Structural Considerations and Implications Related to Foundation Movements in AASHTO LRFD

In the United States, highway bridge design practice is based on the Load and Resistance Factor Design (LRFD) method developed by the American Association of State Highway and Transportation Officials (AASHTO). In AASHTO LRFD, which is based on the concept of limit states, the effect of foundation movements on structural elements is expressed as a force effect rather than a geotechnical resistance. In fact, all design codes worldwide recognize this observation by including a representation of structural effects of foundation movements as a force. AASHTO LRFD uses the designation “SE” for the geotechnical demands to be considered. An associated load factor, γSE, is specified for each load combination where SE is applicable. The product of γSE and SE is the factored demand, or factored force. The structural effect of foundation movements is manifested in the form of additional force effects such as induced torques, moments, and shears in a bridge structure that can lead to adverse consequences such as cracking. In AASHTO LRFD, the SE load factor occurs in four out of the five load combinations for Strength Limit State and three out of the four load combinations for Service Limit State. This paper presents a study that explores the structural considerations and implications related to use of SE load factor and the effects of foundation movements in AASHTO LRFD.

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  • English

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  • Accession Number: 01849826
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Jun 27 2022 11:37AM