report futsal court kemasek

COMPREHENSIVE REPORT ON THE FAILURE OF ROOF TRUSSES SYSTEM AT FUTSAL COURTCADANGAN PEMBANGUNAN PUSAT KOMERSIL RANTAU PETRONAS YANG MENGANDUNGI 1 UNIT KOMPLEKS MEMBELI-BELAH DAN REKREASI DI ATAS SEBAHAGIAN LOT

6490, DI RANTAU PETRONAS, MUKIM KERTEH, DAERAH KEMAMAN, TERENGGANU DARUL IMAN UNTUK TETUAN : METRO KEMASIK SDN. BHD.

__________________________________________________________________________________________________________- 1 -D:\from THUMB-DRIVE(130607)\spmegasb\petronas-tggnu\futsal court\design report kemasek.doc

1.0 INTRODUCTION

An incident occurred during the roof construction for Futsal Court on 26 June 2007 at about 4.00

pm. It was reported that the construction workers heard a loud noise as if resembling tearing of

metal plates and disintegration of bolts. It was also noted that a few interior columns especially

facing Main Curve Corridor deflected significantly in outward position especially at column end.

Cracks to column face occurred at the lower region close to the ground/base level. No crushing to

concrete column detected hence cracks occurred in tension face known as tension crack.

At the time of incident, it was recorded that all roof trusses and purlins has been installed while part

of insulation work still in progress. No M & E installation work was carried out (Refer to Figure 1)

FIGURE 1

Orbtech Engineering Corporation Sdn Bhd, (OECSB) contractually as the main contractor, had

suspended the roofing installation work and immediately erected temporary support in the form of

scaffolding assembly upon the directive by Superintending Officer. Hazard tape was installed along

the building perimeter secluding the area from unnecessary personals.




The roof fabricator and installer for the project is S.P. Mega Sdn. Bhd. (SPMSB). On the other hand

Design Pro Consult Sdn Bhd (DPCSB) was appointed by SPMSB for the jointing design. A joint visit

was conducted on 3rd July 2007 at about 3.00 pm followed by a technical meeting chaired by

KLCCPSB. The outcome from the meeting resulted several remedial work proposals, monitoring

requirements and general review of the jointing design.

Upon the meeting, DPCSB has taken an initiative to provide detail calculation as well as reviewing

the overall incident. The purpose of this report is to outline the initial design approach, detailed

design, failure mode and recommendations based on technical aspect and observation. This report

is prepared with full responsibility and without prejudice.

2.0 WORK SCOPE OF DESIGN PRO CONSULT SDN BHD

In terms of contractual arrangement, OECSB appointed SPMSB as the roof fabricator and installer.

The contract require design proposal and endorsement from Professional Engineer appointed by

SPMSB for the jointing adhering to the roof truss design prepared by MECIP (M) Sdn Bhd. (MECIP).

DPCSB was given a set of construction drawing showing the required roof truss numbers,

dimensions, profile, support locations, purlin arrangement and roofing materials.

As such, the workscope for DPCSB mainly is to verify the joint details at main spine - column, truss

- beam and splice connections as proposed in the construction drawings upon finalization of

fabricators shop drawing. DPCSB made a comprehensive comparison between the proposed

connection details and the new connection details (if any) and shall be discussed further in Section

5 of this report.

Technically, the jointing design will show the joint locations, number of bolts required, bolts sizes,

arrangement, grade, embedded/anchored length, connecting plate details (sizes, thickness and

material grade) as well as splice plate details. In principle, this exercise shall not cover structural

beam and column design both under ultimate limit and serviceability. It is assumed that these

structures have been adequately designed and detailed.




3.0 FUTSAL COURT TRUSS DESIGN DATA

From the construction drawings provided, the following data were extracted and used as a basis for

jointing design.

Steel Structures

Main spine members 406.4 mm x 7.9 mm x 77.6 kg/m CHS

Top chord members 140 mm x 5.0 mm x 16.6 kg/m CHS

Internal members for the triangulated form 114 mm x 3.6 mm x 16.6 kg/m CHS

Curved angle approximately 8.5 degree

Steel selfweight 77 kN/m3

Steel Grade 43A/S275

Bolt Grade 8.8

Roofing dead load 0.06 kN/m2

Insulation and purlin 0.06 kN/m2

M & E services 0.25 kN/m2

Live load 0.25 kN/m2

Wind load (uplift) 0.25 kN/m2

These data shall be used in deriving internal forces, determining the splice joint requirement,

connecting plate and bolts.

