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CODE OF PRACTICE FOR SITE SUPERVISION – Site Supervision Reports

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Site Supervision Reports

Site supervision reports are required to be completed by all TCPs whenever they carry out site safety supervision activities. These reports should be filed and maintained at the site office for the inspection of the BA. AP/RSE/RGE/AS are required to keep their inspection records at site such as notes/photo records and the works items inspected on site, particularly during the critical stages of works.

CODE OF PRACTICE FOR SITE SUPERVISION – Interstream Communication

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Interstream Communication

Interstream communications are as important as within-stream communications in order to facilitate effective supervision. TCPs shall take all reasonable and practical steps to inform their counterparts of any aspects of the works which have concern or may cause concern on matters related to safety.

CODE OF PRACTICE FOR SITE SUPERVISION – Critical Stages of the Works

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Critical Stages of the Works

Table 1 of the Technical Memorandum specifies that higher grade TCP and/or more frequent site inspections up to full time may be required at critical stages of the works. Such more frequent site inspections at critical stages are set out in Table 9.1.

The RC should notify the AP, RSE and RGE of the commencement date and estimated time for completion of the critical stages of works in sufficient time before commencing the critical stages to ensure that the respective TCPs would perform their supervision roles during the carrying out of the critical stage of works on site.

In addition, the AP, RSE, RGE, or RC may determine that certain sections of the works are particularly difficult or risk prone or that the consequences of a non-conformity may be serious. In these cases any party may notify his counterparts that he considers the section of works to be a critical activity and be included in the supervision plan.

CODE OF PRACTICE FOR SITE SUPERVISION – TCP qualifications and experience

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TCP qualifications and experience

The minimum qualifications and experience required for each grade of TCP are set out in Table 2 of the Technical Memorandum. Experience, wherever mentioned in this Code, means relevant working experience as defined in Note

(1) in Table 2 of the Technical Memorandum.

Academic qualifications required for each grade of TCP are recognised in accordance with the following principles :
1. Diplomas and certificates must have been awarded by the Institutes of Vocational Education, or the previous Technical Institutes, operated under the Vocational Training Council;
1. Higher diplomas and higher certificates must have been awarded by universities funded by the University Grants Committee, or the Institutes of Vocational Education or the previous Technical Institutes operated under the Vocational Training Council;
1. Bachelor degrees and higher degrees must have been awarded by universities funded by the University Grants Committee or currently

recognised by the Hong Kong Institute of Architects (HKIA), the Hong Kong Institution of Engineers (HKIE) or the Hong Kong Institute of Surveyors (HKIS);

Degrees awarded by universities or institutes other than those mentioned in (c) above are classified as higher diplomas;
- Non-graduate vocational qualifications awarded by institutions other than those mentioned in (a) and (b) above are subject to the acceptance of the BA;
- Notwithstanding (d) above, other overseas degrees or higher degrees may be recognised by the HKIA, HKIE or HKIS and, if so, will be accepted under (c) above. Evidence of such recognition should be produced to the BA by the AP, RSE, RGE or RC when appointments of TCPs with such qualifications are proposed in the supervision plans; and
- Overseas or other local diplomas/certificates or higher diplomas/ higher certificates may be accredited by recognised accreditation bodies such as the Hong Kong Council for Accreditation of Academic and Vocational Qualifications (formerly Hong Kong Council for Academic Accreditation) if their qualifications are equivalent to that conferred by institutes operated under the Vocational Training Council. Evidence of such accreditation should be produced by the AP, RSE, RGE or RC to the BA for acceptance before making proposals on appointments of TCPs with such qualifications.

Details of the professional and academic qualifications and the relevant disciplines that are acceptable for TCPs of grade T1 to T5 should be as set out in Tables 8.4 to 8.8 respectively.

TCP qualification and experience accepted during transitional period before 22 December 2005 or accepted pursuant to the corresponding recognition and requirements prescribed in this paragraph are recorded at Appendix X.

CODE OF PRACTICE FOR SITE SUPERVISION – Combination of Supervision Resources

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Combination of Supervision Resources

To facilitate the deployment of TCPs under different resources situations, a higher grade TCP may take up the duties of a lower grade TCP in his stream provided that the requirements for relevant qualifications and experience of the lower grade are satisfied.

