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JACK PHILL IPS ' BU I LDING
128 MAIN STREET
i' GORE
SEISMIC ASSESSMENT REPORT
REPORT PREPARED FOR;GORE DlSTR i CT COUNCIL.
REPORT PREPARED BY:Peter Stevenson (CPEngSTEVENSON BROWN LTD.
D ISTRI BUT I ON :Gore Disf-rjct- Council:
STEVENSON BROWN LTD; eCOPY
DATE: 1 7 Sept ember 2015
REFERENCE NO: 15066
Revision; A
STEVENSON BROWN LTD
Structural and Fire Engineers
1 EXECUTIVE SUMMARY
A Detailed Seismic Assessment was carried out for the building owned by Dr Jack Phillips at
128 Main Street, Gore. The purpose of the investigation was to establish whether the existing
building meets the minimum requirements for earthquake strength set out in the NZ Building
Act 2004 and the Gore District Council Earthquake Prone Buildings Policy, and to identify
remedial work that will improve the building s seismic performance.
The seismic performance of the building was assessed in terms o^ percentage of new building
standard (%NBS).
This analysis indicates an overall score for the building of <20%NBS. This is means the building
is Earthquake Prone (i.e. <34%NBS) as defined by the New Zealand earthquake prone building
legislation.
The repair of damaged mortar joints is a minimum level on maintenance and improvement
required to make this assessment valid.
To meet the requirements of the earthquake prone building legislation the building is
required to be improved to a level above 33%NBS. By carrying out the following work the
overall capacity of the building will be increased to 35%NBS (which is above the earthquake-
prone threshold):
• Tie the URM walls into the floor/roofdiaphragm;
• Repair the damaged areas of the 1st floor diaphragm;
• Install a seismic frame to support the Gridline B wall (Figure 4);
• Install a 'wind-beam' to support the URM wall (on Gridline A) at 1st floor diaphragm
level/ adjacent the stair;
• Stabilise the ornament above the SE corner entrance.
To get the capacity of the building above 67%NBS, as recommended by the NZSEE,the
following additional work is required:
• Restrain the parapets by bracing them back to the roof structure;
• Install a steel seismic frame to improve the gridline C wall (Figure 5);
• Install a steel frame to improve the gridline 2 wall (Figure 6);
• Buttress (or demolish) the free-standing URM west boundary wall.
This assessment has not included a detailed analysis of non-structural items that may be
present in the building.
Seismic Assessment-128 Main St, Gore Revision A Page 2 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
2 CONTENTS
1 Executive Summary..............................................................................................................2
3 Introduction .........................................................................................................................4
4 Basis for the Assessment......................................................................................................4
4.1 Information on Existing Building.................................................................................^
4.2 References............................................................................,...-..................................^
5 General Building Description................................................................................................5
5.1 Building Form & Condition...........................................................................................5
5.2 Material Properties ......................................................................................................8
5.3 Minimum Level of Improvement/Maintenance ..........................................................8
6 DSA Assessment...................................................................................................................9
6.1 General Description (Section 10 Revision AISBE).........................„....„........................9
6.2 Analysis Me^o6...........................................................................................................9
6.3 Earthquake Capacity ....................................................................................................9
6.4 Earthquake Demand................-..................................................................................^
6.5 Results of DSA........................................................................................................... 10
6.6 Improvement Options for Building........................................................................... 11
7 Seismic Grades and Relative Risk...................................................................................... 14
8 Seismic Restraint of Non-Structural Items........................................................................ 15
9 Conclusion......................................................................................................................... 15
Appendix A-Existing Building Plans & Sections
Appendix B - Photographs of Existing Building
Seismic Assessment -128 Main St, Gore Revision A Page 3 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
3 INTRODUCTION
A Detailed Seismic Assessment (DSA) of the building at 128 Main Street/ Gore, has been
completed using the NZSEE Assessment and Improvement of the Structural Performance of
Buildings in Earthquakes (2006) Guidelines including Corrigendum No.4.
As with any assessment of an existing building, it is important to bear in mind that the
conclusions reached, can change as new information becomes available. The assessment of
unreinforced masonry buildings is the subject of on-going research and assessment
techniques are constantly being updated and improved. In addition to this, other
information, which was not 'accessible' during the initial assessment may only become
obvious when more of the building fabric is exposed during construction work. So, this report
should be considered a living7 document that can be updated and refined as more
information comes to light and as seismic improvement work on the building proceeds.
