4 Information needed for the execution of the works

4.1 General

4.1.1 Prior to the execution of the work, all necessary information shall be provided, requirements (in accordance with EN 1997-1) in particular, but not limited to the following:

  • a) details of the soil nailing project and the construction sequence and programme;
  • b) site investigation report, incorporating geotechnical classification and engineering properties of the ground in which the soil nails are to be located;
  • c) information regarding all other boundary conditions, including underground services, existing foundations (and their sensitivity) and requirements relevant to the location and performance of the soil nails;
  • d) details of ownership of the ground into which the soil nails are to be installed;
  • e) details of any agreement required to gain access to ground into which the soil nails are to be installed.

4.1.2 The information regarding the site conditions shall cover:

  • a) site investigation data about the ground conditions for execution of the soil nailing works according to EN 1997-1 and EN 1997-2;
  • b) the geometry of the site (boundary conditions, topography, access, slopes, headroom restrictions);
  • c) the existing surface of underground structures, services, known contamination and archaeological constraints;
  • d) the environmental restrictions, including noise, vibration, pollution;
  • e) the future ongoing activities, such as de-watering, tunnelling, deep excavations;
  • f) where the site may be subject to tidal working or flooding, cold climatic conditions or allied restrictions, details of such restrictions;
  • g) details of expected groundwater levels, perched water levels and fluctuations;
  • h) the conditions of buildings, roads and services adjacent to the work, including any necessary surveys.

4.2 Special features

4.2.1 Design aspects shall cover, where relevant:

  • a) definition of the Geotechnical Category and the design life of the works;
  • b) assessment of the site investigation data with respect to the design assumptions;
  • c) overall design of the soil nailing works;
  • d) the relevant temporary phases of execution;
  • e) specification of the soil nailing system;
  • f) any other items in the design to which special requirements exist during execution.

4.2.2 Execution information shall include the following:

  • a) specification regarding the working procedures and sequence;
  • b) definition of the reporting procedure to deal with unforeseen circumstances, or with any conditions revealed or considered during construction, which appear to be worse than those assumed in the design;
  • c) definition of the reporting procedure, if an observational method of design is adopted or monitoring is required;
  • d) specified levels, co-ordinates and tolerances shall be shown on plans, or in the specification, together with the positions, levels and co-ordinates of fixed reference points at or near the work construction site;
  • e) definition of tolerable limits of the effects of soil nailing (deformations, settlements, noise, vibrations, grouting loss) on existing and proposed structures;
  • f) the location of main grid lines for setting out.

4.2.3 Testing, supervision and monitoring information shall cover, where relevant:

  • a) a schedule of any trials and testing and acceptance procedures, for materials incorporated in the soil nail structure;
  • b) a schedule of preliminary trials (if required) and of relevant tests and control;
  • c) the results from the evaluation of trials and tests;
  • d) if necessary, specification regarding sacrificial nails;
  • e) a specification for monitoring the effects of soil nailing on adjacent structures and services and for interpreting the results.

EN 14490:2010 Execution of special geotechnical works – Soil nailing