The Department of Transport and Main Roads (DTMR) recently reviewed and updated their technical specification for Construction Surveying (MRTS56). From 1st April 2021, this document will dictate the surveying requirements for specific construction types such as earthworks, pavements, road furniture, underground assets, bridges and structures, during the civil construction works for any DTMR project.
Significant amendments were made to the document, including expansion of the requirements for the protection of survey marks (section 7.3). This section was strengthened with the inclusion of Witness Points 1 & 2 and Hold Points 4-7. Witness Points 1 & 2 detail the contractor’s obligations with respect to the protection, reinstatement, reporting and management of primary and secondary control marks critical to the project. Hold Points 4-7 trigger an assessment to be undertaken by a cadastral surveyor to identify cadastral marks that may need protecting prior to any construction works commencing for footings, excavations and destruction of concrete structures such as kerbs and footpaths – refer Table 7.3.3 below.
Section 22.214.171.124 of MRTS56 reinforces how to protect survey marks.
- A consulting cadastral surveyor should be engaged to determine the likelihood of any survey marks being interfered with on a construction project.
- If marks will be interfered with, then a pre-construction Identification Survey plan (Ident plan) should be completed to locate and verify survey marks, and place recovery marks.
- Depending on the size and nature of the project, a post-construction Ident survey may be required to re-establish sufficient cadastral survey marks and PSMs. Further surveys may also be required to re-establish the pre-construction horizontal and vertical control networks.
The revisions to MRTS56 by DTMR are a significant step forward in preventing the reckless and blatant destruction of survey marks on civil construction projects in Queensland and will ultimately assist in preventing irreparable damage to a critical state asset.
For more information on the protection of survey marks refer to our blog of 24th November 2020 – Your mission should you choose to accept it: Protect & Preserve Survey Marks