Sung Kwang Sweaters Ltd. (11653) Ibrahim Tower, Plot # 313,314,315, Wireless Gate, Chandona, Gazipur

(+23.99159N, 90.39469E)

19.MAY.2014

Identified Priority 1 Concerns

1st Priority 1 Concern

The Building engineer said that shear

links were provided in the flat slab

column joints in construction, but this is

not shown on the Construction

drawings.

Our calculations for punching shear at

the typical column, found that the

shear stress is satisfactory under

gravity load without shear links

required. However, due to the lack of

lateral stability system, an increase in

stress caused by unbalanced moment

due to lateral load needs to be

considered.

Furthermore, the slab is very thin with

respect to its span: the span to

thickness ratio is 6100/184 = 33, more

than the 30:1 ratio usually used to

control deflections.

1st Priority 1 Concern (Continued)

Thinner flat slab will lead to an

increase in short-term and long-term

deflections and reduce the punching

shear resistance as well.

The thin flat slab without drop panel

and perhaps without shear

reinforcement is not sufficient to resist

the punching shear stresses in a

seismic load case, which will cause the

slab to fail suddenly and the building

will collapse subsequently in the event

of a moderate earthquake.

2nd Priority 1 Concern

The raised floor has been built on the

3rd floor; the total superimposed dead

load is 4.7 kPa. This will increase the

superimposed dead load for the floor

by 3.7 kPa (original 1.0kPa allowance

only) Furthermore, the additional load

from machine will make the live load

heavier than the design loading: 5.0

kPa.

250mm

Raised floor with

200mm sand filling

and 50mm screed and

tile

The machine is installed on a raised

floor. There is no information of the

weight of machine, but estimated to

have an operating weight of around

700kg per machine

Identified Priority 2 Concerns

Column to be checked

Based on the load

rundown analysis of the

building, it turns out to be

YELLOW status for all

checked columns that

have similar loading

condition and design.

Which requires that all

floor loadings must be

carefully monitored and

provided loading plan must

be strictly maintained.

Identified Priority 3 Concerns

We require that these items be

investigated in a Detail

Engineering Assessment

The overall structural

arrangement does not appear to

have any rational form of lateral

stability system to resist the

wind or earthquake loads. A

lateral load analysis is required

to be carried out.

The design engineer needs to

check the deflection storey drift,

column beam and slab stresses

under lateral wind and seismic

load.

Overall Stability System

We require that these items be

investigated in a Detail

Engineering Assessment

The overall structural

arrangement does not appear to

have any rational form of lateral

stability system to resist the

wind or earthquake loads. A

lateral load analysis is required

to be carried out.

Priority Actions

Problems Observed Summary

ITEM 1: (1st Priority 1) The flat slab may not be sufficient to resist the punching shear force under lateral load. thin flat slab without drop panel and shear ITEM 2: (2nd Priority 1) The raised floor at level 3 exceeds the design loading. ITEM 3: (1st Priority 2) The typical columns have low factor of safety with respect to their loading capacity. ITEM 4: (1st Priority 3) No lateral load resistance system.f

ITEM 5: (2nd Priority 3) There is no waterproofing provided on the existing roof.

Item No. Observation Recommended Action Plan Recommended Timeline

1The flat slab may not be sufficient to resist the punching

shear force under lateral load.Reduce loads on the floor to a maximum of 2.0 kPa Immediate – Now

2The flat slab may not be sufficient to resist the punching

shear force under lateral load.

Carry out the full analysis of the structure to check all element of the

building under lateral load. Check for punching shear with the un-

balanced moment. Lateral loads (wind and seismic) as per BNBC must

be applied.

Carry out intrusive testing of the structure to determine the actual

concrete and rebar strengths

6-weeks

3The flat slab may not be sufficient to resist the punching

shear force under lateral load.

Carry out the strengthening work to increase the punching shear

capacity.

Carry out the strengthening work to provide the lateral load resistance

system.

6-months

4 The raised floor at level 3 exceeds the design loading.Consider suspending activities in this area or installing props beneath

this floor to spread the load over several slabs.Immediate – Now

5 The raised floor at level 3 exceeds the design loading.Building engineer need to review and re-analysis for this area with the

actual loading and actual rebar on site.6-weeks

6 The raised floor at level 3 exceeds the design loading.

If found necessary to do so, carry out the strengthening work to

support the extra loading or break out the raise floor and take out the

sand filling.

6-months

Item No. Observation Recommended Action Plan Recommended Timeline

7The typical columns have low factor of safety with respect

to their loading capacity.

Factory Engineer to review design, loads and columns stresses in area

identified above.

Verify insitu concrete stresses either by 100mm dia. cores or existing

cylinder strength data.

6-weeks

8The typical columns have low factor of safety with respect

to their loading capacity.

Produce and actively manage a loading plan for all floor plates within

the factory giving consideration to floor capacity and column capacity.6-months

9 No lateral load resistance system.Building engineer to check and provide the solution for lateral resisting

requirements of the structure.6-weeks

10 No lateral load resistance system.As per the results of structural analysis, the building needs to be revised

to accord with BNBC building codes with regard to lateral stability.6-months

11 There is no waterproofing provided on the existing roof. Provide a proper waterproof layer on the roof level. 6-months