Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
Revision
-
Date
1.7.2004
Page
1 of 20
1.
PURPOSE
1.1
This Circular details the policy and procedures for registration and updating of records of
sizeable man-made slopes, retaining walls, disturbed terrain and natural terrain hazard
mitigation measures (collectively termed features). This revision covers the latest changes
in the registration procedure to speed up the process of registration and updating of
features in the Slope Catalogue. It takes into account the recommendations on registration
of features in the Director of Audit Report No. 38 – Chapter 10: Slope safety and landslip
preventive measures, and the inclusion of natural terrain hazard mitigation measures in
the Slope Catalogue as agreed by the Standing Committee on Slope Safety.
1.2
Any feedback on this Circular should be referred to the Chief Geotechnical
Engineer/Slope Safety (CGE/SS).
2.
POLICY
2.1
The Slope Safety (SS) Division of the GEO maintains a catalogue of sizeable man-made
features for use in the Landslip Preventive Measures (LPM) planning and
implementation, slope maintenance and dealing with slope safety related issues, and for
access by geotechnical practitioners and the public. In order to have this Catalogue
updated and maintained, GEO Divisions and their Consultants who deal with the features
in discharging their duties are required to provide updated information they obtain on the
features and to report new, modified or “missed” sizeable features for registration to the
SS Division as stipulated in this Circular.
2.2
As agreed by the Standing Committee on Slope Safety on the need for regular inspection
and maintenance of natural terrain hazard mitigation measures, these features (i.e. the
mitigation measures) should be registered in the Slope Catalogue with a responsible party
and maintenance agent identified by the Lands Department in the SIMAR register.
3.
RELATED DOCUMENTS
3.1
CEDD Operation Procedure OP-13 - Slope Catalogue Updating and Maintenance.
3.2
District Practice Note No. PN 107 - Registration of Slopes and Retaining Walls.
3.3
District Practice Note No. PN 131 - Provision of Information for Registration of
Unregistered Features.
3.4
Environment, Transport and Works Bureau Technical Circular (Works) (ETWB TCW)
No. 29/2002 – Geotechnical Control for Slopes and Retaining Walls.
3.5
GEO Circular No. 30 - Stage 1 and Stage 2 Geotechnical Studies of Slopes and Retaining
Walls.
3.6
GEO Report No. 68 - The New Priority Classification Systems for Slopes and Retaining
Walls (1998).
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
Revision
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Date
1.7.2004
Page
2 of 20
3.7
GEO TGN No. 15 – Guidelines for Classification of Consequence-to-Life Category for
Slope Features.
3.8
Geoguide 5 - Guide to Slope Maintenance.
3.9
Practice Note for Authorised Persons and Registered Structural Engineers (PNAP) 168 Registration of Slopes and Retaining Walls, Buildings Department.
3.10
Works Bureau Technical Circular (WBTC) No. 13/99 - Geotechnical Manual for
Slopes – Guidance on Interpretation and Updating.
3.11
Works Bureau Technical Circular (WBTC) No. 9/2000 - Registration and Updating of the
Catalogue of Slopes.
3.12
Works Bureau Technical Circular (WBTC) No. 16/2001 - GEO Checking Certificate for
Slopes and Retaining Walls.
4.
DEFINITIONS
4.1
Class A Features --- see Annex GC15 A1.
4.2
Consequence Category --- Definition given in WBTC No. 13/99.
4.3
Computerised Slope Register and Location Plans (CSRLP) --- The CSRLP is a
Digital Slope Map System which contains the feature boundaries, registration numbers
and basic map details in 1:1,000 scale and is maintained by the Survey Division of the
CEDD.
4.4
Feature --- A feature is (i) a slope or a retaining wall, or a combination of both, (ii)
disturbed terrain, or (iii) natural terrain hazard mitigation measures. The criteria for
feature registration, the types of features not fit for registration (see 4.8 below) and the
feature registration system are defined in Annexes GC15 A2 and GC15 A4.
4.5
Landslide Database (LD) --- A computerised database of the landslip incidents reported
to the GEO.
4.6
Landslip Preventive Measures Information System (LPMIS) --- A computerised
database system containing information on studies and upgrading works on slopes
included in the Landslip Preventive Measures (LPM) Programme.
