Materials and methods one chapter 2 foundation (week 3 quiz)

soil types

There how many and can get quite involved with a field of soil mechanics has its role in determining what exist underfoot which will impact on determine the best foundation system to design use.

underpinning

There will be sites or properties where nebhoring buildings may extend right up to the property line or very close to it.Measures must be taken in order that the neighboring buildings are protected agains damages during closed excavation

Foundations

These Take all the live and dead load from the structure above and transfers them to the ground below where they dissipate into the earth

Expansion Joints

These are also of resilient material that acts as a cushion against two adjacent components expansion occurs when the temperature warms in the summer and contraction occurs when the temperature cools in the winter

settlement

This occurs when the soil around and beneath the foundation adjusting to any loan that is placed on top of the soil it is natural behavior as to how the soil reacts

form work

This was mentioned previously of note here for Mark is sustainable method where it can be used repeatedly former lease compounds allow the forms to be removed without any concrete adhering to it making them available and ready to use at the next job

soil tests

To investigation sub surface soil conditions at the site in determining the best and most economical foundation type to use. This amount as to how deep the foundation shall be and what materials to use for this construction

slabs

1Typically used for floors at basements and cellars. A. Grade to support the slab must be level and plumb. B. Waterproofing system is next installed (See #6) C. Reinforcing for the slab is first installed which takes the form of a mesh that is sized in guage thickness . If greater loads are expected, then the reinforcing is designed accordingly . D. Chairs and Bolsters Supports that keep the reinforcing in place and these also become a part of the slab. E. Slab concrete is poured typically following a " checkerboard pattern of "x " amount of area for quality control

Foundation design consideration

A .water table - what are is always present within soils levels determined as per precipitation amounts B. Adjacent structures and narrow lot Dash urban areas were temporary bracing for adjacent structure is required while the new work is being performed C. Shallow vs deep - soil test boring reports and log determine the best foundation system D. Budget and costs - foundation costs can easily take up to 60% of construction budget

Drainage for retaining and foundation walls

A :weep holes - located along the bottom of the wall where collected water escapes B: perforated drain pipe- below the wall which collects and diverts water away

benched

A condition where the soil is placed at an angle to prevent it from sliding back into the excavation

test boring

A hole drilled into the ground at the site of a proposed structure in order to obtain samples of the subsurface soil for examination and testing in a laboratory. Based on these tests, the soils engineer recommends the type of foundation and the allowable soil bearing pressure.

Caisson

A long cylindrical reinforced concrete foundation element formed by drilling into firm soil and pouring concrete into the hole.

column footing

A spread footing, generally square or rectangular in plan, used to support a single column.

Spread Footing

A wide shallow footing usually constructed of reinforced concrete.

common materials for small scale retaining walls

A- stone gravity wall B- vertical or horizontal oriented Timberwall C- reinforced concrete or concrete block for large scale retaining walls

A,B,C of underpinning

A-Existing foundations may not be large enough to carry loads leading to settlement problems such as differential settlement B- Change to the building use that may affect and ur change live load conditions C-New construction near a building narrow lots may disturb the soil around adjacent foundations or if the new foundation may need to deeper that existing adjoining ones

Wood timber piles

A. Cluster- a group or arrangement of piles B. Pile cap- A reinforced concrete pad to connect the columns to piles C. Point of refusal- the furthest that a pile can be driven E- pile materials can be either timber steel or wood

Pile types

A. End bearing pile- a pile whose tip extends into rock and dense souls with firm resistance

Spread foot design

A. Excavation --Should be done to the proposed depth allowing adequate clearance. B. Formwork - Composed of plywood and framing lumber with form release compound applied to allow for proper removal after the concrete is poured. C. Footings are first poured containing steel reinforcing temperature bars. D. Key- Continuous channel that bonds footing and foundation wall as one in addition to preventing slippage. E. Steel reinforcing for foundation wall is first installed, then the concrete is poured. F. Foundation wall extends beyond the gradeline to prevent direct contact between the wood frame construction and the ground.

