICP-treated soil was dependent on the CSR and NL. Moreover, acceptable relationships between the excess pore water pressure ratio and dissipated energy were found for both MICP-treated and untreated samples. Furthermore, Bender element tests results proved that shear wave velocities had a stronger relationship with rather than CSR, while, MICP treatment changed the relationship between and liquefaction resistance.

Liquefaction evaluation method of coral sand: Case study on the ports in Indonesia

While the liquefaction evaluation methods of siliceous sand have undergone extensive studies, few research efforts were conducted to establish standard for the liquefaction susceptibility of coral sand. The current study develops an innovative method to evaluate the liquefaction potential of coral sand. Specifically, the method integrates the grain-size distribution of coral sand, effective overburden stress and equivalent seismic acceleration. Scanning electron microscopy image of coral sand was processed to reveal the microstructural characteristics of coral sand. The correction equation for standard penetration resistance of coral sand in Indonesian ports was given based on geotechnical investigations, and the recommended values of correction factors were proposed for the regions lacking relevant data in the previous period. The process for liquefaction evaluation method of coral sand was described and applied to evaluate the liquefaction potential of coral sand in Indonesian port projects. This study demonstrates the feasibility of integrating standard penetration test and grain-size distribution for liquefaction evaluation of coral sand.

Site Characterization and Liquefaction Hazard Assessment for the Erenler Settlement Area (Sakarya Province, Turkey) Based on Integrated SPT-Vs Data

The focus of this study is to examine the soil properties and liquefaction potential of the Erenler center district in a critical tectonic zone that can produce large earthquakes, such as the North Anatolian Fault Zone (NAFZ). In this sense, 40 surface wave measurements and 52 geotechnical drillings were employed. Accordingly, the liquefaction potential index (LPI), liquefaction severity index (LSI), Ishihara boundary (IB) curve, and Ishihara-inspired index (LPIISH) liquefaction approaches from geotechnical and geophysical methods were used as integrated. All liquefaction analyses were examined for two scenarios, Mw: 7.4 1999 Izmit (amax: 0.41 g) and Mw: 7.0 1967 (amax: 0.28 g) Mudurnu. According to the analyses, almost all of the study area showed liquefaction risk in the Izmit scenario. In the Mudurnu scenario, liquefaction risk distribution decreased parallel to acceleration. The LPI, LPIISH, and IB liquefaction risk results for both scenarios support each other. On the other hand, it was determined that the probability of liquefaction was lower in the LSI evaluation. The spatial distribution of the liquefaction potential of the Vs-based and SPT-based LPI assessments had a similar pattern. These results show that the LPI approach, originally SPT-based, can also be calculated based on Vs. In addition, according to Vs30-based (average shear wave velocity at 30 m depth) soil classification criteria, low-velocity character E and D soil groups dominate the Quaternary alluvial basin. This indicates that deformation-induced failures may occur even in areas with a low probability of liquefaction in similar strong ground motions. In addition, the evaluation of liquefaction with many approaches in two different bases within the scope of the study constitutes a novelty for the study area and liquefaction analyses. While performing diversified liquefaction analyses and approaches will contribute to obtaining more reliable soil liquefaction results, more case studies are needed to elucidate these comparisons.

