Working on offshore wind farms

Offshore & Wind farms

For more than a century the world has explored the seas and oceans to discover and subsequently produce oil and gas fields. Due to the energy transition to renewable energy sources, those same locations are once again in focus, but instead of building platforms that serve the oil and gas industry, wind turbines and wind parks are being build.

Obviously experiences gained with offshore oil & gas construction  are now used to construct these wind turbines and wind parks. Thus Allnamics’ knowledge and experience with offshore  foundation design, construction  and  testing is a valuable commodity, especially when it comes to the installation of monopoles, a special focus area of Allnamics.

For more information on the possibilities Allnamics Offshore Services can offer for your project, please contact Joost Bakker at bakker@allnamics.eu.

urk-img_6026_allnamics-1600-offshore
PDA Offshore piles

MonoPiles

Allnamics has been involved in many projects where monopiles formed the foundation of the offshore structures . Given our  knowledge and experience with this  type of foundations, Allnamics has become a sought after  consultant for the installation of large diameter monopiles (such as the 22-m (72-ft) diameter open pipe piles that were used for the Hong Kong-Zhuhai-Macau Bridge Project).  Many of these monopoles are installed with vibratory hammers and Allnamics’ pile driving prediction software provides a unique tool to simulate this.

Want to know more? Contact Joost Bakker at bakker@allnamics.eu.

Offshore Predictions Vibratory Hammer

Nowadays, the usage of offshore vibratory hammers is no longer limited to just positioning and setting up a pile. Whereas until recently a impact hammer  was used to actually drive the pile , the vibratory hammer is increasingly used to perform this task, even  to the final penetration depth.

Similar topile driving predictions for impact hammers , the pile installation by means of a vibratory hammer  can be simulated. With comparable results to PDP, one can study the efficiency of a vibratory hammer, the maximum reachable penetration ( refusal) depth, the maximum stresses and the contribution to pile fatigue. Using the AllWave-VDP Expert software, the algorithms of which reflect  a large database of predicted and measured results, leads to reliable predictions.

Vibratory Driving Predictions will result in efficient pile design, including efficient pile driving process with the appropriate vibratory hammer, without unexpected troubles.

For more information about our offshore vibratory driving predictions please contact Nicolas Moscoso at moscoso@allnamics.eu or Peter Middendorp at middendorp@allnamics.eu

Fatigue analysis, Prediction and Monitoring

During its lifetime an offshore foundation pile is continuously loaded by dynamic forces as a result of the wind, current and wave action. Fatigue is therefore an important design factor.

During pile driving the stress variations lead to fatigue as well and therefore this aspect should be analyzed. .

Allnamics can perform this fatigue analysis in two ways:
1. By predicting the stress levels during installation as part of the pile driving prediction for impact hammer (PDP) or vibratory hammer (VDP) and its effect on the fatigue of the (mono)pile
2. By measuring the real stress levels and its changes during pile driving, by performing PDA or VDA during installation. For measurements at certain spots additional spot monitoring can be applied as well, e.g. at locations with diameter or wall thickness changes, connection crowns, welds or flange.

Want to know more? Contact Joost Bakker at bakker@allnamics.eu.

Offshore Pile Driving Prediction

Pile Driving Predictions are performed to predict the pile, soil and pile driving hammer behavior during installation of foundation piles, incl. large diameter monopiles. By doing this  during the engineering stage, problems and augmented costs during installation can be avoided. The pile driving hammer must be able to deliver enough energy to install the pile to its designed penetration depth. At the same time pile stresses during installation should be kept within acceptable limits. For the dynamically loaded foundations, such as monopiles of wind turbines, fatigue damage is to be considered as well and therefore the pile stresses during installation should be limited.

By making Pile Driving Predictions using the AllWave-PDP software , answers to thesetypes of questions can be generated by modeling the pile, soil and hammer and simulating the installation process. And these predictions can be made for offshore piles in the same way as they are done for onshore applications.

 

For more information about our offshore pile driving predictions please contact Joost Bakker at bakker@allnamics.eu.

