scholarly journals CAPACIDADE DE CARGA DE FUNDAÇÕES E VERIFICAÇÃO DE RECALQUES A PARTIR DE PARÂMETROS DO ENSAIO PANDA 2 E DE OUTROS ENSAIOS IN SITU

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Antônio Carlos Ferreira Tonhá ◽  
Renato Resende Angelim
Keyword(s):  
Load Capacity ◽  
Deep Foundations ◽  
Practical Application ◽  
Empirical Methods ◽  
Compacted Soil ◽  
Spread Footing ◽  
Design Load ◽  
Dynamic Penetration ◽  
Semi Empirical

RESUMO: O presente trabalho tem como objetivo comparar a capacidade de carga de fundações rasas, tipo sapata, usando os valores de resistência à penetração dinâmica do ensaio PANDA 2 em solo tropical compactado, em substituição aos parâmetros obtidos pelos ensaios CPT e SPT, que implementam os métodos de dimensionamento tradicionais, bem como de fundações profundas, tipo estaca. Além disso, o trabalho abrange a análise do recalque em cada uma das situações propostas. A comparação foi feita a partir do cálculo da capacidade de carga de sapata e de estaca de dimensões predefinidas por meio de métodos teóricos e semi-empíricos. Os resultados para uso do PANDA 2 foram satisfatórios, apresentando pouca variabilidade quando comparado ao uso do SPT e CPT para dimensionamento de fundações no solo estudado. Quanto aos recalques, como esperado, o recalque previsto para a estaca foi relativamente menor que o recalque para a sapata. A principal contribuição deste trabalho foi a aplicação de nova tecnologia disponível para investigação geotécnica de campo, o ensaio Panda 2, em métodos de cálculos de previsão de capacidade de carga e de recalque de fundações.ABSTRACT: This study aims to compare the load capacity of shallow and deep foundations, spread footing and piles, using dynamic penetration resistance values of PANDA 2 test in tropical compacted soil, replacing the parameters obtained by CPT and SPT that implement the traditional methods of capacity of design load. Furthermore, this research includes also the settlements analysis in each of the situations proposed. The comparison of the load capacity of footing and pile with predefined dimensions was made through theoretical and semi-empirical methods. The PANDA 2 results use were satisfactory, with little variability when compared to SPT and CPT use for foundations design in the studied soil. With regard to settlements, as expected, the settlement for pile was relatively lower than the settlements on footing. The main contribution of this paper was the practical application of Panda 2 results use, through methods of estimate foundations load capacity and settlements.

scholarly journals VERIFICAÇÃO DO DESEMPENHO DAS ESTACAS INJETADAS AUTOPERFURANTES EXECUTADAS EM SOLOS ARENOSOS PARA CONSTRUÇÃO DE USINA EÓLICA

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Rodrigo Cerqueira Rogerio
Keyword(s):  
Structural Characteristics ◽  
Load Capacity ◽  
The Self ◽  
Executive Processes ◽  
Empirical Methods ◽  
Deep Drilling ◽  
Load Tests ◽  
Different Diameters ◽  
Semi Empirical

RESUMO: Apresenta-se neste trabalho a solução adotada para execução das fundações do Parque de Usina Eólica localizado no Ceará, com a utilização das estacas injetadas autoperfurantes, executadas em presença de solos arenosos. No qual consiste em perfurar o solo com altíssima velocidade por rotação e “pull down”, através da injeção simultânea de nata de cimento com medias pressões. Ocasionando na estaca um diâmetro final que pode obter o dobro do bit de perfuração, de acordo com o tipo de solo, gerado pelo efeito do jato da nata de cimento. Detalhando os processos executivos, verificando os aspectos técnicos e operacionais, para melhor compreender as características estruturais deste elemento. De forma a verificar “in situ” o desempenho deste novo tipo de fundação profunda, foram realizadas provas de carga, em estacas com diferentes diâmetros e comprimentos, realizadas em perfis estratigráficos de solos arenosos, para melhor avaliação de sua capacidade de carga. Analisando-se os ensaios das provas de carga interpretados a base da extrapolação da curva carga versus recalque e das previsões da capacidade de carga, obtidas por meio dos métodos semi-empíricos de correlação com ensaios de penetração (SPT), avaliando os padrões de execução desta tipologia de estaca injetada para comunidade geotécnica. ABSTRACT: This paper aims to establish the selected solution to except the foundations of the Wind Energy Park in Ceará (Brazil), with an executive methodology of the self-drilling injection piles framed in loco in Sandy soil. In which the soil drilling is done with the highest speed by rotation and pull down, through the simultaneous injection of grouting with medium pressures. This kind of drilling causes in the pile a final diameter that can get the double bore bit, according to the type of soil, done by the grouting blast. The executive processes are detailed as a whole, and also presenting the pile materials composition, in order to understand the structural characteristics of this element. To verify the performance of this new kind of deep drilling, instrumentations were done: settlement control and load tests in constructions with different structural characteristics, in self-drilling injected piles with different diameters and length, done in stratigraphical sandy, for a better evaluation of its load capacity. Analyzing the essays of load tests interpreted in the basis of curve extrapolation load versus settlement and the previsions of the load capacity, obtained by semi-empirical methods correlating with the penetrations methods (SPT), offering information to the geotechnical community.

