Liquefaction Evaluation Research Articles

Liquefaction evaluation on sand-like gravelly soil deposits based on field Vs measurements during the 2008 Wenchuan earthquake

During the 2008 Wenchuan earthquake, extensive liquefaction of sand-like gravelly soil deposits was observed over an area of about 500 × 200 km2. Since gravel content significantly affects the stiffness and liquefaction resistance of gravelly soils, it has become an ongoing challenge for engineers to reliably and cost-effectively assess the liquefaction resistance of such soil deposits with different gravel contents. To this end, the procedures for consistently assessing the liquefaction resistance of sand-like gravelly soils were first put forward based on the previously proposed improved CRR-Vs1 characterization model for binary mixtures, which converts the liquefaction evaluation of sand-like gravelly soils into the assessment of liquefaction resistance of the base sand matrix with an equivalent stiffness. Then, in-situ gravelly soils sampled from the earthquake-impacted area were tested to parameterize the proposed characterization model. Lastly, liquefaction case histories of gravelly soils compiled during the 2008 Wenchuan earthquake were recompiled and restudied to validate the performance of the proposed characterization model. Typical liquefaction case history studies show that the proposed characterization model successfully predicts the severe liquefaction hazard at the Banqiao school site and the marginal liquefaction phenomenon at the Jiangyou thermal power plant site. Comparisons between the proposed characterization model and the 54 recompiled liquefaction case history datasets demonstrate that the proposed characterization model can accurately discriminate both the liquefied and non-liquefied case histories. These validation results in turn suggest that the proposed characterization model is highly feasible for engineering applications on a regional scale covering various gravel contents.

Energy-Based Liquefaction Evaluation: The Port of Kushiro in Hokkaido, Japan, 2003 Tokachi-Oki Earthquake

Energy-Based Liquefaction Evaluation: The Port of Kushiro in Hokkaido, Japan, 2003 Tokachi-Oki Earthquake

Reliability‐based state parameter liquefaction probability prediction using soft computing techniques

The state parameter (ѱ) accounts for both relative density and effective stress, which influence the cyclic stress or liquefaction characteristic of the soil significantly. This study presents a ѱ‐based probabilistic liquefaction evaluation method using six soft computing (SC) techniques. The liquefaction probability of failure (PL) is calculated using the first‐order second moment (FOSM) method based on the cone penetration test (CPT) database. Then, six SC techniques, such as Gaussian process regression (GPR), relevance vector machine (RVM), functional network (FN), genetic programming (GP), minimax probability machine regression (MPMR) and multivariate adaptive regression splines (MARS), are used to predict PL. The performance of these models is examined using nine statistical indices. Additionally, plots such as regression plots, Taylor diagrams, error matrix and rank analysis are shown to assess the SC model's performance. Finally, sensitivity analysis is performed using the cosine amplitude method (CAM) to assess the influence of input parameters on output. The current study demonstrates that SC models based on state parameter predict PL effectively. RVM and MPMR models closely follow the GPR model in terms of performance, which is superior to the other models. Notably, two equations are generated using GP and MARS models to predict PL. The results of the sensitivity analysis reveal the magnitude of earthquake (Mw) as the most sensitive parameter. The outcomes of this research will offer risk evaluations for geotechnical engineering designs and expand the use of state parameter‐based SC models in liquefaction analysis.

Evaluation of soil liquefaction in the city of Hatay triggered after the February 6, 2023 Kahramanmaraş-Türkiye earthquake sequence

This study investigates the consequences of consequences of liquefaction hazards following the February 6, 2023, Kahramanmaraş Earthquakes in Hatay, Türkiye. Field reconnaissance surveys were conducted in areas prone to liquefaction, including recent alluvial basins, the Amik (Amuq) Plain, and the Asi (Orontes) River. Specifically, attention was given to İskenderun (Alexandretta), Dörtyol coasts, the Hatay Airport region, and Demirköprü village near the Asi River. Observations indicated that geological and geomorphological factors primarily influenced liquefaction ejecta and liquefaction-induced lateral spreading in these areas. In Dörtyol, liquefaction manifestations were observed on the coastline, which has undergone natural processes, while in İskenderun, they occurred on human-made extended reclaimed land. Additionally, liquefaction manifestations in the Hatay Airport region were impacted by the drained Amik Lake, and those in Demirköprü Village were influenced by the fluvial nature of the Asi River and its sub facies. The sites experiencing liquefaction and lateral spreading mainly comprised coastal deposits, lacustrine sediments, and sub facies of the meandering river, such as point bars, abandoned channels, and levees. Consequently, the study underscores the significant correlation between geomorphology and liquefaction hazards in the context of the 2023 Kahramanmaraş-Türkiye Earthquakes. Considering these factors may facilitate further research and the identification of sites susceptible to liquefaction.

