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Piles are largely back-rotated in sliding slope or subjected to lateral spreading. This paper reveals for the first time that response of these piles (e.g., displacement, rotation, bending moment, and shear force) is amplified against forward rotating piles. In particular, magnification is detrimental, once normalized rotational stiffness (NRS) of the piles is around a singularity value (i.e., normalized singularity stiffness, NSS). New expressions are developed to gain the NSS value, the magnification degree, and the sliding depth to incur the singularity. The NRS is assessed using 1g model tests. The solutions are adopted to capture the response of the model piles, to detect new failure mechanism of Showa Bridge, and to check the safety of Christchurch bridges. The main conclusions are as follows: (i) piles are prone to response amplification, when subjected to lateral spreading or in sliding slopes. (ii) The NRS is only slightly affected by soil movement profiles and sliding depths. (iii) Showa Bridge collapsed from displacement amplification of back-rotated piles. Finally, (iv) the roller connections between girder and piers, and an integral abutment and piers are proved to be effective to curb the amplification. The amplified response needs to be assessed in practice to lessen failure of back-rotated piles. Key words: piles, theoretical predictions, singularity, earthquake, soil-structure interaction. Les pieux sont largement retournes en pente glissante ou soumis a un etalement lateral. Dans cet article, on constate pour la premiere fois que la reaction de ces pieux (par exemple, le deplacement, la rotation, le moment de flexion et la force de cisaillement) se trouve amplifiee par rapport aux pieux retournes vers l'avant. Ce phenomene d'amplification est particulierement dommageable, lorsque la rigidite de rotation normalisee (<< NRS >>) des pieux se situe autour d'une valeur de singularite (c'est-a-dire rigidite de singularite normalisee, << NSS >>). De nouvelles expressions sont developpees pour obtenir la valeur NSS, le degre d'amplification et la profondeur de glissement afin d'obtenir la singularite. La NRS est determinee a l'aide des essais du modele 1g. On adopte des solutions pour saisir la reponse des pieux modeles, afin de decouvrir le nouveau mecanisme de defaillance du pont de Showa et de determiner la securite des ponts de Christchurch. Les principales conclusions sont les suivantes : (i) les pieux presentent une tendance a l'amplification de la reponse, quand ils subissent un etalement lateral ou dans les pentes de glissement. (ii) Le NRS n'est que peu affecte par les profils de mouvement du sol et les profondeurs de glissement. (iii) Le pont Showa s'est effondre a cause de l'amplification du deplacement des pieux retournes. Finalement, (iv) les liaisons par rouleaux entre la poutre et les pieux, ainsi qu'une culee et des pieux integres, ont demontre leur efficacite pour freiner l'amplification. En pratique, il est necessaire d'evaluer la reponse amplifiee pour reduire la defaillance des pieux retournes. [Traduit par la Redaction] Mots-cles : pieux, predictions theoriques, singularite, tremblement de terre, interaction sol-structure., Introduction Piles are routinely installed to underpin high-rise building, bridges, offshore foundations, and to stabilize sliding slope and costal revetments, to name a few. These piles may be subjected to [...]

The stability and dynamic response of coal pillar is of great importance in underground coal mining. In this paper, a series of uniaxial compressive experiments were first carried out to investigate the mechanical properties of coal. Subsequently, a statistical constitutive damage model for coal was proposed and applied to the numerical simulation. The proposed strain damage softening function showed almost the same goodness-of-fit on the experimental curve. According to this investigation, a numerical model FLAC3Dwas created to investigate the dynamic behavior of the coal pillar under different load percentage (LP). Modelling suggests that the incident and transmitted wave stress evolution observes similar rule and its process can be divided into three stages, namely, static preload, dynamic disturbance, and stabilized stages. The effects of dynamic disturbance intensity are also studied at 10 MPa, 20 MPa, and 30 MPa of peak stress, respectively. The results indicate that under the same load percentage, the peak incident and transmitted wave stress increase with the increase of dynamic disturbance intensity. On the contrary, the attenuation decreases. It is also observed that the failure zone interior the coal can be predicted by the wave propagation.

