Abstract This study was carried out in an instrumented and monitored embankment divided into two symetrical sections and constructed with compacted treated soils (i.e., a silty soil and a clayey soil) exposed to the same atmospheric conditions in a continental climate, with oceanic influences. It aimed to investigate changes of bare soil surface moisture (w) and corresponding suction (s) as result of soil water evaporation processes on a monthly time scale. Seasonal variations in the w (and s) measurement in both soil surfaces show overall consistency with the meteorological measurement within the study area. The paper also examines the ability of four air temperature-based potential evaporation (PET) formulations to capture the process of evaporation at the site. Results indicated that soil water evaporation is controlled by both atmospheric and soil conditions. And, during the most significant drying time period, the measured s consistently increased and the corresponding w decreased suggesting a relatively significant water evaporation effect. However, the monthly predicted PET data varied from a maximum of over 120 mm/month to less than 50 mm/month during the drying time, depending on the used method. The continuously monitored soil surface suctions are used for discussing the variations of evaporation according to the predicted PET method and time period at the site.

RESUMO: Neste artigo analisa-se a influência dos efeitos construtivos incrementais (EI) e da interação solo estrutura (ISE) em edifícios altos de concreto armado com fundações superficiais assentes sobre solos arenosos. Foram realizadas avaliações dos EI e ISE nos parâmetros de instabilidade global, deslocamentos horizontais máximos, cargas de fundação e recalques de uma planta simétrica e uma não simétrica de um edifício com 23pavimentos. Para análise do EI considerou-se a variação do módulo de elasticidade ao longo do tempo, bem como as fases de aplicação de cargas na edificação. Para análise do ISE foi considerado o meio contínuo e o modelo de cálculo considera uma série de molas discretas sob a base da fundação da edificação. Os resultados mostram uma redistribuição significativa nos esforços da fundação e sugerem que a não consideração desses efeitos em conjunto na estrutura pode levar a projetos que não atendam as especificações de norma quanto aos parâmetros de estabilidade e deslocamentos globais da estrutura.

Abstract: The influence of incremental constructive effects (IE) and soil-structure interaction (SSI) on high-rise buildings of reinforced concrete with shallow foundations on sandy soils were analyzed. IE and SSI evaluations were carried out by the parameters of global instability, maximum horizontal displacements, foundation loads, and settlements of a symmetrical and non-symmetrical plant of a 23-storey building For the analysis of the IE, the variation of the modulus of elasticity was considered over time along with the phases of application of loads in the building. For ISS analysis, the continuous medium was considered, and the calculation model considers a multi-spring-mass system under the foundation of the building. The results show a significant redistribution in the foundation efforts and suggest that a failure in considering these effects along with the structure can lead to projects that do not meet the standard specifications regarding stability parameters and overall structure displacements.

ABSTRACT The liquid limit (LL) is an important parameter for soil classification systems. The use of the cone penetrometer technique for measuring the liquid limit is an attractive alternative method since the percussion method is highly operator dependent. In this article, the importance of specifying the procedure and equipment used to determine the LL of a clay soil is highlighted using LL test results conducted on different clay soils. The results of LL, obtained by the percussion method proposed by Casagrande (LLc) and by the penetration cone method (LLp) on clay soils of different geological origins and plasticity were compared. The LLp values were determined using the British cone (20 mm fall cone penetration) method. The LLc values were determined using different hardnesses of Casagrande apparatus. The LL test results show that variations on the investigated methods depend on the mineralogy of the clay soil and the hardness base of the Casagrande cup. The data obtained for kaolinites and illites minerals or low LL soils yielded LLp>LLc. The results obtained for smectite minerals or soils with high LL values indicated LLp<LLc and a greater dispersion among the results. Statistical analyses of residues show that empirical LLp-LLc correlations through a linear regression analysis should be used with caution.

A forma dos grãos tem importante papel na avaliação da distribuição granulométrica das partículas de um solo. Entretanto, a maioria das técnicas de peneiramento evidencia que os grãos são esféricos e descritos por um único parâmetro, o diâmetro. Este trabalho teve por objetivo estudar a aplicação da análise de imagens, aliada ao grau de esfericidade e à teoria dos fractais, como ferramenta para mensurar parâmetros de forma e textura superficial de duas areias de características supostamente distintas da região da Grande Vitória, Espírito Santo, Brasil. Os resultados dos parâmetros de forma e textura superficial das amostras são apresentados e discutidos. As análises dos resultados para a variável esfericidade mostram diferenças estatísticas significativas entre as duas areias de origens diferentes. A areia de jazida de cordão litorâneo (AJ) apresentou grau de esfericidade ligeiramente superior e textura superficial mais lisa do que a de rio (AR), indicando que as areias AJ sofreram maior intemperismo em razão do transporte.

The Shape of sand grains plays an important role in evaluation of soil particle size distribution. However, in most sieving techniques it is assumed that grains are spherical and can be described by a single parameter, diameter. Moreover, the subjectivity of the tests used to estimate sand roughness makes it difficult to obtain data that accurately represent reality. The aim of this paper was to study the use of image analysis together with the degree of sphericity and fractal theory as a tool to measure the textural parameters of the shape and surface texture of two types of quartz sands with supposedly distinct characteristics from the region of Vitória, Espírito Santo, Brazil. The results of the shape and surface texture parameters of the samples are presented and discussed. Statistical analyses of the results for the sphericity variable showed significant statistical differences between the two sands of different origins. The results show that river sands (RS), though having been subjected to a greater degree of transport and attrition, do not have a greater degree of roundness and a smoother surface texture than sands from the coastal spit (BS). The values obtained in the test were statistically analyzed, and again it was confirmed that the sand of the BS has a slightly greater sphericity and smoother surface texture than that of the RS, indicating that the BS sands underwent greater weathering due to transport.