The common foundation types

A. Spread Footings - The most common type consisting of a foundation wall and footing which extends both sides of the foundation wall. B. Cantilever Footing - Similar to a spread footing , only here the footing extends beyond the foundation wall on one side. C. Column Footing - Or pier extending beyond the dimensions of the column it supports . D. Mat Footing - A continuous footing system should columns be spaced where it may be impractical or too expensive for individual column footings E. Stepped Footing - The same as a spread footing that is used for sloping sites to maintain proper code required frost line depth throughout . F. Tie Beam - Horizontal foundation component designed to transfer loads to individual foundations such as pile caps which transfer loads into piles for distribution into the earth

load-bearing capacity

A.Bedrock- offers the best support, for example Manhattan Island B. Sandy gravel - Good support and drainage qualities here in Nassau- Suffolk County's C.Silt- becoming finer in quality stable and OK to use as per make up D. Clay is unstable where it will absorb water and expand only to shrink upon evaporation

soil types list

A.Rock- solid mass material the strongest and most stable material to build upon. B.Boulders- Either too hard to lift such one hand or requires two C.Cobble- Can be lifted with one hand generally palm sized D.Gravel- Can be lifted with the thumb and forefinger E.Sand- Each particle is visible but cannot be individually picked up F.Silt- Usally too small to be see individually G.Clay- Plate shapes that is smaller than silt H-Peat- This is organic matter plant decay and not suitable to build upon

honeycomb

Air voids within the concrete as a result of poor pouring techniques that will undermine the structural integrity of the concrete. Good practices call for continuous vibration of the concrete during pouring to prevent honeycombing .

Within foundation system

All components being the footings, walls and slabs are separate as they are formed and poured individually . These are considered as exterior located and as such will be subjected to seasonal temperature extremes that will involve expansion and contraction in addition to water penetration potential.

Drainage Mat

Allow ground water to flow away from substructure

Soldier beans and lagging

Combination of these two element where A. Soldier beam - steel W - shapes driven into the ground at close intervals prior to excavation B.Lagging- As earth is removed heavy wood planks are placed against the beam to hold back earth

Precast slurry wall

Concrete is precast off site with younger and groove edges that join sections together

Steel piles

Can be H shaped sections, which are heavy wide flange sections ranging from 8 to 14 inches in depth and width, can carry loads ranging from 50 to 200 tons by being welded

topsoil

Carefully removed and stored on site for later landscaping reuse

Unified soil classification system

Classification of soils, widely used in engineering practice, based on amount of coarse particles, fine particles, or organic material.

Codes

As they set the safe standards for design they also provide the set loads based on the proposed use for the building for example with the following A-residential is based on 40 pounds per square foot B- commercial Mercantile is based on 100 pounds per square foot

tie beam

As used per soil conditions and seismic design column footings are linked together with reinforced concrete to avoid slippage

Frost lines

Be careful that the excavation goes below the frost line depth to prevent any extent of upheaval by the soil action through the year

Frost line

Between the surface And depth where the souls will be subjected to seasonal freezing and thawing. Footings must be located below the frost line depth to prevent upheaval as a result of constant Freestar frost line maps indicate the first line depths for any region

foundation wall

Foundation Walls: Can either be of poured concrete with reinforcing (see #12) or of Concrete Masonry Units - Block. A. Concrete Block contains voids. ( Will be discussed later under Masonry) B. Reinforcing is inserted within the voids, then filled with grout . C. Horizontal ties or reinforcing is also placed within the mortar joints. D. These tie all the materials together for structural integrity. E. The grout (B) acts as a bond at the footing key.

Water stop

It was in the material that is used to seal joints within concrete construction materials are neoprene synthetic rubber etc. joints or minute openings between each concrete components that can easily be a passage for water to penetrate to within

waterproofing

Keeping the water out within surface conditions done as follows: A- compacted earth-to ensure level surfaces for concrete slab serving as floors B-compacted gravel allows water to drain away from the foundation C-protection board polystyrene material 1/4-1/2" fake which is moisture resistant and use as an insulator also rigid insulation D: Sheet PVC membrane-how this is installed 1. concrete surface must be smooth finished and dry 2. a primer coat is then apply to ensure adhesion 3. Sheet membrane is applied next all seems must shed water away 4. Perforated drain water collects here and is diverted away from the foundation to a remote on site disposal field or tapping into a public drainage system

Batter Boards

Reference points offset a given distance from the building line and set prior to excavation.

uniform settlement

Settling occurs at roughly the same rate throughout all parts of a building

Rakers

Sloping brace to support sheathing fastened into the main vertical brace by a raker with a kicker being a temporary footing supporting it at the bottom

Crosslot bracing

Temporary steel columns are first driven into the ground then horizontal walerd are next installed to support searching form work or crossties

