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Seismic Design of Geosynthetic-Reinforced Soil (GRS) Bridge Abutments with Flexible Facing

项目名称：	Seismic Design of Geosynthetic-Reinforced Soil (GRS) Bridge Abutments with Flexible Facing
摘要：	Geosynthetic-reinforced soil (GRS) systems, in which the soil mass is reinforced in layers with a polymeric geosynthetic (e.g., strips, grids, or sheets) and, in most typically used systems, the layered reinforcement is fixed to facing elements that constitute the outer wall, have over the past several decades been used to construct retaining walls, embankments, slopes, and shallow foundations. GRS systems may have rigid or flexible facings; the latter entail use of dry-stacked modular concrete blocks, timber members, large rocks, gabions, or other segmental materials. Experience has demonstrated that GRS systems, particularly those with flexible facing, offer a low-cost, easily constructed, and structurally reliable alternative to conventional designs in many applications. An application that has gained increasing interest in recent years is bridge abutments, where GRS system advantages can include enhanced tolerance of differential foundation settlement, greater adaptability to low-quality backfill, and faster and technically less demanding construction methods. Full-scale tests and some in-service demonstration projects have confirmed these advantages, but the lack of rational, reliable design and construction guidelines for GRS bridge abutments impedes wider adoption of this promising technology. National Cooperative Highway Research Program (NCHRP) Report 556: Design and Construction Guidelines for Geosynthetic-Reinforced Soil Bridge Abutments with a Flexible Facing, provides guidelines for static loading conditions. To facilitate their acceptance by engineering practitioners, the design methods presented in that report adopt the format and methodology of guidelines issued by the National Highway Institute, American Association of State Highway and Transportation Officials, Federal Highway Administration, and other organizations. To advance this new technology, especially in seismically active regions, it is essential to develop a rational design method and associated construction guidelines for GRS bridge abutments that address seismic loads and the dynamic interaction of GRS abutments with the bridge superstructure. This research aims at developing such guidelines. The research will build on current seismic design methods for GRS segmental walls, which can be divided into two categories: pseudo-static methods and displacement methods. Design methods in both categories have been developed for situations where the self-weight of the soil is the predominant load; these methods are not intended to apply specifically for GRS bridge abutment walls where the top surface is generally subject to large, sustained, and often eccentric loads. The research will include shake-table testing and dynamic finite-element parametric analysis. The research results will supplement the guidelines presented in NCHRP Report 556 to represent a comprehensive basis for application of GRS systems with flexible facing in bridge abutments.
状态：	Completed
资金：	300000.00
资助组织：	Federal Highway Administration<==>American Association of State Highway & Transportation Officials (AASHTO)<==>National Cooperative Highway Research Program
项目负责人：	Lemer, Andrew C
执行机构：	University of Wisconsin, Milwaukee
开始时间：	20060918
实际结束时间：	20120229
主题领域：	Bridges and other structures；Geotechnology；Highways；Research；I30: Materials