forest road assessment using, recording and maintaining the asset david killer - forestry civil...

Forest Road Assessment

Using, recording and maintaining the asset

David Killer - Forestry Civil Engineering - 23 October 2007

23 October 2007 Forest Road Assessment David Killer2

what are forest roads for?


the main users of many forest roads


road condition survey

• to define the usage of each segment of road in terms of low, medium or high for the following categories: timber traffic, light vehicles, cyclists, horses, walkers and other

to decide on the optimum surfacing solution for each usage combination

to record the actual condition against the optimum to estimate the cost of moving to the optimum

surfacing solution


road condition survey (cont’d)

to assess the strength of roads for harvesting purposes (GPR and FWD)

• to record the condition of other features which include: the sensitivity of the area to water (this determines the attention paid to side ditches and culverts), the condition of side drains, surface potholes, road shape and vegetation

• data transferred to an Arc9 geodatabase


inputting usage data


surface characteristics

max size mm coarser >><10 10 20 40 75 100 125 >125

husky x x x x x xwalk x x x x x

more horse x x x x xtolerant cycle x x x xdown van x x x x

HGV x x x xrally x x xfwdr x x


survey vehicle


Scotland England Wales FCEAssets

Class A roads - m 2,675,339 752,100 504,071 3,931,510 Class B roads - m 3,145,902 2,058,805 1,824,663 7,029,370 Class C roads - m 1,962,407 1,049,710 1,147,840 4,159,957 Total Forest Roads - m 7,783,648 3,860,615 3,476,574 15,120,837 Other unclassified roads -m 1,562,438 4,910,325 482,634 6,955,397

Road density Class A/B m/Ha 8.8 12.8 18.3 10.9 Road density Class A/B/C m/Ha 11.8 17.6 27.3 15.0 Road density Class A/B/C/Other m/Ha 14.2 40.0 31.0 22.0

Area - Ha 658,572 219,143 127,561 1,005,276

Condition Survey (For all Class A/B/C roads)survey days (technician only) days 365 169 116 650 data process days (technician only) days 778 386 348 1,512 Total Technician time days 1,144 555 464 2,162

data capture and processing


results of road assessment

1. Record of road usage and actual condition

2. Recommendations for achieving optimum condition for actual usage

3. Access to funds for recreation/health

4. Improved knowledge of road strength and improved targeting of maintenance resource

5. GIS video record of all forest infrastructure

6. Better predictions of serviceability of forest and minor public roads


bottom line

• FC has 4,000km of Class A roads• Assume these are re-surfaced every 10 years• using 1T/m = 400,000T of stone pa• assume an average of £5/T = £2M• aim for 10% saving from targeted maintenance• allowing for cost of survey the net saving =

£100k pa• 40k T of stone = saving of 4k T of CO2

RUTT

Roads Under Timber Traffic

RUTT ProjectRoads under Timber TransportA joint study by Forestry Civil Engineering & the University of Nottingham


Left hand side wheel path6.10%SoakedRiskJ. Jones TPCS19/Sep

Right hand side wheel path5.00%SoakedRiskJ. Jones TPCS19/Sep

Test due on 10th October?SoakedRiskJ. Jones TPCS18/Sep

Trial 7

6.20%SoakedRiskJ.M. Artic + FCE ML06/SepTrial 6

5.17%SoakedType 1John Scott LGP18/AugTrial 5

Material at Scotland Lab SoakedType 1J.M. Lorry&Drag + FCE ML

08/AugTrial 4

Rut bottom - Right hand wheel track5.70%

Wheel Track - 0 to 7cm depth3.90%SoakedType 1John Miller (J.M.) Aritc24/JulTrial 3

Material at Scotland Lab SoakedType 1FCE ML27/JunTrial 2

N/ADryType 1FCE ML (Multi-Lift)26/JunTrial 1

RemarksMoisture Content

ConditionMat.VehicleDateTrial

RUTT Project - Ringour Trials Laboratory Results


Section T2A - Artic Timber lorry (Super-Single) Relationship between No. of Passes and Depth of rutt

1.175

1.180

1.185

1.190

1.195

1.200

1.205

1.210

1.215

0 20 40 60 80 100 120

No. of Passes

Dep

th (

m) Transverse Distance - 2.5m

Transverse Distance - 2.6m




Trial 7 TPCS Highway Loaded Section T4

1.05

1.1

1.15

1.2

1.25

1.3

Transverse Width

Dis

pla

cem

ent

mm

Zero Passes T4

20 Passes T4

40 Passes T4

70 Passes T4

100 Passes T4

Original


SIEVE ANALYSIS RESULT - Trial 7

0%

20%

40%

60%

80%

100%

0.0 0.1 1.0 10.0 100.0

Sieve Size (mm)

% P

assi

ng

Upper Limit - Swedish Spec

Lower Limit - Swedish Spec

Left Hand Wheel Path

Right Hand Wheel Path

Poor Material Grading Analysis


Some Points about the Trials

• Each trial involves running vehicles over the section 100 times, measuring at set intervals.

• The section was watered every 10 passes.• The first two trials were designed to

compare rutting in dry and wet conditions.• The fourth trial involved two vehicles

running in different tracks to allow comparison under the same conditions. An important development.


Some More Points about the Trials

• The seventh trial employed a vehicle fitted with the Tireboss system running at three increasing tyre pressure configurations on the drive and trailer axles. The steering axle tyre pressure could not be altered from normal.

• An eighth trial was conducted running the Multi-Lift with all tyres at 70 psi in one track and at 110psi in a second track.


Observations so far

• The main factors that influence rutting are moisture content and tyre pressure/load.

• It is thought that rutting is proportional to the highest tyre pressure / axle load combination (this includes the steering axle).


The Final Message

• It was found that tyre pressures varied enormously, some unnecessarily high at 125 psi.

• If road damage equates to high tyre pressures

• Get a tyre pressure gauge and stop these guys wrecking your roads and their tyres


Tyre Pressure Gauge

forest road assessment using, recording and maintaining the asset david killer - forestry civil...

Documents

forest roads slide

road shape

segment of road

forest infrastructure

record of road usage

processing slide

road condition survey

survey vehicle slide