DCCS500 – Construction for Small Buildings
Assignment No 1 [20% of overall]
This assignment is relevant to the following Learning Outcomes:
LO1 – Identify geotechnical factors and substructures.
LO2 – Compare building types and structures.
Due Date: Week 6 (10/07/2023)
Answer all questions. All questions carry equal marks (10 marks each)
Section A – LO1: Identify geotechnical factors and substructures
1. (a) Site investigations is carried out to provide information on a site’s surface and subsurface conditions, the results of which will determine the design of earthworks and foundations for structures. Explain any three (3) information/issues to check out for when conducting site investigation for a proposed four bedroom residential building in the Mount Wellington suburb, Auckland. (6 marks)
(b) Describe two (2) reasons why it is important to carryout site investigation for the proposed four bedroom residential building in the Mount wellington suburb. (4 marks)
2. (a) There are several foundation types used for small building construction. Identify two (2) types of foundations that can be used for light timber-framed residential buildings. (4 marks).
(b) Explain the conditions under which the two foundations types you have identified in 2(a) can be used. (4 marks)
(c) Identify two (2) types of soils according to Section 3 of NZ 3604 that we do not want under a foundation footing. (2 marks)
3. The NZS 3604: 2011 is the standard that covers timber framed buildings. In your own words explain five (5) types of buildings covered by this standard (10 marks).
4. (a) The primary functional requirement of a foundation is to ensure strength and stability. Therefore, foundations should be designed so that any settlement is both limited and uniform under the whole of the building. Explain three (3) factors you would take into consideration when designing a foundation. (6 marks).
(b) Describe Scala penetrometer test, and what it is used to measure. (2 marks)
(c) Describes what needs to be done if some structural elements of a building is not covered by NZS 3604. (2 marks)
5. (a) Explain four (4) things that may cause settlement of foundations in buildings. (8 marks)
(b) Identify the minimum soil bearing capacity covered by NZS 3604? (2 mark)
6. (a) Using your free hand, sketch and label a typical section of an ordinary timber pile foundation designed for vertical loads only. The diagram should be according to NZS 3604 requirements. Use the following design details to guide your sketch: (10 marks)
• Depth of pile below CGL is 450 mm (Auckland clay – 450mm below CGL)
• Concrete footing pad size – 200mm (100mm of timber pile to be embedded into concrete footing)
• Pile height 450mm to underside of bearer
• DPC between pile and bearer
• Timber pile size is 125mm x 125mm square
• Timber pile treatment is H5
7. (a) Section 6 of the NZS 3604 provides design requirement for foundation and subfloor framing. Use the information provided in the NZS 3604 to answer the following questions:
(I) Identify the minimum height requirement that a timber pile can have above ground level? (2 mark)
(II) Identify the minimum cross section for a round timber pile? (2 mark) (III) Identify the minimum cross section for a square sawn timber pile? (2 mark)
(b) Explain briefly the following timber piles:
(i) Braced timber pile (2 mark).
(ii) Driven timber piles (2 mark).
Section B – LO2: Compare building types and structure
8. Buildings can be classified according to the materials used for their construction. One type of classification is the timber framed buildings commonly used for residential buildings in New Zealand. Explain five (5) distinguishing characteristics of light weight timber buildings. (10 marks)
9. A three bedroom house of about 130m2 is to be constructed in Otahuhu for a client with a very tight budget and time. You have the option of advising the client to go for either masonry structure or timber framed structure. Compare the two building structures in terms of cost, construction time, availability of material, fire resistance and durability. (10 marks)
10. Using your free hand, sketch and label a light timber framed wall, identify at least ten (10) components/elements of a typical timber framed building. (10 marks)
