Assessment Of Liquefaction Susceptibility Research Articles

Modelling and validation of liquefaction potential index of fine-grained soils using ensemble learning paradigms

This study explores the utilization of ensemble-based soft computing techniques for predicting the liquefaction potential of fine-grained soils. Generally, deterministic methods are used to assess the possibility of liquefactions. However, recent advancements have highlighted the implementation of machine learning techniques considering the diverse geotechnical characteristics for liquefaction susceptibility analysis. The current study predicts liquefaction potential index (LPI) of soils using five ensemble-based soft computing paradigms viz., decision tree, random forest, gradient boosting, AdaBoost, and XGBoost regressors. Various influential factors including stress parameters, depth of soil stratum, peak ground acceleration, earthquake magnitude, cyclic stress ratio, fine content, and SPT- N value, were used for estimating the LPI of soils. Experimental results of the employed models were assessed using multiple statistical indices. The results demonstrate that the employed XGBoost model achieved higher predictive accuracy with 99 % accuracy (based on R2 index) during the testing phase. Overall results exhibit that the employed XGBoost paradigm can be utilized as a viable alternative to empirical approaches, enabling an early assessment of liquefaction susceptibility in different engineering projects. This will expedite identification and evaluation of liquefaction hazards, allowing engineers to make more informed decisions.

Assessment of Liquefaction Susceptibility of Fine-Grained Soil based on Soil Classification

Assessment of Liquefaction Susceptibility of Fine-Grained Soil based on Soil Classification

Initiation and mobility of recurring loess flowslides on the Heifangtai irrigated terrace in China: Insights from hydrogeological conditions and liquefaction criteria

Heifangtai terrace is famous in China for its irrigation-induced loess landslides. The frequently recurring loess flowslides initiated along the platform margin of the irrigated Heifangtai terrace have caused 42 fatalities and significant economic losses due to their long-runout and high-speed mobility. Yet it is still unclear if the recurring loess flowslides almost always initiate in the same places, and their initiated conditions and subsequent mobility behaviors have not been fully evaluated. To better understand such under-researched questions, we selected three typically recurring loess flowslides on the Heifangtai irrigated area. We performed multiple geophysical surveys using electrical resistivity tomography (ERT) and multichannel analysis of surface waves (MASW). We tested water content, density, and strength of loess using in-situ profile sampling. In addition, we examined the steady-state shear behaviors of saturated loess utilizing a ring shear apparatus under undrained conditions. The geophysical signatures and in-situ loess property profiles showed that hydrogeological conditions are crucial to initiating the recurring loess flowslides. The results also demonstrated that the shear liquefaction behavior of saturated loess controls the mobility after the failure of the loess flowslides. Liquefaction potential was assessed based on a chart showing the liquidity and plasticity index, pore pressure ratio, and steady-state line, which were developed as new criteria of liquefaction susceptibility assessment. The novel criteria essentially contain general information about fine-grained soil's nature, state, and behavior. These findings provide a better understanding of the dynamic mechanisms of the loess flowslides and their implications for landslide hazard mitigation.

Assessment of Liquefaction Susceptibility in Sedimentary Deposits on the Western Side of the Antalya Urban Area (Turkey)

Assessment of Liquefaction Susceptibility in Sedimentary Deposits on the Western Side of the Antalya Urban Area (Turkey)

Liquefaction Phenomena Induced by the 26 November 2019, Mw = 6.4 Durrës (Albania) Earthquake and Liquefaction Susceptibility Assessment in the Affected Area

On 26 November 2019, an Mw = 6.4 earthquake struck the central-western part of Albania. Its impact comprises secondary earthquake environmental effects (EEE) and severe building damage within the Periadriatic and the Tirana Depressions. EEE comprised mainly liquefaction phenomena in coastal, riverine, and lagoonal sites of the earthquake-affected area. From the evaluation of all available earthquake-related data, it is concluded that liquefaction sites are not randomly distributed within the affected area but are structurally and lithologically controlled. The affected areas are distributed within NW–SE striking zones formed in graben-like syncline areas with NW–SE trending fold axes. These graben-like areas are bounded by NW–SE striking marginal thrust faults and are filled with geological formations of Neogene to Quaternary age. These NW–SE striking zones and structures coincide with the NW–SE striking seismogenic thrust fault of the November 2019 earthquake as it is derived from the provided fault plane solutions. An approach for liquefaction susceptibility assessment is applied based on geological and seismological data and on liquefaction inventory. From the comparison of the compiled liquefaction inventory and the susceptibility maps, it is concluded that the majority of the observed liquefaction has been generated in very high and high susceptible areas.