Combination of supervision resources is only permitted for those types of works that are to be carried out concurrently on site.

In order to combine the resources required for one or more types of building works, or to combine the duties of TCPs, the application of scale factors as specified in paragraphs 8.4 to 8.11 should be followed and Form C at Appendix IV should be used for the calculations. Form C should be appended to the supervision plan submitted to the BA.

In using Form C to calculate the combination of TCPs, the following steps should be followed :
List those types of building works or street works for which supervision resources are to be combined.
Group the types of works into concurrent and non-concurrent works (Column 1). Only TCPs under concurrent works may be combined.
Obtain the Notional Supervision Input (Column 5) corresponding to the Frequency Level of Site Inspection from Table 8.2.
The Adjusted Supervision Input (Column 6) is the product of the Scale Factor (Column 2) and the Notional Supervision Input (Column 5).
List the grades of TCP that are to be combined in Column 7.

List the grades of TCP with combined duties in Column 8.
Sum up the Supervision Input required for those TCPs who are to be combined as the supervision input required for the TCP with combined duties (Column 9).
Derive the number of TCP with combined duties (Column 10) and Frequency Level of Site Inspection required after the combination of TCPs (Column 11) using Tables 8.2 and 8.3. The derived frequency level of site inspection should not be less than the minimum inspection frequency as set down in Table 1 of the TM.

The AP, RSE and RGE, after calculating the supervision input in accordance with paragraph 8.15, may further combine TCPs of the three streams in accordance with the same principles.

If the different types of works are not to be grouped and that the duties of TCPs are not to be combined, the adjusted supervision input for different types of works with a scale factor of more than one should also be calculated in Form C by using columns 1 to 6 and 11.

CODE OF PRACTICE FOR SITE SUPERVISION – Supervision Requirements

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1 Supervision Requirements

Determining the required TCPs and their frequency level of site inspections

The grades of TCP and their minimum frequency level of site inspections required for each functional stream for various types of building works or street works are set out in Table 1 of the Technical Memorandum. More frequent supervision requirements during critical stages are specified in paragraph 9 of this Code.

For building works with significant geotechnical content, the RSE would only be required to provide a team of site supervisors where there was structural works.

For foundation works in Scheduled Areas Nos. 1, 2 and 4 and in Designated Area of Northshore Lantau, additional supervision from the RGE’s stream is required on top of the supervision requirements for foundation works given in Table 1 of the Technical Memorandum. Note 5 to Table 1 of the Technical Memorandum refers.

Scale of the Works

The effect of the scale of the works should be considered in determination of supervision requirements. It shall be assessed by a scale factor of the works.

A measurable item and a basic value of which are assigned for each type of building works or street works. The scale factor of a type of works is the ratio of the estimated value of the measurable item of the works to the basic value. The scale factor is capped at 2.

The measurable items and their basic values to be used for the assessment of the scale factor of various types of building works or street works are set out in Table 8.1. Unless otherwise specified, the measurable items represent the total cost, average cost per month, or quantity of the respective type of building works or street works to be carried out. The BA may review and amend the measurable items and their basic values from time to time.

CODE OF PRACTICE FOR SITE SUPERVISION – Building Works with Significant Geotechnical Content

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1 Building Works with Significant Geotechnical Content

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

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

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.

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.

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.

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.

CODE OF PRACTICE FOR SITE SUPERVISION – Quality Supervision for Foundation Works

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Quality Supervision for Foundation Works

Quality supervision of foundation works should be provided by the RSE and his TCP T5 and T3, as well as by the AS of the RSC and his TCP T4 and T2. Depending on the nature of the various stages of foundation works, TCPs should either be full-time on site or inspect certain percentage of the works as specified in this Code.

The stages of the various types of foundation works are shown in Table 6.3. Actual supervision requirements will be imposed by the BA at plan approval and consent stage on a case-by-case basis depending on the scale and extent of the foundation works.