4.7
Natural Terrain Hazard Mitigation Measures (NTHMM) --- Natural Terrain Hazard
Mitigation Measures are classified into two categories for registration in the Slope
Catalogue. They are Stabilisation Measures (NS) and Defence Measures (ND). The
registration system is defined in Annex GC15 A4.
4.8
New Priority Classification System (NPCS) --- The NPCS is a system for prioritising
follow-up LPM action on features in the Slope Catalogue.
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GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
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4.9
Non-Registrable Features --- Features which by their dimensions and/or type do not fit
the criteria for registration are set out in Annex GC15 A2.
4.10
Slope Catalogue --- The inventory containing pertinent information of sizeable
man-made features in the Hong Kong Special Administrative Region (HKSAR).
4.11
Systematic Inspection of Features in the Territory (SIFT) --- A project that formed
part of the SIRST project. It was undertaken by the Planning Division and its Consultants
to identify registrable features in the HKSAR using Aerial Photograph Interpretation
(API) techniques and existing topographic plans. The project was completed in June
1997.
4.12
Systematic Identification and Registration of Slopes in the Territory (SIRST) --- A
project that collected and retrieved information on sizeable man-made features in the
HKSAR. This project was commissioned in July 1994. The first part was the SIFT
project as described in 4.11 above. Site inspections were then carried out on the identified
features. Slope field data were collected including updating of field sheets for features in
the 1977/78 Catalogue of Slopes, registration of all newly discovered features, updating
of modified features and collection of NPCS parameters. The SIRST project was
completed in September 1998.
4.13
Slope Information System (SIS) --- The SIS contains computerised information
including the slope field data, the digital slope map from CSRLP, landslip incidents, GIU
ground investigation location data and other slope-related data. New layers added
include information on geology, natural terrain landslides, disused tunnels, district
information, horizontal drains, ground anchors, ducting for water-carrying services and
LPM information.
5.
AUTHORITY AND RESPONSIBILITY
5.1
The SS Division is responsible for updating and maintaining the Slope Catalogue and the
Slope Information System (SIS). The SS Division also arranges training to GEO staff for
using the SIS.
5.2
The Survey Division of CEDD is responsible for the upkeep of the digital slope map. In
this connection, the Chief Land Surveyor of CEDD (CLS/CEDD) registers the boundaries
of and assigns registration numbers to registrable features.
5.3
The Landslip Preventive Measures (LPM) Division 1 is responsible for the establishment,
updating and maintenance of the computerised Landslip Preventive Measures Information
System (LPMIS) and the Landslide Database (LD).
6.
PROCEDURE
6.1
CHECKING OF FEATURE PRIOR TO REGISTRATION
6.1.1
The criteria for feature registration and the types of non-registrable features are given in
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
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Annex GC15 A2. The initiating GEO Divisions should check the information of the
features to be registered to ensure they are registrable and are not in conflict with other
registered features prior to submitting them to the SS Division to carry out the registration
process. In case of any uncertainty in deciding whether a feature should be registered,
CGE/SS should be consulted.
6.2
REGISTRATION SYSTEM
6.2.1
The registration system for features is given in Annex GC15 A4.
6.2.2
When a feature is newly formed/constructed or identified and it meets the registration
criteria, the responsible GEO Division/Project Department should request CGE/SS to
register the boundary and obtain a registration number for the feature. Only permanent
features and features with construction works substantially completed and the actual
boundary determined will be assigned registration numbers; design proposals will not.
The requesting party should follow the procedures in Section 6.3 below and submit the
relevant information to CGE/SS. CGE/SS will then complete a Feature Registration
Number Request Form (Annex GC15 A6) and arrange with CLS/CEDD for assignment
of a registration number and updating of the CSRLP. Upon receipt of the registration
number and the updated Slope Location Plan from CLS/CEDD, CGE/SS will inform the
requesting party and proceed with the slope cataloguing work.
