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Pile Testing

Allnamics can perform pile monitoring or pile load testing by offering the full range of non-destructive pile testing methods, both onshore and offshore. This may include both high strain testing and low strain testing such as:

We can offer our clients any (combination) of these testing services on a cost-effective basis, while providing sound technical test data interpretation.   


 Rapid Load Testing

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With Rapid Load Testing the duration of the load is such that all pile parts are constantly under compression and move in the same velocity range.  This allows the modelling of the pile as a single mass spring system, resulting in a simple straightforward method of analysis, the so called Unloading Point Method (UPM).  

There is a growing awareness that pile capacities determined by High Strain Dynamic Testing with signal matching techniques such as CAPWAP™, DLTWAVE and AllWave-DLT heavily depend on the assumptions made by the person analysing the test results and yield a wide range of results, especially for cast in situ piles (Holeyman et. al. 2001), Viana da Fonseca 2003([download id="7"]), Herten et al. 2013([download id="19"])).    Consequently it is virtually impossible to calibrate these signal matching based methods against static load tests, since calibration requires consistent results for each method.

This is one of the reasons that in 2010 the Dutch CUR commission adopted the Rapid Load Testing technique (over the high strain dynamic testing) as the results are consistent and virtually independent of the person analysing the test data if the data is analysed with the Unload Point Method (UPM).   

According to this guideline, the load on the pile can be considered a “rapid” load if the duration of the load is longer then 10 times the time it takes for a stress wave to travel from the pile top to the pile toe or in a formula :


10 <  T/(L/cp)  ≤ 1000                                 


where Tf is the load duration, L the pile length and cp the stress wave velocity of the pile material.

  Devices on the market for Rapid Load Testing are:

  •  Statnamic  (STN)
  •  Pseudo Static Pile Load Tester (PSPLT)
  •  StatRapid (STR)
  •  Hybridnamic (HBN)
  •  Spring Hammer (SPH)
Allnamics provides Rapid Load Testing services with Statnamic and StatRapid devices.  Allnamics also supplies components for this equipment (e.g. servo-accelerometers, load cells, spring system materials), complete sets of Rapid Load Testing monitoring equipment (e.g. the PDR and Reyca), and the monitoring and analysis software Allnamics-RLT.
Statnamic devices are manufactured by Berminghammer (
StatRapid devices are manufactured by Cape-Holland (

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In response to market demand for Rapid Load Testing the company Cape-Holland ( has manufactured Rapid Load Testing devices (the so-called StatRapid) based on dropping a mass on a soft cushioning system. StatRapid systems are indicated by the maximum rapid load they can achieve. For example, a StatRapid 8MN device can achieve rapid loads ranging from 0.2MN to 8 MN. Higher and lower capacity devices are available.


A StatRapid 8MN system consists of a lifting and guidance frame, a modular drop mass (allowing for a mass up to 40 tonnes), a catch mechanism and a modular soft spring system. The size and duration of the load can be adjusted by varying the drop mass weight, the spring stiffness and the lifting height. The system is hydraulically operated and has sensors for a proper vertical and stable position. It should be noted that the dead weight of the drop mass can also be used for the first (static) loading cycle.


The catch mechanism catches the drop mass after bouncing up from the springs. This prevents unwanted rebounds and allows for successive cyclic testing  with increasing loads similar to static load cycling testing.  In accordance with the CUR and ASTM standards the load, displacement and acceleration are measured near the pile top and then recorded. The load is measured with one or more load cells, the displacement with an optical system (Reyca) and the acceleration with a servo accelerometer.


The required load duration for Rapid Load Testing depends on the pile length. The modular set up allows for the tuning of the StatRapid system for piles with different lengths before going to site, which can be checked with the Allnamics-RLT simulation program.

The PDR, Allnamics' testing monitoring system, and the associated monitoring and analysis Allnamics-RLT software allow the reporting of the  Rapid Load Test results according the ASTM D7383-10 standard and CUR 230 Guideline.


statnamic-testing-2nd-penang-bridge_bored-pile_1_smallHistorically load testing of piles has been limited to static and dynamic tests.  More recently Rapid Load Testing (RLT) techniques like Statnamic (STN) and Statrapid (STR) have been introduced, which have benefits over the existing techniques.


The most commonly deployed form of Rapid Load Testing is referred to as 'Statnamic™', which has been in regular use throughout the world since the early 1990s.  The technique was originally conceived in the late 1980s through a collaboration between Berminghammer Foundation Equipment and TNO Building Research.  It was developed to incorporate the advantages that dynamic pile testing has over static pile testing without the disadvantages.  With an ever increasing emphasis in inner cities to reuse foundations (especially piles) techniques to examine the performance of piles without the need for large reaction systems are of great interest.


The Statnamic test applies a force to the pile head over a typical duration of 120 milliseconds through the controlled venting of high pressure gas.  The gas is the product of the combustion of a fast burning fuel within a piston (fuel chamber).  At the top of the piston are vents that are sealed by a load hanger retaining a reaction mass.  At some point the pressure within the piston is high enough to force the reaction mass upward at accelerations in the order of 500 m/s2.  This process generates a downward load on the test pile, resulting in pile velocities up to 1 m/s.


For foundation design it is necessary to derive the 'equivalent' static load-settlement curve from the Statnamic data.  The most common method to do this is referred to as the Unloading Point Method (UPM).


The proper application of the Unloading Point Method (UPM) is prescribed in the Cur 230 Dutch Guideline for the interpretation of Rapid Load Testing results.


PDR, option PDA with combinedacceleration  transducers               vvvgf08yphijn;k


T he objective of  Pile Driving Analysis (PDA) is to control hammer, pile and soil performance during pile driving, whether with an impact or a vibratory hammer. The pile is instrumented with (combined) acceleration and strain transducers near the pile top. The transducers are connected to the PDR monitoring system mounted on the pile, from where signals are transferred either wirelessly by Wifi or an Ethernet cable to a PC-notebook. 

The objective of pile instrumentation is to obtain force and velocity signals as a function of time. The force in the pile at a certain level versus time is derived from the signals of strain transducers, while velocity is derived by integration of the acceleration signals obtained from the accelerometers. With these two independently obtained signals it is possible to make a quick assessment of the energy delivered to the pile, and of the pile driving resistance, while even a rough estimate of the Static Resistance during driving (SRD) can be made.

After the pile has been driven and taking into account a set up period a Dynamic Load Test (DLT, also called PDA Test) can be excuted. A signal matching analysis can be performed by means of the measured signals in order to make an  estimate of the static bearing capacity of the pile. The wave equation program AllWave-DLT has been especially adapted for this purpose