Evaluation Of Liquefaction Potential Research Articles

Evaluation of liquefaction potential of subsoil strata of Visakhapatnam city based on SPT N values

Evaluation of liquefaction potential of subsoil strata of Visakhapatnam city based on SPT N values

Evaluation and analysis of liquefaction potential of gravelly soils using explainable probabilistic machine learning model

Majority of the presently available machine learning (ML) models employed to assess the liquefaction potential of soils are for sands or sands containing silt fraction. In the current study, an explainable ML (EML) model has been developed using the updated liquefaction database of gravelly soils. The Chinese dynamic cone penetration test (DPT) and shear wave velocity test results of gravelly soils are used in the analysis. A new empirical correlation between these two in-situ tests’ results is developed using the final processed database. The light gradient boosting machine (LightGBM) is trained using this processed dataset and further tuned using Fast and Lightweight AutoML library (FLAML). The final tuned model shows relatively better deterministic and probabilistic predictive performance for the test sites as compared to the conventional method. An EML technique, SHapley Additive exPlanations (SHAP) is applied to provide further comprehension into the predictions. The developed LightGBM-SHAP model has achieved a right balance between explainability and accuracy. The obtained SHAP plots are consistent with almost all the existing domain knowledge (DK) in gravelly soil liquefaction. The developed model thus fills the gap between the ML-based procedures and the traditional DK of gravelly soil liquefaction.

Development of Energy-Based Site-Specific Correlations to Evaluate Liquefaction Potential

Development of Energy-Based Site-Specific Correlations to Evaluate Liquefaction Potential

Evaluation of liquefaction potential by standard penetration test and shear wave velocity methods: a case study

Evaluation of liquefaction potential by standard penetration test and shear wave velocity methods: a case study

The use of screw driving sounding in soil assessment in Metro Manila, Philippines

A coastal portion of the Greater Metro Manila Area, Philippines, is situated primarily on Quaternary alluvium deposits, which are likely to liquefy. Liquefaction is a hazard that occurs when loosely packed, saturated sediments at or near the ground surface lose their strength, caused by an earthquake. Currently, the standard in determining the soil properties and liquefaction potential of a site is by using conventional geotechnical techniques such as the standard penetration test (SPT). However, this method has disadvantages in terms of cost, logistics and workforce. The screw driving sounding (SDS) test was developed to estimate equivalent SPT parameters such as N-value and fines content, which are then used for liquefaction analysis. This paper presents a comparative analysis between SDS and SPT in selected schools in the Greater Metro Manila Area, Philippines. Moreover, soil classification and site-specific liquefaction potential evaluation were also estimated using the data acquired from the SDS test. Overall, the results of the study prove that the SDS test is an effective alternative method for soil investigation and estimation of the liquefaction potential.

Probabilistic of in Situ Seismic Soil Liquefaction Potential Based on CPT-Data in Central Jakarta, Indonesia

Jakarta City located at the northern part of Java Island has a potential liquefaction since there are many soil layers as a qualified as liquefaction susceptible, such as: silty sand and sand. The effects of liquefaction occurrence on saturated silty sand and sand during earthquakes can have potential to damage structure. A case history using CPT-data randomly taken from Central Jakarta region was compiled and back analyzed to investigated probability of liquefaction. The present study focuses on the probabilistic evaluation of liquefaction potential of this region, considering silty sand and sand layers related to CPT soundings. Silty sand was found as a thin layer or a lens between silty clay, silt and clay which was classified as a soft soil layer, and the sand layer is mostly found as a hard bottom layer. Normalization of tip CPT resistance (qc) corrected by an effective overburden stress was not only used to thick layer of silty sand and sand, but also it was applied to determine liquefaction potential existed as the “thin” layers. The silty sand and sand layers have a probability of liquefaction (PL) between 5 to 50% for magnitudes and distances of 500 years with PGA less than 0.42 gal.

Evaluation of Liquefaction Potential based on Cone Penetration Test (CPT) and Semi-empirical Methods