6.3
PROCEDURES FOR REGISTRATION AND UPDATING OF INFORMATION FOR THE
SLOPE CATALOGUE
6.3.1
Private Features Checked by the GEO or Removed
6.3.1.1
District GEs shall request the responsible AP/RSEs to submit the relevant feature data as
stipulated in District Practice Note No. PN107 and PNAP 168 for all new features or
newly modified existing features which result from any private development especially
for site formation works and slope/retaining wall upgrading works.
The District Divisions will provide a Checklist for Updating of Feature Records as shown
in Annex GC15 A7 to the SS Division.
The District Divisions shall ensure the following information is included:
6.3.1.2
a)
Boundary and location plans (1:1,000 scale) showing all new/modified features,
existing features within and immediately adjacent to the site which have been
assessed as part of the development, and confirmation on whether these features
are checked to current standard;
b)
Slope/Retaining Wall Records and a soft copy of feature data as per Appendices
C & D of PNAP 168 submitted by the AP/RSE; and
c)
A list of features that are removed as a result of the development.
The SS Division shall ask for feature numbers from CLS/CEDD and inform the AP/RSE
directly with a copy of the letter to the relevant District Division. CGE/SS will also
advise Lands Department in order that the maintenance responsibility shall be determined
or confirmed as appropriate.
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GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
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6.3.2
Public Features Checked by the GEO and Features Upgraded Under the LPM
Programme or Removed
6.3.2.1
The responsible government departments or the relevant GEO Divisions are required to
provide information to CGE/SS under WBTC No. 9/2000 for all new features or modified
existing features or existing public features removed which result from any public
development works or LPM works. In accordance with ETWB TC(W) No. 29/2002, the
boundaries of new features and modified existing features should be determined by
survey.
6.3.2.2
The SS Division will ask for new feature numbers from CLS/CEDD and inform the
requesting department and the relevant GEO Divisions.
6.3.2.3
To advance the process of registration of newly formed features, the Environment,
Transport and Works Bureau (ETWB) requires project departments to forward the key
feature information to CGE/SS for initial registration when the construction work has
been substantially completed and the actual feature boundary determined. The key
information includes the Feature Registration Number Request Form (Appendix C of
WBTC No. 9/2000), the preliminary slope/retaining wall key data (based on Annex
GC15 A9) and a 1:1000 location plan showing the boundary of the feature together with
photo(s) of the general view of the feature. Upon receipt of the information, CGE/SS will
proceed to the initial stage of registration and CLS/CEDD will provide the digital feature
boundary. Upon completion of the initial registration, CGE/SS will notify the project
department or relevant District Division of the feature registration number and advise
Lands Department in order that the maintenance responsibility would be determined or
confirmed as appropriate.
6.3.2.4
When the detailed information becomes available, the project department will forward
the information as per Appendix D of WBTC No. 9/2000 to CGE/SS. CGE/SS shall then
update the information of the newly formed features in the Slope Catalogue.
6.3.2.5
For public features that have been checked by the GEO, the relevant District Division
shall provide Checklist for Updating of Feature Records to CGE/SS as per Annex GC15
A7.
6.3.2.6
For features upgraded under the LPM Programme, the relevant GEO Division shall
provide the information as listed in Appendix D of WBTC No. 9/2000 to CGE/SS for
updating of the Slope Catalogue.
6.3.3
Features Affected by Landslip Incidents
6.3.3.1
Depending on the number of incidents, the LPM Division 1 will normally forward soft
copies of the updated Incident Numbers and co-ordinates to SS Division at the end of
each month, together with the registration numbers of the features affected by the landslip
incidents.
6.3.3.2
Depending on the number of incidents, the LPM Division 1 will normally provide soft
copies of the landslip incident reports to the SS Division within 3 months after the
incidents are reported by the District Divisions to them.
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GEO Circular No. 15
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Records of Features
Issue No.
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6.3.3.3
The LPM Division 1 will provide soft copies of the record form of incidents on features
submitted by other government departments to the SS Division every 6 months for
inclusion in the Landslide Layer of the SIS.
6.3.3.4
To expedite feature registration and updating of the Slope Catalogue, the relevant
District Division will provide updated information of feature conditions such as
boundary, type, geometry and details of repair /remedial works carried out to the SS
Division within 2 months after completion of the repair/remedial works.
