STATRAPID: the method of Rapid Pile Load Testing
Pile Load Testing
Allnamics is all about pile testing. With a wide range of testing techniques, Allnamics is capable to test any pile for its integrity, bearing capacity and stiffness. Being one of the pioneers in this field of pile testing, Allnamics founders, have contributed major knowledge to pile testing nowadays. Either Static, Dynamic or Rapid Load Testing. The latter is one of the innovations of Allnamics founders for pile testing. In 1990 the Statnamic method has been developed. Later followed by an alternative Rapid Load Testing: the StatRapid Load Test. That brings the total of testing techniques for bearing capacity to:
- StatRapid Load Testing
- Dynamic Load Testing
- Static Load Testing
- Bi-directional Load Testing
- StatNamic Load Testing
All can be performed onshore as well as offshore. For small micro piles as well for huge Monopiles.
PDA Pile Driving Analysis
Foundation piles have been installed well since… well, Always! That implies Quality Assurance requires measuring during driving PDM or PDA (Pile Driving Analysis or Pile Driving Monitoring PDM) to check the installation process e.g. pile stresses, blow counts, and hammer performance. Both for impact hammers as vibratory hammers (VDA Vibratory Driving Analysis or VDM, Vibratory Driving Monitoring ).
After driving, the bearing capacity will increase in time (set-up). By measuring during a redrive, the static pile/soil behaviour and accordingly its static bearing capacity can be obtained by AllWave-DLT Signal Matching (DLT Dynamic Load Testing).
VDA Vibratory Driving Analysis
When piles are installed by means of a vibratory hammer, instead of an impact hammer, comparable measurements like with a PDA can be performed.
During Vibratory Driving Analysis or Monitoring (VDA) all information during installation is monitored, including performance and behaviour of pile, soil, and vibratory hammer. Monitoring of pile stresses in relation to fatigue of the pile material, penetration speed, hammer frequency and efficiency, and more, are part of total quality control for piles installed with vibratory hammers. For foundations piles and large diameter monopiles. Onshore and offshore.
SLT – Static Load Testing
Being the basis of all test, Allnamics performs static tests, both in compression and tension. Vertical, horizonal or under any slope.
With the equipment dedicated and designed for this type of test (see Allnamics Quad), high quality readings of load and settlements can be obtained.
The SLT is especially suitable for:
– Piles with relatively small capacity
– To determine design factors for shaft and toe resistance
– To determine load-displacement behaviour
– Trouble shooting
DLT – Dynamic Load Testing
After development started somewhere mid-sixties, it was in the seventies and eighties of last century, that the Dynamic Load Test has been developed as a mature testing method. At that time offshore constructions were built for exploring oil at locations with, until then, unknown soil conditions. As an alternative for the Static Load Test, the Dynamic equivalent has positioned itself in the row of pile testing methods.
Allnamics founders are pioneers in this field. It all led to a series of monitoring systems starting with the FPDS (Foundation Pile Diagnostic System) up to Allnamics’ PDR nowadays.’
The mean reason to perform Dynamic Load Testing is to obtain information about the pile behaviour during (static) loading. The dynamic equivalent is much faster and less time consuming than Static Load Testing.
The application of DLT (internationally also known as PDA or High Strain Dynamic Testing) is especially suitable for:
- Piles with high bearing capacities, where it’s hard to mobilise enough static force to load the pile statically up to failure, i.e. offshore piles
- Prefabricated concrete piles, able to resists the high impact stresses of the DLT
- Piles with a homogeneous cross section along the shaft
- Offshore and nearshore projects
For other piles, other methods are more suitable. For instance, applying DLT to cast in situ concrete piles, bored piles or CFA’s, the high impact loads leads to (too) high impact stresses with possible damage to the pile. Reduction of the impact load to limit the stresses to the concrete strength, leads for this type of piles to a low mobilised bearing capacity. Furthermore uncertainty in cross-section and concrete quality results in reduced accuracy of the analysis. These types of piles are preferably tested by Rapid Load Testing, StatNamic or StatRapid, for which the maximum stresses during the test are significantly lower.
RLT – StatRapid Load Testing
Allnamics can choose to perform Rapid Load Tests with two different types of testing. For test loads up to 16 MN, StatRapid will be often used. For higher loads the Statnamic Load Testing method is available. With this test method loads up to 65 MN, and, in the near future, up top 150 MN, are possible.
Do you want to know more about Rapid Load Testing? Contact Peter Middendorp at pmiddendorp@allnamics.com
Bi-directional test (O-Cell)
The Bi-directional test is an alternative for the Static Load Test for bored concrete piles. Characteristic of this type of pile testing is that the load is applied somewhere halfway in the pile, instead of at the top of the pile.