scholarly journals Use of the dynamic load test to obtain the pile capacity – the Brazilian experience

DYNA ◽  
2021 ◽  
Vol 88 (217) ◽  
pp. 169-177
Author(s):  
Tiago de Jesus Souza ◽  
André Querelli ◽  
Felipe Vianna Amaral de Souza Cruz ◽  
Pablo Cesar Trejo Noreña
Keyword(s):  
Dynamic Load ◽  
Load Capacity ◽  
Test Procedure ◽  
Field Tests ◽  
Load Test ◽  
Deep Foundations ◽  
Pile Capacity ◽  
Dynamic Load Test ◽  
Load Tests ◽  
Semi Empirical

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.

On the Prediction of Wave-added Resistance with Empirical Methods

2015 ◽  
Vol 31 (03) ◽  
pp. 181-191 ◽  
Author(s):  
Rob Grin
Keyword(s):  
Wave Reflection ◽  
Service Performance ◽  
Prediction Methods ◽  
Added Resistance ◽  
Practical Application ◽  
Empirical Methods ◽  
Sea Trial ◽  
Short Waves ◽  
Trial Analysis ◽  
Semi Empirical

There is continuous research on analytical, numerical, and (semi)empirical methods to predict wave-added resistance. Most of this research focuses on a particular area, like motion-induced wave added resistance, wave-added resistance in short waves, or is limited to head seas only. The practical application of most methods is therefore often limited. Moreover, most methods require detailed information on hull lines and results are rather sensitive to the discretization of those hull lines. Since 2006, MARIN has been investigating the feasibility of empirical methods that do not have those limitations. They only require the main particulars to predict wave-added resistance. Within the Sea Trial Analysis Joint Industry Project (STA-JIP), a method was developed for the correction of wave-added resistance in head seas covering both the motion-induced and the wave reflection-induced component. This method was further refined and extended to all wave directions within the service performance analysis JIP (SPA-JIP) in 2008. This article presents the results of the comparison between the prediction methods and model tests for almost 50 different ships, comprising more than 1500 tests in regular and irregular seas.

Semi-empirical methods versus dynamic load testing in piles

Geotecnia ◽  
2015 ◽  
Vol 135 ◽  
pp. 89-113
Author(s):  
Jean Felix Cabette ◽  
◽  
<br>Heloisa Helena Silva Gonçalves ◽  
<br>Fernando Antônio Marinho ◽  
◽  
...  
Keyword(s):  
Dynamic Load ◽  
Load Testing ◽  
Empirical Methods ◽  
Semi Empirical

scholarly journals Finite element analysis of reinforced concrete deep beam with large opening

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elsayed Ismail ◽  
Mohamed S. Issa ◽  
Khaled Elbadry
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
The Other ◽  
Deep Beam ◽  
Web Openings ◽  
Design Load ◽  
Large Opening