The phenomenon of soil liquefaction can be an induced effect of earthquake shaking where the saturated soil loses some or all of its bearing capacity and stiffness. Likewise, the increase of water pressure in the soil pores under the seismic wave causes a decrease of the shear strength. As a result, the soil becomes liquefied and susceptible to producing permanent deformations. The phenomenon of liquefaction is generally unpredictable, and neglecting it can influence the stability of structures and infrastructure foundations. Since the 1964 Alaska and Niigata earthquakes, more research works have been conducted to assess land liquefaction vulnerability. This study is undertaken in this field, whose objective, on the one hand, is to signal the phenomenon of liquefaction in the north of Morocco as a geo-technical part known for its instability and, on the other hand, to study the semi-empirical methods to adequately evaluate the liquefaction potential while specifying the most appropriate method for our case study. Similarly, the study is based on data derived from experimental results of in-situ tests applied to the embankment crossing the valley of "Oued Gharifa" on a high-speed rail line section from KP 228+400 to KP 229+375. Moreover, this research aims to show and discuss the evaluation of liquefaction potential of the experimental results of the CPT (cone penetration test) using three semi-empirical methods, namely the Juang method, the Olsen method, and the Robertson method. In doing so, we are going to compare the application results of the three semi-empirical methods in light of evaluating the liquefaction likelihood of the studied area, taking into account the nature of the soil, the variation of the safety coefficient, and the liquefaction potential for each method as well. Doi: 10.28991/CEJ-2023-09-02-013 Full Text: PDF

Evaluation of liquefaction potential in flow liquefaction area in Palu City after the 28th September 2018 Donggala-Palu Earthquake

The occurrence of flow liquefaction phenomena, locally termed Nalodo, during the Donggala-Palu earthquake on 28 September 2018 destroyed some residential areas and infrastructures in Palu City and Sigi Regency. Evaluation of liquefaction potential in the flow liquefaction areas is required to assess the liquefaction susceptibility of the area to future earthquakes. This paper presents the results of liquefaction potential analysis in the Balaroa, and Petobo areas based on the SPT method. A calculated peak ground acceleration was used for each location. Based on the analysis, all the liquefied soil layers are still liquefiable, especially in the Balaroa area, causing a significant ground settlement. These results imply that flow liquefaction areas are still susceptible to liquefaction during a big earthquake event. Thus, restriction of re-inhabitants in the liquefaction areas is necessary, and the infrastructure development in the areas requires a proper engineering design to mitigate earthquake-induced liquefaction hazards in the future.

Liquefaction potential evaluation on reconstruction project of irrigation canal in the Jono Oge and Lolu Village

In Indonesia's liquefaction history, the province of Central Sulawesi was severely affected in several locations when a 7.5 Mw earthquake occurred in September 2018. This study aims to evaluate the liquefaction potential and generate the liquefaction hazard map in the reconstruction project of the Gumbasa Irrigation Canals passed through Jono Oge Village and Lolu Village, closely related to the liquefaction event in the Sigi Regency area. Using the simplified procedure method by Idriss and Boulanger, the Liquefaction Factor of Safety (FOS) was calculated for each layer of soil from thirteen (13) locations of soil investigation test at the end of 2021 by the Ministry of Public Works and Housing. Furthermore, it was followed by calculating the Liquefaction Potential Index (LPI) and Liquefaction Severity Index (LSI). The analysis results show that the construction work area has the liquefaction potential with the observed groundwater level. It is mapped on irrigation canals along the Jono Oge Village and Lolu Village to know the critical segment of the irrigation project. Hereafter, an irrigation canal segment named BGKN-45 to BGKN-46 in Jono Oge required a specific mitigation plan to prevent damage from liquefaction in the future.

Liquefaction potential hazard study at UIN Datokarama, Palu City, Central Sulawesi

In June 2019, the Asian Development Bank approved emergency rehabilitation and reconstruction assistance (EARR) to help Indonesia rebuild better critical infrastructure damaged by the 2018 Palu-Donggala earthquake. One of the EARR sub-projects is the reconstruction of Universitas Islam Negeri (UIN) Datokarama that suffered significant damage from the combined effects of the tsunami and earthquake. The design for the building's reconstruction incorporated better principles of deconstruction, including pile foundations to ensure the facilities are earthquake, tsunami, and liquefaction resistant. This study purpose is to evaluate liquefaction potential and estimate its severity or damage potential to structures in the reconstruction site. Liquefaction potential will be assessed in two ways, first by using soil deposits grain sizes distribution method from Japan technical standards for port and harbour facilities and second by safety factor against liquefaction (FOS) method using the SPT-based liquefaction triggering analysis with the revised magnitude scaling factor (MSF) relationship by Idriss and Boulanger. Liquefaction Potential Index (LPI) from Iwasaki will be used for estimating liquefaction severity. The analysis is performed on dataset taken from 6 boreholes in location dominated by saturated sandy soil and shallow ground water. Based on the result, liquefaction potentially triggered at various depth with consistent LPI index at > 15, The reconstruction site has a very high liquefaction risk.

