General & Temporary works

Question 1

610 What RIBA Stage is on site construction?

Answer 1

Stage 5 Manufacturing and Construction

Question 2

611 What is buildability?

Answer 2

The ease of constructing a project. The better buildability a project has the easier it will be to construct. Early contractor involvement can felicitate buildability

Question 3

612 What are the benefits of offsite construction rather than in situ

Answer 3

• Better quality control
• Shorter programme less time to build on site plus potential for cheaper labour and materials
• Less resource on site
• Improved health and safety – accidents are more likely to happen on site
• Sustainability may have a lower carbon footprint through speed, efficiency and reduced waste

Question 4

613 What is the difference between building and civil engineering works?

Answer 4

Buildings cover mostly structures:
* Houses/flat, shops, offices warehouses, schools, hospitals etc.
Whereas civil engineers tends to cover more infrastructure projects:
* Roads, rails, runways, bridges, flood defences, services (water, gas, power and data)

Question 5

614 What are temporary works?

Answer 5

Temporary works are works that are undertaken to facilitate the main works but will not ultimately form part of the permanent works. Examples such as scaffolding, trench support, temporary propping & formwork. Generally they are required for safety reasons. Sometimes the temporary works will be left in and become part of the main works if it is easier than removing them. Sacrificial formwork being an example.

Question 6

616 What is shoring?

Answer 6

Shoring is a type of temporary works that gives buildings or excavations stability and prevents collapse.

Question 7

619 What is substructure?

Answer 7

Substructure is the part of a building below the ground floor slab. It is used to transfer the imposed loads of a superstructure into the ground and give the building structural stability. It includes piling, basements & retaining walls.

Question 8

620 What is ground heave?

Answer 8

This is when the ground swells up and puts pressure on a structure which can result in the structure moving from its intended position. Usually occurs in clay soils and it is an upward force on the structure.

Question 9

621 What are some techniques for ground improvement?

Answer 9

• Vibro compaction
• Vibro stone columns
• Vertical drains and vacuum consolidation
• Soil mixing
• Dynamic compaction

Question 10

622 What are the different forms of excavation?

Answer 10

• Site clearance
• Strip topsoil
• Reduced level dig
• Cut and fill
• Excavations for foundations

Question 11

623 What are the key factors a contractor should consider when excavating? (137)

Answer 11

• Nature of the soil, cohesive/non cohesive
• Services/drainage are there know services in the area. How close will the excavation be to them. Will it need to be hand dug. How close are they to existing buildings
• Temporary works, shoring and access/egress
• How large a machine will be needed
• Groundwater table, Will the excavation need to be pumped to avoid build-up of water.
• Will a coffer dam be required.

Question 12

624 Explain some techniques to waterproof a building?
* Tanking, materials such as asphalt, polythene sheeting, bitumen applied internally.
* Drained cavity, cavity walls are built and a small amount of seepage is expected. This is then collected in the cavity and either gravity drained or pumped away.

Question 13

625 Have you come across the terms SUDS?

Answer 13

Yes, it stands for Sustainable Urban Drainage Systems and it’s a method of managing storm water during heavy rainfall periods (although, at skirting beck SUDS were used to assist in managing additional overflow from a flood storage reservoir). It can help encourage infiltration and attenuation. Can help reduce the reliance on existing drainage infrastructure.

Question 14

626 Can you detail a typical road build-up?

Answer 14

• Sub base compacted and rolled – Larger crushed stone, compacted in layers and used to aid stability for the road. 100 – 250mm
• Base course – 70 – 150mm
• Binder course – Sits on top of the sub based and is used to cap it and stop it moving while giving the next layer something to adhere too. 50 -100mm
• Wearing course this is the top layer, usually intended to be sacrificial. It gets exposed to the majority of the loads and as its exposed to the elements can end up cracked from the weather. Eventually it can be planed off and relayed while (in theory) the sub and binder layers stay intact therefore reducing the time and cost of the repair. 20 – 40mm

Question 15

What are the OGC gateway stages

Answer 15

Gate 0 – Strategic Assessment
Gate 1 – Business Justification
Gate 2 – Delivery Strategy
Gate 3 – Investment decision
Gate 4 – Ready for Service
Gate 5 – Benefits Realisation and Operational Review

Question 16

At what OGC gateway stage do you do your cost cost planning

Answer 16

Order of cost estimate at stage 0 - Strategic Assessment

Elemental cost plan at stage 1 - Business justification

Cost plan at stage 2 - Delivery strategy