Numerical Evaluation of Liquefaction During Vibratory Pile Driving in Saturated Sand

Numerical Evaluation of Liquefaction During Vibratory Pile Driving in Saturated Sand

Thermodynamic and exergetic evaluation of CO2 liquefaction for ship transport

CO2 liquefaction is significant to ensure CO2 transport safety and improve efficiency. Aiming at the temperature and pressure required for ship transport, this paper examines four liquefaction schemes including the compression refrigeration system, the Linde Hampson system, the precooled Linde Hampson system and the Claude system. The thermodynamic and exergetic ananlysis models are established primarily and total power consumption, liquefaction efficiency as well as exergy efficiency of the four systems are calculated and compared. The precooled Linde Hampson system shows the best performance with the three indicators of 391.74 kJ/kg, 97.97 % and 55.86 %, respectively. Additionally, exergy destruction among the system components are analyzed for Linde Hampson system and precooled Linde Hampson system. The maximum exergy destruction stem is from compressors. Another thing to note is that the proportion of the total exergy destruction with Joule-Thomson (J-T) valves are 19.38 % and 2.63 %, respectively. Furthermore, the replacement of the J-T valve by a liquid expander allowed for 9.35 % and 0.94 % electric power saving for the two systems, respectively. The pressure drop before and after the J-T valve directly determines the effect of this change. The research results could provide some vital reference for choosing proper CO2 liquefaction methods and reducing energy consumption during the process.

Numerical Evaluation of Static Liquefaction–Induced Flowslide Causing the Edenville Dam Failure, Michigan

Numerical Evaluation of Static Liquefaction–Induced Flowslide Causing the Edenville Dam Failure, Michigan

Probabilistic evaluation of earthquake-induced liquefaction using Bayesian network based on a side-by-side SPT–CPT database

In situ tests such as standard penetration test (SPT) and cone penetration test (CPT) are often conducted to evaluate the probability of earthquake-induced liquefaction. However, the models adopted have seldom attempted to utilize SPT and CPT data simultaneously. In this study, a side-by-side SPT–CPT database at historical earthquake sites is established; then, a Bayesian network model is constructed to predict the probability of soil liquefaction based on this database, with which the SPT and CPT data are utilized simultaneously. Next, comparative studies are undertaken to illustrate the superiority of the Bayesian network-based probabilistic soil liquefaction model developed over other models, in terms of six SPT- and CPT-based conventional liquefaction models in the literature and two Bayesian network-based models. It should be noted that the liquefaction sites with two in situ tests are scarce and side-by-side SPT–CPT data can be incomplete, which leads to challenges in applying the Bayesian network model developed. To address this problem, correlations between SPT and CPT data are analyzed, and these correlations are further included in the Bayesian network model; as a result, a modified Bayesian network model is reached. Finally, the influence of the proportion of missing data in the incomplete SPT–CPT data on the liquefaction prediction accuracy is discussed.

