DEFORMATION-BASED DESIGN OF GEOTECHNICAL COMPOSITE FOUNDATION SYSTEMS INCORPORATING COLUMNAR SUPPORT WITH OR WITHOUT GEOSYNTHETIC REINFORCEMENT

结合有或没有土工合成材料加固的柱支撑的土工复合基础系统的基于变形的设计

• 批准号: 0408281
• 负责人: George Filz
• 金额: --
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-15 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0408281&HistoricalAwards=false
• 关键词: DEFORMATION; BASED; DESIGN; GEOTECHNICAL; COMPOSITE

An important type of geotechnical composite system incorporates columns of strong material installed in soft clay, with an overlying layer of coarse-grained soil that may include geosynthetic reinforcement. The purpose of the overlying "bridging" layer is to transfer loads from embankments or structures into the columns, thereby reduceing differential settlements. Existing design methods for such systems provide widely-varying requirements for geosynthetic reinforcement, and there is no consensus regarding which of these methods, if any, is accurate. Furthermore, none of the existing methods provide means for predicting differential settlement magnitudes. This research will include (a) pilot-scale tests of square and round columns moving up into a geosynthetic-reinforced soil layer; (b) new data collection from two contemporary, full-scale field installations, (c) three-dimensional mathematical analysis of the behavior of geosynthetic reinforcement layers considering orthotropy, orientation, and stress concentrations, and (d) three-dimensional numerical analysis of the entire geotechnical composite system. These tasks will be coordinated to determine the effects of the important system parameters, including: the layout, spacing, diameter, stiffness, and strength of the columns; the size and shape of caps on top of the columns; the material properties, depth, orientation, and ultimate strength of the geosynthetic layer(s); the properties of the bridging layer above the columns; the properties of the soft clay between the columns; the depth of the bridging layer; the interface behavior at the top and bottom of each geosynthetic layer; and the surface loading. The broader impacts of this research include the development of tools for more economical and reliable design of foundation systems for transportation embankments and structures. The investigators will engage minorities, women, and undergraduates in their research. They will involve interested individuals, committees, and organizations from the U.S. and international community in the research, and they will promote communication, networking, and partnerships related to geotechnical composite foundation systems incorporating columnar support and geosynthetic reinforcement.

岩土复合系统的一种重要类型结合了安装在软粘土中的强材料柱，其中包含一层粗粒土壤，其中可能包括地质合成增强。 上覆的“桥接”层的目的是将载荷从路堤或结构转移到列中，从而减少差分定居点。 现有的此类系统的设计方法为地理合成增强提供了广泛不同的要求，并且关于哪种方法（如果有的话）尚无共识。 此外，现有的方法均未提供用于预测差分结算幅度的手段。 这项研究将包括（a）正方形和圆形柱的试验尺度测试，向上移动到土工合成的土壤层； （b）从两个现代的全尺度现场安装中收集的新数据，（c）考虑到异端，方向和应力浓度的地理合成增强层的行为的三维数学分析，以及（d）对整个地球技术组合系统的三维数值分析。 这些任务将进行协调以确定重要系统参数的影响，包括：布局，间距，直径，刚度和柱的强度；圆柱顶部的帽子的大小和形状；地质层的材料特性，深度，方向和最终强度；列上方的桥接层的性质；列之间软粘土的特性；桥接层的深度；每个土工合成层顶部和底部的界面行为；和表面载荷。 这项研究的更广泛的影响包括开发用于更经济和可靠的基础系统用于运输路堤和结构的工具。 调查人员将与少数民族，妇女和本科生一起研究。 他们将涉及来自美国和国际社会的感兴趣的个人，委员会和组织在研究中，并将促进与岩土技术复合基础基础系统有关的沟通，网络和合作伙伴，并结合了柱状柱子支持和地质合成增强。