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Dynamic amplification takes decades of study. For example, as a result of the 1960 earthquake, the soil and drift displacement amplification were characterized for Concepción city (Poblete and Dobry, 1968). However, the 2010 El Maule earthquake surprisingly delivered a twopeak spectrum for the site. The peak of high periods is attributed to the site, while for low periods to the source. The study of the displacement records of the Concepción Centro and San Pedro de la Paz stations identifies two pulses for this event (Ruiz and Saragoni, 2012). The characteristics of these pulses and their frequencies are related mainly to Love-type surface waves. The foundation soils of the stations are made up of sands, whose cyclical horizontal deformations allow estimating their rigidity degradation; and theoretically an increase in their vibrating periods. This prediction is validated by examining the shift registers and acceleration spectrograms for the stations. The deformations and periods vary their magnitudes throughout the record. The period of the degraded soil in the strong phase of the earthquake can be related to the period measured by the H/V method. The estimated period with the "Autocorrelogram" technique (Sandoval and Saragoni, 2016) can also be understood as an average of the previous ones. This gives access to evaluation of the period of the soil in different phases or magnitudes of earthquakes, useful in seismic hazard studies. [ABSTRACT FROM AUTHOR]

Plants of Bambusa vulgaris Schrad. ex Wendl are a viable option to generate environmental, social and economic benefits. However, there are problems in the propagation via organogenesis of this species such as the low in vitro multiplication coefficient, which limits its propagation. The research was aimed to determine the effect of 6-benzylaminopurine and the immersion time on the multiplication, morphophysiology and biochemistry of B. vulgaris shoots in temporary immersion systems. Morphophysiological and biochemical variables were evaluated in shoots grown at different BAP concentrations (0; 6.6; 13.2 and 26.4) at immersion times of one, two or three minutes, for 30 days of cultivation. In those systems, the lower concentration of BAP (6.6 µM) and immersion time of two minutes favored the emission of new shoots. It was associated with an increase in the content of total chlorophylls, lignin and total phenols in shoots. Based on these results, a protocol was established for the propagation via organogenesis of B. vulgaris plants in Temporary Immersion Systems, with a high emission of new shoots in vitro, which can be applied to other bamboo species. [ABSTRACT FROM AUTHOR]

Introduction: The design of spread footings over a lime-treated soil is studied as an important topic in geotechnical and environmental engineering. With the emergence and use of algorithms, it is possible to solve optimization problems in engineering, leading, for example, to decreased amounts of materials, time, energy, and work. Objective: This research aims to optimize the CO2 emission and cost of building spread footings over a treated soil with hydrated lime using the modified simulated annealing algorithm (MSAA). Method: The parameters for shear strength (cohesion and friction angle) was calculated of a silty soil of the Guabirotuba geological formation of Curitiba (Brazil) stabilized with different lime contents (3, 5, 7 and 9%) at different curing times (30, 90, and 180 days). Then with these parameters, the geometry of the spread footings was optimized with MSAA minimizing the cost and CO2 emissions of their construction. For the design constraint of the structures the ultimate bearing capacity of the soil was used as criteria, the settlements produced by the service load, and the base safety factor Results: The results show that most of the problems converge to the same solution for costs and CO2 emissions without depending on curing time and lime content used, due to the solutions being restricted primarily by the maximum permissible settlements. Conclusions: With the increase in lime content, the cohesion of the mixtures increased for all curing times studied ant the friction angle had no major variations in relation to the amount of lime administered or to the curing time employed. Costs and carbon dioxide emissions for spread footing construction converge to the same results. In this sense, 9% lime can be avoided, and small percentages of lime (i.e. 3-5%) are appropriated to ground improvement and reduce the costs of this procedure. On the other hand, the MSAA can be designated as a robust algorithm due to having achieved almost equal results and, in some cases, better results compared with other algorithms to solve problems reported in the literature. [ABSTRACT FROM AUTHOR]

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During a high-magnitude earthquake, drag loads can be induced by liquefaction of soils, defined as the additional vertical load caused by the settlement after soil liquefaction around the pile due to yielding and volume decreasing in soft soils layers, causing a downdrag displacement. In several projects, the magnitude of these loads and settlements caused by downdrag in piles is not well defined. In this research, we advance towards estimating this drag loads and their impact on projects. For this purpose, a case study considering the 2010 Maule earthquake was analyzed, comparing methodologies of shaft loads against numerical modelling results using nonlinear finite element method, in order to estimate the range of settlement, shear stress at the soil-structure interface, the axial loading in the pile and the volumetric strain, among others. It can be demonstrated that the studied piles show downdrag with its consequently drag loads, which is shown as the effective mobilization in the surrounding soil of the southeast and northeast piles, with a strain of 0.2% and 0.1% respectively. These strains imply an additional shear stress in the soilstructure interface, with axial loadings of 45 and 36 ton respectively. [ABSTRACT FROM AUTHOR]

The employment of piled raft foundations constitutes a variant of foundation in grounds with very compressible soils and under large loads. Of vital importance in the design process it is the estimation of the settlement and the proposal of the quantity of piles that guarantee the compliance of the criteria of bearing capacity and allowable settlements. Experimental results suggest that when the depth of foundation increases, the foundation begins to work as a compensated foundation diminishing the total settlements. In this work, results of loads versus settlements obtained with the employment of professional computational programs and spreadsheets programmed in MathCad are shown. It is demonstrated the influence of the depth of foundation on the decrease of the settlement in piled raft foundations. [ABSTRACT FROM AUTHOR]