By casting a device, the cell, into the concrete, somewhere halfway or near the pile toe, force and settlements at this level can be measured. The upperpart is pushed upward, being the counter force for the downward test load on the lower part. After the test, the measured results are used to construct the load-settlement graph comparable to that of a Static Load Test.
The Bi-directional test will be applied for piles with higher capacities, with significant shaft friction to mobilise enough counter force to mobilise the shaft and toe resistance of the lower part.
Pile Integrity Testing (Sonic Integrity Testing)
The Sonic Integrity Test has been developed by the engineers of Allnamics, in the seventies of last century.
The test determines imperfections in concrete piles: Cracks, changes in cross sectional area, soil inclusions, voids and other imperfections.
The Pile Integrity Test or Sonic Integrity Test is the first, fast and rough, check on the quality of cast in situ piles.
Sonic Logging
Sonic Logging is performed by lowering sensors in cast in tubes. By sending a sonic signal through the concrete by the transmitter to the receiver, information about possible defects and concrete area over the cross sectional area will be obtained.
Sonic Logging is mainly used for bored piles with large diameters and diaphragm walls.
PAPERS AND ARTICLES
Allnamics has made many contributions to international conferences. These publications are available via the Allnamics database. A selection can be found below:
StatRapid used on instrumented piles for optimization of design parameters for high rise building in The Hague
Author(s): van Dorp, van Delft, IJnsen Year: 2019 Language: English Where: Proc., Pfahl-Symposium 2019, Braunsweigh 107 ABSTRACT: For a new high rise development in the center of The Hague (NL) heavily loaded piles have to be installed through the existing basement floor of an underground car park. The project and its environmental boundaries required for […]
Determination of Discontinuities in Piles by Integrity and Signal Matching Techniques
Author(s): Middendorp, P., Reiding, F.J. Year: 1988 Language: English Where: 3rd International Conference on The Application of Stress Wave Theory on Piles, Ottawa, Canada INTRODUCTION: The quality of the signals, obtained by sonic integrity testing of piles has been improved considerably with the introduction of digital signal processing. This allows the introduction of a new […]
Pile Integrity Testing in the Netherlands
Author(s): Middendorp, P., Schellingerhout, J. Year: 2006 Language: English Where: 10th International Conference on Piling and Deep Foundations, DFI , Amsterdam INTRODUCTION: Pile foundations are widely applied in the Netherlands because of the soft soil conditions. One of the popular pile types are cast-in-situ piles, which have to be integrity tested to get accepted. Integrity […]
Prediction and Monitoring of Installation of Offshore Foundation Monopiles for Windfarms
Author(s): Van Dorp, Moscoso, Bielefeld, Verbeek Year: 2019 Language: English Where: Offshore Technology Conference in Houston, Texas, USA INTRODUCTION: Upon recently, most offshore foundations were based on a number of driven piles that were installed with an impact hammer. With the increase in offshore windfarms two major developments have occurred: the shift from jackets to […]
The influence of stress wave phenomena during Statnamic Load Testing
Author(s): Middendorp, Bielefeld Year: 1995 Language: English Where: First International Statnamic Seminar, Vancouver INTRODUCTION: The Unloading Point Method (UPM) has become a standard tool for the analysis of Statnamic (STN) load testing signals. The method is based on the assumption that the pile can be modeled as a concentrated mass and springs. Modeling is only […]
Pile Foundation design philosophy and testing program for a new generation diesel fuel plant
Author(s): Romano, M.C., Middendorp, P, Doornbos, S. Year: 2010 Language: English Where: DFI Conference, Geotechnical Challenges in Urban Regeneration, London, UK INTRODUCTION: The company NESTE-OIL is building a plant for the production of a new generation NExBTL diesel fuel in the Port of Rotterdam The Netherlands. The fuel is produced from renewable vegetable oil as […]
Keynote lecture: Statnamic the engineering of art.