Concrete Structures

Column size 400 mm x 400 mm

Beam size (receiving end) 450 mm x 1400 mm

Concrete Grade 30 N/mm2 at 28 days

These data shall be used for designing main spine column connection.




4.0 CHANGES MADE TO THE ROOF TRUSS

Generally the truss assembly consists of a single member main spine (or bottom chord), two

parallel members as top chord and a three piece triangulated internal members. There are Four (4)

splice plates and Two (2) end connections between main spine and column. (Refer Figure 2) . Two

(2) stages of design calculation and shop drawing were produced and submitted for approval due to

changes informed by SPMSB.

FIGURE 2

Stage 1

At this stage, the connection design, details and shop drawings were produced based on the

following roof truss data :-

Roof span 40.4 meter

Bottom chord profile straight

Truss members generally adopting RHS assemblage




The design was performed conservatively treating the overall arrangement (in a lattice form) as a

single member. This exercise however shall is null and void as the second stage design supersede.

Stage 2

At this stage several changes were incorporated as listed :-

Roof span 60.4 meter

Bottom chord profile curve at approximately 8.5 degree

Truss members generally adopting CHS assemblage

The design was again performed conservatively treating the overall arrangement (in a triangulated

form) as a single member. It was noted that curved roof structures exhibit horizontal force compared

to straight profile. However, this horizontal force is not significant in the case of compression bolting

connection with the presence of connecting plate that will distribute the force into surface pressure

to the column and localized effect shall be checked. This horizontal force however may be

significant to the structural column as it act as a concentrated load pushing the column outward.

The deflection of receiving columns is beyond the work scope in this exercise.

A design proposal was submitted together with the construction drawing for approval as shown in

Appendix A and Appendix B.




5.0 COMPARISON BETWEEN SHOP DRAWINGS AND CONSTRUCTION DRAWINGS

As mentioned earlier, DPCSB performed a comparison exercise between shop drawings produced

by SPMSB and construction drawings. This exercise acts as a benchmark and safeguards any new

changes pertaining to the details. The summary of this comparison is shown in Table 1.

COMPARISON BETWEEN SHOP DRAWINGS AND CONSTRUCTION DRAWINGSElement Shop Drawings Construction Drawings

Main spine 406.4 x 7.9 x 77.6 kg/m CHS 406 x 6.3 CHSTop chord 140 x 5.0 x 16.6 kg/m CHS 139 x 3.2 CHS

Internal 114 x 3.6 x 9.83 kg/m CHS 114 x 3.2 CHSBolt @ Main spine column 6 Nos M24 grade 8.8 6 Nos M20 grade 8.8Intermediate Bolt column 4 Nos x 2 M24 grade 8.8 5 Nos x 2 M20 grade 8.8

Top Bolt beam 2 Nos x 2 M24 grade 8.8 -Plate Splice 1 * 12 mm thk (500 x 600) Details not indicatedPlate Splice 2 * 12 mm thk (280 x 280) 6 mm thk (150 x 150)

Table 1 : Comparison Between Shop Drawings and Construction Drawings

Note *

i) Splice 1 at main spine

ii) Splice 2 at top chord

The reason behind these differences can be summarized based on the following :-

Availability of materials different suppliers may stock slightly different

specifications of structural steel.

Design requirements as per DPCSB calculation

Detailing a classical case for Plate - Splice 2 where a 150 x 150 mm splice plate

will not hold a 139 mm CHS in place as no space available to secure the bolts.

It is clearly observed that DPCSB proposal in the shop drawings exhibit a safer approach in all

technical aspects. As for the intermediate bolts, although 4 Nos of bolts being used (compared to 5

bolts) but it was compensated with larger bolt diameter and additional 2 top bolts. In addition, these

changes are necessary due to the assembly of roof trusses at the receiving end.




