STRUCTURAL METHODOLOGY REPORT UNDERPINNING TO …
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1 202087R001Rev0 Structural Methodology Report 23 September 2021 People Architecture [email protected] Attention: Steven Christoforidis Dear Steven STRUCTURAL METHODOLOGY REPORT – UNDERPINNING TO EXISTING WALLS OF THE EXISTING HOUSE AT 5 REGENT STREET PUTNEY This report has been prepared at your request to address the methodology and sequence of the proposed underpinning works to the existing brick walls for the proposed excavation and construction of the new basement storage rooms. This is to confirm that we have examined the above existing building to determine its structural suitability for the proposed alterations as noted below, and as shown on the Architectural Drawings. We confirm that the existing building is suitable, provided that the proposed new structural work is carried out in accordance with the methodology and construction sequence indicated below and to the future specifications and drawings prepared by a suitably experienced and qualified practicing consulting structural engineer. If works are carried out in accordance with our design and construction methodology this will pose negligible risk to neighbouring properties. Methodology 1. Install underpinning beams to support the existing timber bearers and remove the existing isolated brick piers. 2. Underpin both the internal and external walls with either mass concrete or brickworks to the level of 300mm below the base of the excavation if still in soil otherwise if in rock to 50- 100mm below subgrade level (to be confirmed by final design). 3. Proceed with excavation and construction of the basement storage rooms. Construction Sequence This section should be read in conjunction with the attached markup. 1. Remove existing flooring for head height clearance as required during construction. 2. Install underpinning steel beams to support the existing subfloor bearers. 3. Demolish existing isolated brick piers. 4. Begin local excavation in soil and underpin the internal brick wall with either mass concrete or brick works. The underpinning should follow the sequence of A, B, C, D and E as per the attached markup. 5. Underpin the external brick walls with either mass concrete or brick works. The underpinning should follow the sequence of 1, 2, 3 and 4 as per the attached markup. This will require the existing roof over the patio to be temporarily propped. 6. Prepare subgrade for sub-base installation of granular material to be specified by engineer.
Transcript of STRUCTURAL METHODOLOGY REPORT UNDERPINNING TO …
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202087R001Rev0 Structural Methodology Report
23 September 2021
People Architecture
Attention: Steven Christoforidis
Dear Steven
STRUCTURAL METHODOLOGY REPORT – UNDERPINNING TO EXISTING WALLS OF THE
EXISTING HOUSE AT 5 REGENT STREET PUTNEY
This report has been prepared at your request to address the methodology and sequence of the
proposed underpinning works to the existing brick walls for the proposed excavation and
construction of the new basement storage rooms.
This is to confirm that we have examined the above existing building to determine its structural
suitability for the proposed alterations as noted below, and as shown on the Architectural
Drawings. We confirm that the existing building is suitable, provided that the proposed new
structural work is carried out in accordance with the methodology and construction sequence
indicated below and to the future specifications and drawings prepared by a suitably experienced
and qualified practicing consulting structural engineer. If works are carried out in accordance with
our design and construction methodology this will pose negligible risk to neighbouring properties.
Methodology
1. Install underpinning beams to support the existing timber bearers and remove the existing isolated brick piers.
2. Underpin both the internal and external walls with either mass concrete or brickworks to the level of 300mm below the base of the excavation if still in soil otherwise if in rock to 50-100mm below subgrade level (to be confirmed by final design).
3. Proceed with excavation and construction of the basement storage rooms.
Construction Sequence
This section should be read in conjunction with the attached markup.
1. Remove existing flooring for head height clearance as required during construction.
2. Install underpinning steel beams to support the existing subfloor bearers.
3. Demolish existing isolated brick piers.
4. Begin local excavation in soil and underpin the internal brick wall with either mass concrete or brick works. The underpinning should follow the sequence of A, B, C, D and E as per the attached markup.
5. Underpin the external brick walls with either mass concrete or brick works. The underpinning should follow the sequence of 1, 2, 3 and 4 as per the attached markup. This will require the existing roof over the patio to be temporarily propped.
6. Prepare subgrade for sub-base installation of granular material to be specified by engineer.
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7. Pour the concrete base slab with a spoon drains adjacent to the new underpinning walls.