4 BASIS FOR THE ASSESSMENT
4.1 INFORMATION ON EXISTING BUILDINGThe information we have used for the DSA includes:
• Visual inspection of the exterior of the building.
• Visual inspection of the interiorofthe building.
• No existing (original) drawings for the building were available for review.
• Drawings of the existing building have been prepared to assist in the analysis. A copy
of these are included in Appendix A.
4.2 REFERENCESThe following references were used for the analysis:
• New Zealand National Society for Earthquake Engineering (June 2006} "Assessment
and improvement of the Structural Performance of Buildings in Earthquakes"
(AISPBE).
• "Section 10 Revision Seismic assessment of Unreinforced Masonry Bwldings^ issued
aspartofCorrigendum No.4 of the N2SEE^/5P6f (2006) Guidelines. April 2015.
• Building Act (2004), New Zealand Government.
• Gore District Council/ Earthquake-prone Buildings Policy.
• New Zealand Building Code.
• NZS 1170. NZ Loading standard.
Seismic Assessment-128 Main St, Gore Revision A Page 4 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
5 GENERAL BUILDING DESCRIPTION
5.1 BUILDING FORM & CONDITIONThe building is located at 128 Main Street/ Gore. It is generally a two storey, unreinforced
masonry (URM) building with the following features. The existing Ground floor and Upper
floor plan are described in Figure 1 and Figure 2 below.
©—B
Cast if uncolumns supportingcone rate encased
sttil btlfnT (not
confirmed)
Figure 1: Ground Floor Plan (Note: North points up the page parallel to Gridfine 1)
• Building constructed in 1901;
> There does not appear to have been any strengthening done to the building in the
past;
' There have, however, been a number of alterations to the building;
' The most significant (as far as structural performance is concerned) is the addition of
the large shop-front windows along the Main Street elevation (on Gridline 2) and the
south end elevation (on Gridline C);
' The lintels over the large shop-front windows are most likely concrete encased steel
beams. This is to be confirmed during the construction of any seismic improvements;
' Also, existing ground floor walls on Gridline B appear to have been removed and
replaced with a beam (probably concrete encased steel, though this was not
confirmed) and cast iron posts;
Seismic Assessment-128 Main St, Gore Revision A Page 5 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
Alterations that have been done upstairs are not significant as far as the structural
performance is concerned;
Figure 2: Upper Floor Plan (Note: North points up the page parallel to Gridline 1)
• The building has an irregular floor plan, as can be seen in Figures 1 & 2;
• The building is generally constructed with solid clay brick walls. The sidewalls are
triple brick (350mm thick) along Gridlines C & 1, and are double brick (230mm thick)alonggridlinesA& 1;
• The walls are the same thickness all the way up the building, including the parapets;
• Every 4th course is a header course (common bond);
• The lime/sand mortar is considered 'medium-soft' hardness;
• There is some erosion of the mortar joints in the parapet along the top of the west
wall(Gridlinel);
• There is mortar erosion at 1st floor level, in the east end of the north wall (Gridline A);
• There is also mortar erosion at the north end of the east wall parapet (Gridline 2),
where the plaster has become detached;
• The bricks appear to be in reasonable condition and are considered 'medium'
hardness;
• The walls all appear to be plumb;
Seismic Assessment" 128 Main St, Gore Revision A Page 6 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
All original chimneys appear to have been removed down to top of parapet level;
There are parapets on all sides of the building including on top of the internal brick
wall onGridline B;
The walls do not appear to have any DPC layers constructed within them;
There is an ornament on top of the parapetoverthesoutheastcorner entry door;
There is a free standing (3.7m high) triple brick wall on the west boundary;
There are effectively 2 hipped roofs on the building. One between Gridlines A & B
and one between Gridlines B & C (see Figure 3);
Timber nrliin } boardsover purltns-
Triple brick wall
Double bfich v all
Figure 3: Section through existing building.
The roofs are clad with corrugated steel, which is supported on sarking boards/ over
timber purlins, which in turn are supported on timber rafters at 450 centres;
The 150x50 ceiling j'oist, at 450 centres/ support the original 200x15 sarked ceiling.
