Soil Nailing and Geosynthetic Reinforcement for Seismic Loads

*** Michalowski 9634193在过去的几年里，在美国和日本的主要地震事件之后，人们对加筋土结构的兴趣增加了。加筋土结构在地震中表现得很好，几乎没有表现出结构上的破坏。本项目研究此类结构的稳定性分析。考虑了土钉和土工合成加固，并考虑了地震荷载作为基础加速度模式。两个主要目标是：(a)在理解土壤加固机制方面取得进展，包括一些“非传统”的合成加固，如薄连续细丝；(b)发展用土钉或土工合成材料加固土壤结构的分析和合成技术，并以一种对设计实践有用的方式展示结果。分析是基于塑性理论的定理。土钉或土工合成材料的贡献是通过在能量平衡方程中包含额外的功耗散项来解释的。研究了颗粒土塑性流动的非结合性对稳定性分析结果的影响。考虑的结构荷载包括自重、作为边界荷载施加的力以及由于地震加速度（基底震动）引起的惯性力。这项研究将通过对土钉或土工合成增强结构的稳定性进行新的分析，并通过开发一种新的方法来模拟用连续螺纹（细丝）加固的土壤，从而促进该领域的知识状态。它也将有助于工程设计实践。我们将努力创建有用的设计图。

*** Michalowski 9634193 There has been an increase in interest in reinforced soil structures following the major seismic events in the U.S. and in Japan in the last few years. Reinforced soil structures appear to have performed very well during earthquakes, and showed little structural distress. This project addresses the stability analysis of such structures. Both soil nailing and geosynthetic reinforcement are considered, and seismic loads, given as patterns of base acceleration, are accounted for. Two major objectives are: (a) progress in understanding of soil reinforcement mechanisms, including some "non-traditional" synthetic reinforcement such as thin continuous filament, and (b) development of techniques for analysis and synthesis of soil structures reinforced with soil nails or geosynthetics, and presenting results in a manner useful for design practice. The analysis is based on the theorems of plasticity theory. The contribution of soil nails or geosynthetics are accounted for through inclusion of additional work dissipation terms in the energy balance equation. An effort is made to investigate the influence of non-associativity of plastic flow of granular soils on the results of the stability analysis. The structural loads considered include self-weight, forces applied as boundary loads, and inertial forces due to seismic acceleration (base shaking). This research will contribute to the state of knowledge in the area through development of a new analysis for stability of soil-nailed or geosynthetic-reinforced structures, and through development of a new approach to modeling of soils reinforced with continuous thread (filament). It will also contribute to engineering design practice. An effort will be made to create useful design charts.