15 minute breakout

1. What are the 2 basic different types of foundations? When would we use one versus the other?

2. In each of the two types – what are the subtypes and when would you use them?

Shallow and deep foundations

•Shallow – soil directly below walls and columns bear the weight of the building. Cheaper. Ideal for high water table and relatively light building.

•Deep – Soil conditions directly below the building not suitable therefore structure required to reach deeper to appropriate soil conditions.

Shallow – Types.

A. Slab on grade – high water table – common in BA

B. Crawl Space – common for wood frame – access to utilities

C. Basement – Storage and utilities

Slab on grade- assembly•Trench for utilities

•Trench for footings

•Rebar in footings

•Pour footings

•Waterproof membrane

•Sand

•Reinforcing for slab

•Concrete slab pour

Footings for crawl spaces and basements.

spread the force of the vertical loads of columns and walls over more soil area

•Spread footing

•Column footing

Concrete footings and foundations

• Foundations poured separately from vertical carrying structure.

• Waterproofing issues

1. Drain the water –remove pressure on walls

2. Keep water out of the building

Deep foundations – Pile driving•Reach down to bedrock for poor soil conditions

•Pile caps/ grade beams support columns and walls

•Concrete slab

Deep foundations –

Mat slabs, Excavation and retaining walls

•Mat slab – very think slab (6’) with a lot of steel reinforcing that replaces individual column footings

•Excavation sequence

1. Drive soldier beams – steel into ground

2. Place wood lagging between beams as you excavate down to retain soil

Below grade foundation walls and waterproofing•Protection board

•Waterproof membrane

•Concrete retaining wall