Under this are battens and a more recent plaster board ceiling;
The ceiling joists are pocketed into the URM walls for support. The condition of the
joists, where they pocket into the walls, is uncertain. This was not confirmed because
of access difficulties;
The 1st floor structure consists of 100x19 T&G floor boards (fixed over each joist with
2/60x2.5 diameter nails), supported on 300x50 floor joists at 450 centres;
A large section of the upper floor boards have been lifted (probably for inspection) in
the area beside the wall of the stairway;
There is also some damaged flooring in the north end of the kitchen and the west side
of the toilets;
There is an original 10mm thick T&G ceiling fixed to the underside of the floor joists;
The floor joists are pocketed into the URM walls for support;
The condition of the joist ends, within the pockets is uncertain. This can be confirmed
during the construction of any improvements;
The ground floor will most likely consist of timber Joists, supported on bearers, which
are supported on piles (this was not viewed). There is little sub-floor ventilation so
the ground floor structure may not be in good condition. This will not affect the
seismic performance of the building though and isa general maintenance issue;
Seismic Assessment -128 Main St, Gore Revision A Page 7 of 15
STEVENSON B ROWN LTD
Structural and Fire Engineers
• The walls are most likely supported on a stone foundations or weak concrete strip
foundations;
• Apart from a small crack between the end of northern most lintel support and the
brickwork, there are no significant cracks within the building and there is no obvious
signs of foundation settlement;
• There is fine cracking in the plaster work and cornices around the building.
• The ground is most likely to consist of Class D sub-soils as defined in NZS 1170.5
(assessed from a visual inspection of the topography only-a geotechnical
assessment has not been carried out);
• The building is importance level IL2 as defined in NZS 1170.0;
The inertia forces, generated within the building structure during earthquake shaking will be
resisted by the URM walls, both in face loading (out-of-plane) and in-plane loading. In its
existing configuration, the roof and upper floor diaphragms cannot be relied upon to support
the face-loaded walls at these levels.
5.2 MATERIAL PROPERTIESThe following material properties where used for the DSA of the building. These were
assessed using the NZSEE AISPBE Section 10 Revision (April 2015) document.
Table 1: Material Properties
i?,l^iiMi
Mortar
Bricks
!>'^;;t'^i!l«lt'it'o}'^
Medium/Soft
Medium
"Y'/'JK^
^rof^^.-m1'/?'1
yt'?)(^ilfl^
(?lr^j
3
26
l^h^^isi'^/
f'^fa;)»?^i??
'^(yB^Jjf'.S^li.
(t^lrNj
12
«<'d(f-;-?W
(^^
0.4
ftj?l|i[bfeiill:
^i"ii'fr[il-?:].iT>
; !>!. .
0.45
^wjHy
f'p) •
(|!'Wf1)
18
^ Note that the material properties have not been obtained from site specific tests. Rather they are thelower bound strength properties that would be expected for this type of construction.
5.3 MINIMUM LEVEL OF IMPROVEMENT/MAINTENANCEFor this analysis, a minimum level of building maintenance has been assumed.
It has been assumed that the brick walls will remain intact during earthquake shaking. As
mentioned above, there are areas of the wall (particularly at higher levels) where the mortar
has been unprotected and has eroded. In some of these areas the lime/sand mortar has
leeched away or become very soft as a result of the moisture exposure, which has left the
brick in these areas with little support. Repairing the exterior mortar joints is the minimum
level of maintenance required before this analysis is valid.
The deteriorating mortar joints are to repaired by raking out the very soft mortar with a
finger (or some other soft tool) and tooling in new lime sand mortar. All of the affected
mortar joints (and other unprotected joints) are then to be repointed with a cement based
mortar.
Seismic Assessment -128 Main S{, Gore Revision A Page 8 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
6 DSA ASSESSMENT
6.1 GENERAL DESCRIPTION (SECTION 10 REVISION AISBE)The contents of this section are an extract from the Section 10 Revision Document of the
AISPBE.
When assessing and retrofitting URM buildings/ such as this one, it is important to understand
the potential seismic deficiencies and failure hierarchy of these buildings and their
components.
The most hazardous of these deficiencies are inadequately restrained elements located at
height, such as street-fadng facades/ unrestrained parapets/ chimneys/ ornaments and gable
end walls. These are usually the first elements to fail in an earthquake and are a risk to
people in a zone extending well outside the building perimeter.
The next most critical elements are face-ioaded wails and their connections to diaphragms
and return walls. Even though their failure may not lead to the building's catastrophic
collapse, they pose a severe threat to life safety.
