Liquefaction Potential Index Values Research Articles

Sequential Gaussian simulation predicts soil liquefaction potential

The Yellow River Delta is covered with a large number of pipelines, but due to the complex soil composition in the region, ensuring that pipelines are not damaged by soil liquefaction is an important issue at present. Based on the simplified method of the cone penetration test (CPT), the sequential Gaussian simulation (SGS) can probabilistically simulate the liquefaction potential index (LPI) in the study area to solve the problem of the smoothing effect occurring in the kriging method. In this study, 10 experiments were conducted in the Yellow River Delta to evaluate soil liquefaction within the site using uncertainty analysis by the SGS method. The results indicate that (1) All LPI values in the study area are less than 5, with an overall sub-moderate liquefaction potential. (2) The results of the variogram model show that the Gaussian function model has the best fit with a Root Mean Squared Error of 0.429. The results of the e-type simulation realizations illustrate that the soils around the three sites S1, S5, and S10 exhibit high LPI values, distributed in a band in the middle of the western and eastern parts of the site. (3) Uncertainty analysis was performed using LPI = 2 as a threshold to explore the distribution of areas of moderate liquefaction potential and areas of low liquefaction potential in the study area. (4) Improvements were made to address the current problem of inappropriate values of liquefaction thresholds and the lack of medium liquefaction potential thresholds by proposing when LPI = 20 as the liquefaction threshold, LPI = 10 and 16 as the thresholds for low liquefaction potential, medium liquefaction potential and high liquefaction potential.

Liquefaction hazard mapping of the south-central coastal areas of Bangladesh

Liquefaction can cause significant damage to the built environment; therefore, assessing the liquefaction hazard in a seismically active region is essential to minimize the risk. This study attempted to evaluate the liquefaction potential of the south-central coastal areas of Bangladesh by calculating the liquefaction potential index (LPI) considering a scenario earthquake of Mw = 7.5 having a peak ground acceleration of 0.15g. For calculating LPI, both standard penetration test blow count (SPT-N) and shear wave velocity (Vs) data have been used in this study. The results show that the study area's LPI values vary from 0 to 37. A liquefaction hazard map is prepared for the area using the calculated LPI values from Vs data shows about 8% of the study area is very highly susceptible to liquefaction hazard, whereas 62% of the area falls under high hazard-prone area while about 28% and 2% area of the study have respectively low (0<LPI ≤5) and very low (LPI = 0) liquefaction potentiality. In addition, after analyzing the study area's fluctuating groundwater level (GWL) during the last 20 years, it has been observed that the GWL is likely to rise, thereby intensifying the potentiality of liquefaction hazards in the future. The outcome of this study will help engineers, urban planners, and policymakers to prepare a risk-sensitive land use plan and to develop a robust earthquake emergency response plan to reduce seismic risk.

Evaluation of Liquefaction Potential Index in the Educational Infrastructure Reconstruction Project at the University of Tadulako, Palu City, Central Sulawesi

On September 28, 2018, The Palu-Koro fault triggered an earthquake of Mw 7.5. at a depth of 20 km and 72 km northeast of Palu City. As a result, the University of Tadulako suffered significant damage post this earthquake. The Ministry of Public Works and Housing was assigned to reconstruct this location, which was located near the epicentre, and there are alluvium deposits of the Holocene age with loose sand soil and shallow groundwater levels on-site. Based on the Indonesian Seismic Code SNI 1726:2019, it is necessary to propose liquefaction potential and mitigation for building planning. The study aims to calculate the Safety Factor (S.F.) against liquefaction using a simplified procedure by Seed-Idriss and developed methods by Idriss-Boulanger. The S.F. was used as an input to determine the Liquefaction Potential Index (LPI) by Iwasaki et al. The study showed different categories of LPI values. The highest LPI value was found at BH-05, with a very high liquefaction potential. The soil depths susceptible to liquefaction are up to 9 meters. Application of deep foundation penetrating liquefiable soil layer is recommended as the mitigation. It is necessary to conduct further studies on the deep foundation analysis to be applied to this location.