Probability Liquefaction On Silty Sand Layer On Central Jakarta

Indonesia has a strong earthquake risk. The effects of saturated silty sand liquefaction during earthquakes can be very damaging. Liquefaction is the threats to the safety of structures, and the evaluation of liquefaction potential is essential in locations with silty sand layers. Research was performed at BPJS Branch Office building project in CentralJakarta with 7 floors when conducted the substructure or deep foundation design. This research uses cone penetration test (CPT) data to evaluate the potential and probability of liquefaction. At the same time, this research also predicts the bearing capacity (Qu) of single pile embedded on silty sand layer at conditions of Non-Liquefaction (NL) and Liquefaction (L) due to an earthquake. The research results showed that silty sand layers were classified as the susceptible layers to the liquefaction potential after plotted of CPT data into the graphic from Robertson & Campanella method [1] and signed by zone A. However, bearing capacity (Qu) when condition of NL and L was only different around 10 to 11%, it can be considered that the single pile remains stable during occurrence the liquefaction and capable to support the upper structure system. This assumption is also strengthened by the analysis result of probability liquefaction (P[L]) for sand and silty sand layers, the average of (P[L]) based on the maximum earthquake acceleration (PGA) T = 50 years exists in the range < 5 % to 10 % and it can be stated that [P(L)] is very low to low [2] and it can be concluded that the sand and or silty sand layers at study area is hard to category as a liquefiable layer.

Evaluation of Liquefaction Potential of Kolkata City, India: A Deterministic Approach

Evaluation of Liquefaction Potential of Kolkata City, India: A Deterministic Approach

Determination of Best Criteria for Evaluation of Liquefaction Potential of Soil

Determination of Best Criteria for Evaluation of Liquefaction Potential of Soil

Application of the Coupled Markov Chain in Soil Liquefaction Potential Evaluation

The evaluation of localized soil-liquefaction potential is based primarily on the individual evaluation of the liquefaction potential in each borehole, followed by calculating the liquefaction-potential index between boreholes through Kriging interpolation, and then plotting the liquefaction-potential map. However, misjudgments in design, construction, and operation may occur due to the complexity and uncertainty of actual geologic structures. In this study, the coupled Markov chain (CMC) method was used to create and analyze stratigraphic profiles and to grid the stratum between each borehole so that the stratum consisted of several virtual boreholes. The soil-layer parameters were established using homogenous and random field models, and the subsequent liquefaction-potential-evaluation results were compared with those derived using the Kriging method. The findings revealed that within the drilling data range in this study, the accuracy of the CMC model in generating stratigraphic profiles was greater than that of the Kriging method. Additionally, if the CMC method incorporated with random field parameters were to be used in engineering practice, we recommend that after calculating the curve of the mean, the COV should be set to 0.25 as a conservative estimation of the liquefaction-potential interval that considers the evaluation results of the Kriging method.

Efficient three-dimensional soil liquefaction potential and reconsolidation settlement assessment from limited CPTs considering spatial variability

In engineering practice, a two-dimensional (2D) geotechnical cross-section is often used to assess soil liquefaction potential and its consequences on civil structures in a specific site for a given earthquake scenario. However, selection of a representative 2D cross-section for a real site is a challenging task because subsurface soils often exhibit spatial variability (e.g., spatially varying soil stratigraphy and engineering properties) in a three-dimensional (3D) subsurface space. Therefore, liquefaction assessment results interpreted from selected 2D cross-sections for representation of a 3D subsurface space may be unconservative, or even biased, leading to significant risk to civil infrastructure. Furthermore, assessment of 3D subsurface models demands higher computational effort than 2D cross-sections, presenting an additional obstacle. To tackle these issues, this study develops a novel and computationally efficient method for 3D liquefaction assessment with appropriate consideration of soil stratigraphy and property spatial variability within a 3D subsurface space. The proposed method integrates the cone penetration test (CPT)-based simplified liquefaction assessment methods with a novel 3D soil stratigraphy and engineering properties modelling method to characterize the spatially varying soil liquefaction potential and liquefaction-induced settlement for a given earthquake scenario in 3D. The proposed 3D method is illustrated using exploration data from Christchurch, New Zealand. An illustrative example indicates that the proposed method can properly assess significantly non-uniform and heterogeneous soils, and evaluate liquefaction potential and liquefaction-induced settlement of soils within the selected methodologies in a 3D subsurface space.