When all of the building components are tied together and the out-of-plane failure of the
walls is prevented/ the building will behave more as a complete entity and the in-plane
elements (which are generally stronger) will come into action.
6.2 ANALYSIS METHODThe displacement based design approach, set out in the N2SEE AISPBE (June 2006) Guidelines
(including the Section 10 revision/April 2015), was used for the assessment of this building.
6.3 EARTHQUAKE CAPAcmUsing the failure hierarchy described in section 6.1 the capacity of each element was assessed
and its capacity recorded.
The building was first assessed assuming there is no effective connection between the walls
and the floor/roofdiaphragms. In this case, the overall capacity of the building is governed by
theout-of-plane response of the Tree-standing' perimeter URM walls.
The building capacity was then assessed assuming the walls are effectively tied in to the
diaphragms and the inertia forces can be transferred into the in-plane wall elements.
6.4 EARTHQUAKE DEMANDEarthquake demands were calculated using the parameters outlined in Table 2.
Table 2: Design Earthquake Parameters
I te on)
Building importance level:
100%NBS design level earthquake:
Soil type:
/^IsiFal'lsJ^fl)
IL2
500 year return period
D
r^iton^-
NZS 1170.0
NZS 1170.0
N2S 1170.5
Seismic Assessment -128 Main St, Gore Revision A Page 9 of 15
STEVENSON B ROWN LTD
Structura! and Fire Engineers
ik^?1
Zone factor 2:
Near fault factor N(T,D):
Return period factor R:
Structural Performance Factor Sp:
Out-of-plane wall response damping:
Diaphragm Response damping:
In-plane-wall rocking response damping:
In-plane-wail shear response damping:
/^Wf'^H'Wn
0.18
1.0
1.0
1.0
5%
15%
15%
15%
li^iton^ ' .' •
N2S 1170.5
NZS 1170.5
NZS 1170.5
N2SEE Guidelines
NZSEE Guidelines
NZSEE Guidelines
NZSEE Guidelines
NZSEE Guidelines
6.5 RESULTS OF DSAThe building in its current condition has an estimated capacity of <20%NBS/ which
corresponds to a Grade E building (as defined in Section 7 below). This means that the
existing building is earthquake prone and that strengthening work is required to meet the
requirements of the N2 Building Act 2004 and the GDC Earthquake prone Building Policy.
The roof and 1st floor diaphragm connections are not capable of restraining the face loaded
masonry walls during an earthquake. This leaves the exterior walls of the building with little
or no support at roof level and at 1st floor level; effectively, they will behave as unsupported
cantilevers, which are free to rock outwards away from the building during a shake. Analysis
of this mechanism has shown that the walls rocking in this manner will have less than
20%NBS capacity. The exact level is difficult to quantify because of unknown variables such
as the soil conditions and the 'horizontal-spanning' capacity of the walls (which is the subject
of current research). So, to ensure the building behaves as a unit during shaking the
connections between the diaphragms and the walls need to be improved. This along with
other improvements are described in section 6.6.
The analysis results are summarised in Table 3 below:
Table 3: DSA Results Summary
,„,
1
2
3
4
5
;^i^ih?iri^hw'di
Perimeter wails without
being tied into the
floor/roof diaphragms.
Roof Diaphragms.
1st Floor Diaphragm.
Parapets of Gridlines 1 & A
(out-of-plane response).
Upper level walls on
Gridlines 1 & A (out-of-plane
response).
w^
<20%NBS3'5
100%NBS2
100%NBS2
55%NBS1
90%NBS1
i^uU^-;'^^l'!i'«|;i)frcw^ysifrrGii^i!!ii^?)
^J/?1^! •
Tie the perimeter of the floor/roof
diaphragms into the URM walls.
No additional work required.
No additional work required.
Brace top of parapets back to roof
structure.
No additional work required.
Seismic Assessment-128 Main St, Gore Revision A Page 10 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
'^m
6
7
8
9
10
11
12
13
14
15
f^TH^e^s?l*!^i!li:
Lower level walls on
Gridlines 1 & A (out-of-plane
response).
The section of Gridline A
waH adjacent the stair, (out-
of-plane response).
Parapets of Gridlines 2 &C
(out-of-plane response).
Upper level walls on
Gridlines 2 & C (out-of-plane
response).