Influence of Groundwater Table Fluctuation on Liquefaction Potential Analysis Using Cyclic Stress Approach

In addition to earthquakes, groundwater table (GWT) also contributes to uncertainty in liquefaction analysis, so it needs to be considered. This research was conducted by analyzing the liquefaction potential with a cyclic stress approach using standard penetration test data and cone penetration test data with varied GWT in a case study of building design in Sleman, Yogyakarta Special Region. The liquefaction safety factor (FS L ) was calculated to obtain the liquefaction potential index (LPI) and liquefaction severity index (LSI). Based on the survey results, the GWT ranges from -6 m to -8 m. Referring to the FS L , there are several soil layers that have liquefaction potential at all GWT variations. The shallower the GWT, the greater the LPI and LSI values at the same point will be. Changes in GWT from -8 m to -6 m cause changes in the LPI and LSI classifications at several points. Based on LPI classification, the location belongs to high to very high category at -8 m and -7 m GWT and very high category at -6 m GWT. Based on LSI classification, the location belongs to low category at -8 m GWT, and low to moderate category at -7 m and -6 m GWT.

Assessment of the liquefaction potential of the Arifiye (Sakarya) region with multidisciplinary geoscience approaches in the GIS environment

The severity of damage under building load during an earthquake, one of the most critical geophysical and geotechnical engineering problems, varies according to soil types. Therefore, the liquefaction problem constitutes an essential phenomenon, especially for the settlements located on alluvial units in high seismicity regions. This study used standard penetration test (SPT), and share wave velocity (Vs) based approaches to evaluate the liquefiability in the Arifiye region in the North Anatolian Fault Zone (NAFZ) with 40 drillings and 35 seismic measurements considering the Izmit (Mw: 7.4) and Mudurnu (Mw: 7.0) earthquake scenarios. In this context, three different approaches (Liquefaction potential index (LPI), Ishihara boundary curve (IB), and Ishihara-inspired index (LPIISH)) were employed. The maps from these assessments were prepared in the Geographic Information System (GIS) environment. It was determined for the study area that the lakeside and northern part of the NAFZ linearity, which has a very shallow groundwater table and low Vs values, are vulnerable to liquefaction hazards for all approaches. On the contrary, the south part of the NAFZ linearity is defined as non-liquefiable. Although the Vs and SPT-based LPI maps considerably overlapped, some differences in LPI values emphasized the importance of integrated use of the geophysical and geotechnical methods. Hence, liquefaction analysis with different approaches will enable it to operate according to the most cautious situation in risk management.

Influence of source-to-site distance and diagenesis on liquefaction triggering of 200,000-year-old beach sand

Liquefaction triggering of the outcropping 200,000-year-old Ten Mile Hill beds sand facies (Qts) near Charleston, South Carolina is characterized in this paper. The characterization includes evaluating the relative susceptibility to liquefaction of Qts assuming a uniform seismic load and using seismic cone penetration testing at 46 sites, the ratio of measured small-strain shear wave velocity to estimated small-strain shear wave velocity (MEVR), and the liquefaction potential index (LPI). The computed LPI values indicate a slight decrease in the liquefaction susceptibility of Qts moving away (5 to 30 km) from the likely source of the 1886 Charleston earthquake (Mw ~ 7). Also characterized is the liquefaction potential of Qts during the Charleston earthquake and a range of other earthquake loadings. The results for the range of other earthquake loadings are summarized in terms of liquefaction probability curves, which provide a method for mapping liquefaction potential in Qts. A back-calculated, lower-bound diagenesis correction factor of 1.11 for areas of Qts where liquefaction surface manifestations were not observed agrees well with the published data.

Liquefaction investigation of Balaroa, Central Sulawesi on liquefied and non-liquefied areas

On September 28, 2018, an earthquake occurred in Central Sulawesi with Mw 7.5. This earthquake caused severe damage in Balaroa due to liquefaction that resulted in flow-slide that destroyed 1357 houses. Some fears arose related to the recurrence of the disaster. A study was conducted in the Balaroa liquefied area and the non-liquefied area nearby to examine the ground condition of the site that may not be appropriate for residential purposes. The investigation adopted Liquefaction-Triggering-Based Standard Penetration Test (SPT) Procedure by Idriss and Boulanger, and then was analysed further using Liquefaction Potential Index (LPI) by Iwasaki et al. Data for analysis were obtained from soil investigation at the liquefied area, i.e., at beginning and middle of the flow-slide area, and at outside of the flow-slide end which represented a non-liquefaction area. The results showed that in the liquefied area, the LPI values of 24 and 25 were categorized as very high liquefaction potential, whereas, at the non-liquefied area nearby, the LPI was found about 4 that was in the range of low liquefaction potential. High liquefaction potential conditions occur when thick layer(s) of liquefied soil is found at the upper part of the ground with 4 m or more thickness.