Assessment of small strain dynamic soil properties of railway site Agartala, India, by bender element tests

Small strain dynamic properties of soil are the primary input parameter in seismic ground response analysis studies. This study examines the small strain shear modulus (Gmax) and damping ratio (ξ) using bender element (BE) tests on subsoil samples along with evaluation of liquefaction potential (sandy soil) using well-accepted cyclic resistance ratio relationship collected from a railway construction site at Agartala, North Eastern (NE) state of India. The objective of this study is to develop a database and empirical relationship on dynamic properties of Agartala soil which may help to carry out future site-specific seismic hazard studies of Agartala city and other regions with similar soil properties. Experimental results indicate that shear wave velocity (Vs), Gmax, and ξ vary within a wide range such as 60.61 to 234.64 m/s, 5.3 to 104.6 MPa, and 8.9 to 22.1% .respectively depending upon the type of soil and a closed form empirical equations are proposed to calculate Gmax for different types of soil. Besides, a validation study also highlights well agreement of results on Vs obtained through experimental measurement and field in situ-based relationship. Finally, higher liquefaction susceptibility of the study area is reported based on calculated liquefaction potential index (LPI).

Evaluation of Liquefaction Potential of Nagpur Region Using SPT Data: Field Assessment

Liquefaction is a complex, controversial but important topic in the Geotechnical engineering especially in earthquake sensitive regions. This secondary effect of earthquake causes severe damage to infrastructure. Nagpur is third largest and fastest growing and developing city in Maharashtra. The main aim of this study is to map the Nagpur city in the view of liquefaction potential occurrence and to make readily available data for further use and research. SPT-N based method is used for liquefaction assessment of soil encountered in the Nagpur region during investigation. The liquefaction potential is assessed regarding component of factor of safety (FS) along the depth of different soil stratum encountered during investigation. This liquefaction potential is evaluated at 56 representative sites in the city using Standard penetration tests (SPT) conducted and recorded in bore holes. Present study for computing liquefaction potential shows sensitivity in computing liquefaction against the SPT blow count and peak ground acceleration. For estimating Cyclic Resistance Ratio (CRR), the SPT-N value is corrected which indicates that the soil in the region is not identical at all locations, water table is of fluctuating nature and N values are varying according to soil properties but are mostly on higher sides which means that liquefaction potential is much low.

Effect of stratigraphic model uncertainty at a given site on its liquefaction potential index: comparing two random field approaches

Random field theory is often used to model spatial variability of geo-material boundary and property. The results of random field generation based on different theories are quite different; however, few studies discuss the effects of adopting different random field approaches on the established stratigraphic models and their influence on engineering analysis. This article compares two random field approaches for evaluating liquefaction potential at a selected site. Here, based on the results of cone penetration tests (CPTs) at the study site, stratigraphic models are constructed using a continuous random field (conditional random field, CRF) and a discontinuous random field (Markov random field, MRF). Note that the MRF parameters were calibrated with the statistical parameters used in CRF. A series of geological profiles representing realizations of the derived CRF-based and MRF-based stratigraphic models are generated. Then, the liquefaction potential index (LPI) is calculated using the simplified procedure with a simulated geological profile and associated soil parameters. Finally, by repeating the analysis for all realizations of random stratigraphic models, the mean and the coefficient of variation of LPI are determined. Meanwhile, the uncertainty of stratigraphic models generated by CRF and MRF approaches is quantified and expressed as information entropy. Next, the relationship between stratigraphic model uncertainty (as an entropy) and LPI variation (or uncertainty) is established. The results show that: (1) the generation of the stratigraphic model is affected by the chosen random field approach, and the distribution of MRF-based strata is more continuous compared with that of CRF-based strata; (2) due to this effect, the strata uncertainty of CRF simulation is more uniform compared with that of MRF; (3) the information entropy and LPI uncertainty obtained using CRF exhibit moderate correlation, while these parameters obtained using MRF exhibit a strong positive correlation.

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.

Evaluation of liquefaction potential by energy-based and stress-based methods and gene expressing programming (case study: Tabriz city)

ABSTRACT Liquefaction in soil layers is a vital factor intensifying earthquake damages.This study compares the numerical evaluation process and the results of two methods based on stress and energy. It is inferred from the calculations that the stress-based method predicts a higher liquefaction potential with a lower safety factor as it promises liquefaction in deeper soil layers. In return, liquefaction tends to occur at a shallower depth with higher intensity in the energy-based method. Through applying the two approaches based on the data collected from different areas around Tabriz, a liquefaction-zoning map is presented. Despite being far from the fault, the central to the western and the southwestern parts of Tabriz has a high liquefaction potential. Eventually, based on the evaluated liquefaction potential using the stated methods and adopting the gene expression programming (GEP) approach, an equation is introduced to estimate the liquefaction potential for the case study. The predictions of the proposed models were consistent with the findings of experimental methods, demonstrating appropriate statistical measures and parametric analysis. It can also be concluded from the results of the parametric analysis, that the parameters of maximum acceleration, earthquake magnitude, and SPT number have more great impact on soil liquefaction.