Lower level walls on
Gridlines 2 & C (out-of-plane
response).
Free standing, west
boundary wall (out-of-plane
response).
Gridline B wall (in-plane
response).
Gridline C wall (in-plane
response).
Gridline 2 wall (m-plane
response)
Ornament on the parapet
above the SE corner
entrance.
»^)
100%NBS1
30%NBS1
35%NBS1
100% NBS1
100%NBS1
45%NBS
32% NBS1
40%NBS1
37%NBS1
<33%NBS5
-.\,^M^^Ihl^iH^^^K^i[^nrito,;' •••^^m?^ -:Y-^ '':^-: :\
No additional work required.
Install a wind-beam' to restrain the
wall at 1st floor level.
Brace top of parapets back to roof
structure.
No additional work required.
No additional work required.
Buttresses required to increase the
walls rocking capacity.
Note 3.
Install a structural steel earthquake
frame between the ground and upper
floor level. Refer to Figure 4.
Install a structural steel earthquake
frame around the shop-front window.
Refer to Figure 5,
Install a structural steel earthquake
frame around one of the shop-front
windows. Refer to Figure 6.
Core drill down through the top of the
ornament into the parapet and grout
in a stainless steel rod to hold the
ornament in place.
Notes:
1. Assumes the work described in 2 and 3 below is completed,
2. Repair damaged areas of the 1st floor diaphragm.
3. Repair very soft mortar joints and re-point affected areas of the exterior brickwork, as a minimum level
of maintenance. Refer to section 5.3.
4. Target level of strength to be determined by building owner.
5. Level of strength estimated only.
6.6 IMPROVEMENT OPTIONS FOR BUILDINGAfter the minimum level of maintenance work is carried out, as described in section 5.3, the
overall capacity of the building can be increased to 35%NBS (which is above the earthquake-
prone threshold) with improvements outlined in Table 4 below.
Seismic Assessment-128 Main St, Gore Revision A Page 11 of 15
STEVENSON B ROWN LTD
Structural and Fire Engineers
Table 4: Improvements required to achieve 35%NBS
lt)i:s!jui
1
2
3
4
5
6
tljij^)({^^ii}iei)!iiF:ii^^i[hi(-r°li'to)riid.^ite'?iiH(^lksl!f§ :"-/v^1^ '^••- . ..'
'Stitch' the perimeter of each floor and roof diaphragm into the URM walls with
steel angle brackets (fixed to the joists) and M12 threaded rod anchors fixedinto the brickwork (the condition of the jojsts, where they are pocketed into the
brickwork, are to be checked at this stage because this is a high risk area for
decay).
Repair the areas of the Ifloordiaphragm that have decayed as a result of
water damage (refer to floor plan in Appendix A).
Reinstate the areas of the 1st floor diaphragm that have been lifted for access
into the floor space (refer to floor plan in Appendix A).
Install an earthquake frame to support the Gridline B wall (see Figure 4).
Support the Gridline A wall (at mid-height)/ adjacent the stair, at 1st floor
diaphragm level, with a 'wind-beam'.
Secure the ornament located atop the SE parapet.
Implementing the improvements outlined in Table 4 takes the building out of the earthquake
prone category and no other work is then required to meet the requirements of the NZ
Building Act 2004 or the GDC Earthquake prone Building Policy.
However/35%NBS is still considered earthquake risk and it may be desirable to improve the
building's seismic resistance further. In fact/the NZSEE recommend that if a building is to be
strengthened then a level of at least 67%NBS should be targeted. To get the overall capacity
of the building over 67%NBS the improvements listed in Table 5 are required. Note that the
target design level is to be decided by the building owner and can be greater than this, e.g.
100%NBS.
Table 5: Improvements required to achieve greater than 67%NBS
i^-ii'i!
1
2
3
4
IStE^)'i^V:)rM?J^;if^i'^eil!CQ.iJi^i;5l[(1pU^'^'Iifi;/^^|£^
Stabilise the parapets by bracing them back to the roof structure.
Install an earthquake frame to support the Gridline C wall (see Figure 5).
Install an earthquake frame to support the Gridline 2 wall (see Figure 6).
Buttress (or demolish) the free standing URM west boundary wall.
Note that the repair work mentioned in Tables 4 & 5 are a concept design only. The final
details are to be confirmed during the developed design process, which will be undertaken
when and if the building owner wishes to proceed with improving the building's seismic
resilience.
