Technical articles
Questions from ongoing projects, answered with reference to the relevant standards and illustrated with anonymised examples. Each article fits on one page – for reading in the browser and as a PDF for filing.
TECHNICAL ARTICLES
01–05-
01Geotechnics
Investigation depth for HDD crossingsPDF ↓
How deep must the exploratory points extend below a horizontal directional drilling – under roads, railways and lakes?
DIN EN 1997-2 Annex B.3 · DIN 4020 · DIN 18324 · DVGW GW 321 -
02Geotechnics
Rotational stiffness of WTG shallow foundationsPDF ↓
What rotational stiffness does the manufacturer require – and what does the ground beneath the foundation contribute?
DIBt guideline for wind turbines · DIN EN 1997-1 · Gazetas 1991 -
03Geothermal
BHE field and balance ratio over 25 yearsPDF ↓
Why does a borehole heat exchanger field cool down over the years, and how much thermal recharge does it need?
VDI 4640 Part 2 · SIA 384/6 · line source model -
04Geothermal
Seawater heat on the Baltic coastPDF ↓
How much heat does the sea supply in winter – and where do physics and water law set the limit?
WHG §§ 8, 9 · WaStrG § 31 · LAWA O 5.23 · LNatSchG SH § 35 -
05Feasibility Studies
Ground risk before investmentPDF ↓
What do existing data say about the ground before a decision is made on a site or route?
DIN EN 1997-2 · DIN 4020 · BNatSchG § 30
METHOD SHEETS · HOW WE EVALUATE
M01–M03-
M01Method
Layer boundaries with confidence levelPDF ↓
How do a borehole and a cone penetration test become one cross-section – and how can you tell which boundary is confirmed?
DIN EN ISO 22476-1 · DIN EN ISO 14688-1 · Robertson 2016 -
M02Method
Plausibility check of borehole logsPDF ↓
Which errors from field logging and transcription does a fixed set of checks detect before the log is turned into annexes?
DIN EN ISO 14688-1/-2 · DIN EN ISO 22475-1 · DIN 4023 -
M03Method
Robertson chart in glacial tillPDF ↓
Why does the cone penetration test classify overconsolidated glacial till as sand?
Robertson 2010, 2016 · DIN EN ISO 22476-1 · DIN 18196
EACH ARTICLE AS A WEB PAGE AND AS A PDF (A4, 1 PAGE) · EXAMPLES ANONYMISED · LOCATIONS AT REGIONAL LEVEL