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

(E)-N′-(2-Chloro­benzyl­idene)-4-methoxy­benzohydrazide

The mol­ecule of the title compound, C15H13ClN2O2, adopts an E geometry about the C=N bond. The dihedral angle between the two benzene rings is 62.7 (2)°. In the crystal structure, mol­ecules are linked through inter­molecular N—H⋯O hydrogen bonds, forming chains running along the c axis

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

Nonlinear modelling and adaptive fuzzy control of PEMFC

To improve the stability and performance of fuel cells, the operating temperature of proton exchange membrane fuel cells (PEMFC) should be controlled within a specified range. However, most existing mathematical models of PEMFC are too complex to be applied effectively in the control process. In this paper, adaptive fuzzy identification and control models of PEMFC are developed based on input-output sampled data and experts\u27 experience. The parameters of the identifier and controller are regulated by an adaptive learning algorithm, the network structure and the rule database are modified by adjusting the parameters. In the end, the simulation results of the online control model are presented and show the effectiveness