ANALISIS KERENTANAN TANAH TERHADAP BAHAYA LIKUIFAKSI BERDASARKAN DATA PENGUJIAN SPT

Aceh is a province in Indonesia that was hit significantly by the 26 December 2004 disaster. The province was also hit by the M 6.5 Pidie Jaya earthquake on 7 December 2016. Several damages induced by liquefaction, i.e., sand boils, were observed in these two seismic events. Liquefaction is defined as the transformation of granular material from a solid to a liquefied state. This Liquefaction phenomenon can cause damage to buildings and infrastructures built on it. This study presents the results of liquefaction assessment using the standard penetration test (SPT). A borehole was sunk at Rundeng Village, Johan Pahlawan sub-distrit, Aceh Barat distrit to collect the SPT data. This location was selected as several facts, i.e., low water table, built of sand layer, and high seismicity region were suggested for this Rundeng village. Three different models of Esteva (1974), Donovan (1970), and Mc Guirre (1977) were used to estimate the cyclic stress ratio (CSR). A model developed by Seed and Idriss (1982) was employed to estimate the cyclic resistance ratio (CRR). From the calculation of potential liquefaction evaluation, the cyclic stress ratio (CSR) value highly depends on the earthquake magnitude. The greater the earthquake magnitude, the greater the CSR value becomes. Soil layers from SPT data at a depth of 3,50 m – 13,00 m have a value of (N1)60cs > 30 which means the soil is too dense to liquefy and classified as non-liquefiable soil. From the SPT data, it can be seen the soil will be liquefied if an earthquake with a magnitude ≥ 8 occurs.

CPT-Vs correlations for post-glacial sediments in Metropolitan Vancouver

A comprehensive Seismic Cone Penetration Test (SCPT) database for post-glacial sediments in Metro Vancouver is compiled to assess and establish relationships between CPT parameters and shear-wave velocity (Vs). Five world-wide and one existing Fraser River Delta (FRD) specific empirical CPT-Vs correlations are examined and found to have limited applicability in predicting Vs from our SCPT database. Region-specific CPT-VS models are then developed from a training dataset using 4 different regression approaches and 6 different CPT parameters combinations. The regression approaches include multi-linear (MLR) and nonlinear (NLR) regressions, and Random Forest and Extreme Gradient Boosting supervised ensemble machine learning models. The performance of different models and CPT parameters combinations is assessed using a testing dataset. The machine learning models are found to perform slightly better than MLR and NLR models in predicting Vs. Based on performance and practicality, a final CPT-Vs model is selected and applied to predict Vs for 59 compiled CPTs in the region. The comparison between predicted CPT-Vs profiles and measured Vs profiles in similar geology units confirms accuracy of our developed model. The developed CPT-Vs prediction models can be employed to obtain Vs profiles for site response analysis, compare CPT- and Vs-based liquefaction evaluation methods, or map Vs30 in Metro Vancouver.

One-dimensional Site Response Analysis and Liquefaction Evaluation of Can Tho City, Vietnam

Can Tho is the biggest city in the Mekong River Delta, one of the five national central cities in Vietnam. However, it has not been studied regarding seismic hazard estimation. For this purpose, one-dimensional nonlinear site response analysis of this city was performed in this paper. The measured in-situ profiles and corresponding geotechnical site investigation and laboratory test data were utilized to develop the site model for site-specific ground response analysis. A suite of earthquake records compatible with the Vietnam rock design spectrum (TCVN 9386:2012) was used as input ground motions at the bedrock. The results show that Peak Ground Acceleration (PGA) increases from the bedrock to the surface. Maximum PGA is 0.083g for O Mon district (P1) and 0.073g for Cai Rang district (P2). The maximum shear strain is reported to be 0.35% for P1 and 0.45% for P2. The recommended amplification factors are 1.7 for P1 and 1.9 for P2. Even though Can Tho city is composed of soft layers, liquefaction is unlikely to occur.

Evaluation of flow liquefaction in Nerlerk berm using collapse surface approach

Numerical investigation of flow liquefaction in Nerlerk underwater berm is done considering field data. The flow failure criterion proposed by Najma and Latifi is used to determine flow initiation and spreading via the Berm structure. This is done using Abaqus user material subroutine (UMAT) for coding Dafalias-Manzari constitutive model. The undrained triaxial tests are used for the calibration and verification of constitutive model coding. Application and performance of flow failure criterion are checked for these models. Then, Nerlerk underwater berm is numerically modeled considering calibration of constitutive model parameters from field investigation data. The performance of the stress ratio criterion is compared to the liquefaction determination method based on plastic modulus. Analyzing flow failure in a 3D numerical model of a real case is done for the first time, adding a constitutive model to commercial software in conjunction with two different flow detection equations defined as solution-dependent variables in developed user material code. This study reveals the ability of developed code in numerical modelling of flow failure initiation and expansion in a real case numerical model, which is the main target of this study.

