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In the current paper, the effect of tensile softening parameters, the tensile strength σt and the initial slope k1 of the stress-crack width curve, on the structural size-effect law in bending of concrete are studied by a bending model. The model results show that the size-effect law in bending strength normally presented by flexural strength and beam height diagram (σf-logH) is strongly dependent on σt and k1. With increase of beam height, the general size-effect law in bending can be characterised as a fast reduction stage followed by a stable decreasing stage and finally converged to the tensile strength of concrete. With increasing tensile strength, the σf-logH curve goes up and the value of dσf/dlogH gradually increases. In the meantime, for a given beam height, bending strength increases with increase of k1. The model predictions are compared with experimental results. Good agreement between model predictions and experiments has been obtained. [ABSTRACT FROM AUTHOR]

Field lateral load tests were conducted on two single 1.5 m diameter large bored piles in Hong Kong. The test piles are embedded in superficial deposits and weathered rocks with various degrees of decomposition. In this paper, the pile load test results are interpreted and reported. A simple and rational method of back-analysis for long piles, using inclinometer data and assuming a fourth-order polynomial to represent the shape of soil reaction profile, is introduced. The method, requiring only simple spreadsheet-type operations, makes it possible to incorporate non-linear concrete behaviour in the back-analysis, and to deduce the p-y curves for future design of piles in similar ground conditions. In order to verify the rational method, an analysis is carried out using the back-analysed p-y curves, and the predictions are found to agree well with the measured pile head deflections. This proposed method demonstrates how p-y curves are back-analysed rationally for long piles embedded in complex ground conditions, in contrast to traditional back-analyses using recommended p-y curves for a uniform soil stratum. [ABSTRACT FROM AUTHOR]