Seismic Assessment -128 Main St, Gore Revision A Page 12 of 15
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Connect roofdlaphragm to walls
Connect flowdiaphragm to walls
Brace parapets h> roof
Connect roofdjaphrafjffl to walls
Remove existingposfs, shown
dotted Existing concrete encasesteel beam to be confirm
Consh-ucf- new reinforced
concrete foundation for
seismic frame.
Figure 4; Possible improvements including a seismic frame to support the Gridline B wall.
stabilise ornament
Brace parapets to roofx
Veranda shown dotted
Figure 5: Possible improvements including a seismic frame to support the Gridline C wall.
Seismic Assessment -128 Main St, Gore Revision A Page 13 of 15
STEVENSON BROWN LTD
Structural and Fire Engineers
stabilise ornament
-Brace parapets to reof
•Install new steelUB Misinic framtwithin shop-ffontwindow.
is^l:
l3S£-.^
[?==5? ~vsM
•Repair damagedmortar worft
Figure 6: Possible improvements including a seismic frame to support the Gridline 2 wall.
7 SEISMIC GRADES AND RELATIVE RISK
Table 4, taken from the N2SEE Guidelines, provides the basis of a proposed grading system
for existing buildings, as one way of interpreting the %NBS building score. It can be seen that
occupants in Earthquake Prone buildings (less than 34%NBS) are exposed to more than 10
times the risk that they would be in a similar new building. For buildings that are potentially
Earthquake Risk (less than 67%NBS), but not Earthquake Prone, the risk is at least 5 times
greater than that of an equivalent new building. Broad descriptions of the life-safety risk can
be assigned to the building grades as shown in Table 4.
A+
ABcD
E
Table 4: Relative
HS>100
80 to 100
67 to 79
34 to 66
20 to 33
<20
earthquake Risk
www t<n[s ;ra pirora >:
<1
1 to 2 times
2 to 5 times
5 to 10 times
10 to 25 times
more than 25 times
|llM.-T*mi*I?TI1
low risk
low risk
low or medium risk
medium risk
high riskvery high risk
The New Zealand Society for Earthquake Engineering (which provides authoritative advice to
the legislation makers, and should be considered to represent the consensus view of New
Zealand structural engineers) classifies a buildings achieving greater than 67%NBS as "Low
Risk", and having "Acceptable (improvement may be desirable)" building structural
performance.
Seismic Assessment-128 Main St, Gore Revision A Page 14 of 15
STEVENSON BROWN LTD
Structural and Fife Engineers
8 SEISMIC RESTRAINT OF NON-STRUCTURAL ITEMS
During an earthquake, the safety of people can be put at risk due to non-structural items
falling on them. These items should be adequately seismically restrained, where possible, to
the NZS 4219:2009 "The Seismic Performance of Engineering Systems in Buildings .
A detailed assessment of any such elements is outside the scope of this assessment.
9 CONCLUSION
This Detailed Seismic assessment for the building at 128 Main Street, Gore, indicates an
overall score of <20%NBS, which corresponds to a Grade E building, as defined by the N2SEE
building grading scheme. This is means the building is Earthquake Prone (i.e. <34%NBS) as
defined by the New Zealand earthquake prone building legislation.
The repair of damaged mortar joints is a minimum level on maintenance and improvement
required to make this assessment valid.
The building is to be improved to a levei above 33%NBS to meet the requirements of the
earthquake prone building legislation. By carrying out the following work the overall capacity
of the building will be increased to 35%NBS (which is above the earthquake-prone threshold):
• Tie the URM walls into the floor/roof diaphragms;
• Repair the damaged areas of the 1st floor diaphragm.
• Stabilise the ornament above the SE corner entrance;
• Install a seismic frame to support the Gridline B wall (Figure 4);
• Install a 'wind-beam'adjacent the stair, to support the URM wall (on GridlineA) at 1st
floor diaphragm level.
To get the capacity of the building above 67%NBS as recommended by the NZSEE, the
foliowing additional work is required:
• Restrain the parapets by bracing them back to the roof structure;
• Install a steel seismic frame to improve the gridline C wall (Figure 5);
• Install a steel frame to improve the gridline 2 wall (Figure 6);
• Buttress (or demolish) the free-standing URM west boundary wall.
This assessment has not included a detailed analysis of non-structural items that may be
present in the building.
