Dynamic performance of the Becker hammer drill and penetration test

1993 ◽  
Vol 30 (4) ◽  
pp. 607-619 ◽  
Author(s):  
Alex Sy ◽  
R.G. (Dick) Campanella
Keyword(s):  
Dynamic Performance ◽  
Drill Pipe ◽  
Standard Penetration Test ◽  
Extensive Study ◽  
Coarse Grained ◽  
Energy Output ◽  
Stress Wave Propagation ◽  
Penetration Test ◽  
Foundation Design ◽  
Variable Energy

The Becker penetration test (BPT) blow counts are commonly correlated to the standard penetration test (SPT) N-values for foundation design and liquefaction potential assessment in coarse-grained soils. Most of the existing correlations, however, do not adequately account for the variable energy output of the ICE 180 diesel hammer used in the Becker system, and the shaft resistance acting on the Becker pipe is often ignored. To obtain reliable BPT–SPT correlations, an extensive study of the BPT has been conducted at several sites in British Columbia. Dynamic measurements of Becker drill rigs and penetration tests were conducted that included hammer combustion and bounce chamber pressures, as well as force and acceleration near the top of the drill pipe. The dynamic field data are presented, including the maximum energy transferred to the top of the Becker pipe (ENTHRU). An energy approach for correcting Becker blow counts to a reference ENTHRU level of 30% of the hammer-rated energy is proposed. Different combustion conditions, drill rigs, and pipe sizes are investigated in the study. The test results show that ENTHRU is a fundamental and useful parameter for normalizing the BPT blow counts to account for the variable energy transfer from the diesel hammer. Key words : penetration test, dynamic measurement, energy, pile driving, diesel hammer, stress-wave propagation.

Becker and standard penetration tests (BPT–SPT) correlations with consideration of casing friction

1994 ◽  
Vol 31 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Alex Sy ◽  
R.G. (Dick) Campanella
Keyword(s):  
British Columbia ◽  
Energy Transfer ◽  
Stress Wave ◽  
Standard Penetration Test ◽  
Energy Output ◽  
Rational Approach ◽  
Stress Wave Propagation ◽  
Penetration Test ◽  
In Situ Tests ◽  
Foundation Design

The Becker penetration test (BPT), through correlations with the standard penetration test (SPT), is widely used for foundation design and liquefaction assessment in gravelly soils. Most of the existing correlations, however, do not adequately account for the variable energy output of the diesel hammer used in the Becker system, and shaft friction on the Becker casing is ignored. An alternative and more rational approach to BPT–SPT correlations is presented, based on experimental and numerical studies conducted at the University of British Columbia. The research involves performing SPT, BPT, and other in situ tests at several sites in British Columbia and includes dynamic measurements of energy transfer in the SPT and BPT. Stress-wave measurements and wave-equation analyses are used to evaluate the effect of friction on the BPT blow count. New BPT–SPT correlations are proposed that consider the energy transfer in both tests and explicitly consider casing friction in the BPT. A recommended procedure for estimating equivalent SPT N60 from BPT blow count is presented. Key words : Becker penetration test, standard penetration test, dynamic measurement, pile driving, stress-wave propagation.

scholarly journals PROPOSTA DE APLICAÇÃO DE RESULTADOS DE SONDAGENS COM MARTELO LEVE (DPL) NO CAMPO EXPERIMENTAL DA UNIFOR EM PROJETOS DE FUNDAÇÕES PARA PEQUENAS CARGAS [ Proposal for the Application of Dynamic Probing Light (DPL) Results in the Experimental Field of UNIFOR in Foundations Projects for Small Loads ]

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Marcos Fábio Porto de Aguiar ◽  
Fernando Feitosa Monteiro ◽  
Francisco Heber Lacerda de Oliveira ◽  
Yago Machado Pereira de Matos
Keyword(s):  
Bearing Capacity ◽  
Standard Penetration Test ◽  
Coefficient Of Determination ◽  
Deep Foundations ◽  
Penetration Test ◽  
In Situ Tests ◽  
Foundation Design ◽  
Experimental Field