Assessment of Seismic Site Response and Liquefaction Potential for Some Sites using Borelog Data

Assessment of Liquefaction susceptibility of soil is very important aspect of disaster risk reduction for a particular region. The present research is an investigation to find out the liquefaction capability for the sites of Jalandhar and its surrounding region, Punjab (India) using semi empirical approach of Idris and Boulanger. Initially, the response of Ground  has been analyzed with the help of DEEPSOIL software for evaluating the maximum ground acceleration values (PGASUR) at surface using five earthquake motions of magnitude, M = 6.0, 6.8 and 7.3 selected from worldwide recorded database based on seismicity of the region. The investigated PGA values ranges from 0.196 g to 0.292 g for the sites under investigation. Soil’s potential against liquefaction for 45 locations has been carried out using PGASUR results so obtained. It has been observed that eighteen sites out of forty-five are found to be susceptible to liquefaction. In order to help structural designers and geotechnical engineers for the preparation of realistic plan towards disaster risk reduction for the region, PGASUR contour map of obtained results and liquefaction hazard maps for earthquake of magnitude 6.0 and 7.0 has been prepared on geographical information system (GIS) platform using QGIS software. Doi: 10.28991/cej-2020-03091605 Full Text: PDF

Liquefaction Susceptibility Assessment Using Geotechnical and Geological Manners of Northern Thailand

Soil site investigations such as boring logs, basic soil properties, spectral analysis of surface wave, and the examinations of geologic and geomorphologic were performed in Mae Lao area to investigate the susceptibility of liquefaction after the 6.2 Mw Chiang Rai Earthquake 2014. The study area was found to lay on a complex geological formation and geotechnical behavior with a condition of the high groundwater table. Being located on a high seismicity area (intensity V-VII Mercalli) governs the study area as a concern for high liquefaction hazards. Liquefaction susceptibility-based compositional criteria, soil resistance, and geologic criteria have been established, and consequently, the character of liquefaction potential is defined.

Comparative analysis of liquefaction susceptibility assessment methods based on the investigation on a pilot site in the greater Lisbon area

In Portugal, particularly in the greater Lisbon area, there are widespread alluvial sandy deposits, which need to be carefully assessed in terms of liquefaction susceptibility and risk zonation. For this purpose, a pilot site has been set up, as part of the European H2020 LIQUEFACT project. An extensive database of geological and geotechnical reports was collected and a comprehensive site investigation campaign was carried out, including boreholes with standard penetration (SPT), piezocone penetrometer and seismic dilatometer tests as well as geophysical methods, complemented by undisturbed soil sampling for laboratory characterisation. The assessment of liquefaction susceptibility based on field tests was made using the simplified procedure, considering the factor of safety against liquefaction (FSliq), which relates the cyclic resistance ratio (CRR) with the cyclic stress ratio (CSR). While the computation of the CSR is relatively straightforward, the reliability of the CRR strongly depends on the adopted in situ testing technique. Alternative approaches to liquefaction assessment have been proposed, based on quantitative liquefaction damage indexes, namely the Liquefaction Potential Index (LPI) and Liquefaction Severity Number. In this paper, the geotechnical field data is integrated in these distinct approaches to liquefaction assessment. A comparative and in-depth analysis of the conventional approach is presented and the inclusion of specific information on soil type, as a means to overcome the observed differences, is discussed particularly for SPT and VS results. The combination of these criteria enabled to clearly identify the most critical layers, in terms of liquefaction potential and severity.