PDA Offshore
recorder-05_allnamics-1600-offshore
PDA Westermeerwind

Offshore Pile Driving Monitoring / Pile Driving Analysis (PDM/PDA)

Whenever a pile is driven it is important to know that the installation went well and this obviously also applies to offshore constructions. To ensure that this is the case measurements can be taken during pile driving (Pile Driving Monitoring or PDM) and these measurements can then be further analyzed for additional information (Pile Driving Analysis or PDA) .  This can be done whether the pile is driven with an impact hammer or a vibratory hammer.
After driving, the bearing capacity will increase with time (due to set-up). By monitoring during a redrive, the static pile/soil behavior and accordingly its static bearing capacity can be obtained by analyzing the measurements using the signal matching process with  the AllWave-DLT software (a so-called High Strain Dynamic Test, commonly referred to as a Dynamic Load Test).

Want to know more? Contact Joost Bakker at bakker@allnamics.eu.

Offshore Vibratory Driving Monitoring / Vibratory Driving Analysis (VDM/VDA)

When piles are installed by means of a vibratory hammer, instead of an impact hammer, PDM and PDA can still be performed.
During Vibratory Driving Monitoring all information during installation is monitored, including performance and behavior of pile, soil and vibratory hammer. Monitoring of pile stresses (and their contribution to fatigue of the pile material), pile penetration (both in absolute terms and as a function of time) and hammer frequency and efficiency are just a few of the parameters to ensure quality control for piles installed with a vibratory hammer.

Want to know more? Contact Rob van Dorp at vandorp@allnamics.eu.

VDA Offshore

Offshore Dynamic Load Testing (DLT)

After initial developments in the 1960s, Dynamic Load Testing evolved into a mature testing method during the 1970s and 1980s. At that time offshore structures were built to explore and produce oil and gas at locations with, until then, unknown soil conditions. Since static load tests could not be performed under water an alternative had to be developed, and Dynamic Load Testing  has become a widely accepted  pile testing methods

Allnamics founders are pioneers in this field, and played an essential role in the development of various  monitoring systems from the original FPDS (Foundation Pile Diagnostic System) to the current Allnamics’ PDR.
The main objective of performing a Dynamic Load Test is to obtain information about the pile behavior during (static) loading. Measurements during a redrive, i.e. after set-up of the soil, are then used to assess the static behavior of the foundation pile, using the signal matching process with the AllWave-DLT software.

 

Want to know more? Contact Joost Bakker at bakker@allnamics.eu.

urk-img_5638_allnamics-1600-offshore
stn-opstelling_allnamics-1600-offshore

Offshore Statnamic Loading Tests

For the high capacity of offshore foundation piles and monopiles, Allnamics make use of the StatNamic test method. With this test method loads up to 65 MN, and in the near future up to notice up to 150 MN, are possible.

Do you want to know more about StatNamic testing? Contact Peter Middendorp at middendorp@allnamics.eu

Offshore Monitoring Equipment

The offshore monitoring  are centered around the in-house developed PDR (with an external Wi-Fi antenna) with sensors to monitor strain and accelerations. Depending on the application  sensors that are suitable for under water use can be provided.

Want to know more? Contact Joost Bakker at bakker@allnamics.eu

Case PDR Allnamics
thewash3_allnamics-1600-offshore

Under Water Monitoring

When under water hammers are used to install the offshore piles, the monitoring sensors need to be waterproof as well. Allnamics developed special sensors that are certified to be waterproof at depths up to 500 m.

Want to know more? Contact Joost Bakker at bakker@allnamics.eu

Offshore Pile Instrumentation

Many parameters can be monitored during and after installation of offshore foundation piles.  Allnamics can provide instrumentation to address special project requirements. For more information about the possibilities that Allnamics Offshore Services can offer for your project?

Contact Joost Bakker at bakker@allnamics.eu

Strain gauge directly glued on the steel.

PAPERS EN ARTICLES

Allnamics has made many contributions to international conferences. These publications are available via the Allnamics database. A selection from that:

PUBLICATIONS ARE COMMING SOON

Publications are coming soon

How a dieselhammer works

Autor: Voitus van Hamme Year: 1981 Language: Nederlands This Dutch thesis with Englisch summary describes […]

From very small to gigatic piles

Autors: Peter Middendorp, Rob van Dorp Year: 2012 Language: Dutch The theme ‘Foundations in Motion’ […]

Renovation of pile foundations for homes in Zaanstad

In this (dutch) article is a discription given of the way how a wooden paalfundering […]

allnamics-silhouette

Start typing and press Enter to search