An improved characterization model of liquefaction resistance by shear wave velocity for binary mixtures with consideration of coarse content

This paper aims to develop an improved CRR-Vs1 characterization model for soil liquefaction evaluation for binary mixtures via a series of DEM simulations of drained monotonic tests, undrained cyclic tests and shear wave velocity measurements. The contributions of different contact types to the mean effective stress of binary mixtures depend mainly on the coarse content and to a negligible extent on the confining pressure and particle size ratio. The threshold coarse content, denoting the mechanical behavior transition of binary mixtures, can be identified either by the macroscopic evolutions of critical state lines or the distributions of microscopic contact forces. The skeleton reinforcement factor m decreases approximately linearly with the increase of coarse content, while the skeleton supporting factor b exhibits a nonlinear decrease relationship with coarse content, both of which are influenced by particle size ratio. Under the condition of the same equivalent skeleton void ratio, a Vs-correction function and a CRR-correction function are introduced to consistently describe the nonlinear coarse content effects on the shear wave velocities and liquefaction resistances of binary mixtures. The improved CRR-Vs1 characterization model with consideration of coarse content is established by relating the shear wave velocity and liquefaction resistance of binary mixtures to those of the base fine or coarse matrix using the concept of equivalent skeleton void ratio. Application of the proposed characterization model to real geotechnical materials requires laboratory element tests to determine the Vs-correction function and the CRR-correction function, together with the CRR-Vs1 benchmark curve of the base fine or coarse matrix.

A cone penetration test database for multiple thin-layer correction procedure development

Cone penetration tests (CPTs) are a commonly used in situ method to characterize soil. The recorded data are used for various applications, including earthquake-induced liquefaction evaluation. However, data recorded at a given depth in a CPT sounding are influenced by the properties of all the soil that falls within the zone of influence around the cone tip rather than only the soil at that particular depth. This causes data to be blurred or averaged in layered zones, a phenomenon referred to as multiple thin-layer effects. Multiple thin-layer effects can result in the inaccurate characterization of the thickness and stiffness of thin, interbedded layers. Correction procedures have been proposed to adjust CPT tip resistance for multiple thin-layer effects, but many procedures become less effective as layer thickness decreases. To compare or improve these procedures and to develop new ones, it is critical to have pairs of measured tip resistance ( q m) and true tip resistance ( q t) data, where q m is the tip resistance recorded by the CPT in a layered profile, and q t represents the tip resistance that would be measured in the profile absent of multiple thin-layer effects. Unfortunately, data sets containing q m and q t pairs are extremely rare. Accordingly, this article presents a unique database containing laboratory and numerically generated CPT data from 49 highly interlayered soil profiles. Both q m and q t are provided for each profile. An accompanying Jupyter notebook is provided to facilitate the use of the data and prepare them for future statistical learning (or other) applications to support multiple thin-layer correction procedure development.

State of the practice on energy-based liquefaction evaluation and research significance

<p>Since the 1964 Niigata and Alaskan earthquakes, which incurred severe liquefaction damage, liquefaction-related design for infrastructures and buildings has been developed exclusively on the principle of force equilibrium. However, the energy concept is increasingly recognized as superior for simplified and robust liquefaction designs because of the uniqueness of energy capacity in soil failures regardless of the differences in earthquake loads. The energy-based liquefaction evaluation method (EBM) has been pursued by many investigators where dissipated energy for liquefaction is focused in place of liquefaction strength defined in the conventional stress-based method (SBM). Furthermore, the EBM enables sound liquefaction-related designs without resorting to sophisticated but highly variable/tricky numerical analyses and contributes as a scale to measure the reliability of those numerical tools. Thus, the EBM, though short of practical use in today's engineering works, should be able to serve as a simplified liquefaction evaluation tool besides the SBM. We reviewed the basic idea as well as the recent developments of the EBM together with the supporting data. We also discussed how to simplify and approximate the energy-based liquefaction behavior to implement robust evaluations in practical problems. The EBM liquefaction evaluation steps were delineated and exemplified by case studies for practicing engineers compared to the SBM.</p>

Towards a novel method for liquefaction evaluation of silty sands

Towards a novel method for liquefaction evaluation of silty sands

Liquefaction evaluation of large pier foundations by undisturbed sampling method called GS sampling for coral pebble mixed soil

Liquefaction evaluation of large pier foundations by undisturbed sampling method called GS sampling for coral pebble mixed soil

