Construction Site Preparation: Staking Out

Preparation for Construction

• Focuses on the processes involved in readying a site for building.

Staking-Out the Building

• Method of driving stakes for batter boards to define building corners and foundations for excavation
• Begins with relocation of boundary points and property lines.
• Measure the front corner monuments to determine the required setback.
• Drive stakes, then stretch string
• Determining building corners:
  • Drive stake A at one side of the lot
• Measure from Stake A to Stake B to obtain the width
• Estimate right angles from stakes A and B, measure building length
• Drive temporary stakes C and D to mark rear corners. C-D should equal A-B
• Ensure diagonals A-D and B-C are equal and draw lines
• Transfer building lines to batter boards

Key elements for the Staking stage

• Stakes: sharpened wooden sticks as posts driven in ground for boundaries/batter board support.
• Strings: plastic cords/galvanized wires across batter boards indicating wall/foundation outlines.

Laying the Batter Boards

• Batter boards are horizontal boards that establish a building's height, as well as the height of footing trenches and foundations.
• Leveling achieves batter boards using line levels, carpenter's levels, or transits.
• Batter board height can match or sit slightly higher than the finished foundation.
• Batter boards: are wood sticks or boards nailed horizontally at the stake
• They function as a horizontal plane to reference the building measurements from.

Key tools

• Spirit Level: tool for checking vertical/horizontal alignment.
• Plumb Bob: Weight on a string for vertical line check.
• Plastic Hose Filled With Water: for horizontal leveling of batter boards without transit.
• 3-4-5 Multiples With the Steel Tape Measure: manual method to square building lines.

Formwork and Shoring

• Formwork is the temporary structure that shapes and supports fresh concrete until it cures.
• Shoring: temporary supports that carry forms for beams and slabs.

Forms for Concrete Construction can use these materials

• Lumber: should be partially seasoned.
• Plywood: providing smooth surfaces, should be waterproofed, Grade "A", and at least 1/2" thick.
• Steel: in the form of pans for joist construction, steel decking, or corrugated steel.
• Fiber Boards
• Phenolic Boards: heat-resistant, used in adhesives, exterior/marine plywood, and laminated products.

Lumber and Steel for Forms

• Lumber should be partially seasoned, slightly wet to prevent swelling/distortion.
• Lumber should be dressed at least one side with even edges for non-exposed surfaces.
• Joints in forms dressed true to edge for tight column, beam, and girder connections.
• Tongue-and-grooved stock creates tight floor/wall panel joints.
• Sizes include 2-in. stock for columns/beams/girder bottoms, 1-in. stock for floors and girder sides, 2x4s for struts/shores and uprights
• Crude oil/petroline prevent concrete adhesion, preserve forms, wetting with water acceptable for surfaces to be plastered
• Wire ties/bolts/rods hold wall forms; rods preferred if arranged for removal without metal within 1 inch of surface; wire ties for light work.
• Plywood forms are waterproof, Grade "A", and at least 1/2" thick where smooth surface is required.

Additional formwork elements

• Knee Brace
• Kicker
• Braced T- and L-heads
• Single Post Wood Shore
• Ledger Blocking
• Stringers
• Jack
• Adjustable Metal Shores
• Bracing
• Sills
• SILL PLATE
• BRACING
• COLUMN FORMS
• Usually wood
• They keep column forms and tops of wall forms from spreading under the fluid pressure of newly placed concrete
• They have a square or rectangular cross section
• WALL FORMS
• SPREADERS usually of wood, space and keep the wall or forms apart
• FORM TIES
• PLYWOOD SHEATHING
• HORIZONTAL WALERS
• WOOD STUDS

Types of Form Ties

• SNAP TIES: notched/crimped to snap off below concrete surface after stripping forms.
• SHE BOLTS: waler rods threaded onto the ends of an inner rod for stripping, the waler rods are reusable.

Scaffolds

• Support workers/materials on structure faces.
• Metal shoring components:
  • Ledger: horizontal brace.
• Brace/diagonal: adjustable or fixed.
• Standard: vertical support.
• Accessories: heads, jacks, and bases.

Metal shoring assembly:

• Ground/sleepers, base, jacks, and standards should all be prepared
• The tower has 4 standards, braces are fixed to stabilize
• The remaining components are loosley fitted. This ensures standards are checked for verticality and that ledgers are tightened
• The scaffold boards/ladders are positioned
• Additional ledgers/braces can be added along with additional braces
• Once the levels are complete, jacks/heads will be positioned
• To finalize the Level of the Jack head any required jack bracing is fitted
• The primary beams are positioned, clamped and leveles
• The Secondary beams can be positioned and clamped to primary beams. Plywood decking to follow

Construction Tools and Equipment

• Tools/equipment in construction consists of four groups:
• Hand Tools: Powered by man.
• Power Tools: Powered by non-human forces.
• Equipment: Large, complex tools/machines for specific jobs.
• Heavy Equipment: Very large, powerful equipment.

Hand Tools

• Pry bar: opens boards used in concrete forming and removal.

