Assessment Of Soil Liquefaction Potential Research Articles

Initial assessment of soil liquefaction potential for selected sites in Hilla city, Babylon Governorate, Iraq

The current research focused on the use of some geotechnical characteristics for the initial assessment of soil liquefaction at sites in the city of Hilla, Babylon Governorate. Five sites were chosen in the city centre and relatively close to the Shatt Al-Hilla. Geotechnical properties data were used to separate soils that can be classified as liquefiable from those that are not. The criteria used in this study were of two types: the Second Chinese Criteria, which is based on the natural water content and liquid limit; and the Modified Chinese Criteria, which depends on the clay content and liquid limit for the liquefaction potential of the soil. The results of this study showed that in the Second Chinese Criteria the risk of soil increases with an increase in the natural water content and a decrease in the liquid limit; however, in the Modified Chinese Criteria, the liquefaction potential increases with a decrease in the clay content to less than 10% and in the liquid limit to less than or equal to 32%.

Probability based Assessment of Soil Liquefaction Potential in Vijayawada Region (CRDA)

Risks of liquefaction are commonly related to saturated cohesionless soils that have low plasticity and density. As liquefaction causes severe destruction to structures and risk of losing lifeline it is important to study the liquefaction potential for CRDA region because for the development of AP capital heavy structures are being constructed and a population increase is being expected in this region. In the current investigation, soil resistance to liquefaction was analyzed in each bore log in consideration of significant soil characteristics such as grain size, fines content, unit weight, saturation percentage, SPT N-value, and soil origin. The safety factor for liquefaction is evaluated using data from several bore holes that were collected and used for this purpose. The approach recommended by Seed and Idriss was utilized to assess the safety factor for liquefaction. The obtained results from the semi-empirical calculations are further compared to the results obtained from Software for more reliability.

Vs-based assessment of soil liquefaction potential using ensembling of GWO–KLEM and Bayesian theorem: a full probabilistic design perspective

Vs-based assessment of soil liquefaction potential using ensembling of GWO–KLEM and Bayesian theorem: a full probabilistic design perspective

Seismic Soil Characterization to Estimate Site Effects Induced by Near-Fault Earthquakes: The Case Study of Pizzoli (Central Italy) during the Mw 6.7 2 February 1703, Earthquake

Many of the urban settlements in Central Italy are placed nearby active faults and, consequently, the ground motion evaluation and seismic site effects under near-fault earthquakes are noteworthy issues to be investigated. This paper presents the results of site investigations, the seismic site characterization, and the local seismic response for assessing the effects induced by the Mw 6.7 2 February 1703, near-fault earthquake at the Madonna delle Fornaci site (Pizzoli, Central Italy) in which notable ground failure phenomena were observed, as witnessed by several coeval sources. Even though recent papers described these phenomena, the geological characteristics of the site and the failure mechanism have never been assessed through in-situ investigations and numerical modeling. Within a project concerning the assessment of soil liquefaction potential and co-seismic ground failure, deep and shallow continuous core drilling, geophysical investigations and in-hole tests have been carried out. Subsequently, the geotechnical model has been defined and the numerical quantification of the different hypotheses of failure mechanisms has been evaluated. Analyses showed that liquefaction did not occur, and the excess pore water pressure induced by the shaking was not the source of the ground failure. Therefore, it was hypothesized that the sinkhole was likely caused by earthquake-induced gas eruption.

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<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.

Analysis of Soil Liquefaction Potential through Three Field Tests-Based Methods: A Case Study of Babol City

During earthquakes, ground failure is commonly caused by liquefaction. Thus, assessment of soil liquefaction potential in earthquake-prone regions is a crucial step towards reducing earthquake hazard. Since Babol city in Iran country is located in a high seismic area, estimation of soil liquefaction potential is of great importance in this city. For this purpose, in the present research, using field-based methods and geotechnical data (such as unit weight of soil, relative density, SPT number, shear wave velocity and cone tip resistance) of 60 available boreholes in Babol, three liquefaction maps were provided. Finally, one comprehensive liquefaction map was presented for soil of Babol city. The obtained results in this paper are well in line with the previous investigations. Based on the results, the factor of safety in 45% of the study area is less than one (liquefaction occurrence). In addition, the results indicate that since each field-based method requires particular data, applying various field tests is necessary for a more accurate liquefaction assessment.

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.

Assessment of Soil Liquefaction Potential in Kamra, Pakistan

In seismically active regions, soil liquefaction is a serious geotechnical engineering problem that mainly occurs in saturated granular soils with a shallow groundwater table. Significant seismic hazards are present in Kamra, Pakistan. With the rapid increase in construction in recent years, the evaluation of liquefaction is now considered to be more important for land use planning and development. The intent of this study is to highlight soil liquefaction susceptibility that will eventually support the national authorities in developing guidelines for sustainable development and the mitigation of liquefaction. The typical subsoil profile of Kamra consists of silty gravel (GM) overlain by silty sand (SM), poorly graded sand (SP), and fill layers. Kamra is close to the active Ranja–Khairabad fault with a peak ground acceleration of 0.24g. The river Sehat and the Ghazi Brotha canal pass through the study area. In this study, the soil liquefaction potential in Kamra was assessed at 10 different sites (50 boreholes) by using a stress-based procedure for calculating the factor of safety against soil liquefaction. The results revealed that the middle layers, i.e., poorly graded sand and silty sand in the subsoil profile, are extremely susceptible to liquefaction during earthquakes with magnitudes between 7.5 and 8.0 in Kamra. The correlation between the factor of safety and the equivalent clean-sand-corrected standard penetration test (SPT) blow counts according to the earthquake magnitudes was developed and can also be utilized for areas adjoining Kamra that have the same subsoil profile.