Assessment of liquefaction susceptibility in Quaternary deposits: A case study from Jhapa Bazar area, eastern Nepal

Liquefaction is generally experienced in unconsolidated fine- grained sediments during the large earthquakes. In Nepal, the southern part of the country comprises Quaternary deposits called as Indo-Gangetic deposit. Sand and silts are dominant in this zone, where groundwater level is also relatively high. In eastern Nepal, several places have experienced ground fissures, sand boiling, and liquefaction during the large earthquakes in the past history. There are several factors including soil properties, groundwater level, grain size of sediments and ground acceleration that contribute to ground liquefaction. The eastern Nepal faced a devastating earthquake in 1934 (magnitude of 8.4), Udaypur earthquake in 1988 (magnitude of 6.6) and Sikkim-Nepal earthquake in 2011 (magnitude of 6.8) and there is still possibility of similar large earthquakes in future. Liquefaction was reported in many places during Nepal-Bihar earthquake that indicates possibility of liquefaction during similar earthquakes. Liquefaction potential values are calculated from sediment grain size, subsurface geology, groundwater level and standard penetration test (SPT)-N values. The epicenter, magnitude, and other parameters of Nepal-Bihar earthquake have been used to calculate the liquefaction potential. A liquefaction susceptibility map has been prepared in the study area that comprises low, medium, and high liquefaction potential zones. About 20% of the study area including Jhapa Bazar and its surrounding area seems highly susceptible to liquefaction.

LPI Based Earthquake Induced Soil Liquefaction Susceptibility Assessment at Probashi Palli Abasan Project Area, Tongi, Gazipur, Bangladesh

This study aims at evaluation of seismic soil liquefaction hazard potential at Probashi Palli Abasan Project area of Tongi, Gazipur, exploiting standard penetration test (SPT) data of 15 boreholes, following Simplified Procedure. Liquefaction potential index (LPI) of each borehole was determined and then cumulative frequency distribution of clustered LPI values of each surface geology unit was determined assuming cumulative frequency at LPI = 5 as the threshold value for liquefaction initiation. By means of geotechnical investigation two surface geological units—Holocene flood plain deposits, and Pleistocene terrace deposits were identified in the study area. We predicted that 14% and 24% area of zones topped by Pleistocene terrace deposits and zones topped by Holocene flood plain deposits, respectively, would exhibit surface manifestation of liquefaction as a result of 7 magnitude earthquake. The engendered hazard map also depicts site specific liquefaction intensity through LPI values of respective boreholes, and color index, which was delineated by mapping with ArcGIS software. Very low to low, and low to high liquefaction potential, respectively, was found in the areas covered by Pleistocene terrace deposits and Holocene flood plain deposits. LPI values of both units are such that sand boils could be generated where LPI > 5.

Spatial Variability of CPT Parameters and Silty Fines in Liquefiable Beach Sands

AbstractIncreasing awareness of the role of spatial variability in the assessment of liquefaction susceptibility has driven the need to characterize the vertical and horizontal spatial variability ...

Reconnaissance of liquefaction case studies in 2015 Gorkha (Nepal) earthquake and assessment of liquefaction susceptibility

The Gorkha (Nepal) earthquake of the moment magnitude Mw 7.8 occurred on 25 April 2015, with the epicenter 77 km north-west of Kathmandu at a focal depth of 13 km. After the main shock of the earthquake, a field investigation was carried out in the Kathmandu Valley to collect case histories of geotechnical and structural damages. This paper provides the observations of liquefaction case histories and the liquefaction potential assessment based on Standard Penetration Tests for liquefied and non-liquefied sites were performed. Recorded ground motions from the event are presented and the local site effect on the occurrence of liquefaction is described briefly. Observed liquefaction case studies are presented. Ejected soils at liquefied sites were collected and the particle size distributions of ejected soils were analysed. SPT blow counts and the soil profiles at eight liquefied and non-liquefied sites were obtained. The factors of safety against liquefaction with depth and liquefaction potential index of the eight sites were estimated and compared with observed liquefaction areas during Gorkha earthquake. The liquefaction potential indices obtained from the analysis were found to be consistent with the field observation.

