1                      Building Works with Significant Geotechnical Content

1. Building works with significant geotechnical content include the following types of geotechnical works:
   1. site formation
2. blasting
3. prestressed ground anchors
4. prestressed ground anchors in sensitive sites* (see para 7.3)
5. soil nails
6. cut slopes (in rock or soil) (height > 3 m)
7. stabilization works on rock slopes

• fill slopes (compaction and installation of such surface filter/drainage layers) greater than 5 m high, or less than 5 m high which pose a direct risk to life, i.e. Consequence-to-life Category 1 or 2 in PNAP APP-109 (previously PNAP 234)
• reinforced fill slopes
  • excavation and lateral support, and temporary retaining structures
• depth > 4.5 m (depth > 7.5 m in sensitive sites* – see para 7.3)
  • permanent retaining structures
• diaphragm walls and bored-pile walls
• reinforced fill structures
• cantilever    /    gravity    retaining    walls    (height    >    5    m)    and screen/basement walls (height > 7.5m)
  • ground treatment
• vertical drains, horizontal/raking drains
• grouting and dewatering for cut and cover excavation and tunnel/shaft/cavern construction
• ground water drainage works in Scheduled Area No. 1
  • demolition works affecting slopes and retaining walls
• ground stabilization works using soil nails or anchors
  • foundation
• foundation for buildings in Scheduled Area No. 1
• deep foundation for buildings in Scheduled Areas Nos. 2 & 4 and in Designated Area of Northshore Lantau
• foundation that could affect an existing tunnel/cavern or that could be affected by tunnel works
  • water wells
• well yield test and the effect of proposed water extraction.
  • tunnel      works*      (tunnels/caverns/shafts/associated      underground facilities – see para 7.3)
• cut and cover construction methods
• drill and blast methods
• soft ground tunnel construction techniques

• tunnel boring machine, micro-tunnelling (including directional drilling) and pipe jacking methods
• associated ground support, ground treatment and groundwater control works

1. The list above is not intended to be exhaustive as it only contains the common types of geotechnical works encountered.

1. In normal circumstances, a TCP T3 and a TCP T5 are required to be provided by the RGE to supervise building works with significant geotechnical content. However, a Directorate Site Supervisor (DSS) may be required for geotechnically difficult or sensitive sites marked * in the above list or any other sites as considered appropriate by GEO and BD.

1. Sensitive sites are sites where the works could pose adverse impact to life and/or property. These include sites where works could affect old buildings with shallow foundations, old tunnels/caverns, major roads, railways, water mains, gas mains, slopes, retaining walls or sites with history of instability.

1. The requirements for the provision of a DSS, if considered necessary by GEO and BD, will be conveyed to the AP/RSE/RGE in the approval and consent letters. The name of the DSS should also be given in the supervision plan.

1. A DSS should be a Registered Professional Engineer in geotechnical discipline who holds the position of a partner/director in the firm which prepared the geotechnical content of the submission. The RGE who is responsible for the project can also be accepted as the DSS.