Ass 4 - CPCCBC4011B ed 3 Apply structural principles to commercial low rise constructions PDF

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CPCCBC4011B ed 3 Apply structural principles to commercial low rise constructions...

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CPCCBC4011B: Assessment 4 Apply structural principles to commercial low-rise constructions

ALAN TAKACH TAFE ID No.: 375810077

10 June 2018

Table of Contents LIST OF FIGURES ...............................................................................................................................................3 LIST OF TABLES ................................................................................................................................................ 4 1.

INTRODUCTION .......................................................................................................................................5

2.

BACKGROUND .........................................................................................................................................6

3.

FOOTING SYSTEM ....................................................................................................................................7 3.1 SOIL TYPE/ FOUNDATION TYPICAL OF THE AREA ................................................................................................ 7 3.2 FOOTING SYSTEMS APPROPRIATE TO THE SELECTED BUILDING/ FOUNDATION.......................................................... 8 3.2.1 Stiffened Raft Design Footing ........................................................................................................... 9 3.2.2 Waffle Raft Design Footing ............................................................................................................. 10 3.2.3 Stiffened Raft vs Waffle Raft Footings ............................................................................................ 11 3.2.4 Steel column base detail ................................................................................................................. 11

4.

STRUCTURAL SYSTEM ............................................................................................................................ 14 4.1 STRUCTURAL FRAMEWORK......................................................................................................................... 14 4.1.1 Purlins ............................................................................................................................................. 15 4.1.2 Fly Bracing ....................................................................................................................................... 16 4.1.3 Rafters ............................................................................................................................................. 17 4.1.4 Apex Brace ...................................................................................................................................... 18 4.1.5 Knee Brace ...................................................................................................................................... 19 4.1.6 Cross Bracing .................................................................................................................................. 20 4.1.7 Columns .......................................................................................................................................... 21 4.1.8 Girts ................................................................................................................................................ 22

5.

FLOOR SYSTEM ...................................................................................................................................... 23 5.1 5.2

6.

CONTRACTION JOINTS ............................................................................................................................... 23 FLOOR FINISH .......................................................................................................................................... 24

WALL SYSTEM........................................................................................................................................ 25 6.1 6.2 6.3 6.4

7.

WALL CLADDING...................................................................................................................................... 25 ERECTION OF WALL SYSTEM AND CLADDING ................................................................................................... 27 TYPICAL EXTERNAL WALL SECTION................................................................................................................ 28 WALL BRACING ELEMENTS......................................................................................................................... 29

SERVICES ...............................................................................................................................................30 7.1 7.2 7.3

8.

STORMWATER ......................................................................................................................................... 30 POWER .................................................................................................................................................. 31 ACTIVE AND PASSIVE FIRE PROTECTION ........................................................................................................ 32

ROOF SYSTEM .......................................................................................................................................33 8.1 STRUCTURAL ROOF SYSTEM ........................................................................................................................ 33 8.2 ROOF CLADDING ...................................................................................................................................... 33 8.2.1 Cladding Profile ............................................................................................................................... 33 8.2.2 Base Metal Thickness (BMT) ........................................................................................................... 33 8.2.3 Maximum Support Spacings (mm) .................................................................................................. 34 8.2.4 Roof Cladding Fixing Detail ............................................................................................................. 35 8.3 EAVE GUTTER.......................................................................................................................................... 36 8.4 FLASHINGS .............................................................................................................................................. 37 8.4.1 Corner Flashing ............................................................................................................................... 38 8.4.2 Ridge Flashing ................................................................................................................................. 38 8.4.3 Barge Capping ................................................................................................................................. 39

9. 10.

