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Observed liquefaction distance limit in recent major earthquakes and the global dataset of documented liquefaction (modified from Olson et al. 2005a)
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Estimating the possible region of liquefaction occurrence during a strong earthquake is highly valuable for economy loss estimation, reconnaissance efforts and site investigations after the event. This study identified and compiled a large amount of liquefaction case histories from the 2008 Wenchuan earthquake, China, to investigate the relationshi...
Citations
... Soil liquefaction in recent major earthquakes caused severe damage to buildings and infrastructures and significant economy loss, such as the 2008 Wenchuan earthquake in China [1][2][3], the 2010-2011 Christchurch New Zealand earthquakes [4,5], the 2011 Tohoku earthquake in Japan [6,7] and the 2018 Palu earthquake in Indonesia [8]. Tremendous efforts have been devoted to evaluate liquefaction potential of saturated sandy soil deposits [4,[9][10][11][12]. ...
... It is found that β is almost the same for different cyclic strength curves but α decreases with increasing confining pressures (i.e., corresponding to soil depth in model ground). According to the definition of MSF in soil element test, that is, to normalize the whole CRR tx -N l curve by the CRR tx value at N l = 15 (i.e., CRR 15 ) [30], the relationship between laboratory-obtained MSF and N eq is shown in Fig. 6 and could be used for the subsequent calculation of CSR 7.5 by Eq. (2). In consideration of the low compressibility of the sandy soil (i.e., C c = 0.02), the change of soil density through the model depth is minimal after spin-up and it could be treated as a problem of depth-variation of cyclic strength with the same density. ...
... In recent years, devastating earthquakes occurred frequently with the moment magnitudes (M w ) of 7.9 for the 2008 Wenchuan earthquake in China (Zhou et al. 2018a), 7.1 for the 2010 Canterbury earthquake in New Zealand (Chen and Faccioli 2013) and 9.1 for the 2011 Tohoku earthquake in Japan (Goda et al. 2013) respectively. A large number of buildings were tilted and collapsed due to damage of the foundation structure caused by earthquake loadings beyond the seismic design. ...
In this study, the seismic response and liquefaction mitigation effect of the soil-cement grid improved ground subjected to large earthquake loadings are studied through dynamic centrifuge tests. The model tests included soil-cement grid improved and unimproved model grounds, both of which have a 15-m-thick liquefiable layer underlain by a 2.5-m-thick coarse sand layer. The pre-cast soil-cement grid adopted in this study enables the dynamic responses of the model closer to the real improved ground. The recorded responses of accelerations, excess pore pressures and the deformation of the enclosed soil in the improved ground were carefully analysed with the comparison of the ground without improvement. It shows that the soil liquefaction and post-shaking settlements were effectively mitigated by the soil-cement grid even under very strong shakings. And the restriction effect of the soil-cement grid on dynamic shear strain of the enclosed soil was the most prominent in the middle height, regardless of the intensities of the shaking events. Such mitigating “waist effect” could mainly be attributed to the dynamic soil-grid interaction during shaking. However, the underlain soil layer may experience larger shear strain due to the increasing inertial force of the overlying ground improved by the soil-cement grid.
... The May 12, 2008, M w 7.9 Wenchuan earthquake caused widespread soil liquefaction throughout a vast area of 500 km long and 200 km wide. One salient feature of liquefaction manifestations was the ejecta of gravelly soils, which were mainly distributed around Chengdu Plain where geologic setting typically consists of surface Holocene clayey soils and the underlying relatively thick gravelly soils (Zhou et al. 2009;Cao et al. 2011;Zhou et al. 2018). The liquefaction consequences of gravelly soils show significant differences compared with those of typical sands, and less ground deformation (e.g., settlement) and fewer surface ejecta were observed (Cetin et al. 2002;Wilkinson et al. 2013;Khoshnevisan et al. 2015). ...
The 2008 Mw7.9 Wenchuan earthquake in China caused widespread soil liquefaction and ground failures. A liquefaction case study of gently sloping ground at Yingxiu Town in the near-fault region is presented, which features its relatively thick deposits of sand-gravel mixtures, high soil stiffness, extremely intensive ground motion, large lateral spreading and severe damage of superstructure. The details of ground motion, site condition, field manifestations of liquefaction, subsurface soil profiles and field testing of shear wave velocities are presented. A conceptual binary mixture model is proposed to explain the gravel content effect on the stiffness and liquefaction resistance of gravelly soils. A preliminary liquefaction triggering evaluation method for gravelly soils is proposed by considering the gravel content correction of shear wave velocities based on the existing simplified procedure for typical sandy soils. The failure mechanism of the Baihua Bridge built at this site is explored, and the liquefaction-induced lateral spreading in down-slope direction might aggravate the failure process by imposing a large kinematic load on the piers besides the inertial forces transferred from the superstructure.
