3.
DESCRIPTION
OF DESIGN MEASURES
3.1
Landscape
and Visual Design Measures
During the detailed design stage, the proposed landscape and
visual design measures in Section 14.3.3.2 of the approved EIA report and
Section 14.2.4 of the EM&A Manual are considered. They are proposed as far as practicable. The following sections summarize the
development of these design measures.
3.1.1
Aesthetic
design on the viaducts
·
Optimizing
the sizes and spacing of the bridge columns
In the design process, the sizes of the bridge
columns have been minimized to reduce the bulkiness of the structure. Spacing of the bridge columns has also
adopted an evenly distributed spacing so that the structure would be
aesthetically more pleasing as recommended by the ACABAS. Please refer to Section 6.3.3 of the AIPSLW
in Appendix A and Section 2.1 of the ACABAS Submission in Appendix B
for more details. The ACABAS submission
has been reviewed and accepted by the ACABAS committee in July 2012. Further
ACABAS submission was submitted on 2 January 2013 and was accepted with one
minor comment regarding pier finishes.
·
Fine-tuning
the location of the bridge columns to avoid visually-sensitive locations
As
shown in Figures 14.1.3a to 14.1.3c of the approved EIA report, the visually
sensitive receivers (VSRs) to the section of the HKLR under this Contract are
mainly on the northern coast of Lantau
Figure 2. Photomontage of Proposed HKLR viewed from
Sha Lo Wan
Figure 3. Photomontage of Proposed HKLR viewed from
hiking trail near San Tau
·
For
HKLR, providing aesthetic design on the viaduct, at grade roads and reclamation
(e.g. slim form for viaduct to minimize the bulkiness
of the structure and to blend the viaduct better with the background
environment, featured form of tunnel portals, roadside planting along at-grade
roads and landscape berm on & planting along edge of reclamation area) to
beautify the HKLR alignment
A
slim form has been adopted to minimize bulkiness of the viaduct as discussed in
Section 6.3.3 of the AIPSLW in Appendix
A and Section 3.2 of the ACABAS July 2012 Submission in Appendix B. Tunnel portal
works are not within the scope of this Contract. Roadside planting along at-grade roads will
be discussed in the following Section.
Landscape berm on planting along edge of reclamation area is not
applicable because the section of HKLR covered in this Contract does not
involve reclamation works.
·
For
HKLR, providing aesthetic design on the viaduct, tunnel portals, atgrade roads and reclamation (e.g.
subtle colour tone and slim form for viaduct to
minimize the bulkiness of the structure and to blend the viaduct better with
the background environment, featured form of tunnel portals, roadside planting
along at-grade roads and landscape berm on & planting along edge of
reclamation area) to beautify the HKLR alignment
The
selected soft and grayish natural colour of concrete
for the viaducts has an unobtrusive tone which gives a sense of lightness and
elegance that perfectly blend the proposed structure with the surroundings.
In
addition, a slim form has been adopted to minimize the bulkiness of the viaduct
as discussed in Section 6.3.3 of the AIPSLW in Appendix A and Section 3.2 of the ACABAS July 2012 Submission in Appendix B. Roadside planting along at-grade roads will
be discussed in the following Section.
Landscape berm on planting along edge of reclamation area is not
applicable because the section of HKLR covered in this Contract does not
involve reclamation works.
·
Roadside
planting and planting along the edge of the reclamation is proposed
Roadside
planting is proposed along South Perimeter Road (SPR) and Chek
Lap Kok South Road (CLKSR) adjacent to the proposed
HKLR. Detailed design of the at-grade
planting is shown in Drawing nos. HKLR9/MMH/AIP/AI/LS00009 to
HKLR9/MMH/AIP/AI/LS/00021 of the AIPSLW in Appendix
A. Design codes, considerations,
approaches and details of the at-grade landscape design are discussed in
Sections 2 to 6 of the AIPSLW in Appendix
A. Planting along the edge of the reclamation is not applicable to this
section of the HKLR as no reclamation works is involved.
·
Transplanting
of mature trees in good health and amenity value where appropriate and
reinstatement of areas disturbed during construction by compensatory
hydro-seeding and planting
Transplantation
is proposed for trees in good health with high amenity value and reasonably
high post-transplantation survival rate.
Details of the transplantation proposal are discussed in Sections 2.8
and 6.2.2 of the AIPSLW in Appendix A. Areas temporarily affected by the
construction works, such as temporary road diversion and utility diversion, are
proposed to be re-instated with tree planting, hydro-seeded grass and shrub/
groundcover planting as discussed in Section 6.2.3 of the AIPSLW in Appendix A.
Additional
compensatory tree planting will be provided to meet the compensatory planting
ratio of 1:1 in terms of both number and aggregated DBH. Liaison with AAHK for additional tree
planting area is on-going.
·
Protection
measures for the trees to be retained during construction activities
Protection
of existing vegetation is discussed in Section 2.7 of the AIPSLW in Appendix A. Specification for tree protection is shown in
Appendix B of the AIPSLW in Appendix A.
·
Maximizing
new tree, shrub and other vegetation planting to compensate tree felled and
vegetation removed
As
discussed in Section 6.2.2 of the AIPSLW in Appendix A, compensatory tree planting has been maximized on
site. Additional off-site compensatory
planting area will also be provided where feasible as required.
·
Providing
planting area around peripheral of HKLR and HKBCF for tree planting screening
effect
Tree
planting is proposed on the north side of SPR and CLKSR as shown in Drawing
nos. HKLR9/MMH/AIP/AI/LS/00009 to HKLR9/MMH/AIP/AI/LS/00021 of the AIPSLW in Appendix A. These trees can act as buffer to the adjacent
buildings and partially screen the hard structure of the proposed viaduct. Planting on the south side of the proposed
viaduct is considered infeasible as the bridge columns sit on the seawall.
3.1.2
Night-time
lighting control
·
Aesthetic
design of the bridge form and its structural elements for HKLR, e.g. parapet, soffit, columns, lightings and so on
Consideration
will be given to decorative effects in the lighting design. Subtle down lights will be employed on top of
columns at the navigation channel to illuminate the emerged pile caps over
water. This will serve the primary purpose as a warning to the marine traffic
but at the same time create a nice visual effect on the viaducts at night. The
illumination dissipates towards the base of the column giving the impression
that the structure floats upon water and reduces the perceptible scale and
bulkiness of the bridge. The proposed pilecap
lighting is illustrated in Figure 4
in below.
Figure 4.
Proposed road lighting and pilecap lighting
·
Considering
the decorative urban design elements for HKLR, e.g.
decorative road lightings
Lighting
design has been carefully considered to avoid interference with aviation
traffic. Normal street lightings are located in the central median so that they
will not be in conflict with the Under Deck Inspection Vehicle. All road
lighting on the viaduct will be controlled to prevent any glare or dazzle and
all lighting will not be projecting skyward. A photomontage of the proposed
light poles is shown in Figure 5 below.
Figure 5. Photomontage of Proposed Light Poles