RESUMO: Em meio aos diversos métodos utilizados no Brasil para determinação da capacidade de carga de fundações, a grande maioria parte do índice de resistência à penetração (NSPT). Para o caso de pequenas edificações, devido a fatores geralmente econômicos, a experiência ou a prática regional costumam prevalecer. Sendo assim, são elaborados, muitas vezes, projetos sem um procedimento de cálculo fundamentado em parâmetros comprovados por ensaios geotécnicos, podendo ocasionar problemas na edificação, como recalques excessivos, ou, até mesmo, comprometer a segurança da estrutura. Dessa forma, técnicas mais simples e de baixo custo, como o DPL (Dynamic Probing Light), podem ser uma opção para situações de pequenas cargas, viabilizando projetos fundamentados em ensaios in situ. Partindo de investigações com o DPL, este trabalho tem o objetivo de dimensionar fundações superficiais e profundas para edificações de pequeno porte através de algumas das principais metodologias disponíveis na literatura e verificar a sua eficiência. Por meio de resultados de campanhas de sondagens SPT (Standard Penetration Test) e DPL no campo experimental da Universidade de Fortaleza (UNIFOR), determinou-se a capacidade de carga de fundações superficiais e profundas fazendo aplicação dos índices NSPT e NSPT equivalente obtido pela correlação com o DPL. Identificou-se que essa correlação apresentou coeficiente de determinação satisfatório entre os parâmetros obtidos nos ensaios SPT e DPL para o terreno em questão, mostrando-se o DPL ser uma alternativa pertinente, em termos técnicos para projetos de fundações de obras de pequeno porte.ABSTRACT: Among the various methods used in Brazil of the determination of the bearing capacity on foundations, most part uses the standard penetration resistance (NSPT). For small constructions, due to economic factors generally, experience or regional practice usually prevails. Thus, projects without a reasoned calculation procedure in parameters supported by geotechnical tests are often designed, and may cause problems in the building, as excessive settlements, or even compromise the safety of the structure. In this way, simple and low cost techniques such as DPL (Dynamic Probing Light) may be an option for small loads situations, enabling projects based on in situ tests. This paper proposes to calculate the dimensions of shallow and deep foundations for small constructions and check its efficiency using DPL tests. Through the results of SPT (Standard Penetration Test) and DPL tests in the experimental field of the University of Fortaleza (UNIFOR), the determination of the bearing capacity in shallow and deep foundations was done using NSPT index and equivalent NSPT index obtained by the correlation with DPL. A correlation with satisfactory coefficient of determination was obtained between SPT and DPL tests parameters for the analyzed field, showing up the DPL as an appropriate alternative in technical terms for foundation design of small constructions.

scholarly journals Flipping the classroom: applying the circuit in Foundation Design

2018 ◽  
Vol 5 (2) ◽  
pp. 41-47
Author(s):  
Patrick Borges Rodrigues ◽  
Phillipe Oliveira Novaes ◽  
Stephanny Conceicao Farias do Egito Costa
Keyword(s):  
Learning Process ◽  
Zone Of Proximal Development ◽  
Standard Penetration Test ◽  
Alternative Form ◽  
Proximal Development ◽  
Penetration Test ◽  
Santa Cruz ◽  
Cone Penetration ◽  
Foundation Design ◽  
Challenging Tasks