... In order to determine the liquefaction properties of soils, a number of shaking table liquefaction tests (e.g., Carey et al. 2017;Jin et al. 2018;Chen et al. 2019), cyclic triaxial tests (e.g., Pan and Yang 2018; Wang et al., 2018b), and numerical simulations (e.g., Ye and Wang 2016;Lei and Matthew 2018) were carried out with various forms of soil samples. Similar experimental studies, including Zhou et al. (2018), Bayat & Ghalandarzadeh (2019), and Huang & Zhao (2018), considered soil samples with different components, particle distribution, and loading state, etc. It is worth noting that the above studies primarily focused on homogeneous or well-mixed sands; corresponding conclusions and laws may not necessarily be applicable to stratified structures. ...
The soils are often distributed in a stratified structure. When an earthquake occurs, there are always risks of liquefaction for stratified soils which can cause serious consequences. The research aims to investigate the liquefaction and post-liquefaction deformation of saturated sand with stratified structure. The influences of liquefaction and post-liquefaction deformation were analyzed by varying the thickness, position, and layers of powdery sands. The findings showed that the correlations between the times taken to reach liquefaction for cyclic loading and the thicknesses of the powdery sandy interlayer are non-linear. With the optimal thickness, the powdery sand interlayer can effectively prevent the transfer of power water pressure. And two-layer powdery interlayer in the sample was more favorable to resist pore water pressure than that with single layer. The strength of post-liquefaction deformation and failure patterns are closely related to the distribution of powdery layer. The work provides new research evidence on the liquefaction and failure mechanism of saturated sands with stratified structure under cyclic loading which often happen during earthquakes.
The transport of liquefiable solid bulk cargo is one of the main causes of maritime safety accidents over the past decade. This article innovatively summarized the status quo of research on the liquefaction risk of liquefiable solid bulk cargo during sea transport from three aspects, namely, the properties, moisture content and external induced load of cargoes during their sea transport. The influence of the main physical parameters, the application of modern testing techniques (e.g., transparent soil and PIV) in related fields, and various TML testing methods in IMSBC code were also introduced. Result highlighted external induced load as an important factor affecting the cargo liquefaction during sea transport. The latest trends on the adoption of the liquefaction risk assessment method based on external load were also systematically introduced, and the importance of quantitative risk assessment in practical application was emphasized. This article also analyzed the main challenges encountered in managing liquefaction risk and revealed quantitative risk assessment and liquefaction mechanism as the main trends in related research. Four promising directions for future research were also put forward, which can provide valuable ideas for researchers and managers to further study and control the liquefaction risk of liquefiable solid bulk cargo.
Stone column is one of the prevailing liquefaction mitigation techniques to densify the surrounding soil, expedite the drainage and bring the possible shear reinforcement effect. The mitigation mechanisms of liquefaction triggering and the associated deformation of the improved ground have not been well explored yet, which hinders the development of robust design in engineering practices. Three centrifuge model tests, including a loose sand model, a dense sand model and a dense sand model with stone columns were conducted to explore the individual effect of densification and drainage caused by stone columns on seismic responses of a level silty sand ground, including the excess pore water pressure, acceleration and ground settlement, etc. The densification effect increases the dilatancy of the surrounding soil and hinders the generation of excess pore water pressure during shaking, thus significantly reduces the liquefaction potential and post-shaking settlement as well. However, it amplifies the upward propagating ground motion considerably. The drainage effect in a densified ground with SCs mainly takes place after shaking, and it accelerates the dissipation rate about 5–10 times that of a densified ground without SCs, which helps to quickly restore the ground stiffness and reduce the deformation to some extent. The contributions from the two effects to the post-shaking ground settlement were also observed and discussed. The present study provides insights on liquefaction mitigation mechanisms of the stone column-improved ground and valuable benchmark tests for further analysis.
This Cahier Technique has been produced under the aegis of the French Association for Earthquake Engineering (AFPS). It is an 'Earthquake Geotechnics' handbook providing an overview of the topic of earthquake-induced soil liquefaction. It follows on from Cahier Technique CT no. 22 describing the application of the PS92 rules (AFPS, 2001) and the Guide Technique on the production of seismic micro-zoning studies (AFPS, 1993). Further information on processes for improvement and reinforcement of soils subject to seismic actions is given in the guide by the AFPS-CFMS (2012). The writing of this Cahier Technique is based on the very rich discussions within the AFPS '2020 Recommendations' Working Group, and more particularly the sub-group concerned by the paragraphs relating to soil liquefaction.
This CT examines the various questions relating to earthquake-induced soil liquefaction, covering post-earthquake observations at impacted sites, responses observed in the laboratory, soil investigations by means of in situ tests, and lastly the main methods for assessing the risk and taking it into account in projects. Particular emphasis is placed on the consistency and the organisation of the geotechnical investigations, the means to be implemented, the analysis and study methods, and the simplified, empirical or numerical calculation methods. The studies are considered at two levels: prediction of soil liquefaction triggering, and prediction of the consequences of liquefaction and design of preventive measures.