Table 6.3 Stages of Various Types of Foundation Works
Item No.	Stage	Description
F1	Driven Piles Setting out of piles	Check that the locations of piles agree with approved plans.
F2	(ii) Driving test	Check that design assumptions agree with actual site conditions during driving tests.
F3	(iii) Driving of piles	Check that the accepted working procedures of pile driving are followed and anomalies rectified during pile driving.
F4	(iv) Splicing of piles	Check the accuracy of design details during pile splicing.
F5	(v) Final sets	Check that the required final set has been achieved and the capacity of each pile complied with approved plans.
F6	(vi) Proof test (Verification on the performance of the as-constructed piles by the imposition of test load)	Check that the testing procedures and acceptance criteria of proof tests are in accordance with PNAP APP-18 (previously PNAP 66) and measurements are properly recorded during the test.

Table 6.3 Cont’d

F7	Large Diameter Bored Piles, Barrette Piles and the like Setting out of piles	Check that the locations of piles agree with approved plan.
F8	(ii) Pre-drilling (To determine the proposed founding levels of piles)	Supervise the pre-drilling operation; the logging of soil/rock samples, and to measure the depth of drillholes. Ensure that the retrieved samples are not tampered.
F9	(iii) Verification of founding stratum	Measure the depth of excavation and check the quality of retrieved materials at the founding stratum.
F10	(iv) Installation of piles (Grouting operation when required)	Check that proper working procedures of pile installation are followed and anomalies rectified. Check the correct grout mix, grout pressure and grout volume are being used and the adjacent building structures are not adversely affected.
F11	(v) Preparation of pile base	Ensure that pile base is clean.
F12	(vi) Fabrication and installation of rebar cage and placing of concrete	Check that sufficient and correct amount of rebars are provided and proper concreting method is used.
F13	(vii) Interface core-drilling	Check that the quality of concrete and foundation rock conforms with that specified in the approved plan and that concrete and rock are in good contact at the interface.
F14	(viii) Proof test (Verification on the performance of the as-constructed piles)	Supervise the core drilling operation of the proof test and the logging of concrete/rock samples and measure the depth of drillhole. Ensure that retrieved samples are securely stored and delivered to laboratory for testing.
F15	Mini-piles, Socketted H-piles and the like Setting out of piles	Check that the locations of piles agree with approved plan.

Table 6.3 Cont’d

F16	(ii) Pre-drilling (To determine the proposed founding levels of piles)	Supervise the pre-drilling operation; the logging of soil/rock samples, and to measure the depth of drillholes. Ensure that the retrieved samples are not tampered.
F17	(iii) Verification of founding stratum	Measure the depth of excavation and check the quality of retrieved materials at the founding stratum.
F18	(iv) Installation of piles (Grouting operation when required)	Check that proper working procedures of pile installation are followed and anomalies rectified. Check the correct grout mix, grout pressure and grout volume are being used and the adjacent building structures are not adversely affected.
F19	(v) Installation of rebar and grouting	Check that sufficient and correct amount of rebars are provided and proper grouting method is used.
F20	(vi) Proof test (Verification on the performance of the as-constructed piles by the imposition of test load)	Check that the testing procedure and acceptance criteria of the proof tests are in accordance with PNAP APP-18 (previously PNAP 66) and measurements are properly recorded during the test.
F21	(vii) Post-installation borehole drilling	Verify the rockhead profile and socket length of piles during post-installation borehole drilling.
F22	Rafts and Spread Footings Setting out of rafts and spread footings	Check that the locations and sizes of rafts and spread footings agree with approved plan (or the submitted plans for minor works).
F23	(ii) Inspection of bearing stratum	Check the compliance of ground bearing stratum with approved plans (or the submitted plans for minor works), site investigation reports and design assumptions.
F24	(iii) Fixing of rebars and checking of concrete covers	Check that sufficient amount of rebars and good workmanship are provided.
F25	(iv) Placing, compaction and curing of concrete	Ensure the quality and workmanship of concrete works.
F26	(v) Plate loading test (where required) (To verify the adequacy of ground bearing stratum)	Check that the accepted testing procedures of plate loading test are followed and measurements are correctly recorded.

Note : Foundation unit inspected should be shown in the checklist by each member of the supervision team.