8. Construct pits and other drainage items as per the civil engineers’ recommendations.
The underpinning works and base slab are to be carried out in the sequence above, and the elements are to be designed in accordance with the following:
1. Is in accordance with the relevant requirements of the Building Code of Australia- NCC Part 3.0 Structural Provisions Volume 2 - 2019, Amendment 1; and
2. Is in accordance with the following relevant Standards Australia Codes:
AS/NZS 1170.0-2002 Structural Design Actions: Part 0 - General Principles
AS/NZS 1170.1-2002 Structural Design Actions: Part 1 – Permanent, Imposed and Other Actions
AS/NZS 1170.2-2021 Structural Design Actions: Part 2 - Wind Actions
AS 1170.4-2007 Structural Design Actions: Earthquake Actions in Australia
AS 1720.1-2010 Timber Structures: Part 1 - Design Methods
AS 2870-2011 Residential Slabs and Footings - Construction
AS 3600-2018 Concrete Structures
AS 3700-2018 Masonry Structures
AS 4100-2020 Steel Structures
AS 4678-2002 Earth Retaining Structures
General Comments
We noted that whilst every measure can be taken from a structural design perspective to preserve
the structural integrity of the adjacent structures, there are other factors outside of the parameters
of structural design that can adversely affect the satisfactory performance of the shoring system
such as improper construction techniques or errors, geotechnical issues not predicted in the report,
environmental issues, unforeseen activities occurring outside of the site and so on. it is therefore of
paramount importance that the construction methodology proposed by the builder is reviewed and
monitored by the structural and geotechnical engineers.
The recommendations and opinions expressed in the above report include explicit references to
issues that must be addressed during the construction and detailed structural design phase of this
project. Should these recommendations not be implemented then STRUCTURE Consulting
Engineers accept no responsibility for the performance of the proposed and existing structures.
Yours sincerely,
Wayne Teng
Senior Engineer
Tonkin
Enc Tonkin Markup on Architectural Sketch Design Rev 2
WALL TYPES EXISTING WALL
DEMOLISHED
PROPOSED
SITE B
DY
SITE BDY
SITE BDY
SITE BDY
MEDIA
LAUNDRY
FAMILYDECK
KITCHEN
POOL
DECK
LAWN
WC
BEAM OVER (2.12 U/S)
80
12345
ABSORPTI ON PITABSORPTI ON PIT
RL 41.06RL 40.90
RL 40.14CH 2.275M
RL 40.06CH 2.40M
RL 41.06
BEAM OVER (2.27 U/S)
39 40 41 42
43
4039 4240.4
41.2 41.4 41.6 41.8 42.442.2
42.442.2
New double hung window 600Hx960W/1600SILL
Existing ground level over
Underpinning of existing foundation with new masonry foundation walls
New AG line to perimeter of newfoundation walls & connected to existing absorption pit in the rear yard
41
Remove access door& part wall
39.839.639.439.2
RL 40.06CH 2.40M
STORAGE
STORAGE
STORAGE
BEAM OVER (2.27 U/S)
BEAM OVER (2.12 U/S)
Excavation depth for strip footings approx. 2.4m
Excavation depth for strip footings approx. 1.4m
Excavation depth for strip footings approx. 2.4m
Excavation depth for strip footings approx. 1.8m
6580 4190 3840 7151
1886
5400
4500
3149
6580 4190 5416 10760
PROPOSED AREA 41M21 1
NEW BEAM OVER (2.27 U/S)
NEW BEAM OVER (2.27 U/S)
RL 40.06CH 2.40M
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LEGENDPROPOSED ALTERATIONS & ADDITIONS
WORKS SUBJECT TO BUILDING CERTIFICATE
SCALE
FOR REVIEWDRAWING NUMBERPROJECT ISSUE
NORTH
REVISION
registration no. [email protected] 788 324
DRAWING TITLE
1 : 100 @ A3
SK102/ P2
LOWER GROUND FLOOR PLAN
ALTERATIONS & ADDITIONS5 REGENT ST PUTNEY NSW 2112
1M 5M 10M
Issue Date Description
P1 11/12/20 Prelodgment Issue
P2 15/01/20 Prelodgment Issue
FSR CALCULATION
Site Area= 570M2FSR = 0.5:1Max GFA = 285M2
Existing GFA = 33 (LG) + 130m2 (GF) + 52m2 (FF) = 215m2Existing FSR = 215/570 = 0.37:1
Proposed GFA = 74 (LG) + 130m2 (GF) + 52m2 (FF) = 256m2Proposed FSR = 256/570 = 0.45:1
A
A B C
A
BC
DE
A
Width of ExistingFooting
Length 1100 max
UNDERPINNING DETAIL TO INTERNALBRICK WALL Sequence A, B, C, D and E
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1
2 31 2
1
1
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123
21
32
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1 3 2
UNDERPINNING DETAIL TO EXTERNALBRICK WALL Sequence 1, 2 and 3
Length 1100 max
Width 750 for mass concrete900mm for brick works
Item 1: Remove floor forhead height clearanceduring construction
Item 2: Underpin existingbearers with steel beams
Item 3: Demolish existingisolated brick piers
TONKIN MARKUP ON ARCHITECTURAL SKETCH DESIGN REV 2
