How is liquefaction identified?
Best insight from top research papers
Liquefaction is identified through various methods such as supervised classification using machine learning algorithms based on typical samples , considering geotechnical factors modeled by machine learning for susceptibility assessment , and utilizing the disturbed state concept (DSC) and energy approaches for fundamental procedures in identifying instabilities and final liquefaction . Laboratory analysis involves time-consuming cyclic triaxial tests to study soil liquefaction, with a focus on pore water pressure buildup and granulometric properties of the soil . Geospatial liquefaction susceptibility methods are also employed for assessing exposure of infrastructure networks to liquefaction, aiding in the quantification of national exposure and risk assessment for potential damage . These diverse approaches collectively contribute to the identification and understanding of liquefaction phenomena.
Answers from top 5 papers
More filters
| Papers (5) | Insight |
|---|---|
1 Citations | Liquefaction is identified using geospatial liquefaction susceptibility methods, categorizing areas as very low, low, moderate, high, or very high susceptibility based on infrastructure networks in New Zealand. |
| Liquefaction is identified in laboratory testing by measuring pore water pressure buildup during cyclic shearing of soil samples, influenced by factors like initial density and granulometric properties. | |
| Liquefaction is identified using binary classification methods (random forest, gradient boosting) trained with typical samples, enabling efficient extraction of liquefaction spatial distribution from post-earthquake satellite images. | |
05 May 2021 | Liquefaction is identified through the disturbed state concept (DSC) and energy approaches, focusing on internal mechanisms like critical (Dc) and final (Df) disturbances, rather than external methods. |
| Liquefaction susceptibility is identified by evaluating geotechnical factors like ground elevation, SPT N-value, soil type, and fines content using machine learning algorithms and estimating peak ground acceleration. |
Related Questions
What is the liquefaction potential of clay?5 answersThe liquefaction potential of clay is influenced by its composition and characteristics. Clayey soils generally exhibit a lower liquefaction potential compared to sandy soils, with resistance to liquefaction increasing as plasticity increases. The presence of fine-grained materials like silt or clay can impact the cyclic strength of the soil, with plastic fines typically increasing liquefaction resistance due to their dilitative nature. However, the behavior of non-plastic fines towards liquefaction resistance can be contradictory. In practical engineering applications, estimating the liquefaction potential of clayey soils can be done using the plasticity index, which helps in assessing the soil's susceptibility to liquefaction and guiding safe and economical civil engineering designs.
What does liquefaction do to buildings in earthquakes?4 answersLiquefaction in earthquakes can have significant effects on buildings. The cyclic shear stress during an earthquake can cause an increase in excess pore water pressure and a loss of shear strength in saturated soil deposits, leading to liquefaction. This can result in excessive strains and a continued loss of shear strength, causing damage to buildings. Liquefaction can induce settlements and tilts in buildings, affecting their performance and function. The presence of liquefiable layers can lead to ground settlements, which can impact the stability of structures, especially those with spread footings. The magnitude of settlement and tilt can be influenced by various factors, such as building height, footing width, peak ground acceleration, and thickness of the liquefiable layer. Numerical simulations have been used to study the effects of liquefaction on buildings, providing insights into the mechanisms and parameters that contribute to settlement and damage.
What is the effect of liquefaction on piles behaviour?5 answersThe liquefaction of soil surrounding a pile can induce permanent deformation and a bending moment on the pile due to the lateral displacement of the liquefied soil. The behavior of piles installed in a liquefiable slope has been studied using numerical analysis and centrifuge tests. A modified soil-pile interface model was proposed to simulate the behavior of the pile, which showed good agreement with the centrifuge test results. Destructive damages to deep foundations due to liquefaction-induced lateral spreading have been observed in various events. Physical and numerical modeling studies have been conducted to understand the effects of lateral spreading on deep foundations. Countermeasures have also been examined to tackle this problem. Axial load tests on a full-scale tapered pile showed that skin friction in the liquefied layer initially dropped to zero, but as the liquefied sand reconsolidated, negative skin friction developed around the pile. Negative skin friction in the overlying non-liquefied clay layer was also observed. Centrifuge model tests showed that liquefaction-induced downdrag on piles increased during reconsolidation and exceeded its preshaking value. Pile settlements occurred mainly during shaking, with postshaking settlement being minimal. Numerical simulations and shake table tests on a single pile embedded in a fully saturated sandy foundation showed that soil lateral spreading affects pile behavior. The pile head displacement decreases and the maximum bending moment at the pile bottom increases with the increase of bending stiffness and soil viscosity.
Was the term soil liquefaction first coined?5 answersSoil liquefaction was first recognized and named in the early 1950s by Mogami and Kubo. However, it gained attention in the geotechnical engineering profession in 1964 after large earthquakes in Niigata, Japan and Alaska, USA. Since then, extensive research on soil liquefaction has been conducted in various seismically active countries, leading to breakthroughs in understanding the mechanics of liquefiable soils and the development of evaluation procedures. Additionally, a simpler method for laboratory testing of soil liquefaction has been developed, which takes into account the pore water pressure buildup during cyclic shearing. Furthermore, an experimental investigation has been undertaken to evaluate the stress conditions required to initiate liquefaction and the influence of various parameters on those stress conditions. In summary, the term soil liquefaction was first coined in the 1950s, but it gained significant attention in the 1960s, and research has since been conducted to better understand and evaluate this phenomenon.
Studying the liquefaction effect on pile lateral load numerically?4 answersNumerical analysis has been used to study the liquefaction effect on pile lateral load in several papers. Haque proposed a tunnel-sand pile interaction (TSPI) model using Plaxis 3D to analyze liquefaction numerically. Liu et al. conducted a large-scale shake-table test and validated a 2D FE model to analyze soil-pile-quay wall interaction in liquefaction-induced lateral spreading ground. Gowda et al. conducted three-dimensional finite difference analyses using FLAC3D to understand the effect of liquefiable soils on the seismic performance of piles and pile groups. Li et al. designed a centrifugal shake table test to investigate the liquefied soil pressure on an individual pile of a pile group and developed a finite element model for accurate analysis. Xi and Enquan presented a theoretical investigation on the lateral force of piles in liquefaction sites using fluid mechanics principles.
What are the mechanisms that cause liquefaction to affect pile bucking?5 answersThe mechanisms that cause liquefaction to affect pile buckling include the combination of lateral load and axial load, excessive axial loads, and the effect of soil liquefaction on the lateral displacement of the soil. The buckling failure of piles under the combined action of lateral and axial load has received little attention, but it has been found that the buckling load of the pile decreases with an increase in lateral inertial load. The flexural rigidity of the pile, unsupported length ratio, initial imperfections, and degree of soil layer liquefaction also affect the critical buckling load of the pile in liquefiable soil. Additionally, the liquefaction of sloping ground can induce permanent deformation and a bending moment on the pile due to the lateral displacement of the liquefied soil. The current design methods often overlook the buckling effects of piles in liquefiable soils, and a new design approach is proposed to take these effects into account.