CONCLUSION ......................................................................................................................................... 40 REFERENCES ...................................................................................................................................... 41

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List of Figures Figure 1 Side Elevation of Shed (Under Construction) .......................................................................................... 6 Figure 2 Front Elevation of Shed (Under Construction)......................................................................................... 6 Figure 3 Front Elevation of Shed ............................................................................................................................ 6 Figure 4 Side Elevation of Shed (Under Construction) .......................................................................................... 8 Figure 5 Stiffened Raft Design ............................................................................................................................... 9 Figure 6 Waffle Raft Design ................................................................................................................................. 10 Figure 7 Hold Down Bolts (prior to placement in concrete) ................................................................................ 11 Figure 8 Chemical Anchors (during installation in concrete) ............................................................................... 12 Figure 9 Typical Steel Column Base Detail ......................................................................................................... 13 Figure 10 Overview of The Project's structural framework .................................................................................. 14 Figure 11 Top hat section detail ........................................................................................................................... 15 Figure 12 Top hat roof batten ............................................................................................................................... 15 Figure 13 Purlin/ Rafter connection detail ............................................................................................................ 15 Figure 14 Annotated photograph showing Fly Bracing Detail ............................................................................. 16 Figure 15 Rafter/ Column connection detail ......................................................................................................... 17 Figure 16 Annotated photograph showing The Project’s Apex Brace ................................................................. 18 Figure 17 Annotated photograph showing The Project’s Knee Brace .................................................................. 19 Figure 18 Cross Bracing installed in walls ........................................................................................................... 20 Figure 19 Wall Girt Connection Detail ................................................................................................................. 22 Figure 20 Longitudinal control joint within The Project ...................................................................................... 23 Figure 21 Exposed Concrete Floor System (Prior to application of Sealer) ......................................................... 24 Figure 22 Wall Sheeting Profile ........................................................................................................................... 25 Figure 23 Side Elevation of building showing wall cladding during installation ................................................. 26 Figure 24 Interior view of wall cladding during installation ................................................................................ 26 Figure 25 Typical External Wall Section ............................................................................................................. 28 Figure 26 Effect of wind on an unbraced and braced portal frame structure ........................................................ 29 Figure 27 Basic Illustration of The Project's Stormwater System ........................................................................ 30 Figure 28 Underground Power Conduits during construction .............................................................................. 31 Figure 29 Electrical Sub-board within The Project .............................................................................................. 31 Figure 30 Schematic of Spandex Roof Cladding .................................................................................................. 33 Figure 31 Span Types on Portal Frame Roof Cladding ........................................................................................ 34 Figure 32 Screw fixing detail ............................................................................................................................... 35 Figure 33 Screw fixing locations .......................................................................................................................... 35 Figure 34 Typical External Wall Section with Eave Gutter Detail ....................................................................... 36 Figure 35 Flashings installed to the Exterior of The Project ................................................................................ 37 Figure 36 Corner Flashing .................................................................................................................................... 38 Figure 37 Ridge Flashing ..................................................................................................................................... 38 Figure 38 Barge Capping ...................................................................................................................................... 39

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List of Tables Table 1 Classification of Sydney Clay Soils (Table D2 AS 2870-2011) ................................................................ 7 Table 2 Maximum Support Spacings (mm) .......................................................................................................... 34

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1. Introduction The purpose of this report is to analyse the design and construction of a wide span, steel portal framed building. It will examine various aspects of the selected building including; its footing system, structural system, floor system, wall system, roof system, and its building services. The building selected as part of this project is an existing portal framed shed in the suburb of Richmond, NSW. Discussions included within this report will be supplemented with the use of photographs taken during/ after construction, as well as hand drawn sketches for further clarification when required. This report is limited in that no physical site inspection took place. Instead, the report relies heavily on photographic evidence taken on-site and provided to me by the owner of the property, Mr Jason Arnold. It should be noted that permission was first obtained from Mr. Arnold prior to incorporating his photographs as part of this report. Unfortunately, construction plans and specification sheets were unavailable at the time of writing this report, and therefore, some assumptions have been made and these have been clearly stated wherever applicable.