Author(s): Middendorp. P. Year: 2000 Language: English Where: International Conference on Application of Stress Wave Theory to Piles, Sao Paulo, Brazil CONCLUSIONS: The success of Statnamic stems for a significant part from the concepts and ideas generated by “artist-engineers” and “engineer-artists”. According to Brandl (2000): an excellent engineer requires not only a firm theoretical knowledge […]
Rapid load field tests interpreted with the new Guideline
Author(s): Hölscher, Brassinga, van Tol, Middendorp, Revoort Year: 2009 Language: English Where: 17th International Conference on Soil Mechanics & Geotechnical Engineering, Alexandria, Egypt CONCLUSIONS: Two instrumented driven piles are tested by both SLT and RLT. The measurements lead to the following conclusions: SLTs show a bearing capacity of 1120 kN respectively 1150 kN. The RLT’s […]
Rapid Load Testing: an updated technique towards pile testing efficiency
Rapid Load Testing: una eficiente técnica para pruebas de carga en pilotes Author’s: Moscoso N.; Bielefeld M.W.; Fernández Tadeo C. Year: 2018 Language: Spanish Where: 16 CNG – 6JLEG 2018, Azores, Portugal INTRODUCTION: The article describes the rapid load test history from its invention 40 years ago until nowadays. As the method was being developed […]
International Prediction Event Behaviour of Cfa, Driven and Bored Piles in Residual Soil Experimental Site
Author(s): Viana da Fonseca, Santos, A. Year: 2008 Language: English Where: ISC’2,September 2008 / 240×170 / 688 pages ISBN: 978-972-752-104-3 ISBN: 978-98995625-1. INTRODUCTION: In the north-western region of Portugal, residual soils from granite are dominant. The thickness of these regional saprolitic soils may some times exhibit more than 20m, with more common values of 5 […]
The advantages and disadvantages of Dynamic Load testing and Statnamic Load Testing
Author(s): Middendorp, Ginneken, Foeken Year: 2000 Language: English Where: Sixth International Conference on the Application of Stress Wave Theory to Piles, Sao Paulo ABSTRACT: Pile capacity testing by high strain dynamic loading methods is widely applied because of its economy and efficiency compared to static load testing methods (SLT). Frequently applied dynamic loading methods are […]
Soil investigation and negative skin friction
Grondonderzoek en negatieve kleef Author(s): A.P. Offenberg Year: 1996 Language: Dutch Where: Symposium Geo- en Funderingstechniek INTRODUCTION: Negative skin friction now a well-known and established concept in soil mechanics, about which no news can be reported. The “new” geotechnical standards do not give rise to shocking changes. This contribution, therefore, has nothing new to offer […]
What happens in the soil during pile driving?
Wat gebeurt er in de grond tijdens het heien? Auteur(s): ir. G. DE JOSSELIN DE JONG Year: 1956 Language: Dutch Where: De ingenieur 68e jaargang no. 25 SUMMARY: A) A graphical method is used to determine stress and velocity in rods under dynamic loading conditions. Application to a sample of dry sand gives regions of […]
Thirty years of experience with the wave equation solution based on the method of characteristics
Author(s): Middendorp. P. Year: 2004 Language: English Where: Seventh International Conference on the Application of Stress Wave Theory to Piles, Kuala Lumpur INTRODUCTION: The method of characteristics, as an accurate solution of the wave equation, has a long history of the application. This paper will describe a brief history of the method and the author’s […]
StatRapid Load Tests in the 270th edition of inGEOpres
Auteur(s): Moscoso del Prado Mazza; Fernández Tadeo; Bielefeld Year: 2018 Language: Español Where: inGEOpres – oct 2018 nr 270 INTRODUCTION: Pile loading tests are carried out to verify that the piles have the capacity required to support the structure to be built. Applying a load on a pile instrumented with sensors, these tests are able […]
Re-evaluation of the method to determine pile damage using the Beta Method
Auteur(s): G. Verbeek; G. Goble Year: 2012 Language: English Where: Proceedings of the IS-Kanazawa, Japan INTRODUCTION: In 1979, a paper was published by Rausche and Goble describing a method to determine damage in driven piles using the Beta Method. Over the years this method has become the standard for pile damage assessment in many parts […]
Pile foundation testing of a hurricane resistant jetty
Auteur(s): Middendorp, P., Plooy, P.J., Kruit,D.B Year: 2008 Language: English Where: 8th Int. Conf. Application of stress-wave theory to piles, Lisbon INTRODUCTION: To prevent pile driving problems during the construction of a jetty at Grenada a proof testing approach was applied whereby test pile driving was performed at several places where the jetty was to […]
At the cutting edge of pile driving and pile testing
Autor(s): Middendorp, P., Verbeek, G. Year: 2012 Language: English Where: 9th International Conference on Testing and Design Methods for Deep Foundations; Kanasawa, Japan INTRODUCTION: The worldwide challenges to achieve a greener planet, better communications, cost-effective and fast means of transportation, and the protection against natural hazards (such as earthquakes, floods, tsunamis and hurricanes) continually force […]
Modeling and Observations of Pile Installation using Vibro Hammers in Fraser River Delta soils
Autor(s): David Tara, Peter Middendorp, Gerald Verbeek Year: 2014 Language: English Where: Modeling and Observations of Pile Installation using Vibro Hammers in Fraser River Delta soils INTRODUCTION: There has been significant recent interest in the use of vibratory drivers/vibro hammers to install piles in offshore and nearshore applications around the globe. Recent experience using vibratory […]
Pile Driving Analysis & Vibro Hammers A Viable Combination
Autor(s): Verbeek G.;Middendorp P.; van Dorp R.; Tara D. Year: 2013 Language: English Where: Presentation SuperPile 2013, Minneapolis, MN INTRODUCTION: Presentation held at the SuperPile 2013 conference in Minneapolis, MN. DOWNLOAD: You can download the entire article here, after entering your name and e-mail address. .
