Contents

  • Cover
  • Introduction
  • Essentials
    • Identifying and managing risk
    • Starting the job – be prepared
    • The job is not finished until it is signed-off
  • Basics
    • Roading terms
    • Basics about soil
  • Good construction
    • A well-constructed road
    • A well-constructed landing
  • Earthworks
    • Clearing and stripping
    • Cut and sidecast construction
    • Cut and bench fill construction
    • Full bench construction with end-haul
    • Earthworks compaction
    • Forming the landing
    • Forming curves and in-bends
    • Stabilising cut/fill slopes
    • Fixing weak formation
    • Final grading before metalling
  • Water control
    • Water control overview
    • Water table drains
    • Water table drainage culverts
    • Berms and cut-outs
    • Flumes
    • Silt traps
    • Silt fences
  • Culvert waterway crossings
  • Temporary bridges
  • Metalling
  • Maintenance of roads
    • General maintenance
    • Maintenance of new roads
    • Maintenance of harvesting roads
    • Maintenance of low-use roads
  • Assisting loggers and harvesting rehab
    • Installing deadmen
    • Harvesting track rehab
    • Landing rehab
  • Want to learn more?
  • Glossary

NZ Forest Road Engineering Manual: Operators Guide

  1.  ›
  2. Earthworks ›
  3. Forming the landing
 

Forming the landing

Landings often require large amounts of earthworks. Poor construction can cause major environmental impacts because of the large volumes of material involved.

  • Stumps have been moved to a safe location and put in a trench at what will be the toe of the benched fill.
  • This ensures rotting stumps and roots do not cause the landing problems in the future.
  • Serious tension cracks – the result of poor benching and compaction.
  • Water going into the tension cracks will make the fill heavier and more likely to erode or collapse.
  • The landing formation has been benched.
  • Benches are visible i.e. not covered over with fill.
  • Substandard material and vegetation was removed.
  • Fill has been compacted in layers.
  • Major landing failure caused by poor water control and lack of compaction.
  • Slash on the fill made the problem worse.
  • Material triggered a debris flow which went onto the neighbour’s land.
  • This is a serious environmental incident.
  • Landing design was worked into the “lie of the land” while meeting operational requirements.
  • The goal was met for maximising useable area but minimising earthworks.
  • Stumps and debris were put in a safe location that will not affect harvesting operations.
  • Bird’s nest has failed. There was no safe and stable area for loggers to put slash.
  • Expensive rehabilitation only partly solves the problem as not all material can be reached by the excavator leaving burning the bird’s nest as a remaining option.
  • Drainage is directed away from the fill slopes.
  • The landing has fall so that water does not pool and can be controlled.
  • The landing surface has been track rolled to help shed water. Roller compaction would have a better result.
  • Water has not been directed away from the fill.
  • Water has severely scoured the landing edge.
  • Fill is compacted. The horizontal ‘ridges’ will help reduce erosion.
  • Fill is over-sown.
  • Water is draining through the middle of the skid.
  • This will cause operational problems during logging.
  • Drainage should direct water away from the fill slopes.
  • Slash bench was built as part of the planned construction.
  • Stumps are located on the bench in a safe location.
  • Poor water control has caused heavy scouring at the front of the skid.
  • Water should be directed away from large fills.
  • Construction includes space for truck turning and vehicle parking.
  • A two-stage pad has created extra space to process the wood.
  • A poorly constructed landing has failed many years after building.
  • Slip sites grow poor trees.
  • The landing size is reduced for the next harvest.
  • The visual impact will last for years.
  • The skid has been built with good access for ground-base harvesting.
  • Log corduroy was needed to make the landing accessible to trucks.
  • Corduroy is good at strengthening a failed subgrade because the truck’s weight is spread across the logs.
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