Seismic and Geological Bedrock Depth Estimation at Cavezzo Site (Po Plain, Northern Italy): Example of Passive Geophysical Survey in the Assessment of Soil Liquefaction Potential

Seismic and Geological Bedrock Depth Estimation at Cavezzo Site (Po Plain, Northern Italy): Example of Passive Geophysical Survey in the Assessment of Soil Liquefaction Potential

Liquefaction potential assessment of Guwahati city using first-order second-moment method

Soil liquefaction is the failure of the soil due to the sudden increase in a pore water pressure causing the effective stress to reduce significantly thus losing shear strength, with the resulting effect causing the fluid type behavior of the soil. Guwahati city, the capital of Assam, lies in the northeastern region of India and this whole region is considered seismically very active (seismically sixth position globally). The whole region is categorized in Zone-V according to the seismic zoning map of India as per IS 1893:2002 (Part 1). This region witnessed/experienced several major and great earthquakes in the past such as 1897 Shillong and 1950 Assam earthquakes. The soil deposits of the city mainly consist of an alluvial type of Holocene age and the presence of shallow groundwater table makes it vulnerable to soil liquefaction. In this study, an assessment of soil liquefaction potential of Guwahati city is performed based on the methods proposed by Youd and Idriss (J Geotech Geoenviron Eng 127:297, 2001) and Idriss and Boulanger (2010; CPT- and SPT-based liquefaction triggering procedures, 2014) using standard penetration test data. The evaluation of liquefaction potential is carried out for 82 borehole sites considering the Great 1897 Shillong earthquake of Mw 8.1 with a peak ground acceleration of 0.36 g. In the deterministic approach, the various parameters are involved in the evaluation of liquefaction potential, and the uncertainties of the input parameters as well as model cause the dissimilarity of the result. For instance, the same input parameters for both the models show different factor of safety. Hence, a comprehensive probability approach considering the uncertainty of parameters is essential for the evaluation of liquefaction susceptibility. In this study, reliability analysis for both the models based on first- order second-moment method has been used. The Reliability Index based on input parameters such as cyclic resistance ratio and cyclic stress ratio computed for both the models and subsequent liquefaction probability are established. The result shows the city is in most vulnerable condition even up to 15 m depth considering both the methods proposed by Youd and Idriss (J Geotech Geoenviron Eng 127:297, 2001) and Idriss and Boulanger (2010; CPT- and SPT-based liquefaction triggering procedures, 2014). Therefore, extra measure should be taken while constructing structure in and around the study area.

Effect of Parameters on Equivalent Number of Cycles Using ‎Nonlinear Seismic Site Response Analysis

The concept of equivalent number of uniform stress cycles, is essential for assessment of soil liquefaction potential. In this regard, various procedures are used to convert random acceleration time history to uniform cycles having amplitude of 0.65 of peak acceleration. Equivalent number of cycles (Neq) defines equivalent energy generated by harmonic loading as that imposed by irregular motion during an earthquake. Neq is assumed to be a function of earthquake magnitude. Over the past years, in accordance with development in methods of soil liquefaction evaluation, various methods have been proposed to determinate equivalent number of cycles. In particular, parameters like site to source distance (r), have been related directly to Neq. In this study, more than 80 earthquake records have been investigated and their Neqs are assessed using energy approach and nonlinear site response analysis. It is shown that equivalent number of cycles is related to earthquake magnitude (M), r and depth of originated signals. Unlike previous methods which result in scatter in output data, current approach has led to more uniform and consistent results for each earthquake.

Assessment of soil liquefaction potential based on numerical method- a case study of an urban railway project

Paying special attention to geotechnical hazards such as liquefaction in huge civil projects like urban railways especially in susceptible regions to liquefaction is of great importance. A number of approaches to evaluate the potential for initiation of liquefaction, such as Seed and Idriss simplified method have been developed over the years. Although simplified methods are available in calculating the liquefaction potential of a soil deposit and shear stresses induced at any point in the ground due to earthquake loading, these methods cannot be applied to all earthquakes with the same accuracy, also they lack the potential to predict the pore pressure developed in the soil. Therefore, it is necessary to carry out a ground response analysis to obtain pore pressures and shear stresses in the soil due to earthquake loading. Using soil historical, geological and compositional criteria, a zone of the corridor of Tabriz urban railway line 2 susceptible to liquefaction was recognized. Then, using numerical analysis and cyclic stress method using QUAKE/W finite element code, soil liquefaction potential in susceptible zone was evaluated based on design earthquake.

The use of MASW method in the assessment of soil liquefaction potential

The multi-channel analysis of surface wave (MASW) method is a non-invasive method recently developed to estimate shear wave velocity profile from surface wave energy. Unlike conventional SASW method, multi-station recording permits a single survey of a broad depth range and high levels of redundancy with a single field configuration. An efficient and unified wavefield transform technique is introduced for dispersion analysis and on site data quality control. The technique was demonstrated in the assessment of soil liquefaction potential at a site in Yuan Lin, Taiwan. The shear wave velocity and liquefaction potential assessments based on MASW method compares favorable to that based on SCPT shear wave measurements. Two-dimensional shear wave velocity profiles were estimated by occupying successive geophone spreads at several sites in central western Taiwan, at some of which sand boils or ground cracks occurred during 1999 Chi Chi earthquake. Liquefaction potential analysis based on MASW imaging was shown to be effective for estimating the extent of potential liquefaction hazard.