Lab reports, logs

Test Boringd are lab analyzed by souls engineers and each boring shall have its own lab report which shall provide the following A. Soil description- what exists as per unified soil classification system B. Consistency- Good towards determining foundation type C. Depth of each strata as per classification and consistency D. Water table depth and location of E.Soil strength

Piles

The difference between a like and a caisson is that pile is driven into place

slurry wall

The most difficult and expensive to build using slurry which is a watery-clay mixture it can also be used as a permanent foundation how they are used A- guidewalls - extending down only a few feet preliminary B- excavation- same width as established by the guide all using a clan shell bucket C- slurry contains greater pressure than the surrounding earth acting outwards preventing collapse D-pre assembled steel reinforcing is lowered into the slurry E- concrete is next poured in ad this is being done the slurry is pumped out and filtered for re use F- concrete solidified and the wall are tied back as excavation proceeds

clear and grub

The next step which is the removal of all unwanted debris underbrush grows that would otherwise interfere with the work

Slab on grade

The simplest foundation type characterized by think premiere edges . They can be used for one to two structured with very little to no frost concerns

loads

These are frictional for any foundation design. There are two load classifications that must be thoroughly studied for the right specification and did for all materials for the building from the roof peak to the bottom footing

earthquake (seismic) wave

These are horizontal and vertical force is caused by ground movement maps indicate seismic zones throughout the US where zone five is the most severe California to zone three found here in south eastern New York zone one is very little activity

Strata

These are layers of different soils below the surface of the earth

piles

These are similar to caissons only more slender and are typically used in locations where surface soil conditions are poor for supporting. Two common pile types are: A. End Bearing - Where the pile tip reaches strong supporting strata. B. Friction PileStrength is developed by the friction the pile encounters along its sides should no firm strong strata can be practically reached.

Sheeting

These are temporary walls installed around an excavation perimeter to hold back the earth

Live Load

These are those loads that are within the building but not a part of the building structure they include people furniture equipment vehicles anything that can be brought into or out of the building natural live loads include the following A-snow load not prevalent in Florida but a various levels in New York B- wind load these are based on a maximum three second gust. Wind speed maps provide the load requirement as per location

retaining wall

This is a wall designed to hold back soil creating an abrupt elevation change to the grade. Retaining walls are designed to resist pressures within the earth bearing against it on the uphill side. Like foundations retaining walls are designed as per a soil types be ground water presents see any adjacent structures retaining walls are used at steep sight especially at property lines and with highways and roads that cuts and embankments

Call before you dig

This is required everywhere usually 72 hours before any excavation begins with a valid official permit on site

Dead loads "DL"

This is the building itself included are the weights of the framing, flooring, finishing materials,mechanical equipment, anything attached to the structure down to the foundation and footings. Industry provided tables indicate material weights to contribute to the total dead load which are added up to obtain the actual total debt load

Bulb effects

This is the shape of load dissipation into the earth which is radial upon the loads transferring into the earth from the footing .

Sustainability with site preparation and excavation

To protect and conserve natural habitat and resources with minimum disruption to these caused by work energy labor and machinery minimizing pollution energy use A. Site selection should consider environment located within so as to minimize vehicular travel and minimizing disruption to existing open lands opt for a building renovation to an existing opposed to new from scratch B. Site drainage and preservation of existing natural vegetation to mitigate potential pollution that may be caused by surface runoff or seepage into the ground C- during construction to protect surrounding landscape to be kept

test pits

Trenches dug at the job site that allow visual inspection of the soil strata and direct collection of undisturbed samples.

differential settlement

Unequal settlement of the various parts of a building, which may cause excessive stresses in the structural frame or tilting of the building.

cantilever footing

Unlike spread footings where the toe extends beyond the foundation wall on one side

Stepped Footing

Used for sloping sites where a uniform depth at all points per code must be Maintained

Wood timber piles

Used since Roman times and can extend to depths of 60 feet

mat footing

Used were designed columns are close enough to each other where it may be more economical to merge them all into one single Mat will support the entire building

Sheet Piling

Vertical sheet wood or precast concret placed tightly next to eachother driven into the ground prior to excavation

capillary action

Water penetration within a concrete foundation wall by water seeping through microscopic pores in the material

underfoot

What May look and seem like "terra firma" on the surface may not which can cause an inconvenient to dangerous conditions if subsurface conditions are not given a thorough investigation

concrete

building material made by mixing small stones and sand with limestone, clay, and water

Tie backs

mostly used when construction happens in open space at each level of walers a hole is drilled and steel cables are stretched to tension to hold back the sheeting