Measurement and layout tools

• Folding rule and tape measure: measures boards/pipes/wires.
• Digital rule: measures long distances, like highways.
• Framing square: measures 90-degree angles in framework corners and helps define cutting angles.
• Level: a long, straight tool determines if the horizontal or vertical is exact.
• Chalk line: used for marking lines.

Hammer types

• Claw hammer is an ordinary hammer to drive or remove nails.
• Sledgehammer drives stakes into ground and breaks up concrete/stone.

Types of screwdrivers

• Standard screwdriver: flat tip fits standard slotted screws.
• Phillips screwdriver: X-shaped tip for Phillips-head screws.
• Spiral ratchet screwdriver: which relies on a pushing force rather than a twisting force.

Handsaw types

• Ripsaw has chisel-like teeth designed for ripping or cutting with the grain of wood.
• Crosscut saw cuts across the grain of wood.
• Backsaw produces very straight cuts such as those on trims and mouldings
• Hacksaw is used to cut metals.

Chisel types:

• Wood chisel: trims wood and clears excess material from wood joints.
• Cold chisel trims metals.

Specialized hand tools

• Nail set drives finishing nails below surface of wood trim.
• Pipe wrench turns round objects, specifically pipes.
• Brick trowel places/trims mortar between bricks/concrete blocks.
• Bull float smoothens surface of wet concrete.
• Blind riveter joins sheet metal.

Power Tools

• Power drill: bores holes in wood/metal/concrete.
• Power screwdriver/ screwgun: installs/removes screws.

Power saw types

• Radial arm saw: crosscuts with motor-driven blade on arm over table.
• Table saw cuts large sheets and consists of a blade mounted on an electric motor beneath a table-like surface
• Portable circular saw cuts materials difficult for stationary tools.
• Power miter saw: circular saw mounted for angled cuts in wood.
• Saber saw cuts curves/holes in floors/roofs, small knife-shaped blade moves up/down.

Power hammer types:

• Pneumatic/jackhammer breaks up concrete/asphalt.
• Rotary hammer: like electric drill, with rotating/reciprocating action to drill holes.

Types of nailers and staplers

• Nailer/nail gun: fastens materials by shooting nails into building material.
• Powder-actuated stud driver: gunpowder-powered, drives long pins into wood/steel/concrete.
• Stapler: like nailer but uses U-shaped staples.

Equipment

• Transports materials unlike fluids.

Surveying types of equipment

• Transit measures horizontal/vertical angles.
• Surveyor's level determines unidentified elevation from known point.
• Construction laser creates narrow light beam for measurements.

Types of pumps

• Water pump removes water from holes for construction.
• Concrete pump transports concrete from mixer to form.

Concrete

• Concrete mixer (cement mixer): machine mixes concrete via rotating drum, raw materials are introduced which allows concrete to pour out

Types of welding machines

• Arc welding machine welds materials by melting portions of the metal.
• Laser-powered welder welds material using laser to heat metal.

Heavy Equipment

• Bulldozer is a tractor with a pushing blade which moves earth and clears land of bushes and trees.

Crane types

• Crawler crane: mounted on metal treads for rough terrain.
• Truck crane frame allows driving at site.
• Tower crane/climbing crane is Jacked up to constuct tall buildings floor by floor by a bulit in jack

Excavators

• Excavator Machine that takes material from A to B

Excavator types

• Backhoe General digging
• Trencher Long narrow ditches
• Front end loader scoop or delosit material

HighWay contruction

• Scraper Loads,hauls and dumps soil over medium to long ditances
• Grader Grates and levels the Ground
• Compactor Compacts soil and prepares for paving
• Paver Places,spreads and finishes the pavement

Major Parts of a Building

• Superstructure: Above-ground portion.
• Substructure: Below-ground habitable portion.
• Foundation: Structure for transferring loads to soil.

Substructure types:

• Slab on Fill: slab which rests on ground and not suspended.
• Crawl Space: accessible space beneath the first floor, less than full story height.
• Basement: lower story, partly or entirely below grade.

Foundation Bed

• Also called foundation, meaning:
  • Construction below grade: Footing courses/basement walls
  • Natural material: Earth's surface supporting the construction
  • Special construction: Piling or piers, transmits loads to firm substrata.

Foundation elements

• Foundation bed: The natural material the construction rests on.
• Foundation walls: Retaining wall below grade.
• Foundation piers/columns: Supports below grade.
• Grade Beam: Supports outer wall and bears on column footing
• Footing courses: Lower wall/ or column support/base.