Seismic Assessment -128 Main St, Gore Revision A Page 15 of 15
STEVENSON B ROWN LTD
Structural and Fire Engineers
Appendix A - Existing Building Plans
and Sections
Seismic Assessment -128 Ivlain Street Gore Appendix A
Free standingtriple brick wall Double brick wall
to end of lean-t'o
toiletpmber landing>00mm above
G.F.L.
Window over thebricked up originaldoor opening
//////////y///////////////
Timber partitions
Triple brickwalls to streetfacades.
Cast ironcolumns supportingconcrete encasedsteel beam7 (not
confirmed)
Concrete column
to top of freest-anding brick wall
Ground Floor Structure Plart A^ scale 1:100
•\ rSTEVENSON B ROWN LTD
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373RgltrayStreeLPOBoi5(XH,DunKrn.
Phone 021481195.Emsl petif@ stmduf
26 Main Street, Gore
y ^
Contract No :
\50GGSheet
5Revision A
'/////////////////////.
©--
Upper Floor Structure Plan A4 scale 1:100
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373 Ralliay SlrwtPO Boi SSH. DmMfln.
Ptione 021431135.Emai peE&r@ stnjctures.co^nzstiuctuies.co^nz
26 M^in Street, GoreContract No :
\50GGSheet :
52R.<3vi5ic>n A
Veranda shown dot-ted
South Elevation A^ scale 1;100
-77TTTTTT7T-''rrI •' •'•'•: •:•:•:'; 1:1; l;';';l.lrES:';l;';l;l;l?^^
Infill panelhas not been
heyed into sides
East Elevation A4 scale 1;100
STEVENSON BROWN LTD
Structural and Firp Engineers
373 Flflitray StreetPOBO);S(»4,Oinriin.
P>lone02HBIt95.Emal (Kli-rtg ilnichjfei.co.iy '<
26 Main Street, GoreContract No : | Sheet :
50GG 54R.evi5!on A
Timber sarhing boardsover purlins-
\125x50 raftersst 450 crs-
Triple brick wall
-200x15 timberboard ceiling
Gib ceiling andbattens under
Double brick wall
100x19 T&6 flooringfixed at joists with
2-60x2.5 nails
-300x50 joists at450 crs pocketedinto waits withconcrete.
Gib ceiling andbattens under
10mm T&G ceidng-Concrete encased
steel beam?7 t.b.c. Concrete encasedsteel beam?? overshop front windows
t.b.c.
Timber floor(not inspected)
Veranda
100x19 TSrG flooring
Section A-A A^ scale 1:100
Triple brick wall
Double brick wall
300x50 floor joistsat 450 centres
Veranda
Section B-B A^ scale 1:100
STEVENSON BROWN LTD
Structural and Fire Engineers
373RaBrayShicLPO ftu &(XM. Omsdin.
Pt™e02i4at1S5.Emai pe!ef@ struchj/es.co nz
25 Main Street, Gore
STEVENSON B ROWN LTD
Slructurril .ind Fire Cnsinecrs
Appendix B - Photographs of Existing
Building
View from south.
South end of west wall. Note eroded
mortar joints at top of wall.
--V----Z
Free standing west boundary wall. Parapet on Main St wall. Note damage to
plaster and mortar joints.
Seismic Assessment-128 Main Street, Gore. Appendix B
STEVENSON BROWN LTD
St r uctnr.11 ,in<l Fire Engineers
View along north wall. Main St Wall. Crack between lintel and
brickwork.
West wall elevation
Seismic Assessment-128 Main Street, Gore. Appendix B
STEVENSON 8 ROWN LTD
Slructurdl d n d Fire Engineers
1st floor T&G flooring and nails.
1st floor joists pocketed into wall adjacent Damaged flooring. 1st floor, NE comer.
stair.
Seismic Assessment-128 Main Street, Gore. Appendix B
STEVENSON B ROWN LTD
Strurlurdl ,111 <1 fire Ensincers
Damaged flooring in the toilet area. Damaged floor in the upper floor kitchen
area.
Roof space.
Seismic Assessment-128 Main Street, Gore. Appendix B
STEVENSON B ROWN LTD
Struciurdl dnd Fire Engineers
Ceiling joists and ceiling sarking under.Rafter to ceiling joist connection.
Seismic Assessment-128 Main Street, Gore. Appendix B