Installation of Monopiles by Vibrohammers for the Riffgat Project
Autor(s): L. de Neef, P. Middendorp, J. Bakker Year: 2013 Language: English Where: Pfahlsymposium, Braunschweig INTRODUCTION: The successful installation of 22m diameter steel tubular piles/caissons by vibratory hammers in China in 2011 resulted in a strong interest in the application of vibratory hammers to install steel tubular monopiles for wind turbines, especially offshore. The first […]
Skin friction models for sand from static and dynamic laboratory load tests
Auteur(s): Middendorp,P., van Brederode, P.J. Year: 1984 Language: English Where: 2nd International Conference on Stress Waves, The Hague, Netherlands Proceedings INTRODUCTION: The behavior of a foundation pile during impact loading can be measured or it may be simulated by computerized calculation. Although today measuring techniques and computer algorithms have reached high levels of accuracy, the […]
A digital approach to sonic pile testing
Auteur(s): Reiding, F.J., Middendorp, P., P.J. van Brederode Year: 1984 Language: English Where: 2nd International Conference on Stress Waves, The Hague, Netherlands Proceedings INTRODUCTION: Paper regarding digitizing of SIT measurements. DOWNLOAD: You can download the entire article here, after entering your name and e-mail address .
Hydroblok and Improved Pile Driving Analysis
Auteur(s): Voitus van Hamme, G.E.J.S.L. Jansz, J.W. Bomer H.,and Arentsen, D. Year: 1974 Language: English Where: De Ingenieur Vol. 86, no. 8 INTRODUCTION: In a previous article, a description of a number of features of the Hydroblock has been given, in particular, the properties of the Hydroblock have been compared with those of other types […]
Rapid Pile Load Testing in Barcelona
Pruebas de carga rápida de pilotes en Barcelona Auteur(s): Moscoso del Prado Mazza; Fernández Tadeo; Bielefeld; Year: 2018 Language: Español Where: Obras Urbanas sept – oct 2018 nr 71 INTRODUCTION: The first Rapid Load Tests in Spain were conducted in 2017 in the port of Barcelona. This modern method, standardized worldwide, is a step forward […]
Recent advances of rapid load testing in Asia and Europe
Autor(s): Chew, S.H.; Middendorp, P.; Bakker J.; Chua G. Year: 2015 Language: English Where: Proceedings XVI European Conference on Soil Mechanics and Geotechnical Engineering, Edinburgh, Scotland INTRODUCTION: Rapid Load Testing (RLT), by which a quasi-static load is applied to a foundation pile, is used increasingly as an alternative to static load testing (SLT) and high […]
On the operation of a diesel hammer
Autor(s): Voitus van Hamme Year: 1981 Language: Dutch Where: Technical University Delft, The Netherlands INTRODUCTION: This Dutch thesis with an English summary describes the operation of the diesel hammer and the theory of pile driving. Field measurements are also shown and analyzed. The process of the diesel block is divided into 8 phases: 1. fall […]
From very small to gigantic piles
Autor(s): Middendorp P.; van Dorp R.F. Year: 2012 Language: Dutch Where: Geotechniek Funderingsdag 2012 special INTRODUCTION: The theme Foundations in Motion has been the practice for Allnamics in the short period of its existence since 2010, both literally and figuratively, for several national and international projects in the field of Mini- to Giga-piles. It is […]
Renovation of pile foundations for homes in Zaanstad
Om en om renovatie van paalwoningen voor woningen in Zaanstad Autor(s): Ad Offenberg Year: 1981 Language: Dutch Where: Polytechnisch tijdschrift, editie bouwkunde, wegen en waterbouw INTRODUCTION: In this (dutch) article a description is given of the way how a wooden pile foundation was completed with concrete piles at a renovation in Zaandam the Netherlands. Because […]