The assessment of the student's academic results is one of the most challenging tasks in education because it may be subjective, lack clarity and goals. In addition, many professors and institutions have a deficient comprehension of the assessments' purpose and have used the students' grades as a means to determine the reach of the educational objectives. Trying to address that question, the Circuit is an alternative form of assessment based on the interaction and cooperation between students that aims to verify the results of the learning process through ludic activities. This paper presents the results of applying the Circuit in Foundation Design, an undergraduate course of the 5th-year of Civil Engineering at the Universidade Estadual de Santa Cruz - UESC, in Ilhéus, Brazil, in 2017. The professor decided to use the Circuit in this course as an attempt to enable the students to interact and share what they have learned with their classmates. By doing so, the professor considered the concept of the Zone of Proximal Development, from Vygotsky, assessing the students’ ability to deal with problems with the help of their peers and learn with them. The method, although containing many rules, was easy to apply. The students, divided into groups of three, were expected to create two reports based on data for one Standard Penetration Test – SPT - and one Cone Penetration Test – CPT. Each member of the group played a different role on the activity: the "engineer" produced the report; the "technician" completed the missing data of the tests; the "manager" corrected the final reports. After completing the activity, each student gave feedback on its negative and positive aspects and this information was used to compose the results. From the results, the method showed to be effective because more than half the students pointed out that it developed their sense of responsibility and was innovative. Conversely, it may have failed with respect to the distribution of time, what may have affected the results of the groups. Therefore, the method proved to be promising, but it still demands some improvements for subsequent applications.

scholarly journals Determination of Silty Soil Bearing Capacity in Binzhou China

2015 ◽  
Vol 9 (1) ◽  
pp. 877-880
Author(s):  
Zhang Yunfeng ◽  
Zeng Yifan ◽  
Liu Lanyu ◽  
Wang Shi ◽  
Zhang Youlin ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Active Role ◽  
Original Data ◽  
Standard Penetration Test ◽  
Penetration Test ◽  
Foundation Design ◽  
Silty Soil ◽  
Test Soil ◽  
Engineering Practices ◽  
Engineering Investigation

The characteristical values of bearing capacity of silty soil are determined on different basis in Binzhou area, which causes a great difference in actual work. Based on engineering practices, most original data are counted and calculated for standard penetration test, soil test and double bridge CPT (cone penetration test). The result shows that the bearing capacity is more accurate as concluded by in-situ test data, and also can provide a more helpful method for foundation design, which will play an active role in undertaking the specific engineering investigation work and maintaing the summary of regional emperical values.

Comportement de pieux d'essais instrumentés sous charge horizontale

1993 ◽  
Vol 30 (1) ◽  
pp. 1-11
Author(s):  
R. Frank ◽  
H. Zervogiannis ◽  
S. Christoulas ◽  
V. Papadopoulos ◽  
N. Kalteziotis
Keyword(s):  
Pile Foundation ◽  
Bending Moment ◽  
Standard Penetration Test ◽  
American Petroleum Institute ◽  
Full Scale ◽  
Test Method ◽  
Cohesionless Soil ◽  
Penetration Test ◽  
Cohesionless Soils ◽  
Final Design

This paper describes the behaviour of two test piles (one bored and postgrouted and one simply bored, both 31.7 m long and 0.75 m in diameter) subjected to horizontal loads. These full-scale pile tests were carried out for the actual design of the pile foundation of a pier of the Evripos cable-stayed bridge. This bridge will link the Euboea Island to mainland Greece. The two piles have already been subjected to bearing capacity tests under axial loadings. The inclinometer measurements, taken during the present tests, yielded, in particular, the deformed shape of the piles as well as the bending moments. Conclusions could be drawn for the final design of the pile foundation with respect to horizontal loadings. Furthermore, various calculation methods using p–y reaction curves for cohesionless soils have been checked: the Ménard pressuremeter method, the method of the American Petroleum Institute recommendations, and the Standard penetration test method of Christoulas. These pile tests show that simple measurements, taken on construction sites, can yield interesting results on the actual behaviour of horizontally loaded piles. Key words : pile, horizontal loading, full-scale test, horizontal loads, bending moment, subgrade reaction modulus, p–y curve, cohesionless soil, Standard penetration test, pressuremeter test.

