Explosive ordnance detection for noise barriers

Investigation should begin once the alignment, foundation type and approximate foundation depth are established. At this stage, historical evidence of suspected ordnance, existing utilities, the working strip and construction sections can still be coordinated without substantial redesign. Before drilling, driving or excavation, it must be established which area and depth volume have actually been investigated.

This depends on the foundations and survey environment. Area measurements can cover accessible near-surface zones but do not automatically cover deep tubular steel piles, bored piles or individual foundations. For these interventions, it is assessed separately whether the required location and depth have already been adequately investigated and what supplementary work may be needed.

Required documents include a site and alignment drawing, chainage, foundation or pile schedule, target depths, installation methods, working width, construction phases, utility and as-built drawings and any existing aerial photograph assessments or information from authorities. For phased construction, priorities and handover dates should also be stated.

Information and requirements from authorities are supplied with their date, complete appendices and geographical scope. In Germany, the competent ordnance disposal service, local public-order authority and, where relevant, building-control authority are identified for the project location; outside Germany, local responsibilities apply.

Utilities, drainage, sign foundations, safety barriers, cables, bridge components and existing noise barriers affect accessibility and survey feasibility. Known installations are checked on site and on drawings. Zones that cannot be surveyed reliably receive a clearly identified follow-up measure instead of a blanket assessment.

For plinths, cable trenches or demolition sections, the technical suitability of explosive ordnance detection during construction is assessed. Each working layer is surveyed and evaluated using technical methods before controlled removal in layers with supplementary visual inspection. The steps are repeated down to the agreed excavation base. Excavation layers, hold points, lines of instruction and documentation are established before work starts. Necessary investigations and protective measures are also planned before ground disturbance during demolition. Whether deep pile points have been adequately investigated is assessed separately.

The documentation links the wall alignment, chainage, foundation or pile identifiers, areas and depths investigated, methods used, interference zones, findings and outstanding measures. It must show which foundation points were assessed for the planned working volume and where supplementary work remains necessary.

Relevant factors are wall length, number and depth of foundation points, foundation method, accessibility, traffic management, utility density, surface condition, interference conditions, construction windows, required surveying and the scope of data checks and reporting. Reliable costing therefore requires a current drawing and ground-intervention reference.

Stop work immediately in the affected area. Do not touch, move or expose the object further. Leave the danger area and keep others away without putting yourself at risk. In Germany, notify the police immediately on 110; outside Germany, use the local emergency contact procedure. Then inform site management.