Abstract It is common to observe residences with a high number of pathologies related to differential settlements in the municipality of Cruz Alta, Rio Grande do Sul, Brazil. Motivated by this perspective the first Geotechnical Engineering Experimental Field was implemented in the municipality. Standard penetration test and cone penetration test was conducted to characterize the subsoil and execute 17 excavated piles: nine compression piles and eight reaction piles. This technical note presents and discusses the results of the geotechnical load capacity obtained with the static load test in three different pile conditions: conventional piles, floating piles, and reinforced piles by inserting a crushed stone layer compacted at the bottom of the drilling. The piles evaluated have a length of 3 m and a diameter of 30 cm. The piles are immersed in a layer of unsaturated laterite soil. Conventional piles are extensively executed in the municipality due to the limited equipment of the companies offering this service. In summary, the piles presented low bearing capacity, however, the reinforced piles proved to be a viable alternative in terms of increased resistance. The conventional piles presented low load capacity and significant settlements. The insertion of the reinforcement at the tip of the pile resulted in a resistance gain in the range of 31%. The study of floating piles was important to understand the behavior of the pile base. This technical note will enable the geotechnical understanding for future researchers or designers who will work with this soil condition in the state of Rio Grande do Sul, Brazil.

Abstract This study presents case studies on the implementation of an innovative method of calculating effective driving energy with no need to account for hammer efficiency. The approach is based on measurements of set and elastic rebound, as well as a site-specific parameter (λ) calibration. The study applied this method to steel piles located in the cities of Santos (SP), Itaguaí (RJ), and Óbidos (PA), with the latter site being built in the Amazon region, near the Amazon River. Following coefficient calibration, the effective driving energy estimation technique exhibited a strong correlation with realistic and accurate energies directly obtained from dynamic loading tests. The method provides a highly accurate means of calculating effectively transferred energy to piles due to hammer blows, without relying on knowledge of the driving system performance. In that way, it can be applied to all the piles at the site (100% of them), including those that are not tested. This optimized and agile approach represents a significant breakthrough in foundation engineering and an enhance of pile foundation quality control.

Abstract Most of the time, geotechnical engineering interventions require solutions that necessarily aim for better use of the available space. Many slope stabilization techniques were developed following that assumption, and one of the most applied procedures in Brazil is the soil nailing reinforcement. These engineering techniques are constantly improving. Consequently, a continuous study of the design and behavior of soil nails is important. The technique of vertical nails reinforcement in soil nailing is recent in the Brazilian scenario. Nowadays, some constructors started to use them near the slope face when stabilizing huge excavations. This paper aims to verify the vertical nails’ efficiency in reducing horizontal displacements. We present three numerical modeling analyses using the finite elements method (FEM). The proposed model is a soil nailing of approximately 18m high in a homogeneous subsoil in São Paulo city. Comparing situations with and without vertical nails, as if an inclined face (slope), the results showed that adding those nails could reduce horizontal displacements.

Resumen La mayoría de las veces, las intervenciones de ingeniería geotécnica requieren soluciones que necesariamente apuntan a una mejor utilización del espacio disponible. Muchas técnicas de estabilización de taludes fueron desarrolladas siguiendo esa premisa y uno de los procedimientos más aplicados en Brasil es el refuerzo con clavos del suelo. Como todas esas técnicas de ingeniería están en constante perfeccionamiento, es importante que el diseño y el comportamiento de los clavos de suelo sigan siendo estudiados. La técnica de refuerzo con clavos verticales en el suelo es reciente en el escenario brasileño. Ahora algunos constructores comenzaron a utilizarlos cerca de la cara del talud al estabilizar grandes excavaciones. Este trabajo tiene como objetivo verificar la eficiencia de los clavos verticales en la reducción de los desplazamientos horizontales. Se presentan tres análisis de modelización numérica mediante el método de elementos finitos (MEF). El modelo propuesto es un clavado de suelo de aproximadamente 18 m de altura, en subsuelo homogéneo en la ciudad de São Paulo. Comparando situaciones con y sin clavos verticales, como con una cara inclinada (talud), los resultados mostraron que la adición de esos clavos podría reducir los desplazamientos horizontales.

Resumen La prueba de carga dinámica es actualmente una herramienta importante y habitual para el diseño, control y garantía de calidad de cimentaciones profundas. El objetivo de este trabajo es comparar la capacidad de carga geotécnica esperada a través de métodos brasileños empíricos y semi-empíricos con la carga última del pilote obtenida de la interpretación de Ensayos de Carga Dinámica (ECD). La curva esfuerzo-asentamiento se obtuvo a partir del análisis CAPWAP con golpes de diferentes alturas de caída de energía creciente - procedimiento de prueba propuesto por Aoki (1989). En este trabajo se evaluaron pilotes de tipo Franki, micropilotes y Helice continua. Estas estructuras se probaron en distintas ciudades de Brasil. Además, los resultados del PDA se compararon con las pruebas de carga estática donde se encontró una buena correlación con estas pruebas de campo. El artículo tiene como objetivo proporcionar bases para comparación y orientación a los especialistas de diseño de cimentaciones profundas, así como a quienes desarrollan de manera rutinaria estos proyectos en Brasil.

Abstract The dynamic load test is currently an important and usual tool for design, control, and quality assurance of deep foundations. The objective of this paper is to compare the expected geotechnical load capacity through empirical and semi-empirical Brazilian methods with the ultimate pile load obtained from the interpretation of Dynamic Load Tests (DLT; PDA). The stress-settlement curve was constructed from CAPWAP analysis with blows of different drop heights of increasing energy - test procedure proposed by Aoki (1989). Continuous flight augering (CFA) Franki and Root piles were evaluated in this study. These piles were tested in different cities in Brazil. Additionally, DLT results were compared with static load tests, and a good correlation was found with these field tests. The article aims to provide comparative background to guide foundation designers, as well as those who routinely develop these projects in Brazil.