Assessment of Soil Liquefaction Potential Based on SPT Values at Some Ground Profiles in the North Central Coast of Vietnam

The North Central Coast of Vietnam has a wide distribution of loose sand which is often exposed on the surface. The thickness changes from a few meters to over ten meters. This sand with the loose state can be sensitive to the dynamic loads, such as earthquakes, traffic load, or machine foundations. It can be liquefied under these loadings, which might destroy the ground and buildings. The Standard Penetration Test (SPT) is widely used in engineering practice and its values can be useful for the assessment of soil liquefaction potential. Thus, this article presents some ground profiles in some sites in the North Central Coast of Vietnam and determines the liquefaction potential of sand based on SPT and using three parameters, including the Factor of Safety against Liquefaction (FSLIQ), Liquefaction Potential Index (LPI), and Liquefaction Severity Number (LSN). The research results show that the FSLIQ, LPI, and LSN values depend on the depth of sand samples and the SPT values. In this study, the sand distributed from 2.0 to 18.0m with (N1)60cs value of less than 20 has high liquefaction potential with FSLIQ&lt;1, LPI is often higher than 0.73, and LSN is often higher than 10. The results also show that many soil profiles have high liquefaction potential. These results should be considered for construction activities in this area.

Geostatistical analysis of spatial variability of the liquefaction potential – Case study of a site located in Algiers (Algeria)

Abstract The city of Algiers (Algeria) is a highly seismic area, and therefore, soil liquefaction poses a major concern for structures resting on sandy soil. A campaign of 62 static penetration tests or cone penetrometer tests (CPT) was carried out on a site located in the commune of Dar El Beïda in Algiers. The soil Liquefaction Potential Index (LPI) values were assessed, for each borehole, based on the simplified procedure of Seed and Idriss. On the other hand, the geographic information system and geostatistical analysis were used to quantify the risk of soil liquefaction at the studied site. It is worth mentioning that the (LPI) was taken as a regionalized variable. In addition, the experimental variogram was modeled on the basis of a spherical model. Also, the interpolation of the LPI values in the unsampled locations was performed by the Kriging technique using both isotropic and anisotropic models. Kriging standard deviation maps were produced for both cases. The cross-validation showed that the anisotropic model exhibited a better fit for the interpolation of the values of the soil liquefaction potential. The results obtained indicated that a significant part of the soil is liable to liquefy, in particular in the northwestern region of the study area. The findings suggest that there is a proportional relationship between the risk of liquefaction and the increase or decrease in seismic acceleration.

Liquefaction hazards mapping along Rеd Sеa coast, Jеddah city, Kingdom of Saudi Arabia

This study mainly aims to evaluate as well as to develop maps of the liquefaction potential for Jeddah City in the Kingdom of Saudi Arabia. Data is obtained and used from 214 boreholes associated with standard penetration tests (SPT). Through taking into account comparable seismic hazardous situations to amax = 0.1 g, the liquefaction potential index (LPI) is measured. In order to compile the liquefaction hazard map, LPI values are correlated, showing the quantitative aspects of the liquefiable layers and the area of likelihood of induced disturbance. This data was analyzed within the framework of the Geographical Information Systems (GIS) application. The results show that, with the exception of the sites in the Abhur and Al-Hamra districts where the liquefaction potential is moderate to high, the main part of the city of Jeddah belongs to a very low liquefaction potential area. The developed liquefaction hazard maps will serve as helpful guides for land planning and management in Jeddah city. In addition to that, they serve as an example of the evaluation of the liquefaction hazard that can also be found in other developed cities in the seismic-prone areas of southern and eastern Saudi Arabia.

Local and regional evaluation of liquefaction potential index and liquefaction severity number for liquefaction-induced sand boils in pohang, South Korea

An earthquake of moment magnitude 5.4 occurred on November 15, 2017 in Pohang, South Korea. This earthquake is the second largest instrumented earthquake ever recorded in South Korea and caused extensive damage to the ground and infrastructures. Hundreds of liquefaction-induced sand boils were observed in the rice fields near the epicenter. We calculate the liquefaction potential index (LPI) and liquefaction severity number (LSN) using the existing borehole data from the area, which includes 166 soil borings, to predict local and regional sand boils. Three of the soil borings considered in the dataset are within 47 m from the sand boils, and one is within 174 m from the sand boil. We provide detailed soil profiles at 20 sites (four of which are considered to be at liquefied sites) and soil properties at three sites (two of which are at liquefied sites). The calculated LPI and LSN values are in good agreement with the actual sand boil locations at 19 out of the 20 sites. Then, we use the existing borehole data to produce a regional liquefaction map using interpolation methods. As is common in regional seismic hazard maps, geotechnical and ground motion data are limited; therefore, we assess the uncertainty of important input parameters, such as the peak ground acceleration, water table, and N-value. For the regional maps, the maximum accuracy of the LPI is 69% at an LPI threshold of 2, and that of the LSN is 71% at an LSN threshold of 10. We report some ground settlements in the areas with high LPI and LSN values. Furthermore, we propose models for predicting the sizes and occurrence probabilities of sand boils.

