AllWave software analyses pile driving signals by applying one-dimensional stress wave theory to measurements of force and velocity recorded at the pile head during driving or testing. It processes these signals through numerical simulation and signal matching to derive the static bearing capacity, pile integrity, and soil resistance distribution. The sections below unpack each step of that process in detail.
What signals does AllWave software actually process?
AllWave processes force and velocity signals measured at the pile head during impact or vibratory driving. Strain gauges convert mechanical deformation into a force signal, while accelerometers produce a velocity signal through numerical integration of the measured acceleration. Together, these two signals capture the complete stress wave event travelling through the pile from the moment of hammer impact.
The quality of these input signals determines the reliability of everything that follows. Sensors must be mounted at a specified distance below the pile head to avoid interference from local impact effects, and the data acquisition system must sample at a rate high enough to resolve the short-duration wave events accurately. For offshore applications, Allnamics has developed waterproof sensors certified to depths of up to 500 metres, ensuring that signal quality is maintained even when monitoring takes place below the waterline.
In low-strain testing such as Sonic Integrity Testing (SIT), AllWave processes a different type of signal: the velocity response generated by a small hammer blow at the pile head. This low-energy signal travels down the pile and reflects back from changes in cross-section, material discontinuities, or the pile toe. The AllWave-SIT module converts these reflections into a pile shape expressed as impedance, giving engineers a picture of the pile’s internal condition without applying high loads.
How does stress wave theory underpin AllWave’s analysis?
AllWave is built on the method of characteristics for one-dimensional stress wave propagation. When a hammer strikes a pile, a compressive stress wave travels downward through the pile at a speed determined by the pile material’s elastic modulus and density. At every boundary where pile properties or soil resistance change, part of the wave reflects upward and part transmits downward. Measuring and interpreting these wave components is the foundation of all AllWave analyses.
The one-dimensional wave equation is well suited to slender structural members like piles, where the length is many times greater than the cross-sectional dimension. This assumption holds reliably for driven steel and concrete piles with constant cross-sections, and it allows the software to model the entire pile as a series of discrete segments, each with defined stiffness, mass, and damping properties.
Soil resistance enters the model through soil models that describe how the ground responds to pile movement. AllWave supports three established soil model formulations: the TNO model, the Smith model, and the Randolph model. Each model captures soil behaviour differently, particularly the balance between elastic and plastic deformation and the rate-dependent damping that affects dynamic measurements. Selecting the appropriate soil model for the ground conditions at a given site is one of the key engineering judgements in any AllWave analysis.
What is signal matching and how does AllWave apply it?
Signal matching is an iterative process in which a numerical model of the pile and soil is adjusted until the calculated force and velocity signals at the pile head match the measured signals as closely as possible. Once a good match is achieved, the soil model that produced it is considered to represent the actual soil behaviour, and the static bearing capacity is derived from that model.
The AllWave-DLT module performs signal matching for High Strain Dynamic Tests, including Dynamic Load Testing (DLT) and Pile Driving Analysis (PDA). An engineer begins with an initial estimate of the soil resistance distribution along the pile shaft and at the toe, then runs the forward simulation and compares the calculated signals to the measured ones. Differences between the two guide adjustments to the soil model parameters, and the process repeats until the match meets an acceptable quality threshold.
Signal matching results are consistently more reliable than direct methods such as the CASE method or driving formulae applied directly to field data. However, accuracy depends on several factors:
- Pile geometry: End-bearing steel piles with constant cross-sections and a long free-standing length produce the most accurate results.
- Soil type: Granular soils give better correlation than cohesive soils, where time-dependent behaviour is difficult to capture in a millisecond-duration test.
- Engineer experience: Signal matching is user-dependent. The quality of the result reflects the skill and judgement of the engineer running the analysis.
- Software quality: Suitable software such as AllWave-DLT, combined with a qualified engineer, produces results that are significantly more reliable than simplified field methods.
For Rapid Load Tests, the AllWave-RLT module applies the same matching principle to simulate the test setup and help engineers optimise the test before it is carried out on site.
How does AllWave simulate impact versus vibratory pile driving?
AllWave handles impact and vibratory driving through two dedicated modules because the physics of the two installation methods differ fundamentally. Impact driving generates a single, high-energy stress wave with each hammer blow. Vibratory driving applies a continuous oscillating force that mobilises soil resistance through cyclic motion rather than discrete impacts.
AllWave-PDP for impact hammer driveability
The AllWave-PDP module simulates the pile driving process for impact hammers before installation begins. It models the hammer, pile, and soil system together, producing predictions of pile stresses at every stage of driving, expected blow counts as the pile advances through each soil layer, and the behaviour of both the hammer and the soil under repeated impact loading. This information allows your team to identify the risk of early refusal, where the pile stops advancing before reaching design depth, and to optimise the driving programme to avoid it. For offshore wind foundations, AllWave-PDP results also serve as the basis for fatigue analysis of the pile material.