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2. Background The building selected as part of this project is a portal framed shed located in the suburb of Richmond, NSW. It consists of a single-story shed with a garage roller door and is used as a storage space for agriculture tools and equipment. This building will often be referred to as “The Project” throughout some sections of this report. The Project occupies a footprint of approximately 450 square metres and spans 15 metres wide by 30 metres in length. It consists of five portal frames, and based on the photographs, it is estimated that the ceiling is approximately 7 metres in height.

Figure 1 Side Elevation of Shed (Under Construction)

Figure 2 Front Elevation of Shed (Under Construction)

Figure 3 Front Elevation of Shed

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3. Footing system 3.1 Soil Type/ Foundation typical of the area To determine the soil type/foundation typical to the Richmond area, a desktop study was undertaken based on published geological data from the Department of Resources and Energy. Specifically, reference was made to the Penrith 1: 100,000 Geological Map (Code 9030). A review of the above-mentioned geological map indicates that the site overlies the Clarendon Formation, which typically comprises Clay, clayey sand, and silt. Reactive soils (containing clay) are common throughout New South Wales and are generally problematic to engineers as climatic variations create a high movement potential in both the horizontal and vertical planes. The geological map identifies the Clarendon Formation as being ‘Fluvial’, which means the site was formed from deposits associated with rivers and streams. As such, the area may contain clay deposits of various thicknesses which in turn would affect the soil classification of The Project site. Table D2 of AS 2870-2011, provides Classification of Sydney clay soils, based on the depth of the clay profile. As shown below, the soil classification within The Project area could range from Class S to H, depending on the depth of clay.

Table 1 Classification of Sydney Clay Soils (Table D2 AS 2870-2011)

Due to the “Fluvial” nature of the site, further soil investigation is required to determine the classification of the soil within The Project. At least one borehole log will need to be undertaken to provide a clear understanding of the soil profile and identify the true classification of the soil. Once the classification of the soil is determined, a suitable footing system can then be designed to suit the geological location and intended use of the building.

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3.2 Footing systems appropriate to the selected building/ foundation There are several footing systems that can be designed to satisfy the performance criteria set out within the National Construction Code and Australian Standards. This ensures the footing system provides adequate support to withstand the dead loads and live loads acting upon the structure. As shown in the image below, The Project site utilises a slab-on-ground footing which is assumed to have been constructed with a stiffened raft design.

Figure 4 Side Elevation of Shed (Under Construction)

The following section will detail two examples of footing systems that can be incorporated within the building’s design. Both Stiffened Raft and Waffle Raft footings may be used on The Project site with advantages and disadvantages arising depending on which footing is selected.

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3.2.1 Stiffened Raft Design Footing A stiffened raft footing designed in accordance to AS 2870-2011 will satisfy the performance criteria required to support the structure. This design incorporates reinforced internal and external edge beams which together form an integral structural grid to support the building. AS 2870-2011 provides various specifications for the footing system depending on the site classification and construction method incorporated within the building’s design. The drawing below provides a typical section detail of a stiffened raft footing applicable to The Project. The depth of the concrete beams and reinforcement dimensions have been excluded pending confirmation of the soil classification.

Figure 5 Stiffened Raft Design

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3.2.2 Waffle Raft Design Footing Another footing system that may be utilised within The Project site is a waffle raft design footing. This design incorporates formed voids or waffle pods set directly on grade to create a grid of concrete beams running throughout the footprint and perimeter of the foundation. The void areas underneath the slab, created by the plastic forms or polystyrene blocks, allow for soil movement within the footing system. The drawing below provides a typical section detail of a waffle raft footing with the depth of the concrete beams and reinforcement requirements excluded pending confirmation of the site classification.

Figure 6 Waffle Raft Design

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3.2.3 Stiffened Raft vs Waffle Raft Footings Although Waffle slabs reduce the overall cost of construction due to less excavation and lower volumes of concrete, there are some disadvantages of waffle slabs that should be taken into consideration when compared to conventional raft designs. The main disadvantage of waffle slabs compared to stiffened raft footings is that they are cast onto polystyrene void formers and strips of concrete. Whereas, in stiffene...