Seismic Analysis of Soil Nailed Retaining Structures

9224479 Vucetic本研究项目研究了土钉支护对基坑土体的抗震加固。土钉支护是一种原位土加固技术，在过去的二十年中已经在各种土木工程中得到了试验和应用。基本概念包括在挖掘过程中在地面放置被动包裹体（钢筋），以抑制位移，限制挖掘期间和之后的减压，并形成一个类似于软挡土墙的钉钉体。地震后的现场调查和室内研究表明，土钉结构具有较高的抗震性能。然而，迄今为止，仅进行了有限的研究来评估它们在地震荷载下的响应和可能的破坏机制。开发可靠的设计方法需要这样的研究。随着土钉技术的日益普及，本研究项目将对岩土设计及建造业产生重大影响。该项目包括数值分析、实验室实验（使用土工离心机使小尺度模型承受水平震动）和震后观测。这种综合方法提供了对土钉系统地震反应的透彻理解，并将为其抗震设计提供具体的工程指导。这是加州大学洛杉矶分校和纽约理工大学的合作项目，实验是在伦斯勒理工学院的土工离心机上进行的。

9224479 Vucetic This research project addresses the reinforcement of soil excavations to resist earthquake shaking through the use of soil nailing. Soil nailing is an insitu soil reinforcement technique that has been tested and implemented during the past twenty years in a variety of civil engineering applications. The fundamental concept consists of placing in the ground passive inclusions (steel reinforcing bars) as the excavation proceeds, in order to restrain displacements, limit decompression during and after the excavation, and to form a nailed mass that can behave similarly to a soft retaining wall. Post-earthquake field investigations and laboratory studies have shown that soil-nailed structures are highly resistant to earthquake loading. However, to date, only limited studies have been conducted to evaluate their response and possible failure mechanisms under seismic loading. Such research is needed to develop reliable design methodologies. Given the increasing popularity of soil nailing, this research project will have considerable impact on the geotechnical design and construction industries. This project involves numerical analyses, laboratory experiments -- in which a geotechnical centrifuge is used to subject small-scale models to horizontal shaking -- and post- earthquake observations. This integrated approach provides a thorough understanding of the seismic response of soil- nailed systems, and will result in specific engineering guidelines for their seismic design. This is a collaborative project involving the University of California at Los Angeles and the Polytechnic University, New York, with the experiments being performed on the geotechnical centrifuge at Rensselaer Polytechnic Institute.