6.0 MODE OF FAILURE

The study pertaining to the mode of failure may help in understanding the possible failure

mechanism and able to provide solutions upon identifying the main cause. Damaged to structural

components observed at site is shown in Table 2 :-

DAMAGED TO STRUCTURAL COMPONENTSStructural component Damage observed

1. Roof truss members - general No buckling observed2. Main spine splice plate connection Tearing of splice plate and disintegration of

bolts connections in tension manner and pryingaction (Refer Figure 3)

3 Main spine to column connections Slight distortion of connecting plate,disintegration of bolts connection (largereduction in bond strength between concreteand bolt), bolts moving inward indicatingtension failure, no prying failure observed.

4. Receiving columns top Deflected outward indicating presence ofsignificant lateral force parallel to the bendingplane.

5. Column general Deflection mode exhibit an almost doublecurvature shape with point of contraflexure atcolumn (Refer Figure 4)

6. Column bottom Deflected inward with significant sign of distress(structural cracks) in tension manner. Cracksmay still in active mode (Refer Figure 5)

Table 2 : Damaged to Structural Components

Based on this observation, THREE (3) failure modes can be concluded :-

Connection failure with tearing of splice plates and resulting the top column to

deflect outward

Connection failure at main spine column connection due to internal force resulting

the column to deflect outward

Excessive deflection of column due to external force (lateral) resulting the failure in

main spine column connection




FIGURE 3

FIGURE 4




FIGURE 5

The possible load path :-

Load path analysis will indicate the load movement/transfer in a full structure. This may also indicate

the occurrence of either local or global failure due to internal or external factor.

Roofing Truss (design to identify adequate member sizes) Connection (design to satisfy

bolting requirement based on internal forces) Support reaction (design for end connection bolt,

connecting plate, column face concrete compressive stress based on lateral force and shear for

pinned connection) Column (check under serviceability requirement to provide adequate

stiffness)

Case 1 : Splice Plate Failure

Splice plate failure occur due to the dislocation/yielding of bolts in tension manner, shearing and

prying action (if any). Splice in compression is very unlikely to fail except for shear failure. This type

of failure is considered localized (may occur at only one location). Where splice failure occurred :-




connected members will give way

adjacent members will experience additional forces

effective length of associated members increase

reversible of member internal forces (compression to tension vice versa)

reversible of support reactions (compression to tension)

and the whole truss may collapsed progressively downward and column will pulled

inward.

It is very unlikely for a splice plate at failure to transfer internal forces to the support as the load path

is no longer exist. As observed, the critical columns deflect outward due to a significant lateral force.

In this case splice failure shall not be the principle cause initiating the overall failure. The detail

design of splice connection is discussed in section 7 of this report.

Case 2 : Main Spine Column Connection Failure

The lateral force exerted to the column face is in the form of compressive stress via the presence of

connecting plate. In this case, bolts shall be designed to resist shear and limit in compressive stress

at column face must be checked. This is analogous to steel column concrete base connection

where the presence of steel base plate distribute column axial force to compressive stress of

column. Bolts in compression region is not critical compared to the tension face.

If main spine column connection fail in compression manner :-

the column surface will show sign of distress in the form of concrete crushing

bolts that are initially embedded in the column will be highly compressed and shall

punch deeper into the column due to end bearing failure (for 24 mm diameter bolt, a

minimum force of 13 kN/bolt is sufficient to cause this penetration, taking full

concrete compression strength of 30 N/mm2)

As observed at site, the bolts are being pulled outward (inward of Futsal Court) from its original

position in tension manner instead of compression. This type of failure is also localized and shall not




force the column to deflect outward as the load path is disconnected. This type of failure shall

results in catastrophic failure to the whole truss system. The detailed structural calculations for bolts

in compression region is discussed in Section 7 of this report.

Case 3 : Excessive Deflection of Column due to External Lateral Force

A curved truss profile shall exert lateral force and the magnitude is greatly influence by the curve

angle. Analogous to any foundation system of a building, the receiving column act as a

support/foundation to the truss system. Obviously, failure to a support will immediately propagate to

associated structures/components supported by the system. In other words column failure is not

necessarily localized. This statement also agrees with the load path considered.

Deflection check falls under the serviceability requirement where excessive deflection must be

avoided. As observed at site, the top column deflects outward and must be parallel with the external

force exerted to it. If the column stiffness is insufficient, excessive deflection may occur and

moment induced by this lateral force is greatly magnified especially at base/bottom due to lengthy

lever arm coupled with slenderness effect. The presence of structural cracks at the bottom part

confirmed this argument.

