Appendices 
103 
Dynamic pile load tests are conducted during the first construction phase. The institutions 
commissioned to conduct the tests shall have proven experience in the field of dynamic pile 
load testing and test evaluation. 
If the temporal development of the bearing capacity following installation of the piles is to be 
taken into account in the verification of bearing capacity, a sufficient number of additional pi 
les shall be subsequently driven in as part of the dynamic pile load tests. 
To derive characteristic pile resistance data R k from the measurements of dynamic pile load 
tests R m , the scatter factors defined in DIN 1054 have to be applied in accordance with DIN 
EN 1997-1 (EC 7). Where the supporting ground consists mainly of cohesionless soils, use of 
the scatter factors £ 5 6 and in the case of “calibration of dynamic pile load tests against sta 
tic pile load tests in similar construction measures” is allowed, even if static pile load tests 
have not been carried out at the particular construction site of the structure. This is due to the 
fact that ample experience with static and dynamic pile load tests in cohesionless soils is 
available from other construction projects in the entire area of northern Germany, and proven 
calibration factors thus are available for such soils. In addition, the pile foundations of offshore 
structures normally use steel piling, where scatter due to manufacturing is of lesser impor 
tance and where piling reports are prepared which allow a quantitative evaluation of each in 
dividual pile. 
The dynamic pile load tests have to be supervised and evaluated by the responsible geotech 
nical expert. The complete documentation of the dynamic pile load tests conducted and of 
their evaluation and interpretation, as well as the geotechnical expert’s translation of the re 
sults to the piles which have not been tested, shall be submitted to the BSH immediately after 
completion of the dynamic pile load tests and their interpretation. 
The BSH, supported by expert advice, holds the view that dynamic pile load tests to deter 
mine axial bearing capacity currently are not required for the verification of monopile bearing 
capacity. Generally, measurements may be useful during piling operations in order to check 
pile drivability and driving stresses and to calculate the driving stresses exerted on the pile 
during pile driving. The BSH reserves the right to require monopiles to be subjected to dyna 
mic pile testing for technical reasons or on the basis of recent findings. 
Appendix 3-IV Use of the observation method according to Eurocode 7 
The observation method in accordance with DIN EN 1997 (EC 7) is provided as a method for 
verifying stability against collapse. This method is a combination of normal inspections and 
verifications (forecasts) by means of ongoing measuring inspections of the structure, whereby 
critical situations are controlled by using suitable prepared technical measures. This method 
represents the recognised state of the art for structures the foundation design of which is not 
based on secure engineering experience. The observation period shall be extended to include 
the operating phase. Limit states that can neither be calculated with sufficient accuracy nor 
recognised in good time through observation shall be avoided by working on the safe side 
and through design measures. Where possible, mathematical forecasts shall be supplemen 
ted by experience gained through comparable construction projects. The following prepara 
tions shall be made prior to the start of construction in order to use the observation method: 
• The limits of structural and ground behaviour to be maintained shall be defined. 
• The area in which the structural behaviour will probably take place shall be ascertained 
based on existing survey results.