Comparative Evaluation of Pyrolysis and Hydrothermal Liquefaction for Obtaining Biofuel from a Sustainable Consortium of Microalgae Arthrospira platensis with Heterotrophic Bacteria

This article presents a comparative evaluation of pyrolysis and hydrothermal liquefaction (HTL) for obtaining biofuel from microalgal biomass (MAB). The research was carried out using biomass of a stable microalgae-bacteria consortium based on Arthrospira platensis. A. platensis was chosen because of its simple cultivation and harvesting. Pyrolysis was carried out at temperatures of 300, 400, 500, and 600 °C with a constant rate of temperature change of 10 °C/min; HTL was carried out at temperatures of 270, 300, and 330 °C. The bio-oil yield obtained by HTL (38.8–45.7%) was significantly higher than that of pyrolysis (up to 21.9%). At the same time, the bio-coal yields using both technologies were almost the same—about 27%. Biochar (bio-coal) can be considered as an alternative strategy for CO2 absorption and subsequent storage since it is 90% geologically stabilized carbon.

Formulation and characterization of Anacyclus Pyrethrum Emulgels and its in vitro and in vivo evaluation as cosmeceutical product.

Plants containing high phenolic and flavonoids contents used widely as antioxidant agent by reducing skin photo damaging effects and play important role in skin rejuvenating. This study was performed to explore the cosmetic effects of Anacyclus Pyrethrum extract and to develop stable oil in water (O/W) emulsion base gel loaded with Anacyclus Pyrethrum 10% extract. To explore and quantify phenols and flavonoids present in Anacyclus Pyrethrum extract and determine its cosmetic effects on human skin. Emulgel formulation were developed by mixing o/w emulsion with carbopol gelling agent loaded with Anacyclus Pyrethrum (AP) extract and base gel without AP extract. In vitro study was done for the evaluation of color change, liquefaction, hardness, and pH change at different storage condition for the duration of 12 weeks. For in vivo study, emulgel applied on 13 healthy human volunteer's cheeks to evaluate its cosmetics effects and compared with placebo (base). Facial parameters including skin melanin, redness, sebum, moisture content, and skin elasticity were determined by using mexameter, sebumeter, corneometer, elastometer for the study duration of 12 weeks. Total phenolic content in Anacyclus Pyrethrum extract was 80.04 ± 0.0043 mg GAE/g, and flavonoids were 54.64 ± 0.0076 mg QE/g. Anacyclus Pyrethrum extract found significantly effective in reducing skin photo-damage effects (p ≤ 0.05) as compared base gel. Anacyclus Pyrethrum extract being rich source of flavonoid and phenolic content, acts as strong antioxidant to protect skin against photo-damaging effect and improve skin conditions.

Characterizing the in-situ state of sandy soils for liquefaction analysis using resistivity piezocone penetration test

Estimation of in-situ state is an important step in evaluating the liquefaction potential of sandy soil. Due to the difficulty in obtaining high-quality undisturbed samples, the cone penetration test (CPT) is being widely used to determine the relative density, state parameter, and dilatancy index which indicate the in-situ state of the soil. The resistivity piezocone penetration test (RCPTU) can not only measure standard CPT data (cone tip resistance and sleeve friction), but also measure in-situ pore pressure and the electrical resistivity of the soil. In this study, a new RCPTU-based soil state characterization method has been developed to assess the soil in-situ state characteristics associated with the liquefaction potential. New correlations between in-situ state indices, liquefaction resistance, and RCPTU data have been developed for soil state characterization and liquefaction evaluation. The results indicate that the RCPTU-based soil state characterization provides an independent “first principle” method to evaluate the in-situ state of soils. The correlations developed in this study can be used confidently for evaluating the dilatancy behavior or liquefaction susceptibility of sites involving high-risk engineering.