Ground-motion effects on liquefaction response

This article evaluates the influence of ground-motion characteristics on the liquefaction response of free-field level-ground deposits. Ground motions imposed on liquefiable soils have historically been characterized by the peak ground acceleration (PGA). In simplified procedures for liquefaction evaluation, the use of the ground surface PGA can be justified by the fact that it is closely related to the peak shear stresses developing in the critical zone for liquefaction manifestation, at shallow depths. In nonlinear dynamic analysis (NDA), however, such simplified characterization of the input motion using the bedrock-level PGA can result in large record-to-record variability in the computed response. Record-to-record variability can be substantially reduced by employing more appropriate ground-motion intensity measures (IMs) for specific aspects of the liquefaction response observed in NDA. Among 25 IMs examined in this study, the Modified Acceleration Spectrum Intensity (MASI), defined as the integral of the acceleration spectrum over periods 0.1–1.5 s, is found to be the most efficient IM for the prediction of the pore-pressure response of liquefiable deposits, whereas Velocity Spectrum Intensity (VSI) ranks among the best-performing IMs for response parameters related to ground deformations. Importantly, such “multiple-period spectrum IMs” are shown to perform consistently better than several highly-regarded time-integrated IMs (e.g. Arias intensity, CAV). Conclusions and recommendations are drawn on the basis of a comprehensive series of NDAs involving 180 input motions and 13 deposit models based on characteristic soil profiles from Christchurch.

Spatial variability of seabed liquefaction in the Yellow River Subaquatic Delta based on CPT

The soil composition in the Yellow River Subaquatic Delta is complex, and soil liquefaction is a serious threat to the safety of offshore projects. Two-dimensional soil liquefaction evaluation cannot meet the practical needs of engineering. In this paper, in-situ cone penetration tests (CPT) were used to investigate the classification and distribution of soils. Liquefaction variability prediction analysis was performed for the region by the inverse distance weighting (IDW) and full-cokriging methods using the liquefaction vulnerability index (LVI) and cone tip resistance as sample parameters. The results show that: (1) the overall soil grain size in the offshore direction is coarser than that in the far shore, with the clay content less than 18% at Station S1 in the near shore, but more than 90% at Stations S10 and S5 in the far shore; (2) using IDW to predict the liquefaction potential, which first decreases and then increases in the offshore direction, the one-dimensional reconsolidation settlement (SV1D) predicts better than the other two LVIs; (3) a full-cokriging method with normalized cone tip resistance as the main variable and sleeve resistance (fs) as the auxiliary variable is proposed, and its prediction accuracy is better than that of the ordinary kriging (OK) method.

Investigation of sand liquefaction potential in cyclic triaxial test and some premilinary research results in Vietnam

In the world, cyclic triaxial tests are widely used to evaluate the liquefaction potential of soil and determine the cyclic parameters for seismic design. However, the application of cyclic trixial test for evaluation of soil liquefaction is still limited in Vietnam. This paper introduced the cyclic triaxial apparatus, method and testing procedure to access the liquefaction potential of sand under cyclic loading. The research on some saturated sandy soils with high fine-grained content in Vietnam showed that the research results of soil liquefaction potential is reliable. In which, the liquefaction characteristics of sand are evaluated based on the changes of stress, strain and pore water pressure according to the cyclic cycles, thereby determining the liquefaction point and liquefaction boundary for fine sandy soils at different density levels.

Liquefaction of industrial zone against earthquake loading using laboratory and field measurements

Purpose. To assess the liquefaction of Kirkuk’s industrial region following a series of earthquakes that struck the city during the previous five years based on the current earthquake activity in the region. Methodology. Initially, substantial relationships for shear wave velocity in different types of soil were collected and studied, where the majority of these correlations necessitated the use of standard penetration tests in the field. Indeed, two boreholes were drilled up to a maximum depth of 10 m, and the numbers of blows for conventional penetration tests were measured at various depths in each borehole. The stated shear wave velocity values from the literature, as well as the maximum and lowest shear wave velocity constraints, were employed in a simple technique to estimate the cyclic shear stress induced by earthquake loading. Findings. Based on laboratory and field data, the safety factor against earthquake-induced liquefaction can be determined. When the worst-case scenario was examined using the suggested values of shear wave velocity, the factor of safety against earthquake was reduced by 94 % as the depth increased from 3.5 to 9 m. Originality. No previous study has tried to quantify the liquefaction impact of industrial zone of Kirkuk city as such an important rich-oil area was influenced by series of earthquakes occurrence. More importantly, for the first time field soil samples from on-site boreholes in Kirkuk city have been collected and used for liquefaction assessment since such real field data can be utilized properly in liquefaction evaluation process in the absence of any comparable quantification for the investigated area. Practical value. Precious liquefaction analysis should be performed prior to any proposed project construction in the light of increased earthquake activity in the industrial zone in Kirkuk city (Iraq).

