Abstract This work aims to analyze the behavior of a new post-grouted micropile setup developed in tropical soil. Its main innovation is the use of high mechanical resistance steel pipes (N80 class) for drilling and as a structural component of the micropiles. The pipes have special manchette valves uniformly spaced to allow neat cement grout injection into the soil. Two instrumented micropiles with 0.3 m diameter (after injection) and lengths of 19.4 m and 21 m were installed at Experimental Site III of the University of Campinas (Unicamp). The geological profile of this site presents a sandy clay surface layer (porous and collapsible) followed by a layer of sandy silt (diabase residual soil). The piles were subjected to compressive slow maintained loading tests and were instrumented along their depth with strain gages. No geotechnical failure was observed during the load test. The maximum load achieved by the MC1 and MC2 micropiles were 2.210 kN and 2.470 kN, respectively. The load test data were extrapolated to estimate the ultimate geotechnical pile capacity. The extrapolated geotechnical failure load was above 2.500 kN for both micropiles and similar to those estimated by the Federal Highway Administration FHWA (2005) load capacity method. It was verified that (1) the pile material undergoes creep under stress above 25 MPa on the transversal section of the pile and (2) the debonding effect during the loading process. The micropiles showed higher values of skin friction compared with other piles installed in the same geological-geotechnical context (tropical soil).

RESUMO: Marmeleiros são conhecidos popularmente pelas suas ações medicinais presentes em seus óleos essenciais. A pesquisa objetivou analisar o óleo essencial de folhas de três espécies de Croton (Croton argyrophylloides, Croton jacobinensis, and Croton sincorensis), a fim de verificar se os horários e períodos do ano causam diferenças no rendimento e na composição. Foram coletadas 1500g de folhas verdes de cada espécie em Viçosa do Ceará - CE, às 6 e 12 horas, no período das estações seca e das chuvas. A extração ocorreu pelo método de arraste a vapor de água e a composição foi analisada por cromatografia gasosa acoplada a espectrometria de massa (CG/EM). O maior rendimento de C. argyrophylloides e C. jacobinensis foi no período seco às 12h, e de C. sincorensis foi no período chuvoso às 6h. O biciclogermacreno apresentou maior concentração em C. argyrophylloides (28,09 a 30,59%), C. jacobinensis (25,2 a 30,14%) e C. sincorensis (23,86 e 21,71%), com exceção do C. sincorensis às 6h sendo o majoritário o (E)-cariofileno (25,34 %). O rendimento e a composição das espécies estudadas foram influenciadas pela pluviosidade, temperatura e incidência solar, apresentando diferença estatística entre os horários estudados. As espécies produzem constituintes com propriedades biológicas específicas, podendo ser utilizadas como fonte natural dos mesmos.

ABSTRACT: Marmeleiros are popularly known for the medicinal properties ascribed to their essential oils. This research aimed to analyze the essential oil of leaves from three Croton species (Croton argyrophylloides, Croton jacobinensis, and Croton sincorensis), to verify whether the daily time and harvest season in the year may interfere with their essential oils performance and composition. From each species, 1,500g of green leaves were harvested in Viçosa do Ceará - CE, at 6am and 12pm, during both dry and rainy seasons. Essential oil extraction was conducted by the method of water vapor drag and chemical profile was analyzed by gas chromatography-mass spectrometry (GC/MS). The highest yield was obtained at 12pm in the dry season for C. argyrophylloides and C. jacobinensis, and at 6am in the rainy season for C. sincorensis. Bicyclogermacrene demonstrated higher relative abundance in C. argyrophylloides (28.09 to 30.59%), C. jacobinensis (25.2 to 30.14%), and C. sincorensis (23.86 and 21.71%), and the only exception was at 6am in C. sincorensis, where (E)-caryophyllene was the most abundant compound (25.34%). The yield and composition of the studied species were influenced by rainfall, temperature, and sunlight, presenting statistical significant differences between the different periods studied. The species produce constituents with specific biological properties; and therefore, they can be used as a natural source.