Evaluating model uncertainty of an in situ state parameter-based simplified method for reliability analysis of liquefaction potential

Although the simplified procedure of Seed and Idriss (1971) is commonly used, uncertainties are involved in the collected case histories from field observations, as well as the model development process. There is also a need for risk assessment and performance-based design, such that probabilistic estimates of liquefaction potential. This study investigates the uncertainty in a state parameter-based model of liquefaction resistance and potential evaluation for the simplified procedure of Seed and Idriss (1971) is thoroughly investigated based on cone penetration test data under the framework of the first-order reliability method (FORM). The parameter uncertainty in the state parameter-based liquefaction evaluation model of Jefferies and Been (2015) was also examined. The model uncertainty was also characterized by two statistics calibrated by a database of case histories. With known model and parameter uncertainties, the probability of liquefaction for the state parameter-based model can be determined by the FORM analysis. The results indicate that uncertainty in the state parameter-based model can be characterized by using a mean of 1.03 and a coefficient of variation of 0.12. The results of this study will help extend the use of the state parameter-based model and provide risk assessments of geotechnical engineering design.

Discussion of “Evaluation of flow liquefaction and liquefied strength using the cone penetration test: an update”

Discussion of “Evaluation of flow liquefaction and liquefied strength using the cone penetration test: an update”

Evaluating the applicability of conventional CPT-based liquefaction assessment procedures to reclaimed gravelly soils

Gravelly soils are not well represented in current semi-empirical liquefaction procedures, which raises the question of whether state-of-the-practice liquefaction evaluation methods based on sands are applicable to gravelly soils. This paper investigates the applicability of Cone Penetration Test liquefaction triggering and settlement evaluation procedures to case histories of well-graded reclaimed gravelly soil at CentrePort, New Zealand. Sensitivity studies of the liquefaction triggering analysis show the uncertainty in the cyclic demand is larger than the uncertainty in the cyclic resistance within a critical layer. However, the modelling uncertainty over the entire depth of the fill is larger for the cyclic resistance, which can vary by over 50% due to a single material-characterization parameter, i.e., the fines content or soil behavior type index. Sand-based procedures for evaluation of liquefaction-induced settlement are found to be generally applicable to well-graded gravels that have a dominant silty sand fraction in the soil matrix, though they can overestimate the relative density and therefore underestimate post-liquefaction settlement of gravelly soils. The paper emphasizes the importance of soil composition, dominant soil fraction of the soil matrix, and its effects on the soil packing, penetration resistance, and liquefaction resistance in the context of current semi-empirical liquefaction evaluation procedures. • CPT-based liquefaction procedures are applicable to some gravel-sand-silt mixtures • Soil composition and dominating soil fractions are key to liquefaction assessment • FS L is more sensitive to uncertainties in PGA than FC or I c • Use of a constant FC throughout seemingly uniform fill could be problematic • Sand-based methods overestimate D R and underestimate settlement of gravelly soils

Comprehensive investigation and analysis of liquefaction damage caused by the Ms7.4 Maduo earthquake in 2021 on the Tibetan Plateau, China

Soil liquefaction due to earthquake activity can cause serious disasters, and post-earthquake investigation is the most direct means of understanding liquefaction issues. In this study, a rare large-scale liquefaction event that occurred at a high altitude of 4,200 m on the Tibetan Plateau in 2021 due to the Ms7.4 Maduo earthquake is systematically investigated and analyzed. The macro phenomenon, geology, geomorphology, and geotechnology of the liquefaction zones are presented and compared with previous knowledge. The distribution characteristics of the seismic ground motion in the liquefaction zones is obtained and compared with the current understanding of the triggering conditions of liquefaction. Through comparison with field observations, the applicability of the existing two typical liquefaction evaluation methods is analyzed. Through analysis of a representative bridge failure event that occurred during this earthquake, the deficiency of the currently used specifications for liquefaction discrimination are revealed. The investigation and analysis results of this study on a historically rare liquefaction event are of significance for improving our knowledge of liquefaction caused by earthquakes and for developing liquefaction hazard reduction techniques.