The CT has been written with the intention of underlining the progressiveness of the study methods and showing their consistency and the links between them. It forms part of an approach combining education and sharing of best practices, for broad circulation beyond the community of specialists.
This work has been motivated by the determination of the practitioners confronted with soil liquefaction questions to share a common terminology and a structured view of the main study methods, their implementation and their limits. Its objective is to be a practical reference document providing guidance for selecting investigations and the study methods appropriate for the context of a site and a project. To this end, the text is intended to cover the main aspects of soil liquefaction questions, insofar as possible. Nevertheless, for the sake of conciseness, many questions are discussed relatively briefly, with many references cited in the text for further information. Other aspects are covered in greater detail, such as the estimation of the factor of safety against liquefaction using the simplified method of the National Center for Earthquake Engineering Research (NCEER, Youd et al., 2001) based on standard penetration tests (SPT) and cone penetration tests (CPT), leading to earthquake-induced settlement assessment examples.
This Cahier Technique comprises volume 1 on the state of the art, in which the various aspects of soil liquefaction for its applications to projects are presented in a logical and practical sequence, and volume 2 of Annexes in which examples of applications and specific developments are brought together. The two volumes of this Cahier Technique are not intended to be a prescriptive guide: soil liquefaction problems in projects must be solved in compliance with the requirements of the existing regulations.
Ce Cahier Technique a été réalisé sous l'égide de l’Association Française de Génie Parasismique (AFPS). Il s’agit d’un cahier de "Géotechnique Sismique" qui propose un panorama sur le thème de la liquéfaction des sols sous l'effet de séismes. Il s'inscrit dans la continuité du Cahier Technique CT n°22 qui détaille l’application des règles PS92 (AFPS, 2001) et du Guide Technique relatif à la réalisation des études de micro-zonage sismique (AFPS, 1993). D'autres informations relatives aux procédés d’amélioration et de renforcement des sols sous actions sismiques sont données dans le guide de l’AFPS-CFMS (2012). La rédaction de ce Cahier Technique s'appuie sur les échanges très riches au sein du Groupe de Travail "Recommandations 2020" de l’AFPS, et plus particulièrement du sous-groupe concerné par les paragraphes liés à la liquéfaction des sols.
Ce cahier aborde les différentes questions relatives à la liquéfaction des sols sous l'effet des séismes en évoquant les observations post-sismiques issues de sites impactés, les réponses observées en laboratoire, les reconnaissances des sols au moyens d'essais in situ, pour finir par les principales méthodes d’évaluation du risque et sa prise en compte dans les projets. L’accent est mis en particulier sur la consistance et l'organisation des reconnaissances géotechniques, les moyens à mettre en œuvre, les méthodes d'analyse et d'étude, les méthodes de calcul simplifiées, empiriques ou numériques. Les études s'envisagent à deux niveaux, l'un dédié à la prévision du déclenchement de la liquéfaction des sols et l'autre à la prévision des conséquences de la liquéfaction et la conception de dispositions préventives.
Ce cahier a été rédigé dans un souci de souligner la progressivité des méthodes d'études et de montrer leur cohérence et leurs articulations. Il s’inscrit dans une démarche pédagogique et de partage des meilleures pratiques, pour une large diffusion au-delà de la communauté des spécialistes.
Ce travail a été motivé par la volonté des praticiens confrontés aux questions de la liquéfaction des sols, de partager une terminologie commune et une vision hiérarchisée des principales méthodes d’études, de leur mise en œuvre et de leurs limites. Il a pour objectif de constituer un document pratique auquel le lecteur pourra se référer pour orienter son choix de reconnaissances et les méthodes d'études adaptées au contexte d'un site et d'un projet. Dans cette optique, le texte veut couvrir, autant que possible, les principaux aspects des questions de la liquéfaction des sols. Néanmoins, par souci de concision, beaucoup de questions sont abordées à titre d'information en invitant le lecteur à se référer aux nombreuses références bibliographiques citées dans le texte. D'autres aspects sont traités plus en détails, tels que l’évaluation du coefficient de sécurité à la liquéfaction au moyen de la méthode simplifiée du National Center for Earthquake Engineering Research (NCEER, Youd et al., 2001) à partir des essais au carottier SPT et des essais au pénétromètre statique CPT, pour aboutir à des exemples d’évaluation des tassements sismo-induits.
Ce Cahier Technique comprend un tome 1 relatif à l’état de l’art où les différents aspects de la liquéfaction des sols pour ses applications aux projets s'enchaînent dans une suite logique et pratique et un tome 2 d’Annexes où des exemples d’applications et des développements spécifiques sont rassemblés. Les deux tomes constituant ce Cahier Technique n’ont pas vocation à servir de guide prescriptif, la résolution des problèmes de liquéfaction des sols dans les projets doit s'effectuer en conformité avec les prescriptions des réglementations existantes.