AllWave-VDP for vibratory hammer driveability
The AllWave-VDP module addresses vibratory driving, where the continuous oscillating load requires a different modelling approach. The simulation predicts penetration rate, pile and soil behaviour under cyclic loading, and hammer efficiency throughout the installation. During actual vibratory driving, Vibro Driving Monitoring (VDM) and Vibro Driving Analysis (VDA) complement the AllWave-VDP predictions by recording real-time data on pile stresses, penetration, and hammer frequency. This combination of pre-installation simulation and live monitoring reduces the risk of pile or soil damage during vibratory installation.
What outputs does AllWave produce from pile driving analysis?
AllWave produces a structured set of outputs that give engineers actionable information about pile and soil behaviour at every stage of the driving and testing process. The specific outputs depend on which module is used, but across the software package, the results cover four main areas.
- Bearing capacity: The static resistance of the pile, broken down into shaft friction and end-bearing components, derived from the signal matching process in AllWave-DLT or AllWave-RLT.
- Pile stresses: Compressive and tensile stresses along the pile during driving, which are compared against material limits to assess the risk of structural damage.
- Blow count predictions: Expected hammer blows per unit of penetration through each soil layer, used to plan installation and identify potential refusal zones.
- Pile integrity: For SIT analyses, AllWave-SIT produces an impedance profile that reveals changes in cross-section or material quality along the pile length.
- Soil resistance distribution: The spatial distribution of resistance along the shaft and at the toe, which informs both foundation design and the interpretation of load test results.
- Fatigue input data: Stress histories during driving that feed into fatigue life calculations, particularly relevant for offshore steel monopiles and jacket foundations.
These outputs are most valuable when reviewed by an experienced engineer who can distinguish genuine soil behaviour from artefacts introduced by signal noise, sensor placement, or model assumptions. The outputs from a driveability study also provide a reference baseline against which measurements taken during actual installation can be compared, enabling real-time quality control on site.
When should engineers use AllWave instead of standard pile testing methods?
AllWave adds the most value when standard field methods alone cannot provide the depth of analysis a project requires. Direct methods such as the CASE method give a rapid, approximate bearing capacity estimate from field data, but they do not account for complex soil layering, variable pile properties, or the full wave pattern in the pile. AllWave’s simulation and signal matching approach addresses all of these factors systematically.
Consider using AllWave-based analysis in the following situations:
- Before installation begins: A driveability study using AllWave-PDP or AllWave-VDP identifies risks such as early refusal, excessive pile stress, or hammer incompatibility before mobilisation, when changes are still low-cost.
- When bearing capacity verification is required: Signal matching with AllWave-DLT provides a defensible, engineer-reviewed capacity assessment that goes well beyond what driving formulae can offer.
- For offshore and high-consequence projects: Where remediation after installation is expensive or technically difficult, the additional rigour of AllWave simulation reduces the risk of costly surprises.
- When pile damage is suspected: AllWave-SIT and AllWave-DLT can analyse wave patterns to locate and characterise damage such as horizontal cracks, broken pile tops, or early refusal caused by a compromised pile.
- For fatigue-sensitive structures: Offshore wind monopiles and jacket foundations require stress histories during driving as input to fatigue calculations, and AllWave-PDP generates this data directly.
AllWave is not a replacement for a pile load testing services for foundations where direct force and displacement measurements are needed, particularly for cast-in-situ concrete piles or friction piles in cohesive soils. In those cases, Static Load Testing or Rapid Load Testing provides data that stress wave analysis cannot replicate. AllWave is most powerful when used alongside field testing, with simulation informing test design and signal matching extracting the maximum information from the measurements collected.
How Allnamics Supports AllWave-Based Pile Driving Analysis
We developed the AllWave Software Package in-house, and our engineers use it daily across onshore and offshore projects worldwide. This means we do not simply supply the software and leave your team to interpret the results. We provide the full analysis service, from driveability study through to signal matching and final capacity assessment.
Here is what working with us on AllWave-based analysis includes:
- Pre-installation driveability studies using AllWave-PDP or AllWave-VDP to predict blow counts, pile stresses, and hammer performance before your piling programme begins.
- On-site monitoring with our PDR data acquisition system and high-quality sensors, including waterproof sensors for underwater applications, ensuring that the signals recorded are clean and reliable.
- Signal matching analysis performed by experienced engineers using AllWave-DLT, producing a defensible bearing capacity assessment with a clear account of the soil resistance distribution.
- Pile integrity assessment using AllWave-SIT to evaluate the condition of existing or newly installed piles without applying high loads.
- Fatigue input data for offshore wind and marine foundations, derived from AllWave-PDP stress histories and used directly in your structural fatigue calculations.
- Damage investigation and remedial advice when pile driving signals indicate a problem during or after installation.
Whether you are planning a new foundation programme, verifying installed piles, or investigating a problem on an existing project, our team can help you get the most from AllWave driveability analysis. Contact us to discuss your project requirements and find out which AllWave modules and monitoring services are the right fit for your situation.