Liquefaction susceptibility assessment in fluvial plains using airborne lidar: the case of the 2012 Emilia earthquake sequence area (Italy)

Abstract. We report a case study from the Po River plain region (northern Italy), where significant liquefaction-related land and property damage occurred during the 2012 Emilia seismic sequence. We took advantage of a 1 m pixel lidar digital terrain model (DTM) and of the 2012 Emilia coseismic liquefaction data set to (a) perform a detailed geomorphological study of the Po River plain area and (b) quantitatively define the liquefaction susceptibility of the geomorphologic features that experienced different abundance of liquefaction. One main finding is that linear topographic highs of fluvial origin – together with crevasse splays, abandoned riverbeds and very young land reclamation areas – acted as a preferential location for the occurrence of liquefaction phenomena. Moreover, we quantitatively defined a hierarchy in terms of liquefaction susceptibility for an ideal fluvial environment. We observed that a very high liquefaction susceptibility is found in coincidence with fluvial landforms, a high-to-moderate liquefaction susceptibility within a buffer distance of 100 and 200 m from mapped fluvial landforms and a low liquefaction susceptibility outside fluvial landforms and relative buffer areas. Lidar data allowed a significant improvement in mapping with respect to conventionally available topographic data and/or aerial imagery. These results have significant implications for accurate hazard and risk assessment as well as for land-use planning. We propose a simple geomorphological approach for liquefaction susceptibility estimation. Our findings can be applied to areas beyond Emilia that are characterized by similar fluvial-dominated environments and prone to significant seismic hazard.

Soil Liquefaction during the 20 May 2012 M5.9 Emilia Earthquake, Northern Italy: Field Reconnaissance and Post-Event Assessment

On 20 May 2012, a M5.9 earthquake hit the Emilia-Romagna region in northern Italy. Although it was of moderate magnitude, the quake affected an area up to 17 km from the epicenter, with severe damage and the collapse of several warehouses. Widespread liquefaction phenomena, such as sand boils and ground failures, were observed. Presented herein are the outcomes of a geotechnical post-earthquake reconnaissance survey conducted a week after the main shock in Sant'Agostino, a municipality near Ferrara, which was severely affected by the ground shaking. The presented findings add new liquefaction case records induced by a moderate earthquake in the Italian historical database. Non-invasive, seismic geophysical tests were carried out at four sites in the area of Sant'Agostino during the post-earthquake reconnaissance survey for near-surface geotechnical characterization. Preliminary assessment of liquefaction susceptibility has been carried out using post-earthquake field measurements at the four sites. Predictions based on standard, state of the practice empirical correlations are consistent with the observed liquefaction phenomena.

Effect of Plasticity on Liquefaction Susceptibility of Sand-Fines Mixtures

The usability of the clay fraction as one of the criteria in the assessment of liquefaction susceptibility is questionable since year 2001. The use of plasticity index to replace clay fraction as a controlling parameter in the criterion is proposed. This paper aims to compare the usability of different parameter in describing the cyclic behaviour of sand-fines mixtures with various plasticity characteristics. The sand-fines mixtures were reconstituted by mixing clean sand with two types of plastic fines at different percentages by weight, at a standardized ratio of 80% of clean sand with 20% of plastic fines. All soil samples were mixed using the dry tamping method to achieve a constant relative density of 20% throughout the specimen. The soil specimens are tested with stress controlled cyclic triaxial apparatus under consolidated undrained condition, with an effective confining pressure of 100kPa. The soil specimens were considered liquefy when the value of pore pressure is equivalent to the initial cell pressure, resulting zeroes effective stress in soil specimen. The results showed that the liquefaction resistance of the sand-fines mixtures increased as the value of plasticity index increased. The plasticity index is a better indicator to describe the liquefaction susceptibility of sand-fines mixtures compare to clay content, plastic limit and activity.

Liquefaction susceptibility assessment and study of "La Luciana" tailings dam fault (Spain, 1960) based on historical documents

On 17 August, 1960 the biggest disaster by death toll in Spain, related with a tailings dam fault, took place in Reocin (Santander). The tailings dam La Luciana failed causing the death of eighteen people. After the fault, the mining company carried out several geotechnical tests in the remaining materials of the tailings dam. The results are available to be consulted in the Reocin Mines Documentary Collection, from which we have obtained mechanical Cone Penetration Test (CPT) data near the fault area as well as diverse maps of the dam pre-failure and post-failure. The processing of such data through current analysis techniques has revealed the relationship between the fault of the tailings dam and static liquefaction phenomena.