The bolts at main spine column connection found to be dislocated outward. This is likely due to

the reversible effect where bolts initially designed in compression region experiencing tension force.

Tension and compression connection differ by significant margin. In tension region :-

the integrity of the connection is greatly depending on the bond stress between the

bolt and concrete interface. Maximum bond stress value of 5.0 N/mm2 and 250 mm

embedded length can only take approximately 94 kN tension force per bolt.

end bearing contribution is not available

no contribution from the presence of connecting plate. Dispersion of tension force is

not form of pressure (as in compression region) but rather distributed almost

directly to every bolts.




If the tension force/bolt or bolt is group is not handle properly than the reversible effect at main spine

column connection as well as splice connection is significant enough to cause the whole system

to disintegrate.

7.0 DETAILED DESIGN CONFORMING TO SUBMITTED CALCULATIONS

As mentioned earlier, the original design proposal adopted a conservative approach. As instructed, a

re-check was performed as to satisfy all the technical issues. A commonly known engineering

design software, STAAD III shall be used as a tool to model the roof truss extracting all internal

forces and support reactions. Manual design was performed in accordance to BS 5950. Truss

model and associated results are shown in Appendix C




Part of Structure : Truss T1 Futsal CourtSubject : Main Spine to Column Connection - End Plate Connection (PL-1)

Design by : MahadhirChecked by : Ir. AlwiDate : 29 July 2007Sheet 1/2

References Calculation Result/Output

Clause 4.13.1

Clause4.13.2.2

Analysis Results due to Factored Load from STAAD III ouput inAppendix CCompressive Force, Fx = 990 kNShear Force, Fy = 182 kN

End Plate Connection DesignProposed Components : Using a 600 x 500 x 20mm thk. M.S. plate (PL-1) 6 Nos. M24 grade 8.8 bolts with 28mm dia. holes

End Plate DesignLimit of compressive stress or bearing strength at column face = 0.4fcu= 0.4 x 30N/mm2 = 12 N/mm2

Area of end plate required = Fx/0.4fcu= 990 x 103 / 12= 82500 mm2

Area provided for end plate= 500 x 600= 300000mm2 > 82500mm2 .o.k.

Thickness Determination for End PlateTmin = ((2.5w/pyp)(a

2-0.3b2))1/2

Where :w = actual bearing stress of plate

= 990 x 103 / 300000 = 3.3 N/mm2

Pyp = design strength of plate = 265 N/mm2

a = greater projection of end plate = 96.8mmb = lesser projection of end plate = 46.8mm

Therefore Tmin = 17.46mmThickness provided = 20mm > 17.46mm ..o.k.

Plate size is adequate

Provided thickness ofplate is adequate




Part of Structure : Truss T1 Futsal CourtSubject : Main Spine to Column Connection - End Plate Connection (PL-1)



Clause 6.3.2Table 32

Clause 6.3.3.2Table 32

Clause 6.6.2


Clause 4.2.3

Table 6


Check Bolt in ShearUsing 6 Nos. M24 of Grade 8.8Shear capacity in single shear, Ps = 132 kNTotal shear capacity of bolts= 6 x 132 kN = 792 kN > Fy = 182 kN .. o.k.

Bolt in BearingBolt Bearing Capacity, Pbb = dtpbb

= (24 x 20 x 970) / 103

= 465kN > Fy/6 = 30.3kN ..o.k.

WeldUsing 6mm fillet welds, E43 electrodesEffective length of weld = D = x 406.4 = 1276mmElectrode strength (BS639), pw = 215 N/mm

2

throat size = 0.7 x 6 = 4.2mmStrength of weld/mm = (4.2 x 215) / 103 = 0.903 kN/mmWeld Capacity = 0.903 x 1276 = 1152 kN > Fy= 182kN

Plate in ShearShear per section = 182 kN /2 = 91 kNPv = 0.6pyAvAv = 0.9 [(500 x 20) (3 x 28 x 20)] = 7488mm

2

Pv = 0.6 x 265 x 7488 / 103 = 1190 kN

Since Pv > 91 kN .. o.k.

Plate in BearingPbs = dtpbs = (24 x 20 x 460) / 10

3

= 221 kN > Fy/6 = 30.3 kN o.k.