The AP, RSE and RSC should jointly submit a supervision plan, specifying the name of the TCPs appointed and frequency of inspection and/or extent of supervision, and carry out inspections and supervisions in accordance with the plan. The plan should be submitted prior to or at the same time as consent application for the foundation works. However, no prior approval of the TCPs is required before commencement of the foundation works. The AP/RSE/RSC are responsible to ensure that their TCPs satisfy the qualification and experience requirements specified and should notify the BA of any subsequent changes of TCPs. The plan should be kept on site for the inspection of the BA when required.

The RSE should provide supervision as necessary during all stages in Table 6.3.

The AS of the RSC should provide supervision as necessary during all stages in Table 6.3.

Pre-drilling, interface core-drilling, post-installation drilling and proof test core-drilling for foundation works must be carried out by a Registered Specialist Contractor in the Ground Investigation Field Works category and be supervised by the site supervisors responsible for the quality supervision of foundation works. There is no need to submit a separate supervision plan for the pre-drilling and post-installation drilling works.

CODE OF PRACTICE FOR SITE SUPERVISION – Quality Supervision for Soil Nailing Works

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Quality Supervision for Soil Nailing Works

Quality supervision of soil nailing works should be provided by the RGE and his TCP T5 and T3, as well as by the AS of the RSC (Site Formation) and his TCP T4 and T1.

For all soil nailing works, at least one TCP T3 of the RGE and one TCP T1 of the RSC are required to be resident full-time on site during every stage of the works for each soil nail. The RSC is required to notify the RGE’s TCP T3 before the commencement of any stage of the works. The RSC is also required to prepare detailed inspection, measurement and testing records for each soil nail as per the approved plan requirements.

Table 6.2 Stages of Soil Nailing Works
Item No.	Stage	Description
N1	Pull-out test and any specified site trial	Check whether the test nails are being constructed and the test/site trial procedure is in accordance with the approved plans or as specified by the RGE, and the acceptance criteria for the test/site trial are met.
N2	Setting out of soil nails	Check whether the positions of the soil nails agree with the approved plans.
N3	Drilling of soil nail holes	Check whether the drillhole diameter, length, inclination and bearing are in accordance with the approved plans and any anomalies on ground and groundwater conditions and to report to the responsible person if necessary.

Table 6.2 Cont’d

N4	Assembly of soil nail reinforcement	Check whether the assembly is in accordance with the approved plans, in particular, the length, type and corrosion protection provisions of the reinforcement, adequacy and tightness of any couplers used, adequacy of centralizers to ensure minimum grout cover and the grout pipes are not twisted and free from blockage and are extended to the bottom of the soil nail holes in accordance with the approved plans.
N5	Insertion of soil nail reinforcement	Check whether: cleaning of the hole, e.g. by air flushing is needed to remove any blockage or collapse, or there is any groundwater, which may require a change in construction method, andthe assembly is sufficiently rigid and the correct assembly of soil nail reinforcement is inserted.
N6	Grout and preparation of grout	Check whether the grout used, grout mix, preparation of grout and grout test results meet the requirements of the approved plans.
N7	Grouting of soil nail hole	Check whether: grouting of soil nails is carried out on the same day as insertion of the soil nail reinforcement assembly,grout is injected into the drillhole through the grout pipe with sustained grout return of satisfactory cleanliness and viscosity from the top of the drillhole,grouting operation is carried out according to the approved plans, andexcessive grouting time or excessive grout volume consumed in any drillhole to maintain sustained grout return of satisfactory cleanliness and viscosity, or other anomalies such as excessive ‘settlement’ of grout (as measured along the length of the nail) on cessation of grouting, are reported to the responsible person and recorded.
N8	Construction of soil nail heads and structural supports between nail heads	Check whether the soil nail heads and structural supports are constructed in accordance with approved plans, including the dimensions, materials used, structural detailing and workmanship.

Key records on supervision of soil nailing works (Appendix IX) should also be prepared and certified by the RGE’s TCP T3 who carries out the inspection, measurement or check. A full set of all certified records should be kept on site for the inspection by the BA.

The RGE’s TCP T5 personnel should verify the design assumptions and carry out design review during construction. He should check whether there are any anomalies that may invalidate the functional requirements of his design during his periodic site inspections and follow them up. He should also follow up any anomalies reported to him by the RGE’s TCP T3. If necessary, the RGE should make amendment submissions for the approval of the BA.