Foundation Beds that can be classified

• Rock (solid rock, bedrock or ledge). Undisturbed rock masses forming an undisturbed part of the original rock-formation.
• Decayed rock (rotten rock). Lacking coherent qualities in rock masses
• Loose rock. Rock masses that are detached
• Gravel. Detached rock particles, generally water-worn,
• Boulders. Detached rock masses larger than gravel, generally rounded and worn
• Sand. Non-coherent rock particles smaller than 1¼" in maximum dimension
• Clay. hydrated silicate of alumina, generally mixed with powdered feldspar
• Hard-panmixture of clay or other cementing material with sand
• Silt A finely divided earthy material deposited
• Mud Finely divided earthy material generally containing vegetable matter and deposited
• Mould. Earthy material containing a large proportion of humus or vegetable matter Loam Earthy material containing a proportion of vegetable matter.
• Peat. Compressed and partially carbonized vegetable matter
• Filled Ground. All artificial fills and some natural fills are liable to a more or less uniform. All artificial fills and some natural fills are liable to a more or less uniform but continuous settlement or shrinkage due to the gradual consolidation of the material of which the fill is composed

Soil

• Investigation is required to determine the allowable unit load on the foundation bed.

Allowable Loads

• Investigation is required to determine the allowable unit load on the foundation bed.
• Uniform material: a uniform unit load may be used.
• Non-uniform: the unit load must be reduced to minimize settlement differences.

Site Investigation

• Architects get data on site excavation and building erection.

Investigation Methods

• Test pits: Actual inspection of undisturbed material.
• Test borings: Investigates material no deeper than proposed level.
• Loading tests assist bearing capacity of materials forming foundation

Soil Mechanics

• Two Classes of Soil

Soil Classes

• Course-grained soil: large visible particles.
• Fine-grained soil: small particles like silt and clay.

Soil Stability Factors

• Allowable Bearing Capacity: Unit pressure foundation is permitted to apply on soil.
• Density soil density affects granular soil bearing capacity Measured with Standard Penetration Test and Maximum Dry Density
• Shearing Strength Ability to resist displacement.
• Water Table: Level where soil is saturated with groundwater.

Soil type & capacity is:

• Compact, partially cemented gravels, well-graded with little or no fines
• Compact gravel; gravel and sand mixtures
• Coarse, compact sand; loose gravel; hard, dry clay
• Coarse, loose sand and gravel mixtures; fine, compact sand
• Fine, loose sand; dry, stiff clay
• Soft clay; soft, broken shale
• Organize soils
  • Unsuitable and highly unstable

Excavation and Earthworking

• Excavating digs the earth; to place the foundation.
• Leveling and Grading: change land elevation.
• Stabilizing the Soil: Compacts the soil the structure rests on.
• Protection: Excavator liable for damage resulting to adjoining property.

Shoring transfers load of wall to temporary footings. Elements include:

• Sheet piles: Timbers/pre-cast planks driven to retain earth and prevent water seepage.
• Wales: horizontal beams which tie the sheet piles in place.
• Soldier piles: Steel H-sections.
• Lagging heavy timber planks join horizontally to brace the surface

Supports

• Crossbracing/rakers support wales/soldier piles.
• Tiebacks secure to rock to avoid interfering with excavation.

Excavation processes:

• Needling and underpinning are Processes that use needles - Girders used to support weight of wall
• Dewatering is lowering water table by pumping: Pumps water away from site.

Site Dranage

• Prevents erosion,excess water or ground water from new construction
• Surface Water - Run off over surface
• Ground Water - Water near the surface running through the subsoil

Site Dranage

Types:

• Sub Surface - underground pipes for conveying groundwater.
• Surface - Refers to grading as a site to divert water

Components of sub-surface drainage system

• Catch Basins - used to direct runoff
• Culverts. Channels under roads or walkways

Components of sub-surface drainage system continue.

• Foundation drainage tile or pipe: collection of sub and effluent water
• Drainage Tile- A hallow tile design to help drain water

Surface Drainage components

• Swales- shallow depressions formed intersection

Additional drain tools

• Area drain- receptacle helps collect water
• Dry Weels- Drainage sits linked with gravel
• Absoption Fiend- helps with septic
• Ponds an Marshes are designed catchments

Topography,Slopes

• Structures
• Sit elevated or cut into slope.

Moderate Slope structures

• elevated with linear planer loads.

Land

• Structures are over water with earh pads to prevent water
• EArth berrs
• Check water table

Slope Protection

• ground is reduced divert ground a series of terrices.

Retaining structures

• Inhibit erosion.

Structures for Erosion

• Riprap-stones used in stream.
• Cribbing- concrete to hold materials.
• Bin Wall- retaining wall.

Retaning wall tools

• Gabions- wire
• Retaining- Change of ground elevation
• gravity- resist over turning
• T type-Cantilevered Retaining- uses wall height design
• 1 type- used for abuts

Materials for walls

• Brick- Stone Veneer

Drainage

• Base needs to provide granular
• Dry Store Wall to retain earth

Consideration wall materials

• over and under turning
• Soil thrust

Surface levels

• Paving provide surface for trafic

Suprgrade for Pave

• pavement loag should be undisturbed soil
• The base of pavement aggregate . pavement wear protects base with structure

Two types

• Flexible with concrete on sanf setting bed
• rigit reinforced material over board

Paving

• flexible material to restrin
• rigid Material require re enforcement

###Additional considerations

• texture and important look wise
• wheel chair traffic
• Warn traffic
• Rams need climate contro