6.3.3.5
The LPM Division 1 will provide an updated list of Landslide Study Reports, together
with the corresponding digitised boundaries of the landslide scars, to the SS Division
every 3 months.
6.3.4
Features with DH Orders and Advisory Letters Recommended/ Served
6.3.4.1
DH Orders may be initiated by the District Divisions,LPM Divisions and the SS Division.
Advisory Letters are initiated by the District Divisions. District Divisions will update the
information in the Dangerous Hillside Orders and Advisory Letters Database System
(DADS) regularly, and the information will be directly displayed in the SIS.
6.3.5
Modified Existing Registered Features and Newly Discovered Features
6.3.5.1
Modified/upgraded/newly discovered features or wrongly classified features should be
referred to the SS Division for appropriate follow-up action. A feature is regarded as
wrongly classified only if the basic definition is wrong, e.g. a fill slope is wrongly
classified as a cut slope and vice versa. When necessary, the SS Division will seek
assistance from Planning Division in carrying out API to help determine the feature type,
especially for Class A features.
6.3.5.2
The SS Division will pass all newly identified Class A features (see Annex GC15 A1 for
definition) to the LPM Division 1, for necessary actions.
6.3.5.3
When GEO Divisions or their Consultants identify a new feature, a modified or a
removed existing feature during their site inspection, site auditing work and landslide
inspection/investigation, they should inform the SS Division of the feature removal or the
new/amended feature boundary/definition (see Annex GC15 A4) with a location plan
showing the boundary of the feature. For a newly identified feature, the Division should
duly complete the record form in Annex GC15 A9 or Annex GC15 A10 to CGE/SS
within 1 month after the site inspection/investigation/auditing work.
6.3.6
LPM Status of Slopes
6.3.6.1
Information on the features included in the LPM programme is required for the SIS. The
LPM Division 1 will provide soft copies of the information extracted from the LPMIS
listing the Slope Report Nos., the location of the features, the recommendations made and
details of upgrading/modification work done to the features to the SS Division at
monthly intervals. Upon successful integration of the LPMIS with the SIS, the data can be
extracted directly from the LPMIS.
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Issue No.
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6.3.7
Natural Terrain Hazard Mitigation Measures
6.3.7.1
For natural terrain hazard mitigation measures (NTHMM), there is the need for regular
inspection and maintenance of these features (i.e. the mitigation measures) which should
therefore be registered in the Slope Catalogue with the maintenance responsibility
identified by the Lands Department.
6.3.7.2
Natural terrain hazard mitigation measures are classified into two categories for
registration in the Slope Catalogue, namely stabilisation measures and defence measures,
to be registered as NS features and ND features respectively in accordance with the
definitions given in Annex GC15 A4. Similar procedures for registration as outlined in
Sections 6.3.1, 6.3.2, 6.3.3 & 6.3.5 above are to be adopted, with the Registration Form
GC15 A10 to replace GC15 A9.
6.4
UPDATING OF INFORMATION FOR CSRLP
6.4.1
If the updated information for the Slope Catalogue involves modification of the digital
slope map, SS Division will pass the relevant information to Survey Division for updating
the digital slope map with CSRLP.
6.5
UPDATING OF SIS
6.5.1
The SIS has been prepared to contain pertinent information on features in the updated
Slope Catalogue. It is most important that the SIS is always up-to-date; therefore timely
provision of updated feature information by the relevant GEO Divisions, maintenance
departments, and their consultants is crucial. Errors or inconsistencies found in the
course of using the SIS should be promptly reported to CGE/SS for necessary action. A
standard form for recording suggestion for improvement/updating information in the SIS
is given in Annex GC15 A8.
6.5.2
The monthly summary of amendments/changes to the SIS will be posted in the SIS
Intranet for viewing/downloading.
6.6
UPDATING OF SIMAR RECORDS
6.6.1
The SS Division will provide a monthly summary of the features registered/de-registered
and the feature with boundary/type amendment in the month to Lands Department for
updating of the SIMAR records. For urgent cases such as those arising from landslip
incidents, the SS Division will forward details of individual features to Lands Department
for urgent compilation of SIMAR reports.
7.