Behavior of Nonplastic Silty Soils under Cyclic Loading

The engineering behavior of nonplastic silts is more difficult to characterize than is the behavior of clay or sand. Especially, behavior of silty soils is important in view of the seismicity of several regions of alluvial deposits in the world, such as the United States, China, and Turkey. In several hazards substantial ground deformation, reduced bearing capacity, and liquefaction of silty soils have been attributed to excess pore pressure generation during dynamic loading. In this paper, an experimental study of the pore water pressure generation of silty soils was conducted by cyclic triaxial tests on samples of reconstituted soils by the slurry deposition method. In all tests silty samples which have different clay percentages were studied under different cyclic stress ratios. The results have showed that in soils having clay content equal to and less than 10%, the excess pore pressure ratio buildup was quicker with an increase in different cyclic stress ratios. When fine and clay content increases, excess pore water pressure decreases constant cyclic stress ratio in nonplastic silty soils. In addition, the applicability of the used criteria for the assessment of liquefaction susceptibility of fine grained soils is examined using laboratory test results.

Artificial neural network and liquefaction susceptibility assessment: a case study using the 2001 Bhuj earthquake data, Gujarat, India

This study pertains to prediction of liquefaction susceptibility of unconsolidated sediments using artificial neural network (ANN) as a prediction model. The backpropagation neural network was trained, tested, and validated with 23 datasets comprising parameters such as cyclic resistance ratio (CRR), cyclic stress ratio (CSR), liquefaction severity index (LSI), and liquefaction sensitivity index (LSeI). The network was also trained to predict the CRR values from LSI, LSeI, and CSR values. The predicted results were comparable with the field data on CRR and liquefaction severity. Thus, this study indicates the potentiality of the ANN technique in mapping the liquefaction susceptibility of the area.

Back-analysis of liquefaction in the 2006 Mozambique earthquake

A magnitude 7 earthquake occurred in southwest Mozambique in February 2006, triggering extensive liquefaction around the fault rupture. Samples were recovered from the liquefied soils for laboratory testing to calibrate a numerical model for the assessment of liquefaction susceptibility. Laboratory tests and simulations confirm that the alluvial sands from the area affected by the earthquake have a very high susceptibility to liquefaction, although this depends strongly on the in situ density, which is likely to be low since the soils are deposited in a major flood plain. Since many areas of Mozambique, including parts of the major coastal cities, are on similarly loose and saturated deposits, there could be a significant liquefaction hazard in future earthquakes.

Preliminary Evaluation of Seismic Hazards for Emergency Rescue Route, U.S. 60, Missouri

The Missouri Department of Transportation (MoDOT) has designated segments of a number of highways as emergency vehicle priority access routes in the event of an earthquake, including a section of U.S. Highway 60 in southeast Missouri. The designated transportation corridors must be reopened quickly following an earthquake, so MoDOT initiated a study to evaluate potential seismically induced damage to critical roadways and bridges. This study included evaluation of earthquake-induced landslide potential at two bridge sites, assessment of liquefaction susceptibility, and risk of possible flooding caused by earthquake-induced levee or dam failure along the 45-mile section of U.S. 60 between Poplar Bluff and Sikeston. This study is unique in that the expected degree of roadway damage is not as important a consideration as the ability of emergency vehicles to navigate the road following an earthquake. This is the first comprehensive study of emergency vehicle priority access routes in the midwestern United States. A simple ranking system was developed to assess the susceptibility of critical bridges and roadways to earthquake damage that could deny roadway use. With respect to bridge sites, the St. Francis River and Wahite Ditch bridges were among the most susceptible to traffic-disruptive damage. Based on a detailed investigation, slopes at the Wahite Ditch show marginal stability (1 ≤ FS ≤ 1.1), whereas those at the St. Francis River show instability (FS Liquefaction and flooding potential were estimated for U.S. 60 from Poplar Bluff to Sikeston, MO. Approximately half of this section, from Poplar Bluff to Dexter, is moderately susceptible to liquefaction, as defined by the number of 5-ft soil layers expected to exceed their critical cyclic stress ratios under 10 percent PE earthquake shaking. The entire roadway is moderately to strongly susceptible to liquefaction under 5 percent PE earthquake shaking. Similar results to 5 percent PE shaking are found for 2 percent PE shaking, with the exception of the section of roadway within 5 miles of Sikeston, which is characterized by severe liquefaction potential. Several stretches of U.S. 60 could be flooded and rendered impassable in the event of catastrophic failure of regional waterway levees or failure of the Wappapello Dam.