NOTE:Checking in design for Middle Connection (PL-2) is not performedsince having very minimal forces. Please refer to STAAD output inAppendix C Support reactions for joint 308, 310, 312 and 314.However, this connection detail could consider as enhancement toend truss support.

Bolts are adequate inshear

Bolts are adequate inbearing

1276mm length of 6mmfillet weld is adequate

Plate is adequate in shear

Plate is adequate inbearing




Part of Structure : Truss T1 Futsal CourtSubject : Top Chords to Column Connection Top Plate Connection (PL-3)



Clause 4.13.1

Clause4.13.2.2

Analysis Results due to Factored Load from STAAD III ouput inAppendix CCompressive Force, Fy = 32 kNShear Force, Fx = 211 kN

Top Plate Connection Design (PL-3)Proposed Components : Using a 280 x 280 x 20mm thk. M.S. plate (PL-3) 2 Nos. M24 grade 8.8 bolts with 28mm dia. holes

Top Plate DesignLimit of compressive stress or bearing strength at top face of column= 0.4fcu = 0.4 x 30N/mm

2 = 12 N/mm2

Area of top plate required = Fy/0.4fcu= 32 x 103 / 12= 2667 mm2

Area provided for top plate= 280 x 280= 78400mm2 > 2667mm2 .o.k.

Thickness Determination for Top PlateTmin = ((2.5w/pyp)(a

2-0.3b2))1/2

Where :w = actual bearing stress of plate

= 32 x 103 / 78400 = 0.41 N/mm2

Pyp = design strength of plate = 265 N/mm2

a = greater projection of end plate = 70mmb = lesser projection of end plate = 70mm

Therefore Tmin = 3.6mmThickness provided = 20mm > 3.6mm ..o.k.

Plate size is adequate

Provided thickness ofplate is adequate




Part of Structure : Truss T1 Futsal CourtSubject : Top Chords to Column Connection - Top Plate Connection (PL-3)





Clause 6.6.2


Clause 4.2.3

Table 6


Check Bolt in ShearUsing 2 Nos. M24 of Grade 8.8Shear capacity in single shear, Ps = 132 kNTotal shear capacity of bolts= 2 x 132 kN = 264 kN > Fx = 211 kN .. o.k.


= (24 x 20 x 970) / 103

= 465kN > Fx/2 = 105.5kN ..o.k.

WeldUsing 6mm fillet welds, E43 electrodesEffective length of weld = D = x 140 = 440mmElectrode strength (BS639), pw = 215 N/mm

2

throat size = 0.7 x 6 = 4.2mmStrength of weld/mm = (4.2 x 215) / 103 = 0.903 kN/mmWeld Capacity = 0.903 x 440 = 397 kN > Fx= 211kN

Plate in ShearShear per section = 211 kN /2 = 105.5 kNPv = 0.6pyAvAv = 0.9 [(280 x 20) (1 x 28 x 20)] = 4536mm

2

Pv = 0.6 x 265 x 4536 / 103 = 721 kN

Since Pv > 105.5 kN .. o.k.


3

= 221 kN > Fx/2 = 105.5 kN o.k.









Part of Structure : Truss T1 Futsal CourtSubject : Splice Joint Connection Design Main Spine (PL-1a)

Design by : MahadhirChecked by : Ir. AlwiDate : 19 Feb 2007Sheet 1/2




Clause 4.2.3

Table 6

Analysis Results due to Factored Load from STAAD III ouput inAppendix C

Location ofSplice

Fx Fy(Shear)

Mz(Moment)

12.2m fromsupport

1004kN(Compression)

49kN 71kNm

24.4 fromsupport

1003kN(Compression)

44kN 96kNm

Note : Connection design will be based on maximum value in betweenboth location of splices

Splice Joint Connection DesignProposed Components : Using a 600 x 500 x 12mm thk. M.S. plate 6 Nos. M24 grade 8.8 bolts with 28mm dia. holes

Check Bolt in Shear (Fy = 49 kN)Shear capacity in single shear, Ps = 132 kNTotal shear capacity of bolts= 6 x 132 kN = 792 kN > Fy = 49 kN .. o.k.


= (24 x 12 x 970) / 103

= 279kN > Fy/6 = 8.2kN .o.k.

