ABA Fashions Ltd. Plot #9, Block F, Tongi, Gazipur-1710 ( N, E) 08 MARCH 2014

Transcription

1 ABA Fashions Ltd. Plot #9, Block F, Tongi, Gazipur-1710 ( N, E) 08 MARCH

2 2 Observations

3 3 Highly stressed columns

4 Cursory calculations indicate column at a high working stress. Engineer is to perform detailed calculations and concrete tests to prove column size and (if required): - Control Loading as outlined in page 4 of this report Brick Aggregate Observed 4 Highly Stressed Columns

5 5 Heavy Loading on 4 th Floor

6 Rolled material up to 2m high throughout floor area. N Building Engineer to create controlled loading plans. 6 Heavy Loading on 4 th Floor

7 7 Areas of High Loading

8 8 Areas of high loading throughout building, with some storage from floor to ceiling.

9 9 Consistently heavy loading at toilet blocks (Location Varies) due to additional ceiling slab and service zone between both floor slabs. Rendered Brickwork Perimeter and Internal Walls Number of toilet blocks with additional raised flooring and tile finishes.

10 Number of floor plates in building with addition of multiple screeds and finishes to floor. 85mm build-up over structural floor slab observed on multiple levels 10 Highly Loaded Areas

11 11 Construction Materials vs. Design Strength Requirements

12 Crushed Brick Aggregate appears to have been used in all structural Elements. Building Engineer to check that in-situ strength achieved is sufficient to meet the design requirements for each element type. 12 Materials vs. Design Strength Requirements

13 13 Vertical and Horizontal Extensions

14 14 Vertical Extension

15 Vertical extension built to house canteen. Structure consists of lightweight steel trussed roof with masonry walls. Additional structure built on gridline but uses structure below to transfer wall loads N Steel roof tie-downs appear to be inadequate. 15 Vertical Extension

16 N View A Horizontal extension built on 2 nd Floor to house canteen. Structure consists of lightweight steel trussed roof with masonry walls. View A Steel roof tie-downs appear to be inadequate. 16 Horizontal Extension

17 17 Damage to Columns on Ground Floor

18 Damage observed on columns on the ground floor due to a number of retail unit fit-outs. Appropriate repair required to support columns. 18 Damage to Ground Columns

19 19 Cracking of structure at base of Water Tank

20 N Loading due to water tank has caused some signs of distress to develop in supporting walls and slab. 20 Water Tank

21 21 Triple Height Column Design

22 Fixity assumptions for top and bottom of triple height columns to be assessed by Building Engineer in order to assess Column Slenderness. Columns Adjacent to busy circulation and Loading routes. Building Engineer to assess potential for progressive collapse / requirement for impact protection to columns. 22 Slender Column Check

23 23 Bridging of Movement Joint

24 Movement joint bridging internal partitions. Movement joint bridging the masonry façade on west elevation. 24 Bridging of Movement Joint

25 25 Cracking to Façade Spandrel

26 Cracking observed at a number of locations on the spandrel panels of the building. 26 Cracking to Spandrel Façade

27 27 Cracking at Stair-Landing Interface

28 Cracking observed at underside of stairs landing interface at a number of levels. Building Engineer to assess cause of cracking and ensure these are not of structural significance. 28 Cracking at Stairs Interface

29 29 Priority Actions

30 Problems Observed 1. Highly stressed columns 2. Heavy loading on 4 th floor. 3. Localised areas of high loading. 4. Construction Materials vs. Design Strength Requirements 5. Horizontal and vertical extensions. 6. Damage to ground floor columns. 7. Cracking of Structure at base of water tank 8. Triple Height column. 9. Bridging of movement joint. 10. Cracking to façade spandrel. 11. Cracking to stair-landing interface. 30

31 Item No. Observation Recommended Action Plan Priority 1 Highly stressed columns Reduce building loading including storage to 2.0 kn/m2 on all floors level 2 to roof. Immidiate/Now 2 Highly stressed columns Verify insitu concrete stresses either by cores (100mm diamter) or existing cylinder strength data for all the columns or cores from a minimum of 4 non-critical columns. 6-weeks 3 Highly stressed columns A Detail Engineering Assessment of Factory to be commenced, see attached Scope. 6-weeks 4 Highly stressed columns Produce and actively manage a loading plan for all floor plates within the factory giving consideration to floor capacity and column capacity. 6-weeks 5 Highly stressed columns Detail Engineering Assessment to be completed 6-weeks 6 Highly stressed columns Continue to implement load plan 6-months 31

