THIRD ORDER LEVELLING

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MAIN ROADS Western Australia

Third Order Levelling.doc





Technology
and Environment Directorate

Road and Traffic Engineering Branch



S
tandard

No. 67/08/38

TRIM F
ile
: 04/10038

D
ocument

No. D12#
224694

Issue Date 16/07/2012




THIRD ORDER LEVELLING





This
document is owned and controlled by the Survey and Mapping Manager.


The Senior Geodetic Surveyor is the delegated custodian.


All comments for revision should be submitted to the Senior Geodetic Surveyor.






Authorisation


As Executive Director of the
Technology and Environment Directorate of Main Roads, I
authorise the issue and use of this standard.






.......................................


EXECUTIVE DIRECTOR TECHNOLOGY AND ENVIRONMENT



Date: ___/ ___/ ___



No controlled copies are issued for th
is standard.

The latest copy of this standard is located on the Main Roads Internet site.

A full revision of this Standard was undertaken.


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2



CONTENTS


1.

PURPOSE

................................
................................
................................
...............

4

2.

SCOPE

................................
................................
................................
...................

4

3.

REFERENCES

................................
................................
................................
........

4

4.

DEFINITIONS

................................
................................
................................
.........

4

5.

E
NTRY ONTO LAND

................................
................................
..............................

5

6.

ENVIRONMENTAL IMPACT

................................
................................
...................

5

7.

SPECIFICATIONS AND TOLERANCES

................................
................................

6

7.1

Existing Control

................................
................................
................................
.

6

7.2

Section Tolerances

................................
................................
...........................

6

7.3

Traverse Tolerance

................................
................................
...........................

6

7.4

Levelling Requirements

................................
................................
.....................

6

7.4.1

Instruments

................................
................................
................................

6

7.4.2

Staves

................................
................................
................................
........

7

7.4.
3

Length of Sights

................................
................................
.........................

7

7.4.4

Refraction

................................
................................
................................
..

7

7.5

Data to be supplied

................................
................................
...........................

7

7.5.1

L
evelling Survey exceeding 2km

................................
................................

7

7.5.2

Levelling Survey less than 2km

................................
................................
..

8

7.5.3

Minimum Level Specification

................................
................................
......

8

8.

Appendix A

................................
................................
................................
............

9







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REVISION STATUS RECORD


Page

No

Latest

Revision

No

Latest

Revision
Date

Revision

Description/Reference

ALL


1/
7
/2012

Complete document revision.






































































































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1.

PURPOSE


The purpose of this Standard is to detail Main Roads requirements for establishing
vertical control for all projects.


Refer to

Differential

Levelling

as defined in the ICSM document
Standards and
Practices
-
ICSM Special Publication #1

(SP1 Ver. 2)

Guideline for Control Surveys by
Differential Levelling for the different Orders now adopted in Australia.




www.icsm.gov.au/geodesy/sp1.html




2.

SCOPE


This Standard shall apply for all Third and Fourth Order Levelling for Main Roads.

Advice and further information can be obtained by contacting the Senior Geodetic
Surveyor.



3.

REFERENCES


The following documents relate to this procedure:




䥃IM
-

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-
䥃IM⁓pe捩慬⁐ub汩捡瑩tn
 P1)



Survey and Mapping Guideline “67/08/100” Metadata requirements




4.

DEFINITIO
NS


ICSM

-

Intergovernmental Advisory Committee on Surveying and Mapping

Landgate
-


WA State Land Information Department

SSM


-


Standard Survey Mark

RRM


-


Road Reference Mark

AHD


-


Australian Height Datum











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5.

ENTRY ONTO LAND

It

is the Consultant’s responsibility to seek and obtain permission from landowners,
occupiers or management authorities before entering any property to undertake any
survey and mapping work.

Property includes Crown land which may consist of
Reserves, Nation
al Parks or State Forests.


Survey and mapping work may include,
but is not limited to, the investigation, capture, placement and coordination of survey
control points, the placement and removal of survey control targets, the collection of
digital terrain
models and the undertaking of field audits.


The consultant shall maintain a written report of all contact made with landowners
while working on the survey or mapping contract. Details of landowner contact are to
be outlined in the metadata statement. Any
queries made by land owners with respect
to the project that are unable to be answered by the consultant are to be referred to
the Main Roads project manager.


If access onto land is refused by the owners, the consultant will be required to
immediately con
tact the Main Roads project manager to discuss the need for entry
onto the land. If entry is required for the completion of the contract and there are no
other alternatives, then Main Roads will arrange formal notification using delegated
powers under the
Land Administration Act.


A formal notice of entry requires Main
Roads to provide 7 days notice to the owners. The process to arrange the formal
notice of entry may take some time and the consultant must liaise with the Project
Manager to ensure disruption

to the contract schedule is minimised.



6.

ENVIRONMENTAL IMPACT

All work is to be performed such that environmental impact is minimised. Any breach
of local environmental regulations during the execution of works is the sole
responsibility of the consultant
.


