Response of 20 laterally loaded piles in sand

Closed-form solutions and their associated spreadsheet program (GASLFP) were developed by the first author for laterally loaded free- head piles in elastic-plastic media. The solutions show behaviour of a laterally loaded pile is dominated by net limiting force per unit length (LFP) fully mobilised along the pile to a depth called slip depth. They are characterised by three parameters of Ng, α o and n (to describe the LFP) and the soil shear modulus (Gs). Conversely, these parameters may be deduced by matching the predicted with measured response. To facilitate practical design, in this paper, the input values of Ng, α o, n and Gs were deduced in light of measured response of 20 piles tested in sand. The result allows effect of pile types, installation action, and dry or submerged sand to be clarified. In addition, using analogy to pipeline-soil interaction, a new alternative expression described by the parameters kp, α o and n is proposed to construct the LFP. The use of the previous parameter Ng and the new kp is discussed at length. Critical responses for typical deflection levels have also been provided. This back-analysis is elaborated via three typical cases

Research on basis of reverse genetics system of a Sindbis-like virus XJ-160

As a Sindbis-like virus (SINLV), XJ-160 virus was isolated from a pooled sample of Anopheles mosquitoes collected in Xinjiang, China, in 1990. Recombinant plasmid pBR-XJ160 is an infectious full-length cDNA clone of XJ-160 virus, from which rescued virus BR-XJ160 can be obtained by transcription in vitro and transfection. The BR-XJ160 virus raised in BHK-21 cells was indistinguishable from the XJ-160 virus in its biological properties, including its plaque morphology, growth kinetics and suckling mouse neurovirulence. On basis of pBR-XJ160, the effects of substitutions within nonstructural protein 1 (nsP1) or nsP2 on the infectivity and pathogenesis of Sindbis virus (SINV) have been investigated. We have also confirmed the essential role of E2 glycoprotein, especially the domain of 145-150 (amino acid) aa, in SINV infection through the interaction with cellular heparan sulfate (HS). In addition, we have developed XJ-160 virus-based vector system, including replicon vector, defective helper (DH) plasmids and the packaging cell lines (PCLs). Here we provide an update of main development in the field concerned with XJ-160 virus

Structure nonlinearity and response of laterally loaded piles

In light of a generic limiting force profile (LFP), closed·form solutions for laterally loaded free- and fixed- head piles in elastic-plastic media have been developed, and implemented by the first author into a spreadsheet program called GASLFP. The solutions offer an expeditious and sufficiently accurate prediction of response of lateral piles. Conversely, they allow input parameters to be deduced using measured pile response, as has been conducted for over 70 test (elastic) piles to date. Nevertheless. structure nonlinearity of pile body is an important issue at a large deflection. In this paper, a semi·empirical approach is established to capture pile response owing to structural nonlinearity. Expressions were provided for gaining cracking moment Mcr, flexural rigidity of cracked cross section Eplp. and ultimate bending moment Mult Against measured response of two laterally loaded single piles, back-estimation indicates that (1) the parameters for elastic piles are quite consistent with the previous findings for piles in sand and clay, (2) The proposed variations of Mcr, Eplp and Mult, for nonlinear piles provide good prediction of the pile response against measured data and (3) the modulus of rupture kr of 16.7 (clay) and 33.0(sand) are close 10 those adopted for structural beams, although a very high kr of 62.7 (thus resulting in higher Mcr, ) for a pi le in sand was deduced (shown elsewhere). The use of the kr for beams would render pile deflections of the later pile to be significantly overestimated. The conclusions may be incorporated into design of laterally loaded piles