Geotechnical Services

Geotechnical Services

We provide geotechnical services to a wide range of sectors.


PDP provides geotechnical services to a wide range of clients in sectors including pipelines and other lifelines, land development (residential/commercial/industrial), three waters, quarries and mining, water retaining structures including dams, ponds and stop banks, large/primary industry, transport (roads/rail/ports/airports), energy including renewables and petroleum, and solid waste.  We also provide specialist advice including emergency response, consent reviews and forensic geotechnical engineering.

Services that we provide:

Engineering Geology

  • Mapping – land-based, aerial imagery, UAV (Un-personed Aerial Vehicle or drone), geospatial analysis and digital remote sensing (photogrammetry/LIDAR (Light Detection and Ranging) and InSAR (Interferometric Synthetic Aperture Radar))
  • Geomorphology
  • Landslides assessments 
  • Surface and subsurface erosion – including geophysics interpretation
  • Rock slopes 
  • Faults 
  • Aggregate quarry resources and road construction materials


Geohazards and Lifelines

  • Geohazard identification and risk assessment for lifelines, infrastructure and mining/quarrying including high-pressure gas/petroleum products and water pipelines. This type of work is crucial post a Civil Defence event such as the recent Nelson & Northland floods.
  • Corridor hazard, route selection and options assessments
  • Climate change implications 
  • Landslide, soil slope and rock slope stability assessments 
  • Coastal cliff hazard and risk assessments 
  • Emergency response and assessment


Remedial & Detailed Design

  • Landslide stabilisation – drainage, buttress/retention, shear keys, soil nails
  • Rock slopes – rock anchors, bolting, shotcrete, mesh, abseil rock scaling, rockfall catch fences, rockfall bunds
  • Ground improvement/problem soils – liquefiable ground, re-use of existing materials - sustainability
  • Geosynthetic applications – including geogrid reinforced gravel rafts
  • Deep foundation/excavation support and temporary support – sheet piles
  • Earth retaining structures - retaining walls, gabions, MSE walls
  • Dams, embankments, ponds, canals, tailings facilities and waste rock disposal
  • Stream and coastal erosion protection
  • Earthworks specifications
  • Erosion and sediment control
  • PS1 (Design) and PS2 (Design Review) sign off and tender evaluation


Construction Monitoring

  • Remedial works procurement (tender) process
  • Engineer To the Contract (ETC)
  • Contractor liaison, construction supervision/monitoring and as-builting
  • PS4 sign off


Geotechnical Monitoring

Monitoring for geohazards, dams and remedial works

  • Movement networks (survey, manual and automated)
  • Piezometers and transducers
  • Inclinometers and extensometers
  • Rainfall gauges
  • Drain and stream flow recording
  • Remote monitoring systems


Geotechnical Investigations

  • Desktop review and mapping
  • Perform/supervise/log hand augers, scala penetrometer, drilling, CPT, test pits/open excavations and geophysical (surface and downhole)
  • In situ sampling and testing - permeability, nuclear densometer, compaction trials, clegg hammer
  • Out-sourced laboratory testing including acid sulphate soils


Ground Models, Stability Assessments and Geotechnical Reporting

  • Landslides in all geological terranes
  • Rock slopes – cuttings, quarries, open pit mines, rock mass classification
  • Kinematic assessments including rockfall analysis
  • Seismic assessments - liquefaction induced ground settlements, lateral spreading/stretch, fault rupture risk
  • Subsurface and surface erosion – including tomos
  • Deep and shallow excavations/foundations and piles
  • Earth dams, embankments, ponds, canals - condition assessments and optimizing of existing structures, breach modelling
  • Rivers and streams – erosion, flooding, accretion surveys and stop banks
  • Mining waste rock stack/dump design (co-disposal), tailings dam surveillance, safety and stability risk assessments
  • Dewatering drawdown and settlement, seepage and inflow
  • Resource delineation for aggregate quarries and roading construction materials
  • Land development foundations, retention (retaining walls) and ground improvement – residential/commercial/industrial
  • Road foundation assessments - green and brown fields
  • Ground support, HDD, pipe jacking


Solid Waste

  • Site Investigation 
  • Waste assessments 
  • Landfill engineering design 
  • Liner design – natural and geosynthetic 
  • Management plans 
  • Bond assessment 


Emergency Event Response and Specialist Advice

  • Rapid incident/event response 
  • Forensic geotechnical engineering 
  • Insurance claims post failures
  • Resource consent reviews 
  • Climate change risk assessments – geohazards 


Geotech Staff