Effect of Mean Grain Size on the Small‐Strain Dynamic Properties of Calcareous Sand

Calcareous sand was selected as the prior material for island reclamation in many coastal regions. The mechanical properties of the granular materials are greatly affected by their grain size distribution conditions. The shear modulus and damping ratio are two important parameters for earthquake ground response analysis and liquefaction evaluation. A series of resonant column tests had been performed on calcareous sands with varying median grain diameter and uniform coefficient. The dependence of the shear modulus and damping ratio of the calcareous sand on grain size has been confirmed in this examination. The test results reveal that the shear modulus decreases with a rise in shear strain for calcareous sand samples at a given confining pressure and relative density. The maximum shear modulus tends to increase with confining pressure and relative density. On the maximum shear modulus and void ratio plane, the trend lines of the measured results shift toward up and right position with a rise in grain diameter. The measured results indicate that the influence of uniform coefficient on the maximum shear modulus is neglectable. A revised empirical equation based on the Hardin model had been proposed considering the influence of grain diameter to estimate the maximum shear modulus of calcareous sand. The predicted values show satisfactory agreement with the measured results. The results manifest that the effect of grading condition on small‐strain dynamic properties of calcareous sands cannot be neglected for the evaluation of seismic safety for reclamation engineering sites.

Simplified method for evaluation of liquefaction based on pressuremeter tests (PMT)

Liquefaction is of major concern in many countries subjected to seismic hazard. In practice, prediction of liquefaction is performed using simplified methods based on in situ tests such as the standard penetration test (SPT) or the cone penetration test (CPT). For some applications such as large projects (tunnels, high rise buildings), the Ménard pressuremeter is preferred as it provides a well-established method for foundation design. However, no simplified method to evaluate liquefaction potential has been fully developed for the pressuremeter. Based on pressuremeter calibration chamber and field tests on sands, a chart is proposed for estimating the liquefaction susceptibility of saturated sands. In addition, a method to correct the measured limit pressure from pressuremeter tests is also proposed for tests in sands with fines content. The method was evaluated using extensive data obtained from tests performed in a calibration chamber using clean sand and sand with fines content against 45 pressuremeter tests performed in situ in various soil conditions. Based on these tests, a relationship was obtained between the field data and the chart developed from the calibration chamber tests. The paper also provides suggestions to correct the limit pressure to account for the fines content.

Liquefaction Evaluation Based on Shear Wave Velocity Using Random Forest

Liquefaction evaluation on the sands induced by earthquake is of significance for engineers in seismic design. In this study, the random forest (RF) method is introduced and adopted to evaluate the seismic liquefaction potential of soils based on the shear wave velocity. The RF model was developed using the Andrus database as a training dataset comprising 225 sets of liquefaction performance and shear wave velocity measurements. Five training parameters are selected for RF model including seismic magnitude ( M w ), peak horizontal ground surface acceleration ( a max ), stress-corrected shear wave velocity of soil ( V s 1 ), sandy-layer buried depth (ds), and a new introduced parameter, stress ratio (k). In addition, the optimal hyperparameters for the random forest model are determined based on the minimum error rate for the out-of-bag dataset (ERROOB) such as the number of classification trees, maximum depth of trees, and maximum number of features. The established random forest model was validated using the Kayen database as testing dataset and compared with the Chinese code and the Andrus methods. The results indicated that the random forest method established based on the training dataset was credible. The random forest method gave a success rate for liquefied sites and even a total success rate for all cases higher than 80%, which is completely acceptable. By contrast, the Chinese code method and the Andrus methods gave a high success rate for liquefaction but very low for nonliquefaction which led to the increase of engineering cost. The developed RF model can provide references for engineers to evaluate liquefaction potential.