ANNEXES
7.1
GC15 A1 -
Definition of Class A Features
7.2
GC15 A2 -
Criteria for Registration and Types of Non-Registrable Structures/Features
7.3
GC15 A3 -
(Not used)
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GEO Circular No. 15
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Records of Features
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7.4
GC15 A4 -
Feature Registration System
7.5
GC15 A5 -
(Not used)
7.6
GC15 A6 -
Feature Registration Number Request Form
7.7
GC15 A7 -
Checklist for Updating of Feature Records on Private/Public Development
7.8
GC15 A8 -
Form for Suggestion for Improvement/Updating Information in SIS
7.9
GC15 A9 -
Preliminary Information for Registration of Unregistered Feature Identified
by GEO Division
7.10
GC15 A10 - Information for Registration of Natural Terrain Hazard Mitigation
Measures
( R K S Chan )
Head, Geotechnical Engineering Office
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GEO Circular No. 15
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Definition of Class A Features
These are features considered to have similar circumstances to the Baguio Villas feature which failed
causing loss of life in May 1992, being either a fill slope or retained fill platform that fulfills the
following criteria :
·
assumed not to have been checked by GEO, i.e. interpreted from API to have been formed
before formation of the GCO in 1977 or illegally formed, and not to be “Housing Department
Features”;
·
not to be “Features studied to Stage 2 or equivalent”, i.e. assumed not to have undergone a
GEO Stage 2 study or equivalent, as identified from entries in the most recent updates of the
LPM database;
·
situated adjacent to or traversing a natural drainage line;
·
judged to present a significant hazard, i.e. likelihood of failure in heavy rain;
·
judged to pose a high or very high consequence to life as defined by the Modified B&P
Assessment of Consequence for Fill Features (as given in the Inception Report for Phase 2 of
the SIFT Study) in the event of failure.
Note that :i)
all five criteria must be met for a feature to be classified as Class A,
ii )
all fill features that pre-date the GCO, or are formed illegally, are assumed to be formed
of uncompacted fill. These are likely to present a significant hazard when saturated, i.e.
to have a likelihood of failure in heavy rain, regardless of whether or not they show
signs of distress (i.e. seepage, subsidence, cracking, bulging). However, if it is
considered that there is no possibility of saturation of the fill during heavy rain by
infiltration, groundwater seepage or piping, or broken services and drains, the fill
feature may be judged not to present a significant hazard.
GC15 A1 [1/1]
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GEO Circular No. 15
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Criteria for Registration
The criteria for features requiring registration are as follows :
(i)
cut slopes, including any associated retaining walls, and retaining wall greater than 3m
high;
(ii) fill slopes, including any associated retaining walls, greater than 5 m high;
(iii) fill slopes, including any associated retaining walls, less than 5 m high which pose a
direct risk to life i.e. Consequence-to-life Category 1 or 2;
(iv) disturbed terrain features which contain repairs to landslide scars or comprise a series of
composite cut and/or fill slopes where the ground surface has been disturbed, the natural
slope gradient is greater than 15ºand although the individual slopes do not meet the
height criteria for registration, the total height does meet the criteria for registrations; and
(v)
natural terrain hazard mitigation measures are classified into two categories for
registration in the Slope Catalogue. They are:
(a)
stabilisation measures constructed on natural hillsides to prevent failure, e.g.
boulder buttresses, soil nails and raking drains.
(b)
defence measures to contain landslide debris and hence protect buildings and
infrastructure at the toe in case of landslide or boulder fall from the natural terrain
above, e.g. check-dams, earth bunds and boulder fences.
Note :
1.
A list of structures/features, which should not be registered in the Catalogue of Slopes,
is given in the attached table.
2.
Disturbed terrain features generally covers situations such as repairs to landslide scars,
cemeteries, cleared squatter land and agricultural terraces (existing or now abandoned)
where extensive modifications have been made to the ground surface.
3.
Prior to March 1996, “Consequence-to-life” was referred to as “Risk-to-life”, and
“Category 1”, “Category 2” and “Category 3” were referred to as “High”, “Low” and
“Negligible” respectively in the Geotechnical Manual for Slopes.
4.
If the geometry of a hillside is substantially modified by earthworks (e.g. major
regrading), then the hillside is turned into a man-made slope feature. In such case, it
should be registered as a man-made slope feature.