Analytical solution for seepage pressure of multilayered sand seabed considering interaction between wave-current action and shield tunnel

Existing theoretical studies of the seepage field around subsea shield tunnels under wave action take less account of the tunnel lining permeability, especially the effect of wave and current action on tunnel. Moreover, the solutions generally treat the sand as homogeneous and isotropic, ignoring the influence of multilayered seabed. In this paper, the analytical solutions are presented for the seepage pressure and liquefaction evaluation of sand around tunnel in multilayered seabed under wave and current action. The pore pressure response of pure seabed is obtained by the transmission and reflection matrix method. The mirror image method is introduced to establish governing equation of excess pore pressure reflected by tunnel, and the analytical solution of equation is obtained by Fourier series expansion under the condition of continuous seepage between sand and lining. Based on the superposition principle, the seepage pressure and liquefaction evaluation of sand around tunnel in multilayered seabed are obtained. Then the analytical solutions are compared with numerical and experimental results, and good agreement is obtained. In addition, the influencing factors of wave parameters (wavelength, period, current), seabed parameters (permeability, shear modulus, saturation) and tunnel parameters (lining thickness, lining permeability) are analyzed.

Probabilistic-based seismic fragility assessment of earthquake-induced site liquefaction

As a very complex and uncertain problem, seismic liquefaction is affected by many factors, such as earthquake intensity, site conditions, soil properties, etc. During the past half a century, the state-of-the-art in analysis and evaluation of earthquake-induced soil liquefaction and its consequences as well as the state-of-the-practice in improving seismic stability to resist liquefaction have been made much progress. However, the fragility analysis and assessment for seismic liquefaction of sites have not been paid enough attention to. In this paper, the concept of seismic liquefaction fragility for building sites is proposed. The soil resistance to liquefaction and liquefaction possibility are expressed as a fragility function of ground motion intensity, which can be used to describe minor, moderate and severe liquefaction potential under different ground motion intensity. Combined with the existing research results of seismic liquefaction evaluation, the analysis method of liquefaction fragility is given. Taking a specific site as an example for liquefaction fragility analysis, it is found that taking the calculated exceedance probability of different liquefaction levels as the observation value, the liquefaction fragility function follows both lognormal distribution and log-logistic distribution. With the increase of liquefaction level, the median value of liquefaction fragility function increases, while the site liquefaction fragility curve moves to the right, which shows that the ability of the site to resist more severe liquefaction is increasing. When convolved with the analysis results of liquefaction triggering and hazard, the liquefaction fragility function can be a much efficient tool for seismic liquefaction risk analysis of specific sites.

A probabilistic liquefaction reliability evaluation system based on CatBoost-Bayesian considering uncertainty using CPT and Vs measurements

The existing liquefaction evaluation model inevitably contains uncertainty in the establishment process, which will affect the evaluation of the effect of seismic liquefaction. The purpose of this study is to combine cone penetration test and shear wave velocity test (CPT-Vs) to develop a simplified probabilistic framework for liquefaction potential assessment, and to couple the first-order reliability method (FORM) to reduce model and parameter uncertainties. Based on the case histories of CPT-Vs, the framework uses the Bayesian-optimized CatBoost algorithm to develop a limit state function for liquefaction trigger analysis. Within the framework of FORM, this limit state function parameter and model uncertainties are characterized by the mean (μc) and coefficient of variation (COV) of the soil parameters, which are obtained and calibrated by combining site-specific new information with prior knowledge. Moreover, in the absence of parameter uncertainty, a deterministic model is developed which establishes a mapping function between probability of liquefaction to factor of safety. The study results show that the uncertainty of the limit state function model can be characterized by using μc=1.14 and COV=0.30, and the simplified liquefaction probabilistic framework can provide reasonable liquefaction evaluation results.