The factor of safety of a slope ([F.sub.s]) is invariably assessed using methods underpinned by moment, force, and (or) Shear strength equilibrium concerning slip surfaces. Each method inherently embeds some form of limitations, despite being popularly adopted in practice. In this paper, a new [F.sub.s] is devised using the ratio of ultimate energy ([e.sub.u], upon sliding) over accumulated 'elastic' energy. The [F.sub.s] is then reduced to a simple expression of the power to shear stress and shear strength, by taking soil as an elastic-plastic material obeying the Mohr-Coulomb failure criterion. This expression empowers significant efficacy in gaining the factor of safety (without involving energy or directions of shear stresses). The [F.sub.s] values were calculated for three typical slopes concerning various mechanical properties (dilation, Poisson's ratio, and shear modulus) and effective computational strategies. All of the [F.sub.s] values (to a congruous accuracy of available methods) were obtained in less than 1% the time of conventional numerical analyses. The proposed [F.sub.s], equally applicable to limit equilibrium methods, may be utilized in practice to expedite slope design. Key words: slope, stability analysis, deformation energy, factor of safety, slip surface. Le facteur de securite d'une pente ([F.sub.s]) est evalue a l'aide de methodes invariablement soutenues par moment, force, et (ou) d'equilibre de la resistance au cisaillement sur des surfaces de glissement. Chaque methode integre intrinsequement une certaine forme de limites, en depit d'etre communement adoptee dans la pratique. Dans cet article, une nouvelle [F.sub.s] est mise au point en utilisant le rapport d'energie finale ([e.sub.u], sur glissement) sur une energie accumulee elastique. Le [F.sub.s] est alors reduit a une simple expression de la puissance a une contrainte de cisaillement et la resistance au cisaillement, en prenant le sol comme un materiau elastoplastique obeissant aux criteres de rupture de Mohr-Coulomb. Cette expression donne efficacite significative pour obtenir le coefficient de securite (sans impliquer l'energie ou de directions de tensions de cisaillement). Les valeurs [F.sub.s] ont ete calculees pour trois pistes typiques concernant diverses proprietes mecaniques (dilatation, coefficient de Poisson, et le module de cisaillement) et des strategies de calcul efficaces. Toutes les val[e.sub.u]rs [F.sub.s] (pour une precision discontinue de methodes disponibles) ont ete obtenues en moins de 1 % du temps d'analyses numeriques classiques. Le [F.sub.s] suggere, egalement applicable aux methodes d'equilibre de limite, peut etre accorde dans la pratique pour accelerer notre conception de la pente. [Traduit par la Redaction] Mots-cles : pente, analyse de stabilite, energie de deformation, coefficient de securite, surface de glissement., Introduction Slope stability is largely evaluated in light of the limit equilibrium method (LEM) (Fellenius 1936; Bishop 1955; Janbu 1973; Morgenstern and Price 1965; Spencer 1967; Chen and Morgenstern 1983; [...]