Plate in ShearShear per section = 49kN /2 = 24.5kNPv = 0.6pyAvAv = 0.9 [(500 x 12) (3 x 28 x 12)] = 4492mm

2

Pv = 0.6 x 275 x 4492 / 103 = 741 kN

Since Pv > 24.5 kN --- o.k.







Part of Structure : Truss T1 Futsal CourtSubject : Splice Joint Connection Design Main Spine (PL-1a)




Clause 6.6.2


Clause 6.3.6.3


3

= 132 kN > Fy/6 = 8.2 kN o.k.

WeldUsing 6mm fillet welds, E43 electrodesEffective length of weld = D = x 406.4 = 1276mmElectrode strength (BS639), pw = 215 N/mm

2


Checking Bolts in Moment (Mz = 96kNm)Member force induced by the Moment= Moment / lever arm= 96 / 0.3985 = 241kN

Since 2 bolts (ignoring the centre bolt) at one side considered to resisttensile force induced by the Moment, therefore tensile force per bolt= 241 / 2 = 120.5 kN

Tensile capacity for 1 No. M24 bolt of grade 8.8= 159 kN > 120.5kN o.k.

Combined Shear and TensionWhen bolts are subject to both shear and tension, the followingcondition should be satisfied :

Fs/Ps + Ft/Pt < 1.4(8.2/132) +(120.5/159) = 0.82 < 1.4 o.k.



Bolts are adequate toresist tensile forceinduced by moment

Additional condition issatisfied




Part of Structure : Truss T1 Futsal CourtSubject : Splice Joint Connection Design Top Chords (PL-2a)





Clause 4.2.3

Table 6

Analysis Results due to Factored Load from STAAD III ouput inAppendix C

Location ofSplice

Fx Fy(Shear)

Mz(Moment)

12.2m fromsupport

213kN(Compression)

4kN 3kNm

24.4 fromsupport

213kN(Compression)

4kN 3kNm

Note : Connection design will be based on maximum value in betweenboth location of splices

Splice Joint Connection DesignProposed Components : Using a 280 x 280 x 12mm thk. M.S. plate 4 Nos. M24 grade 8.8 bolts with 28mm dia. holes

Check Bolt in Shear (Fy = 4 kN)Shear capacity in single shear, Ps = 132 kNTotal shear capacity of bolts= 4 x 132 kN = 528 kN > Fy = 4 kN .. o.k.


= (24 x 12 x 970) / 103

= 279kN > Fy/4 = 1kN .o.k.

Plate in ShearShear per section = 4kN /2 = 2kNPv = 0.6pyAvAv = 0.9 [(280 x 12) (2 x 28 x 12)] = 2419mm

2

Pv = 0.6 x 275 x 2419 / 103 = 399 kN

Since Pv > 2 kN --- o.k.







Part of Structure : Truss T1 Futsal CourtSubject : Splice Joint Connection Design Top Chords (PL-2a)




Clause 6.6.2


Clause 6.3.6.3


3

= 221 kN > Fy/4 = 1 kN o.k.

WeldUsing 6mm fillet welds, E43 electrodesEffective length of weld = D = x 140 = 440mmElectrode strength (BS639), pw = 215 N/mm

2


Checking Bolts in Moment (Mz = 3kNm)Member force induced by the Moment= Moment / lever arm= 3 / 0.135 = 23kN

Since 2 bolts at one side considered to resist tensile force induced bythe Moment, therefore tensile force per bolt= 23 / 2 = 11.5 kN

Tensile capacity for 1 No. M24 bolt of grade 8.8= 159 kN > 11.5kN o.k.

Combined Shear and TensionWhen bolts are subject to both shear and tension, the followingcondition should be satisfied :

Fs/Ps + Ft/Pt < 1.4(1/132) +(11.5/159) = 0.08 < 1.4 o.k.



Bolts are adequate toresist tensile forceinduced by moment

Additional condition issatisfied




8.0 EXISTING COLUMN STIFFNESS TO RESIST LATERAL FORCE AND INTERNAL MOMENT

Design Pro Sdn Bhd also would like to address some related technical issues pertaining to this

incident upon studying the failure mode. It is intended to secure all aspects in engineering exercise

as well as to eliminate any potential causes affecting the structural integrity of the overall roof truss

assembly. The following suggestion is based on overall modeling of steel roof truss, r.c. columns

and r.c. beams adhering to the construction arrangement.