Assessment of the range of variation of Nγ from 60 estimation methods for footings on sand

2013 ◽  
Vol 50 (7) ◽  
pp. 793-800 ◽  
Author(s):  
Edgar Giovanny Diaz-Segura
Keyword(s):  
Friction Angle ◽  
Standard Penetration Test ◽  
Estimation Methods ◽  
Penetration Test ◽  
In Situ Tests ◽  
Vertical Loading ◽  
Simplified Method ◽  
Bearing Capacity Factor ◽  
Range Of Variation

The range of variation of the bearing capacity factor, Nγ, was assessed using 60 estimation methods for rough footings on sand subjected to static vertical loading. The influence on the Nγ values of the use of correlations for the estimation of the friction angle, [Formula: see text], derived from in situ tests was also assessed. The analysis shows a marked dependency on the methods used to determine Nγ, showing differences for the same [Formula: see text] values of up to 267% between estimated values. Uncertainty in the estimation of [Formula: see text], due to the use of correlations with in situ tests, leads to a range of variation for Nγ higher than that seen using the 60 estimation methods. Finally, given the regular use of the in situ standard penetration test (SPT) on sands, and based on a series of analyses using finite elements, a simplified method in terms of the SPT N-values is proposed for estimation of Nγ in footings on sands.

GEOTECHNICAL PARAMETERS STUDY USING SEISMIC REFRACTION TOMOGRAPHY

2016 ◽  
Vol 78 (8-6) ◽  
Author(s):  
Rose Nadia ◽  
Rosli Saad ◽  
Nordiana Muztaza ◽  
Nur Azwin Ismail ◽  
Mohd Mokhtar Saidin
Keyword(s):  
Parameter Estimation ◽  
Seismic Refraction ◽  
Standard Penetration Test ◽  
P Wave ◽  
Cohesive Soils ◽  
Penetration Test ◽  
Geotechnical Parameters ◽  
Wave Velocities ◽  
Refraction Tomography ◽  
Loose Medium

In this study, correlation is made between seismic P-wave velocities (Vp) with standard penetration test (SPT-N) values to produce soil parameter estimation for engineering site applications. A seismic refraction tomography (SRT) line of 69 m length was spread across two boreholes with 3 m geophones spacing. The acquired data were processed using Firstpix, SeisOpt2D and surfer8 software. The Vp at particular depths were pinpointed and correlated with geotechnical parameters (SPT-N values) from the borehole records. The correlation between Vp and SPT-N values has been established. For cohesive soils, it is grouped into three categories according to consistencies; stiff, very stiff and hard, having velocity rangesof 575-314 m/s, 808-1483 m/s and 1735-2974 m/s, respectively. For non-cohesive soils, it is also divided into three categories based on the denseness as loose, medium dense and dense with Vp ranges of 528-622 m/s, 900-2846 m/s and 2876-2951 m/s, respectively

A new genetic programming model for predicting settlement of shallow foundations

2007 ◽  
Vol 44 (12) ◽  
pp. 1462-1473 ◽  
Author(s):  
Mohammad Rezania ◽  
Akbar A. Javadi
Keyword(s):  
Genetic Programming ◽  
Programming Model ◽  
Standard Penetration Test ◽  
Shallow Foundations ◽  
Penetration Test ◽  
Case Histories ◽  
Contributing Factors ◽  
Artificial Neural Network Ann ◽  
Gp Model ◽  
Very High

In this paper, a new genetic programming (GP) approach for predicting settlement of shallow foundations is presented. The GP model is developed and verified using a large database of standard penetration test (SPT) based case histories that involve measured settlements of shallow foundations. The results of the developed GP model are compared with those of a number of commonly used traditional methods and artificial neural network (ANN) based models. It is shown that the GP model is able to learn, with a very high accuracy, the complex relationship between foundation settlement and its contributing factors, and render this knowledge in the form of a function. The attained function can be used to generalize the learning and apply it to predict settlement of foundations for new cases not used in the development of the model. The advantages of the proposed GP model over the conventional and ANN based models are highlighted.

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