This paper proposes a new, integrated two-layer model to capture nonlinear response of rotationally restrained laterally loaded rigid piles subjected to soil movement (sliding soil, or lateral spreading). First, typical pile response from model tests (using an inverse triangular loading profile) is presented, which includes profiles of ultimate on-pile force per unit length at typical sliding depths, and the evolution of pile deflection, rotation, and bending moment with soil movement. Second, a new model and closed-form expressions are developed for rotationally restrained passive piles in two-layer soil, subjected to various movement profiles. Third, the solutions are used to examine the impact of the rotational restraint on nonlinear response of bending moment, shear force, on-pile force per unit length, and pile deflection. Finally, they are compared with measured response of model piles in sliding soil, or subjected to lateral spreading, and that of an in situ test pile in moving soil. The study indicates the following: (i) nonlinear response of rigid passive piles is owing to elastic pile-soil interaction with a progressive increase in sliding depth, whether in sliding soil or subjected to lateral spreading; (ii) theoretical solutions for a uniform movement can be used to model other soil movement profiles upon using a modification factor in the movement and its depth; and (iii) a triangular and a uniform pressure profile on piles are theoretically deduced along lightly head-restrained, floating-base piles, and restrained-base piles, respectively, once subjected to lateral spreading. Nonlinear response of an in situ test pile in sliding soil and a model pile subjected to lateral spreading is elaborated to highlight the use and the advantages of the proposed solutions, along with the ranges of four design parameters deduced from 10 test piles. Key words: passive piles, analytical solutions, nonlinear response, soil-structure interaction. Cet article propose un nouveau modele a deux couches integrees servant a representer le comportement non lineaire de pieux rigides charges lateralement et dont la rotation est restreinte, dans des conditions de mouvements de sol (glissement ou etalement lateral). D'abord, la reponse typique d'un pieu obtenue a partir d'essais modeles (avec un profil de charge triangulaire inversee) est presentee, incluant les profils de la force ultime sur le pieu par unite de longueur pour des profondeurs de glissement typiques, et revolution de la deflection, de la rotation et du moment de torsion du pieu selon les mouvements du sol. Ensuite, un nouveau modele et des expressions a forme fermee sont developpes pour des pieux passifs restreints en rotation dans un sol a deux couches soumis a differents profils de mouvement. Troisiemement, les solutions sont utilisees pour etudier l'impact de la restriction en rotation sur la reponse non lineaire du moment de torsion, de la force de cisaillement, de la force sur le pieu par unite de longueur, et la deflection du pieu. Finalement, ces solutions sont comparees avec la reponse mesuree de pieux modeles dans un sol glissant, ou sujet a l'etalement lateral, et celle d'un pieu d'essai in situ dans un sol en mouvement. L'etude indique que (i) la reponse non lineaire de pieux passifs rigides depend de l'interaction elastique sol-pieu avec une augmentation progressive selon la profondeur de glissement, autant dans les sols glissants que dans les sols sujets a l'etalement lateral; (ii) les solutions theoriques d'un mouvement uniforme peuvent etre utilisees pour modeliser d'autres profils de mouvement de sol si l'on utilise un facteur de modification pour le mouvement et pour sa profondeur; et (iii) des profils de pression triangulaire et uniforme sur les pieux sont deduits theoriquement le long de pieux restreints a la tete, a base flottante, et restreints a la base, respectivement, une fois soumis a l'etalement lateral. La reponse non lineaire d'un pieu d'essai in situ dans un sol glissant et d'un pieu modele soumis a l'etalement lateral est elaboree afin de mettre en evidence l'utilisation et les avantages des solutions proposees, ainsi que les valeurs de quatre parametres de conception deduits de 10 essais de pieux. [Traduit par la Redaction] Mots-cles: pieux passifs, solutions analytiques, reponse non lineaire, interaction sol-structure., Introduction Passive piles are known as piles that are subjected to soil movement and are commonly used for stabilising a sliding slope, supporting bridge abutments, and providing a lateral pressure [...]