Estimation of liquefaction potential in Eco-Delta City (Busan) using different approaches with effect of fines content

Soil liquefaction which is a disastrous phenomenon induced by the earthquake, is widely investigated in many researches in geotechnical engineering. In this study, a SPT-N based investigation is carried out to assess the susceptibility of liquefaction in Eco-Delta city, located in the southwestern part of Busan city in South Korea. Data from 229 sites are analyzed for the earthquake of 7.5 magnitude with a peak horizontal acceleration of 0.2 g to carry out the liquefaction potential index (LPI) through two deterministic methods which have different factors of safety (FS). The liquefaction probability is investigated by the deterministic and reliability methods and the liquefaction hazard maps are generated. To observe the effect of fines content and plasticity index on the liquefaction susceptibility, three different cases are considered. It is found that among the four approaches used, Overseas Coastal Area Development Institute of Japan (OCDI) method showed more sensitivity to changes of fines content and plasticity index. The Eco-Delta city is found to be highly vulnerable to liquefaction having 91% of sites with LPI values greater than 15.

Assessment of soil liquefaction potential: a case study for Moulvibazar town, Sylhet, Bangladesh

Liquefaction can intensify the destruction caused by an earthquake; thus, a region with high liquefaction potential could be more disastrous. Bangladesh is surrounded by the Indo-Burma Folded Belt in the east, the Dauki Fault and Himalayan Syntaxis in the north that are known to have occurred high magnitude earthquakes (e.g., Mw > 7) in the past. Therefore, assessing seismic hazards in the regions that are economically growing fast is of great interest. Among many other hazard assessment parameters, soil liquefaction potential index (LPI) can be used to assess seismic hazards. In this study, we have assessed the seismic hazard potential for a small town (Moulvibazar) in the northeast Bangladesh documenting liquefaction potential indices for different surface geological units using an earthquake of moment magnitude Mw 8 having a peak horizontal ground acceleration (PGA) of 0.36 g. Twenty-five standard penetration test (SPT) boreholes were completed within the study area to obtain SPT-N values for two surface geological units: (1) Holo–Pleistocene low elevated terrace deposits (Zone 1) and (2) Holocene flood plain deposits (Zone 2). Using the SPT-N values, the LPI values have been calculated for the soil profile of each borehole. The LPI values in the town vary from 0 to 42.33, whereas values from 1.42 to 7.52 are in Zone 1 and values from 0 to 42.34 are in Zone 2. It has been predicted that 42% and 78% areas of Zone 1 and Zone 2, respectively, might exhibit surface manifestation of liquefaction. The results of this study can be used for seismic risk management of Moulvibazar town.

The Old Adapazarı Atatürk City Stadium Risk Assessment

The land of the Old Adapazarı Atat&amp;amp;uuml;rk City Stadium, which was laid in the center of Adapazarı in the 1950s, was designed as the Sakarya National Garden due to the construction of the new stadium structure. In the National Garden, the masonry stone section to the north of the old stadium was requested to be preserved. In this study, a scientific evaluation has been made in terms of superstructure and soil properties in order to prevent damage in a possible earthquake. Eight cone penetration tests were conducted in the field and the results were evaluated. Liquefaction potential index values were determined for each sounding as a result of liquefaction analyzes performed by cyclic stress analysis and the results were associated with Geographical Information Systems and a liquefaction thematic map was prepared. As a result, it has been concluded that liquefaction may occur in the western part of the ground where the foundation of the building is located.

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 &gt; 5.

Modification of the liquefaction potential index to consider the topography in Christchurch, New Zealand