Abstract Background A series of nonlinear finite element (FE) analyses was performed to evaluate the different design approaches available in the literature for design of reinforced concrete deep beam with large opening. Three finite element models were developed and analyzed using the computer software ATENA. The three FE models of the deep beams were made for details based on three different design approaches: (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978), (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006), and Strut and Tie method (STM) as per ACI 318-14 (ACI318 Committee, Building Code Requirements for Structural Concrete (ACI318-14), 2014). Results from the FE analyses were compared with the three approaches to evaluate the effect of different reinforcement details on the structural behavior of transfer deep beam with large opening. Results The service load deflection is the same for the three models. The stiffnesses of the designs of (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and STM reduce at a load higher than the ultimate design load while the (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) reduces stiffness at a load close to the ultimate design load. The deep beam designed according to (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) model starts cracking at load higher than the beam designed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) method. The deep beam detailed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) and (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) failed due to extensive shear cracks. The specimen detailed according to STM restores its capacity after initial failure. The three models satisfy the deflection limit. Conclusion It is found that the three design approaches give sufficient ultimate load capacity. The amount of reinforcement given by both (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) is the same. The reinforcement used by the STM method is higher than the other two methods. Additional reinforcement is needed to limit the crack widths. (Mansur, M. A., Design of reinforced concrete beams with web openings, (2006)) method gives lesser steel reinforcement requirement and higher failure load compared to the other two methods.

Excited-state localization and energy transfer in pyrene core dendrimers with fluorene/carbazole as the dendrons and acetylene as the linkages

2016 ◽  
Vol 18 (5) ◽  
pp. 4134-4143 ◽  
Author(s):  
Linyin Yan ◽  
Yan Wan ◽  
Andong Xia ◽  
Sheng Hien Lin ◽  
Ran Huang
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Theoretical Model ◽  
Empirical Methods ◽  
Multi Scale ◽  
Td Dft ◽  
Semi Empirical

Multi-scale theoretical model and spectra simulation for dendrimers combining TD-DFT/DFT and semi-empirical methods.

scholarly journals Limitations of the Danish driving formula for short piles

2021 ◽  
Vol 44 (2) ◽  
pp. 1-6
Author(s):  
Silvio Heleno de Abreu Vieira ◽  
Francisco R. Lopes
Keyword(s):  
Load Capacity ◽  
Precast Concrete ◽  
Free Fall ◽  
Technical Note ◽  
Driven Piles ◽  
Concrete Piles ◽  
Load Tests ◽  
Semi Empirical ◽  
The City ◽  
Pile Length

Dynamic formulae are a widely used expedient for the control of driven piles to ensure load capacity. These formulae have considerable limitations when used in the prediction of the load capacity on their own, but are very useful in the control of a piling when combined with other tests. This technical note presents an evaluation of the Danish Formula for 54 precast concrete piles, comparing its results with High Strain Dynamic Tests (HSDTs), Static Load Tests (SLTs) and predictions by a semi-empirical static method (Aoki & Velloso, 1975). The data used in the comparison come from three works in the city of Rio de Janeiro, Brazil. All piles were driven with free-fall hammers and in one particular work the piles were relatively short. The predictions of the Danish Formula were evaluated in relation to the pile length/diameter ratio. It was concluded that for short piles - with lengths less than 30 times the diameter - this formula indicates bearing capacities higher than the actual ones. A correction for a safe use of the Danish Formula for short piles is suggested.

scholarly journals STRUCTURAL AND ELECTRONIC PROPERTIES OF BRIDGED BITHIOPHENE S-OXIDES (BTO) WITH S, S=O, O, SiH2 and BH2 BRIDGE: SEMI-EMPIRICAL AND AB INITIO STUDY

2010 ◽  
Vol 18 (18) ◽  
pp. 1-10
Author(s):  
Banjo Semire ◽  
Isaiah Ajibade Adejoro ◽  
Olusegun Ayobami Odunola
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Ab Initio Study ◽  
Empirical Methods ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Semi Empirical ◽  
Good Agreement

In this paper, we theoretically studied the geometries, stabilities, electronic and thermodynamic properties of bridged bithiophene S-oxide (BTO-X) derivates (with X = BH2, SiH2, S, S=O, and O) by using semi-empirical methods, ab-initio, and Density functional theory. The geometries and thermodynamic parameters calculated by PM3 were in good agreement with that of B3LYP/6-31G(d). The bandgap calculated by B3LYP/6-31G(d) ranged from 3.94eV (BTO-O)-3.16eV (BTO-BH2). The absorption λmax calculated suing B3LYP/6-31G(d) shifted to longer wavelength with X=BH2, SiH2, and S=O due to enhancement of π-conjugated system whereas, BTO-S and BTO-O shifted to shorter wavelengths as compared to dimmer thiophene S-oxide (2TO).

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