GC15 A2 [1/2]
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Types of Non-Registrable Structures/Features
Structure Type
Definition
1. Seawall / marine
structures
The water-facing side of a coastal structure that retains soil or rock
and is constructed of concrete, earth and/or rock.
2. Dams and other
water retaining
structures
All water retaining structures including dams and service reservoir
walls maintained by WSD and private owners (e.g. Discovery Bay
reservoir dam.). (Fill embankments in front of service reservoirs or
other water-retaining structures should be registered.)
3. Basement walls /
screen walls
Concrete walls that form part of a building and which are in direct
contact with soil or rock, with the free air side facing into the
building.
4. Tunnel/shaft lining
Circular or other continuous concrete or steel walls or facings
which are in direct contact with soil or rock. (Tunnel portal slopes/
retaining walls should be registered.)
5. Culverts / covered
nullahs
Underground waterways. (Free standing sidewalls of open
nullahs/catchwaters, catchwater slopes and river banks satisfying
the registration criteria are considered as registrable features.)
6.
Bridge abutments
The concrete / steel structure of a bridge that provides direct
support to the span of a bridge deck. (Fill embankments and
reinforced fill structures and slopes should be registered.)
7.
All temporary
features
Features under construction, e.g. temporary stock piles, quarry
faces and controlled tips. (Abandoned quarry faces and
completed controlled tips should be registered as cut slopes and
fill slopes respectively.)
Note:
Walls which are designed and constructed monolithic with a building or structure will
not be registered. Works departments/GEO Divisions should advise CGE/SS of such
walls if they have already been registered in the catalogue of slopes.
GC15 A2 [2/2]
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Records of Features
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Feature Registration System
Registration Items
Practice to be Adopted
1. Feature Definitions F - Fill slope or platform with a surface sloping at ≥15º and a minimum
fill thickness of 1m and without any associated retaining wall(s).
C-
Cut slope without any associated retaining wall(s).
R-
All retaining walls supporting a slope or platform with a surface
sloping at <15º (fill or natural ground). Where a series of retaining
walls of less than registrable height are on an overall slope greater
than 45º, their height should be combined to judge if they are
registrable.
CR - Cut slope with retaining wall at crest, middle or toe of the slope.
FR - Fill slope with associated retaining wall(s) at crest, middle or toe of
the slope.
DT - Disturbed terrain features which contain repairs to landslide scars or
comprise a series of composite cut and/or fill slopes where the
ground surface has been disturbed, the natural slope gradient is
greater than 15º and although the individual slopes do not meet the
height criteria for registration, the total height does meet the criteria
for registration.
NS - Stabilisation measures constructed on natural hillsides to prevent
failure, e.g. boulder buttresses, soil nails and raking drains.
ND - Defence measures to contain landslide debris and hence protect
buildings and infrastructure at the toe in case of landslide or boulder
fall from the natural terrain above, e.g. check-dams, earth bunds and
boulder fences.
GC15 A4 [1/2]
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Registration Items
Practice to be Adopted
2. Marking of Feature R - plan boundary of the wall
Boundary
F - boundary of the fill slope.
C - boundary of the cut slope.
FR – boundary of the slope and wall.
CR – boundary of the slope and wall.
DT – boundary of the disturbed terrain.
NS – boundary of the natural terrain over which the stabilisation measures
Have been constructed.
ND - boundary of the defense measures.
GC15 A4 [2/2]
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Feature Registration Number Request Form
SURVEY DIVISION
CIVIL ENGINEERING AND DEVELOPMENT DEPARTMENT
Please send this form to the Chief Geotechnical Engineer/Slope Safety of the GEO/CEDD
Part I: Request
To: Chief Land Surveyor / Civil Engineering and Development Department
Project/Contract:
Locality:
File Ref.:
Type1:
C / F / R / CR / FR / DT/ NS / ND *
Approximate co-ordinates: N
E
Status:
Newly formed / identified / modified * (Existing feature no.
Date of formation:
Plan no.2:
Result required on or before:
Remarks:
Signature:
Name & Post:
Department/Company:
)
Date:
Tel. No.:
Fax No.:
* Delete as appropriate
1
Refer Annex GC15 A4 of GEO Circular No.15
2
The plan should be in 1:1000 scale showing the location of the feature and with its graphical boundary highlighted.