In recent years, many have mapped the liquefaction potential index (LPI) to describe the liquefaction hazard at regional scale. Several investigators have calibrated the LPI to field observations of liquefaction-induced ground failure after a number of major earthquakes; the significance of LPI values and their correlation with the severity of liquefaction-induced ground failure can vary greatly depending on the calibration. In this study, the LPI was computed at more than 1200 cone penetration test soundings across the Christchurch area, New Zealand, using peak ground accelerations from the 2011 Christchurch Earthquake. Based on detailed field observations of liquefaction-induced ground failure after the earthquake, it was shown that the LPI has potential for discriminating between areas with no liquefaction-induced ground failure hazard and areas that may experience liquefaction-induced ground oscillations and settlement; however, the LPI performed poorly at sites where severe ground failures occurred, especially at sites that experienced lateral spreading. As many researchers have found a positive correlation between lateral spreading and the proximity and depth of a nearby free-face (i.e., a steep topographic depression, river channel, etc.), a new LPI framework was proposed that includes a parameter named the free-face ratio (FFR). FFR was shown to have a significant correlation with field observations of lateral spreading in Christchurch. It was shown that by incorporating FFR into the LPI framework, modified LPI values are positively correlated with the severity of field observations of liquefaction-induced ground failure in Christchurch. It was also shown that maps can be produced based on LPI and FFR, and such maps rarely underpredict the liquefaction-induced ground failure hazard, unlike maps based on the unmodified LPI.

Assessment of earthquake-induced liquefaction hazard in urban areas of Hanoi city using LPI-based method

Assessment of earthquake-induced liquefaction hazard in urban areas of Hanoi city using LPI-based method

Liquefaction hazard mapping in the city of Boumerd\xe8s, Northern Algeria

The city of Boumerdès, located in Northern Algeria, was badly affected during the May 21, 2003 Zemmouri (Mw = 6.8) earthquake where extensive liquefaction has been reported. The aim of this paper is to assess and to map the liquefaction potential for Boumerdès. We collected and used data from 154 boreholes, 10 down-hole tests, 56 standard penetrations tests (SPT), and inventory of 35 water level points. This data has been analyzed in the framework of geographical information systems (GIS). We assessed the liquefaction potential index (LPI) by considering a seismic hazard scenario corresponding to amax = 0.48 g calculated, using a probabilistic approach, for a return period of 500 years. LPI values have been correlated to compile the liquefaction hazard map that indicates the quantitative characteristics of the liquefiable layers and the induced disruption probability area. Results show that the main part of the city of Boumerdès belongs to a low liquefaction potential area except for a narrow corridor along the Corso waterway, where the liquefaction potential is moderate to high. The obtained results are compatible with the geological, geotechnical and hydrogeological susceptibility to liquefaction of the area. The results also show a good agreement with the observations made after the May 21, 2003 Zemmouri earthquake. The obtained liquefaction hazard maps may serve as useful tools for land management and planning in the city of Boumerdès and as an example of liquefaction hazard assessment that may be applied in other populated cities in northern Algeria’s seismic prone areas.

Application of Dynamic Cone Penetrometer test for assessment of liquefaction potential

This paper presents a new method for the assessment of liquefaction potential, using the in-situ Dynamic Cone Penetrometer (DCP) test. The DCP is a lightweight and portable penetrometer that is considerably faster and cheaper than the boring equipment such as the Standard Penetration Test (SPT). In the present study, the liquefaction potential of liquefiable soils of six different sites was investigated using both the in-situ DCP test and the SPT. Following assessment of the liquefaction potential, the liquefaction potential index (LPI) was calculated for all six sites, again using both of these tests. Finally, the DCP test's capacity to assess liquefaction potential was evaluated by comparing the LPI values obtained from this test, as a new method, with the LPI values obtained from the SPT, as an index and popular method. The results showed that the DCP is equally as capable as the SPT in evaluating liquefaction potential.

Liquefaction potential analysis of the Kashmir valley alluvium, NW Himalaya

We present the liquefaction potential analysis of Kashmir valley alluvium in general with special emphasis to four benchmark localities. The synthetic ground motions from the site response analysis of the valley during the 8 October 2005 Kashmir earthquake of Mw 7.6 are used as input motions. To determine the dynamic properties of soil, 64 SPT (Standard Penetration Test) boreholes spread across the valley were used. The analysis shows that the northwestern part of the Kashmir valley has very high, central part very high to high and southeastern part low to very low liquefaction potential, as measured on the Liquefaction Potential Index (LPI) scale. These results are complemented by the field investigations carried out after the earthquake wherein liquefaction features were observed in the northwestern part of the valley. At the benchmark sites, the soil profiles of Baramulla (Ahtishampora) and Kupwara are unsafe, showing a tendency to liquefy, while as in Anantnag (Khanabal) and Srinagar (Mehjoor Nagar) shallow layers are safe but the deeper layers are unsafe. As far as liquefaction potential is concerned, Baramulla (Ahtishampora) and Kupwara soil profiles show very high LPI values, Srinagar (Mehjoor Nagar) portrays high LPI, but Anantnag (Khanabal) exhibits low liquefaction potential.