In addition to the earlier design data, the following r.c. components were incorporated in the final

model. STAAD III is used in this analytical exercise. Datum shall refer to the ground floor level taken

as 0.00 meter. Finished level for beams shall refer to the top part.

Column size : 400 mm x 400 mm

Roof Beam (perimeter) : 400 mm x 1200 mm (FL + 11.0 m)

Intermediate beam (facing Main Curve Corridor) : 150 mm x 600 mm (FL + 7.0 m)

Intermediate beam 1 (facing Kampong Area) : 150 mm x 600 mm (FL + 3.5 m)

Intermediate beam 2 (facing Kampong Area) : 150 mm x 600 mm (FL + 7.0 m)

Intermediate beam (facing Changing Room) : 150 mm x 600 mm (FL + 7.0 m)

Intermediate beam (facing Sport Complex) : 150 mm x 600 mm (FL + 7.0 m)

Concrete grade : 30 N/mm2

A) Column stiffness

Design Pro Sdn Bhd would like to note the column stiffness in resisting lateral forces hence reducing

the deflection under serviceability requirement. The most critical columns located along the gridline

facing Main Curve Corridor due to the fact that only one intermediate beam (may serve as

restraining member and reducing the effective length of column) at 7.0 meter elevation was

constructed during the incident. The columns facing Kampong Area may received the same forces

but having 2 levels of intermediate beams. The following calculations concentrate on the columns

facing Main Curve Corridor.




A1) Consideration of short or slender column

The column (if considered as braced structures) is slender as the values of lex/h and ley/b are 16

(limit for short column is 15). This value reflect the column segment from ground to intermediate

beam only. Slender column shall induced inherent additional moment.

The second segment from intermediate beam to roof beam is short.

Calculation : (7000 600 / [400]) = 16

A2) Deflection under serviceability requirement

As mentioned earlier, the deflection of column was outward (ie towards the Main Curve Corridor). A

logical explanation would suggest a strong lateral force produced by the curved truss profile

especially by the main spine end support. If this condition can be accepted then the deflection of

columns may be significant enough to disintegrate the whole truss assembly. It is also noted only

construction load were applied to the column at time of incident . Design Pro Sdn Bhd only applied

the minimum unfactored load that may be experienced by the column. The minimum unfactored

construction load considered in this analysis is shown in Table 3.

UNFACTORED CONSTRUCTION LOAD FOR DEFLECTION CHECKLoad type Force (kN) per column

1. 100 % selfweight of roof truss 168.02. 50% dead load purlin, roofing, insulation, M&E 152.03. 100 % unfactored load 647.0

Table 3 : Unfactored Construction Load Considered for Deflection Check

From STAAD-III output, the following results were obtained and tabulated in Table 4.

DEFLECTION CHECK (COLUMN FACING MAIN CURVE CORRIDOR)Load Type Deflection max (mm)

1. 100 % selfweight 872. 100 % selfweight + 50 % dead load 1673. 100 % unfactored load 337

Table 4 : Deflection Results




The theoretical deflection value however may be may be relatively high and not as observed at site

due to the followings :-

Concrete Youngs Modulus of Elasticity (Ec) is taken as 28 kN/mm2. This value may

increase to 32 kN/mm2 (upper boundary value)

Column can be consider as composite material with the presence of steel

reinforcement. The Youngs Modulus of Elasticity for composite material (Ecom) may

give slightly higher value compare to Ec (not considered in this analysis)

Presence of ground beam may increase the global stiffness hence reducing the

deflection (not considered in this analysis)

Presence of roof truss may provide additional restraint in the plane being considered

(not considered in this analysis)

Presence of purlins that may act as diaphragm to roof truss may increase the overall

truss stiffness

The presence of brickwall may contribute to the overall stiffness but may not be

significant in the plane of bending being considered.

The deflection of columns facing Main Curve Corridor however is still significant and can be noted

physically (in the range of 100-200 mm). However, extra precautions must be taken due to the fact

that not ALL load being imposed to the column at time of incident. A larger deflection may be

possible if all loads are mobilized in full manner.

Cracks at columns located close to base may not due to deflection or high compressive stress (no

crushing of concrete observed) but most likely due high bending stress. A rigorous check using

STAAD III shows that a maximum moment of 1872 kNm at support under construction load. If

inadequate reinforcement is provided in this tension region, yielding of reinforcement may occur and

continue with propagation of tension cracks. At full unfactored load, the theoretical bending moment

found to be 3973 kNm.