32 Detail Engineering Assessment This Schedule develops a minimum level of information, Analysis and testing expected as part of a Detail Engineering Assessment. The Building(s) have been visually assessed and it is deemed necessary that a detailed engineering assessment be carried out by a competent Engineering Team employed by the factory Owner. This Request should be read in conjunction with the BUET developed Tripartite Guideline document for Assessment of Structural Integrity of Existing RMG Factory Buildings in Bangladesh (Tripartite Document), the latest version of this document should be referenced. T his document also gives guidance on required competency of Engineering Team. We expect that the following will be carried out: 1. Development of Full Engineering As-Built Drawings showing Structure, loading, elements, dimensions, levels, foundations and framing on Plan, Section and Elevational drawings. 2. The Engineering team are to carry out supporting calculations with a model based design check to assess the safety and serviceability of the building against loading as set out in BNBC-2006, Lower rate provisions can be applied in accordance with the Tripartite Guidelines following international engineering practice, justification for these lower rate provisions must be made. 3. A geotechnical Report describing ground conditions and commenting on foundation systems used/proposed. 4. A report on Engineering tests carried out to justify material strengths and reinforcement content in all key elements studied. 5. Detailed load plans shall be prepared for each level showing current and potential future loading with all key equipment items shown with associated loads. 6. The Engineering team will prepare an assessment report that covers the following: As-Built drawings including Plans at each level calling up and dimensioning all structural components Cross sectional drawings showing structural beams, slabs, floor to floor heights, roof build-ups and Basic design information of the structure Highlight any variation between As-built compared to the designed structure Results of testing for strength and materials Results of geotechnical assessment and testing/investigation Details of loading, inputs and results of computer modelling Commentary on adequacy/inadequacy of elements of the structure Schedule of any required retrofitting required for safety or performance of Structure Any proposals for Retrofitting to follow guidance developed in the Tripartite Document 32

33 Item No. Observation Recommended Action Plan Priority 7 Heavy loading on 4th floor. All Storage loading to be reduced to less than 2kN/m2 until completetion of a Detail Engineering assessment Immidiate/Now 8 Heavy loading on 4th floor. Detailed Engineering to be commenced as per item 1. 6-weeks 9 Heavy loading on 4th floor. Create controlled loading plans for all floors, designating where storage can be placed and can not be placed. 6-weeks 10 Heavy loading on 4th floor. Provide calculations showing the structural adequacy of all columns, taking into account the loading plans and all built structure including additions beyond the original design. 6-weeks 11 Heavy loading on 4th floor. Continue to implement load plan and manage floor loading. 6-months 12 Localised areas of high loading. Reduce Loadings on all floors to 2.0 kn/m2 as per item 1. Immidiate/Now 13 Localised areas of high loading. Detailed Engineering to be commenced as per item 1. 6-weeks 14 Localised areas of high loading. Create controlled loading plans for all floors, designating where storage can be placed and can not be placed. 6-weeks 15 Localised areas of high loading. Provide calculations showing the structural adequacy of all columns, taking into account the loading plans and all built structure including additions beyond the original design. 6-weeks 16 Localised areas of high loading. Continue to implement load plan and manage floor loading. 6-months 33

34 Item No. Observation Recommended Action Plan Priority 17 Construction Materials vs. Design Strength Requirements Detailed Engineering to be completed as per item 1. 6-weeks 18 Construction Materials vs. Design Strength Requirements Verify insitu concrete stresses either by cores or existing cylinder strength data for all the columns or cores from a non-critical column, beam and slab. 6-weeks 19 Horizontal and vertical extensions. Detailed Engineering to be completed as per item 1. 6-weeks 20 Horizontal and vertical extensions. Building engineer to verify and produce calculations that columns and level 10 slab has sufficient capacity to support additional construction. 6-weeks 21 Horizontal and vertical extensions. Building engineer to check, collect information and produce accurate and complete as-built documentation soonest. 6-months 22 Damage to ground floor columns Detailed Engineering to be completed as per item 1. 6-weeks 23 Damage to ground floor columns Qualified Engineer to assess columns and extent of damage assessed. 6-weeks 24 Damage to ground floor columns If damage is not extensive in situ repair may be feasible. If damage is extensive, columns will need to be propped and strengthening options will need to be developed. 6-weeks 25 Damage to ground floor columns Carry out strengthening and repair as required. 6-months 34

35 Item No. Observation Recommended Action Plan Priority 26 Cracking of Structure at base of water tank Detailed Engineering to be completed as per item 1. 6-weeks 27 Cracking of Structure at base of water tank Sections of plaster finish to beams, slabs and walls to be removed to investigate if cracks penetrate the building structure. 6-weeks 28 Cracking of Structure at base of water tank Building engineer to check and provide calculations showing the structural adequacy of supporting columns and slab. 6-weeks 29 Cracking of Structure at base of water tank Building Engineer to carry out design check on beams to confirm that these cracks are non-structural. 6-months 30 Cracking of Structure at base of water tank Carry out strengthening as required. 6-months 31 Triple Height column. Building engineer to check and provide calculations showing the structural adequacy of Triple Height columns, with appropriate checks and design for second order effects if required. 6-weeks 32 Triple Height column. Building Engineer to consider effects of possible vehicle impact to column (progressive collapse / redundancy in structure) and provide adequate impact protection if deemed necessary 6-months 35

36 Item No. Observation Recommended Action Plan Priority 33 Bridging of movement joint Create Flexible seals when repairing cracks at the movement joint. 6-months 34 Bridging of movement joint Ensure new finishes do not bridge the movement joint 6-months 35 Cracking to façade spandrel Investigate external façade cracks to confirm they are not structural. 36 Cracking to façade spandrel Repair as required to avoid possible water ingress and deterioration. 6-months 37 Cracking to stairs landing interface Sections of plaster finish to wall to be removed and extent of crack to be reviewed by Building Engineer. 6-weeks 38 Cracking to stairs landing interface Building Engineer to assess cause of cracking and ensure these are not of structural significance. 36