The extent of supervision required for different stages of soil nailing works is shown in Table 6.2. Actual supervision requirements will be imposed at plan approval stage by the BA on a case-by-case basis depending on the scale and complexity of the slope and the soil nailing works, and the anticipated construction difficulties. The RGE should nominate to the BA, an adequate number of qualified supervision personnel with suitable experience, taking into account the site conditions and the number of soil nails proposed and their lengths. During the construction stage, the RGE should review the adequacy of the supervision team taking into account the likelihood of concurrent construction requiring close supervision under the construction programme.

The RGE’s TCP T5 should provide supervision as necessary during all stages in Table 6.2. Moreover, he is required to provide the following supervision personally :
1. pull-out test and any specified site test – at least 1 nail each of pull-out test and site trial;
1. insertion of soil nail reinforcement – at least 2 working nails at early stage of nail construction;
1. grouting of soil nail hole – at least 2 working nails at early stage of nail construction; and

construction of soil nail heads and structural supports between nail heads – at least one soil nail head.

The RSC’s TCP T4 should also provide supervision as necessary during all stages in Table 6.2. Moreover, he is required to provide the following supervision personally :
1. pull-out test and any specified site test – at least 1 nail each of pull-out test and site trial;
1. insertion of soil nail reinforcement – at least 2 working nails at early stage of nail construction;
1. grouting of soil nail hole – at least 2 working nails at early stage of nail construction; and
1. construction of soil nail heads and structural supports between nail heads – at least one soil nail head.

On completion of installation of soil nails, the RGE shall submit to the BA key supervision records in the form of Appendix IX certified by his TCP T3. Upon review of the supervision records, if the BA considers that there is cause for concern in relation to the quality of soil nailing works, the BA will require the RGE to carry out non-destructive testing (NDT) of at least 1% of soil nails with a minimum of 2 nails per slope (including wall) to verify the length of the installed soil nails.

Several NDT methods for checking the length of installed soil nails are described in GEO Report No. 133 “Non-destructive Tests for Determining the Lengths of Installed Steel Soil Nails”. Alternatively, the RGE may propose other methods for BA’s agreement at the design stage of the project. A test report with the test results and their interpretations together with re-assessment of the adequacy of the installed soil nails (if needed) shall be submitted to the BA for acceptance.

CODE OF PRACTICE FOR SITE SUPERVISION – Quality Supervision Requirements

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1 Quality Supervision Requirements

Scope of Quality Supervision

Quality supervision is applicable for ground investigation field works, soil nailing works and foundation works.

Principles of Quality Supervision

For quality supervision, the principles described in paragraphs 6.3 to 6.6 below will be followed.

In accordance with Building (Administration) Regulation (B(A)R) 37(1) and (2), the RSE and RGE should each give such periodic supervision and make such inspections as may be necessary for building works. For such purpose, they should each have a team of TCPs to inspect the works at a specified frequency and supervise the carrying out of a specified percentage of the works. The RSE, RGE and their TCPs should all be respectively accountable under the BO for the quality of building works but in accordance with their respective responsibilities as specified.

As the RSE and/or RGE have overall responsibility for the works, they should personally inspect and supervise the works at such frequency and extent as they consider appropriate in the circumstances of each case.

The RC, represented by their AS, should have a similar system of supervision as that of the RSE and/or RGE above, but they should give continuous supervision in accordance with B(A)R 41(1). Even if some of the building works are carried out by their sub-contractors, it remains the responsibility of the RC to ensure that the building works and continuous supervision are properly done in accordance with the provisions of the BO and the system of supervision described above.

Inspection records should be kept for each member of the supervision team who should report any non-conformities to the RSE, RGE or AS, as the case may be.

Quality Supervision for Ground Investigation Field Works

All ground investigation field works, in both scheduled and non-scheduled areas, should be carried out by a Registered Specialist Contractor (Ground Investigation Field Works category) (RSC(GIFW)) under proper supervision. To ensure quality of the works, supervision for the different stages of pre-design ground investigation field works, such as drilling/coring, sampling, instrumentation and field testing, should comply with the requirements set out in Table 6.1.