Abstract Residual loads can affect the load transfer and the settlement-induced in-service loadings, although they do not alter the bearing capacity. When residual loads are present and not measured or evaluated, the settlement estimate is greater than predicted if these loads are known. Residual loads can be measured when the pile instrumentation is nullified before pile installation, in the case of displacement piles, or before the first loading in non-displacement piles, such as bored cast-in-place piles, continuous flight auger piles, and micro-piles. In the case of underpinning foundation and piled raft, when the loading transfer is shared by the original and new foundation, or by the piles and the raft, it is essential to know the stiffness of each foundation element to estimate the load partition. If residual loads are present, pile stiffness is greater than when not considered in the design. The paper revisits this theme of practical relevance. A historical review of the most relevant research involving pile residual load measurements, pile loading tests including the interpretation of residual loads locked at a pile toe, and a new procedure for residual loads prediction are provided. A comparison is made of the experimental residual loads observed in some of the instrumented cases and the values estimated with the suggested procedure. The development of residual loads at the pile toe as a function of the toe resistance to total capacity ratio is very similar to the variation of the soil density as a function of soil moisture content in soil compaction.

Abstract In engineering practice, loading varies with time. However, the classical one-dimensional theory of consolidation assumes the stress increase is instantaneously applied. Many approaches to the problem of time-dependent loading have been proposed over the years, from approximate methods to full developments of differential equations. The paper presents a simple method for finding a closed-form consolidation solution for time-dependent loading without the need for differential equations. Two sets of general equations were derived for both excess pore pressure and average degree of consolidation. Equations were solved for linear, parabolic, sinusoidal, and exponential load functions. Stepped and cyclic loads were also addressed and a numerical solution was developed to verify the obtained result. The method proved to be easy to apply and provides solutions with great simplicity. A case study of non-instantaneous loading on soft clay was also analyzed, and settlement prediction showed good results when compared to readings of the settlement plates. practice time However onedimensional one dimensional applied timedependent dependent years closedform closed form linear parabolic sinusoidal functions result simplicity noninstantaneous non instantaneous analyzed plates

Abstract In the design of piles partially embedded in rock, the main factors that influence the strength and deformability of the rock and the transmission of loads from pile to rock are of utmost relevance to pile behavior. Most empirical methods were developed based on data from specific regions. Differences in geological conditions, drilling methods and other features are not considered in most procedures. The article deals with a case of piles partially embedded in rock located in the town of São Lourenço da Mata, Pernambuco, Brazil. The rock mass consists of ancient deposits, formed mainly by granites of different compositions, gneiss and schists. The deposits have been deformed by several tectonic processes. Results from 99 dynamic loading tests enabled comparison between the mobilized lateral and pile toe resistance, with the estimated capacity obtained from the design methods known in the literature. In the prediction, the lateral shear resistance due to pile penetration in residual soil was also considered. Because failure was not reached in the dynamic tests, the estimated capacity was higher than the mobilized resistance.The resistances mobilized by the pile shaft friction in soil, by the pile shaft friction in rock and by the mobilized toe resistance in rock in the dynamic loading tests are compared to design methods known in the literature. Five static loading tests indicated failure loads greater than the mobilized resistance in the dynamic methods. The comparisons allow recommendations of the most consistent design methods to use in similar cases in practice.

O artigo apresenta a análise da interação solo-estrutura de uma construção que revelou, ao longo dos anos, comportamento inadequado de suas fundações. São resumidas análises anteriores de Rosa (2005), incluindo a interação solo-estrutura na previsão dos recalques. Essa nova análise considera, também, a influência das alvenarias na interação. Os recalques distorcionais previstos são analisados em conformidade com os danos, documentados em vários momentos da vida útil da edificação. O modelo de Kelvin foi utilizado para representar o comportamento do solo com o tempo. Verificou-se que, mesmo com as simplificações adotadas, justificadas no artigo, os resultados da análise numérica foram capazes de reproduzir a extensão dos danos, assim como sua localização espacial. Os resultados mostram a importância de uma concepção de projeto de fundações mais realista, contemplando a interação solo-estrutura.

An analysis of soil-structure interaction of a construction with unsatisfactory foundation behavior along time is presented. Previous analyses by Rosa (2005) are briefly described considering soil x structure interaction in predicting foundation settlement. In addition, a new analysis is now presented, including the influence of the masonry in the soil-structure interaction. The predicted distortional settlements are analyzed in conformity with the observed damages documented at various moments of the construction lifetime. Kelvin's model was employed to represent the soil behavior along time. Notwithstanding the simplifications adopted and justified in the article, the results of the numerical analysis were able to reproduce the extent and spatial location of the damages. Such results show the relevance of a more realistic foundation analysis involving soil x structure interaction.