The structural modeling and associated STAAD-III output is shown in Appendix D




9.0 CONCLUSION

Upon comprehensive analytical study, DPCSB conclude the overall issues as follows :

1) Connection proposal based on structural calculation and detailing are in accordance to the

Code of Practice and engineering practice. Adequate provision under both serviceability and

ultimate limit state and as shall not cause any failure.

2) Integrity of proposed connection at main spine column and splices remain intact under

internal forces and inherent behavior of the bolts. This integrity however discounted any

external factor beyond encountered beyond DPCSB work scope

3) Observation, failure mode & load path study and post structural analysis study showed that

the reversible forces experienced by bolts at main spine column connection due to

excessive deflection (in outward position) remain as the main reason that disintegrate the

whole truss system. Damage to main spine column connection and splice joint believed to

be the secondary effect. It is strongly suggested that any rectification proposal to be based

on the main reason.

4) Cross check between proposed and construction details showed a conservative approach

in terms of bolts size, splice plate thickness and splice plate size.

5) It is also suggested to check the adequacy of 400 mm x 400 mm column having adequate

stiffness at 100% unfactored load application. DPCSB rigorous check showed that a

significant amount of deflection had already taken place even at partial load effect.

6) It also suggested to check the provision of reinforcement in the column due to presence of

structural cracks (close to ground level).

report futsal court kemasek

Documents

Beringin Natural Court

Pengenalan futsal

futsal bm sarah hafiz

FUTSAL Pindaan Undang_Undang

Kertas Kerja Futsal

Nota Futsal part 2

1 Buku Panduan E-Court Pengadilan Negeri Temanggung ...pn-temanggung.go.id/tmg/images/ECOURT/E-Book E-Court...Buku Panduan E-Court Pengadilan Negeri Temanggung Kelas IB 4 SECARA ELEKTRONIK

PERATURAN UMUM FUTSAL

lamanpendidikankhaslms.yolasite.comlamanpendidikankhaslms.yolasite.com/resources/Pemilihan Futsal B… · pemilihaivpemain futsal dan bola jaring nama aktiviti tempat aktiviti peringkat

Kertas Kerja Futsal DAM

Sistem Informasi Pemesanan Lapangan Futsal …Sistem Informasi Pemesanan Lapangan Futsal Berbasis Web Dengan Menggunakan Sms Gateway Di United Futsal Kudus Laporan ini disusun guna

SYARAT-SYARAT DAN PERATURAN KEJOHANAN FUTSAL … · SYARAT-SYARAT DAN PERATURAN KEJOHANAN FUTSAL ... dan Undang-Undang Permainan Futsal Persekutuan Bola Sepak ... (Lelaki & Wanita)

Sejarah & Undang - undang dalam Futsal

Buku Log FUTSAL

Sejarah Permainan Futsal

LAPORAN SKRIPSI SISTEM INFORMASI LIGA FUTSAL …eprints.umk.ac.id/5355/1/HALAMAN_JUDUL.pdf · pada masyarakat umum tentang liga futsal, dan mempermudah pendataan pada United Futsal

Kertas Kerja Futsal Pendidikan Khas 2012

Presentation FUTSAL

92107795 Futsal Buku Log

Buku panduan Futsal

Fiesta Futsal Dtac

undang FUTSAL

Assignment Futsal - Group

INDUSTRIAL COURT OF MALAYSIA

THE KL CUP 2017 - dreamvillagefa.com fileFeaturing a flagship FIFA 2 Star 4G astroturf pitch with floodlights as well as a FIFA-spec futsal court ... The Kuala Lumpur Cup will follow

Waj3109 gerko (futsal)

Annual Report of the Supreme Court

court of appeal case

COURT OF APPEAL SUBMISSION

CADANGAN PENGANJURAN KEJOHANAN FUTSAL IPT 2013

Kursus Ulangkaji Jurulatih Futsal sukses

EXISTENCE RECONSTRUCTION OF PROBATE COURT AS …

Kertas Kerja Futsal 2011(Terbuka)

Kejohanan Futsal PUSPANITA Cawangan Sabah 2015

futsal 1m1s