Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Case Histories of Problems with Timber Piles
The object of this publication is to alert readers about the problems and unknowns associated with timber piling. Included are 21 case histories of problems with treated wood piling dealing with installation, usage, marine effects, and environmental impacts. Eight of the case histories concern the most serious problem, the breakage of timber piling during construction (see Figure 1). Usage problems include downdrag, settlement, degradation of wood, and potential fire hazards. Problems in salt-waters include marine borer attack, Chromated Copper Arsenate (CCA) sheathing that fails in about 10-years, breaking from impact forces, and excessive spiral grain. Environmental problems involve preservatives leaching into the water. The three major building codes, BOCA, SBC, and UBC, publish creosote treated timber piling compressive design stresses of 8.6 MPa (1250 psi) for Douglas fir and 8.3 MPa (1200 psi) for southern pine. Compression parallel to grain tests on southern pine timber piling give average values as low as 15.5 MPa (1820psi). The result is an inadequate safety factor of about 1.5. To be safe, engineers should consider designing creosote treated piling with 6.2 MPa (900) psi for Douglas fir and 5.5 MPa (800 psi) for southern pine.
Case Histories of Problems with Timber Piles
The object of this publication is to alert readers about the problems and unknowns associated with timber piling. Included are 21 case histories of problems with treated wood piling dealing with installation, usage, marine effects, and environmental impacts. Eight of the case histories concern the most serious problem, the breakage of timber piling during construction (see Figure 1). Usage problems include downdrag, settlement, degradation of wood, and potential fire hazards. Problems in salt-waters include marine borer attack, Chromated Copper Arsenate (CCA) sheathing that fails in about 10-years, breaking from impact forces, and excessive spiral grain. Environmental problems involve preservatives leaching into the water. The three major building codes, BOCA, SBC, and UBC, publish creosote treated timber piling compressive design stresses of 8.6 MPa (1250 psi) for Douglas fir and 8.3 MPa (1200 psi) for southern pine. Compression parallel to grain tests on southern pine timber piling give average values as low as 15.5 MPa (1820psi). The result is an inadequate safety factor of about 1.5. To be safe, engineers should consider designing creosote treated piling with 6.2 MPa (900) psi for Douglas fir and 5.5 MPa (800 psi) for southern pine.
Case Histories of Problems with Timber Piles
Graham, James S. (Autor:in) / Johnsen, Lawrence F. (Autor:in)
International Deep Foundations Congress 2002 ; 2002 ; Orlando, Florida, United States
Deep Foundations 2002 ; 587-603
01.02.2002
Aufsatz (Konferenz)
Elektronische Ressource
Englisch
Case Histories of Problems with Timber Piles
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