Part II: For CEDD Survey Division Use Only
File Ref.: ( ) in CEDD SY 9/3/301-( )
Job No.:
1:1000 Map Area:
Instructions/Notes:
Part III: Reply
To:
□Accepted
Feature No.:
Slope Location Plan No.:
Remarks:
□ Not accepted
Reason:
Signed:
for Chief Land Surveyor/CEDD
Date:
c. c. CGE/SS □CGE/I □ CGE/ME □ CGE/MW □ CGE/LPM1 □
□
GC15 A6[1/1]
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
Revision
-
Date
1.7.2004
Page
15 of 20
To CGE/SS (Attn. : SGE/ES)
thro’ SGE/
Checklist for Updating of Feature Records on Private/Public Development
1:1 000 Scale Map Sheet Ref.
:
Location
:
District GE Area
:
District File Ref.
:
Name of Development Project
:
Name of AP/RSE/Geotechnical Consultant/Responsible Department* :
Name of Contact Person/Post Title (for government officer only)* :
Address:
Section 1 : Information to be provided to CGE/SS when registered feature(s) has/have been checked up
to current standard (Update to CGE/SS when necessary)
Give registered feature no. and location plan indicating features/portions of features that have been
checked up to current standard :#
Registration No.
Checked up to current standard
1.
Wholly/portion*
2.
Wholly/portion*
3.
Wholly/portion*
---------------------------------------------------------------------------------------------------------------------Section 2 : Information to be provided to CGE/SS after the slope/retaining wall/natural terrain hazard
mitigation measures (NTHMM) have been completed
Slope/Retaining Wall/NTHMM Works Completion Date
(month/year):
(a)
Are there any existing registered feature(s) removed under this development?
If Yes, give registration no. and location plan :#
Registration No.
1.
2.
3.
Y/N
(Please
circle)
Extent of removal
Wholly/portion*
Wholly/portion*
Wholly/portion*
GC15 A7[1/2]
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
(b)
Issue No.
3
Revision
-
Date
1.7.2004
Page
16 of 20
Y/N
Are there any existing registered feature(s) modified or partially modified to
(Please
current standard under this development?
If Yes, give registration number, location plan and feature records and provide details circle)
below:#
Registration No.
Details of modification (see note below)
1.
2.
3.
Note :
(c)
For feature(s) partially modified, please provide details including feature registration
number, extent and type of modification on separate sheets. Please also indicate whether the
feature record covers the whole feature or only the modified part of feature.
Y/N
Are there any new feature(s) formed under this development ?
If Yes, give location plan and records (Individual record is to be submitted for every (Please
feature) and provide details below:
circle)
1.
2.
No. of new features formed :
New Registration No.:#
(for public development if known)
1.
2.
Prepared by
:
Post
:
dated
Checked by
:
Post
:
dated
---------------------------------------------------------------------------------------------------------------------*
#
Delete as appropriate.
Use separate paper if necessary
Note to District GEs :
(i)
The District GE should check the latest information in the SIS for any affected
registered feature(s) within the site.
(ii)
(iii)
Northing/easting gridlines and the feature boundaries should be clearly
shown on the location plans.
For Sections 2(a), 2(b) and 2(c), colour photos should be provided.
(iv)
Send copy to CGE/SS, keep original in District file at float.
GC15 A7 [2/2]
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
To : CGE/SS
Issue No.
3
Revision
-
Date
1.7.2004
Page
17 of 20
(Fax No.2762 2389)
Suggestion for Improvement/
Updating Information
in Slope Information System (SIS)
1.
Suggestion for Improvement
Current Situation/Area to be improved:
Suggestion for improvement:
2.
Updating Information
Information to be updated : (e.g. Feature No., Feature Boundary, DH-Order...etc.)
Current information in the SIS :
Details of updated information to be included in the SIS :
(Please continue on separate sheets if required)
(Please provide supporting information and attach sketch if updated information relates to graphical presentation, i.e. feature
boundary, feature sectional profiles...etc)
Name and Post in Block Letters
From : CGE/SS
Division
Contact Tel. No.
