Design Guidelines for Increasing the Lateral Resistance of Highway-Bridge Pile Foundations by Improving Weak Soils. National Cooperative Highway Research Program (NCHRP) Report 697

摘要

National Cooperative Highway Research Program (NCHRP) Report 697: Design Guide lines for Increasing the Lateral Resistance of Highway- Bridge Pile Foundations by Improving Weak Soils presents design guidance for strengthening of soils to resist lateral forces on bridge pile foundations. Lateral loads may be produced by wave action, wind, seismic events, ship impact, or traffic. Strengthening of soil surrounding the upper portions of piles and pile groupsfor example by compaction, replacement of native soil with granular material, or mixing of cement with soilmay be more cost-effective than driving additional piles and extending pile caps as ways to increase the bridge foundations capacity to resist lateral forces associated with these loads. This report presents computational methods for assessing soil-strengthening options using finite-element analysis of single piles and pile groups and a simplified approach employing commercially available software. The analysis methodology and design guidelines will be helpful to designers responsible for bridge foundations likely to be exposed to significant lateral loads.