The consultant shall ensure any disturbances to the environment are kept to an
absolute minimum. The consultant shall reinstate, clean
-
up and leave the site as
close to its pre
-
disturbed condition as possible on completion of any work or
investigation.


New tracks shall not be formed, existing tracks altered, fencing cut, clearing carried
out, or damage or disturbance made of any kind unless approved by the Main Roads
project manager. The consultant shall be responsible for the cost of reinstating any
d
amage to property or the environment resulting from their work.

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7.

SPECIFICATIONS AND T
OLERANCES

7.1

Existing Control


For every new project it is first necessary to verify the stability of any existing Survey
marks on which the new work is to be based. To ve
rify height,
two way

levelling shall
be carried out through the survey area and the new control, between permanent
stations which ideally are situated at each end of the Project area. ie: (Benchmarks,
SSMs, RRMs)


The starting and finishing control point
s must be verified from their reference marks, if
available, as a further redundancy.


Such existing vertical control shall be Third Order or better.


If the accuracy of the existing datum is in question, or existing Control is minimal,
please contact the
Senior Geodetic Surveyor in the Survey and Mapping Branch for
verification of the datum and advice.



7.2

Section Tolerances


The difference between the forward and backward levelling of any section or any
combination of adjacent sections shall not exceed:




0.
012

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-
牡瑡⁢ased on a‴km⁳e捴楯n,⁳ 景爠
500m映汥le汬楮i⁴he⁤i晦e牥ce⁳ ou汤lnot⁥捥ed ‰.003m.


The獥 f楧u牥猠app汹 fo⁢oth Th楲d
and⁆ u牴 佲Oe爠獵牶eys
.



7.3

Traverse Tolerance


The misclose of a traverse between datum bench marks shall not exceed

0.012

Ke瑲t猬swhe牥K⁩猠 he⁴o瑡氠l楳ian捥 of⁡ 瑲tve牳攠楮i歩komet牥献†



7.4

Levelling Requirements


7.4.1

Instruments


Levels used shall meet the specifications set out below.


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A test for collimation error shall be made before and during the project, by the “Two
Peg Test" method and recorded in the appropriate place. The collimation error should
be adjusted where it e
xceeds 0.0015 metres in a distance of 80 metres.


7.4.2

Staves


Staves used for "Third Order" levelling should be calibrated by Landgate.

These are typically two piece folding type and may also be hired from Landgate. Bar
code Staves should be calibrated over th
e Boya test range using Landgate’s purpose
designed range and software.


From the calibration report, the random graduation error for staves used shall not
exceed 0.0003 metres.

A current certificate of calibration for each staff shall be supplied prior to

the start of
any work.


All staff readings are to be recorded to the nearest 0.001 metres.


Staves used for “Fourth Order Levelling” (Telescopic) must be in good condition and
checked regularly for wear across joins, with all staff readings recorded to th
e nearest
0.001m.


7.4.3

Length of Sights


The length of any levelling sight shall not exceed 100 metres
.

Between permanent stations the total length of backsights and foresights shall be
approximately equal.


7.4.4

Refraction


The centre hair staff reading shall not
be below 0.5 metres for Third Order levelling
and 0.3 metres for Fourth Order levelling.



7.5

Data to be supplied


7.5.1

Levelling Survey exceeding 2km




All field observations shall be recorded in a suitable Level Book or Instrument derived
digital format and the
se records should be kept securely for future reference or query.




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The following data shall be supplied




A data quality statement that meets the requirements of Survey and Mapping
Guideline “ 67/08/100” Metadata requirements



Abstracts of Reduct
ions on Main Roads form 67
-
08
-
38
-
01 (Appendix A)



Documentation of all miscloses and any adjustments
-
in spreadsheet form



Adjusted RL’s of permanent stations established
-
in same spreadsheet form



Access diagrams to newly established permanent stations(RRM, BM
, SSM)



7.5.2

Levelling Survey less than 2km




Documentation spreadsheet showing results, miscloses, adjustments, fixed
stations, new Control placed.



Access diagrams to newly established permanent stations (RRM, BM, SSM).



A data quality statement
-
see Guidelin
e “67/08/100” to define the Order of
survey completed.




7.5.3


Minimum Level

Specification


Optical

and Electronic Levels
-
need to be able to achieve:


Standard Deviation of 1 km double run

Less
than


1.
0

mm

for Third Order

Standard Deviation of 1 km doubl
e run



Less than



2
.0 mm for
Fourth
Order







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8.

APPENDIX A



SURVEY AND MAPPING BRANCH

ABSTRACT OF THIRD ORDER LEVELLING



Page .........

of .........


Date ......./......./.......


ROAD/PROJECT............................................
No.

S
ECTION................................................................................................................
..............
.


SURVEYOR.............................................

INST

No.

..

........

STAFF No..................................
....... C CONST..............................................





Difference in Elevation (metres)

Discrepancy

Adj

Elevation Above A.H.D. (metres)


Distance
km

From B.M. to B.M.

Total
Distance
From

Forward

Backward

Mean

Calibrated
Mean

Partial

Total
Ac
c

Closur
e

Observed

B.M.

Adjusted

Remarks



00