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• lagging in solider piles

  horizontally placed TIMBER between the solider piles

  • to retain the soil behind
• solider piles - predrilling

  provides close control of aligment and location
• solider piles

  • H shaped pilling system
  • set in pre-drilled holes around the priphery of the excavation
  • grouted in weak concrete
• function of deep supports

  • protect people
  • provide support for the nearby structures
• solider piles installed with

  convetional pile-driving equipment

  • in agured holes
• Soldier piles or soldier beams

  • are H-piling set in predrilled holes around the periphery of an excavation.
  • Predrilling is for control of alignment and location.
  • piles are grouted in place with weak concrete.

  Lagging is the timber placed horizontally between the soldier piles to retain the soil behind the excavated area.
• Soldier piles ( berliner wall )

  • installed with conventional pile-driving equipment or in augured holes.

  The soldier piles are driven before the excavation begins, and the lagging is installed as the excavation proceeds down.

  • on sides the wall is SUPPORTED BY
  • anchors drilled and grounted in the soil around the excavation
• Sheet piling (interlocking sheetpiling)

  • earth retention and excavation support that uses steel sheet sections with interlocking edges.

  A hydraulic ram or vibratory hammer installs the sheetpiles in sequence to design depth along the planned wall excavation perimeter.

  
  

  • The sheet piles form a wall for permanent or temporary support.
• Sheet piling CONSISTS OF :

  • steel piles that can be reused

  sheet piles form a continuous wall which is WATERTIGHT.

  
  

  Each pile is lowered by crane into a template that holds it in position.

  Then the piling is driven into place with a pile driver.
• EXCAVATIONS SUPPORTS Bracing - struts

  • narrow excavations, INTERNAL STURTS
  • Before struts are installed, a horizontal member called waler is placed against the soil support.

  Struts are then installed from waler to waler across the excavation.
• • raker bracing is used for very WIDE excavations

  The support for the rakers (driven piles or footings) are installed at the bottom of the excavation.
• Bracing - tieback

  • Tiebacks (or anchors) are structural system which acts in TENSION and receives its support in earth or rock.

  Anchors eliminate obstructions in the excavation inherent in rakers or struts.

  
  

  CONSIST OF:

  • the earth or rock, which provides the support for the system

  
  

  • a tension member (or tendon) which transfers the load to earth or rock.
• Soil nailing

  1. a method of soil reinforcing while it is excavataed from the top down

  placing rebar into the natural soil in an effort to increase its TENSILE and SHEAR strength.

  • done to improve the load-bearing behavior of soil.

  
  

  • The original subsoil is therefore turned into a composite body which is capable of taking up external forces so that the soil is integrated into the structure as a structural component.
• Soil nails are installed in a grid - which function is to create a stable mass of soil.

  This mass of reinforced soil functions to retain the less stable material behind it.
• Soil nailing construction

  1. excavation of a shallow cut.
  2. Then shotcrete is applied to the face of the cut
  3. soil nails are drilled in and grouted.
• Diaphragm walls

  • used in cases of troublesome dewatering and excavation support problems.
  • It involves constructing an barrier beneath the ground surface.

  They are constructed from the surface level by:

  1. excavating a long deep trench.
  2. reinforcement cage is inserted in the trench and concrete placement from bottom to the top.
• Diaphragm walls

  • To prevent the sides of the excavation from collapsing before the concrete is placed, it is filled with a thick bentonite slurry, which bonds to the walls and holds the soil material together.

  To construct the diaphragm walls, deep trenches are excavated in long sections using a special equipment commercially known as Hang Grab.
• trench boxes

  1. where soil will not remain open without caving
  2. support sides of excavatioN
  3. prevent soil colapse
  4. the area between the outside of a trench box and the face of a trench sould be as small as possible
  5. the space between the thrench box and excavation SIDE should be BACKFILLED --> TO PREVENT LATERAL MOVEMENT OF THE TRENCH BOX
  6. installed by pushing into the ground
  7. removed by sling by their special lifting points located on the panels
• intermitten sheating and barcing

  1. vertical alements are disposed at regular distances from each other
• continous sheeting and bracing

  1. vertical elements placed close to each other that they form a continous wall
• trench shielding

  • metal sheets used as vertical elements
• excavation supports systems are used to :

  • minimize the area of an excavation
  • keep sides of excavation stable
  • make sure that movements will not cause damage to any neighbouring structures
• Diaphragm walls

  A PVC (polyvinyl chloride) waterstop joint is placed between each panel. Structures such as below grade facilities should have a waterstop system in place. These waterstops are made of PVC and are formed into Concrete joints during the actual

  concrete placement.
• Diaphragm walls

  The PVC waterstop then bridges the joint between the concrete sections to prevent water from coming through the joint.
• working cycle of a scraper

  1. time of loading
  2. hauilng
  3. spreading
  4. return time
  5. time to TURN back and change gear
• DOZER working cycle

  1. cutting material
  2. pushing load
  3. spreading material
  4. return and maneuver into initial position
• EXCAVATOR working cycle

  1. time of digging and loading excavators bucket
  2. time of relvolving of superstructure
  3. time of emptying excavators bucet
• what affects crane lifting capacity:

  • wind forces
  • swinging the load
  • hoisting speed
  • differences in crane level
  • stopping the load
• concrete advantage

  • can be molded into any shape
• concrete has limited tension resistance thats why we use reinforcement
• formwork - mould for freshly placed concrete, also :

  • supporting structure
  • bracing required to support its weight
• The construction of a concrete building requires:

  horizontal formwork to support the slabs,

  • vertical formwork to support the columns and walls.

  Formworks are required to support loads such as fresh concrete, construction materials (especially rebars), equipment, workers, various impacts and sometimes wind.

  All the applied loads must be supported without collapse or excessive deflection.
• The economic requirements of formwork:

  manufacturing and using forms must lead to low cost of materials, energy and labor.

  -formwork should be as repetitive and as adaptable as possible.

  • the formwork must be able to withstand a good number of reuses without losing the shape.
• The technical requirements of formwork:

  • forms should assure the attainment of the desired shape, size and location of the member in the structure according to the drawings.

  -forms must be strong enough to withstand the pressure of fresh concrete and workingloads; and to maintain their shape during the concrete placing operation.

  formwork must be capable of supporting the designed loads any other applied loads during the construction period.
• The functional requirements of formwork:

  form sections must be of a size that can be lifted into place without too much difficulty and transported from one job site to another, if

  necessary.

  formwork must be dismantled and moved as easily as possible so that construction of the building advances.

  units should be interchangeable so that they can be used for forming different members.
• The basic components of a formwork:

  ▪ sheathing (plywood, steel, wood, OSB),

  ▪ panel frame (dimensioned lumber, steel, aluminium),

  ■ studs and wales (vertical and horizontal elements that support the sheathing or form panels),

  ■ shoring members, (dimensioned lumber, steel or aluminium elements)

  ■ties and other form accessories.
• horizontal formwork

  • for horiz construction elements -> slabs, beams

  vertical formwork

  • foundation walls, columns