An experimental apparatus was developed to investigate the behaviour of vertically loaded free-head piles in sand undergoing lateral soil movement ([w.sub.t]. A large number of tests have been conducted to dale. Presented here are 14 typical model pile tests concerning two diameters, two vertical pile loading levels, and varying sliding depths with the movement [w.sub.f] driven by a triangular loading block. Results are provided for driving force as well as for induced shear force (T), bending moment (M), and deflection (y) along the piles with [w.sub.f] / normalized sliding depth. The tests enable simple expressions to be proposed, drawn from the theory for a laterally loaded pile. The new expressions well capture the evolution of M, T, and y with soil movement observed in current model tests, and the three to five times difference in maximum bending moment ([M.sub.max]) from the two modes of loading. They further offer a good estimate of [M.sub.max] for eight in situ pile tests and one centrifuge test pile. The study quantifies the sliding resistance offered by a pile for the given [w.sub.f] profiles, pile location (relative to the boundary), and vertical load. It establishes the linear correlation between the maximum thrust (resistance T) and [M.sub.max], regardless of the magnitudes of [w.sub.f]. Key worth: ground improvement, model tests, piles, slopes, soil-structure interaction, theoretical analysis. Un appareil experimental a ete developpe dans le but d'examiner le comportement de pieux a tete libre charges verticalement dans du sable qui se deplace lateralement ([w.sub.f]). De nombreux essais ont ete effectues jusqu'a maintenant. Dans cet article, 14 essais modeles typiques couvrant deux diametres de pieux, deux niveaux de chargement vertical et des profondeurs de glissement variables, avec le mouvement [w.sub.f] induit par un bloc de chargement triangulaire, sont presentes. Les resultats informent sur la force motrice, la force de cisaillement induite (T), le moment de torsion (M) et la deflection (y) le long des pieux avec [w.sub.f] / profondeur de glissement normalisee. Les essais permettent de proposer des expressions simples avec une emphase sur la theorie pour les pieux charges lateralement. Les nouvelles expressions representent l'revolution de M, T et y selon les mouvements du sol observes dans les essais, ainsi que la difference d'un facteur trois a cinq fois entre les moments de torsion maximaux ([M.sub.max]) pour deux modes de chargement. De plus, ces expressions offrent une bonne estimation de [M.sub.max] pour huit essais de pieux in situ et un essai centrifuge, L'etude quantifie la resistance au glissement exercee par un pieu pour des profils donnes de [w.sub.f], la position du pieu (par rapport a la frontiere) et le chargement vertical. Une correlation lineaire est etablie entre la poussee maximale (resistance T) et [M.sub.max], et ce peu importe la magnitude de [w.sub.f]. Mots-cles : amelioration du sol, essais modeles, pieux, pentes, interaction sol-structure, analyse theorique. [Traduit par la Redaction], Introduction The study of active piles subjected to combined lateral and vertical loads has attracted significant research effort (Meyerhof et al. 1981, 1983; Anagnostopoulos and Georgians 1993; Aubeny et al. [...]

Abstract: In this paper, limiting force profile for laterally loaded rigid piles in sand is differentiated from the on-pile force profile, from which elastic-plastic solutions are established and presented in [...]

Anthrax is a natural foci disease in Inner Mongolia, which poses a severe threat to public health. In this study, the incidence number, rate and constituent ratio were used to describe the epidemiological characteristics of anthrax in the region from 1956–2018. The molecular correlation and genetic characteristics of the strains were investigated using canonical single nucleotide polymorphisms (CanSNP), multiple‐locus variable‐number tandem repeat analysis (MLVA‐15) and whole genome sequencing (WGS). The epidemiological characteristics of anthrax in Inner Mongolia have altered significantly. The incidence of anthrax has decreased annually without vaccination, and the regional distribution of anthrax gradually transferred from central and western regions to the eastern. Moreover, the occupation distribution evolved from multiple early occupations to predominated by farmers and herdsmen. This change is closely related to policy factors and to changes in the means of production and the living habits of the local population. This indicates that reformulating the control and prevention strategies is essential. Both A. Br. Ames and A. Br. 001/002 subgroups were the predominant CanSNP genotypes of Bacillus anthracis in Inner Mongolia. A total of 36 strains constituted six shared MLVA‐15 genotypes, suggesting an epidemiological link between the strains of each shared genotype. The six shared genotypes ([GT1, 9, 11 and 15] and [GT8 and 12]) consisting of 2–7 strains confirmed the occurrence of multiple point outbreaks and cross‐regional transmission caused by multiple common sources of infection. Phylogenetic analysis based on the WGS core genome showed that strains from this study formed an independent clade (C.V.), and they were positioned close to each other, suggesting a common origin. Further comparison analysis should be performed to ascertain the geographic origin of these strains. [ABSTRACT FROM AUTHOR]

To the Editor: Brucellosis is one of the most common zoonotic diseases worldwide (1). The disease is caused by Brucella spp. and mainly transmitted from its animal reservoirs to humans [...]