Date
To:
†
Suggestion implemented.
†
Suggestion is not accepted because
†
Information updated as request.
†
Information not updated/corrected as requested because
(
for CGE/SS
)
Date
GC15 A8 (1/1)
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
Revision
-
Date
1.7.2004
Page
18 of 20
To: CGE/SS
Preliminary Information for Registration of Unregistered Feature Identified by GEO Division
Feature Type
C / CR / F / FR / R / DT / Unknown *
Location (Address)
Date of Construction
Formed or Modified pre mid-1978 / Formed or Modified post mid - 1978 / Unknown *
Approximate Coordinates
Northing
Easting
SLOPE PART
Material Description
Soil / Rock / Soil & Rock *
Max. Height (m)
Length (m)
Average Angle (deg)
WALL PART
Type of Wall
Retaining wall with level platform / Wall at slope crest / Wall at slope toe / Wall at mid-slope*
Wall Material
Random Rubble / Masonry / Concrete / Gabion / Others*
Max. Height (m)
Face Angle (deg)
Length (m)
INFORMATION ON CONSEQUENCE-TO-LIFE CATEGORY
Facility at Crest
Building / Road / Open Area / Others *
Distance of Facility from Crest (m)
Facility at Toe
Building / Road / Open Area / Others *
Distance of Facility from Toe (m)
Consequence-to-life Category
1 / 2 / 3* (Refer to Table 3 of WBTC No. 13/99)
OTHER INFORMATION : (e.g. signs of distress, seepage, etc.) / REMARKS :
ADDITIONAL INFORMATION TO BE PROVIDED :
(a) Location plan (scale 1:1000) showing the boundary of the feature
(b) Photo(s) showing the general view of the feature
/
Name & Post in Block Letters
Division
Tel. No.
/
Date
* Delete as appropriate, if 'Others' is selected, please specify.
Note :
1. Upon completion of registration, SS Division will return a copy of the 1:1000 plan indicating the registered number of the feature to the
initiating GEO Division.
GC15A9
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Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
Issue No.
3
Revision
-
Date
1.7.2004
Page
19 of 20
To: CGE/SS
Information for Registration of Natural Terrain Hazard Mitigation Measures
Reference No. :
Location (Address) :
Date of Construction :
Formed or Modified pre mid-1978 / Formed or Modified post mid - 1978 / Unknown *
Approximate Coordinates :
Northing
Easting
STABILISATION MEASURES
Types of Measures :
( Tick on the
stabilisation
measures as
appropriate )
□ Boulder Buttress
Total Nos. of Individual Buttress :
□ Soil Nails
Total Nos. of Soil Nails installed :
Max. Length of Soil Nails (m) :
□ Raking Drains
Total Nos. of Raking Drains installed :
Max. Length of Raking Drains (m) :
□ Others #
DEFENCE MEASURES
Type of Measures :
Check-dams
Earth Bunds
Boulder Fences
Others #
Length (m) :
(for earth bunds and boulder fence only)
Max. Height (m) :
OTHER INFORMATION : (e.g. signs of distress, seepage, etc.) / REMARKS :
ADDITIONAL INFORMATION TO BE PROVIDED :
(a) Location plan (scale 1:1000) showing the boundary of the area covering the stabilisation / defence measures.
(b) Photo(s) showing the general view of the stabilisation / defence measures.
/
Name & Post in Block Letters
Department / Division
Tel. No.
/
Date
* Delete as appropriate
# Please Specify
Note :
1. Upon completion of registration, SS Division will return a copy of the 1:1000 plan indicating the registered number of the
stabilisation / defence measures to the initiating GEO Division / Project Department.
2. Depending on the exact locations of the 'stabilisation' measures constructed, different types of 'stabilisation' measures falling into the same
location can be grouped together for registration purpose.
3. Separate forms should be used for 'stabilisation' and 'defence' measures constructed.
4. Separate forms should be used for each 'defence' measure constructed.
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GC15A10
Geotechnical Engineering Office
GEO Circular No. 15
Registration and Updating of
Records of Features
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Issue No.
3
Revision
-
Date
1.7.2004
Page
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