Building foundation

• Riverbeds


  • Contains many types of deposits including boulders
  • Preliminary geologic work is required to avoid issues
• Extensive boulder deposits


  • Easily mistaken for solid rock
• Preliminary jet borings


  Provide the line basis for contouring the top of the rock surface of the harbor
• Local soils


  • Formed in an ancient glacial lake
  • Usually overlie lodgment till
  • Under which is limestone carrying sub artesian water
• 4 Types of bridge pier load

  • Vertical loads
  • Inclined loads
  • Inclined tensions
  • Horizontal thrust
• Bridge foundation design


  • Must consider the specific problem of piers construction
• 3 methods of pier construction

  • Use of open cofferdams (working either in the dry or in water)
  • Use of open dredging caissons
  • Use of compressed air caissons
• Steel pipes up to 52.5 m long


  • Used to format bridge piers in material that could best be described as "soup"
• Caissons


  Must overcome the skin friction associated either sinking through foundation strata
• Frictional resistance


  Can sometimes be overcome by pipe jetting around the cutting edge of caisson
• Cofferdams


  • Common feature of bridge piers and abutments and general foundation work
  • Generally accepted without much thought being given to their geologic environment
• North main pier


  • Founded on basalt
• Basalt


  A hard, dense, dark volcanic rock composed chiefly of plagioclase, pyroxene and olivine and often having a glassy appearance
• South main pier


  • Founded on sandstone
• Sandstone


  A sedimentary rock formed by the consolidation and compaction of sand and held together by natural cement such as silica
• Canadian national railway bridge


  • One of the two six span Canadian national railway
  • Runs over the Miramichi River of New Brunswick
  • Foundation were designed as timber caissons to be floated into place with filled with 'tremie' concrete and topped by masonry piers above water level
• Sir Sanford Fleming


  • A designer, and was gifted with unusual intuition
  • He deducted that the southwest bridge piers would be safe
• Caissons


  A watertight enclosure inside which underwater construction work can be done
• Lethbridge viaduct


  • An outstanding example of benefit work
  • Commonly known as the high level bridge
• Rhaetian railway


  • Largest network of all the private railways in Switzerland
• Grouting


  • One of the most widely used specially techniques in the practice of civil engineering
  • Carried out to overcome geologic defects in foundation beds or to improve upon natural geological conditions
  • Involves injection of semi viscous or slurried materials into each materials under pressure and through specially drilled holes
• Cementation


  Word applied to cases employing a slurry of Portland cement (either alone or mixed with sand)
• Grout


  • Construction material used to embed rears in masonry walls, connect section of pre-cast concrete, fill voids, and seal joints
  • Composed mixture of water, cement, sand and sometimes fine gravel
• Tools associated with applying and removal of grout

  • Grout saw or grout scraper - a manual tool for removal of old and discolored grout. The blade usually composed of tungsten carbide
  • Grout float - tower like tool for smoothing the surface of a grout line typically made of rubber or soft plastic
  • Grout sealer - water based sealant applied over dried grout that resists water, oil and acid based contaminants
• ASCE

  • Known as American society of civil engineering and architects
  • Founded in New York city on Nov. 5, 1852
  • Was the first national engineering society created in the US
• Cement


  The most usual grouting adopted
• Grouting


  Become a means for shaft through water bearing strata
• Tigris


  • Been important transport route in a largely desert country
  • Navigable as far as Baghdad by shallow draft, vessels, but rafts are needed for transport upstream to Mosul