U.S.-Japan Cooperative Science: Use of Reinforcement-Drainage Geosynthetics in Embankment/Wall Construction with Marginal Backfill

0355430韩杰奖支持一项为期三年的国际合作研究项目，该项目由宾夕法尼亚州切斯特市沃勒尔大学的韩杰教授、特拉华州大学的Dov Leshchinsky教授和J.C.柴在日本佐贺大学。 他们将研究在有边缘回填的路堤/墙施工中使用防水水泥-排水土工合成材料。 土工合成材料已成功地用作以下功能中的一种或组合：加固、排水、分离、过滤和/或在土结构中的容纳。 在目前的路堤/墙施工中，土工合成材料主要用作加固路堤/墙的稳定性。 目前的规范要求使用高质量，自由排水，颗粒回填建造机械稳定土（MSE）挡土墙。 然而，由于经济和可用性的限制，边缘回填（包括粘性回填）已越来越多地用于建造隔离墙/墙。 许多研究表明，回填土中细粒颗粒的增加将使回填土更容易受到水分/水的影响。 回填土中水的有害影响是降低强度和模量，增加变形（包括蠕变变形），并通过增加土压力和诱导渗透力使土结构不稳定。 当使用边缘回填时，使用土工合成材料进行排水和加固对填料/墙的性能至关重要。 研究内容包括：（1）土工合成材料的排水特性，特别是土工合成材料在边缘土中的长期渗透特性;（2）土工合成材料层间边缘土的固结特性;（3）土工合成材料与边缘土的相互作用特性，包括直接滑动和拔出;（4）土工合成材料与边缘土的相互作用特性。以及4）使用具有或不具有排水功能的土工合成加固物的围护结构/墙壁的稳定性。 该项目汇集了具有互补专门知识和研究能力的实验室的努力。 该研究将对加筋-排水土工合成材料在边缘土路堤/墙施工中的应用产生影响，并为使用这些双重功能土工合成材料的土工结构设计提供指导。 该项目通过一名博士后和一些本科生的参与促进国际人力资源。 通过交流思想和技术，该项目将扩大我们的基础知识，促进国际理解与合作。 研究结果将在科学会议和科学期刊上传播。 这项研究也将在互联网上公布。

0355430HanThis award supports a three-year international collaborative research project between Professor Jie Han at Widener University in Chester, Pennsylvania, Professor Dov Leshchinsky at the University of Delaware and Professor J. C. Chai at Saga University in Japan. They will undertake a study on the use of reinforcement-drainage geosynthetics in embankment/wall construction with marginal backfill. Geosynthetics have been successfully used as one or a combination of the following functions: reinforcement, drainage, separation, filtration, and/or containment in earth structures. In current embankment/wall construction, geosynthetics have been mostly used as reinforcement for the stability of embankments/walls. Current specifications require the use of high-quality, free-draining, granular backfill for constructing mechanically stabilized earth (MSE) retaining walls. However, marginal backfill including cohesive backfill has been increasingly used to construct embankments/walls due to economic and availability constraints. Many studies have indicated that an increase of fine-grained particles in backfill would make the backfill more susceptible to moisture/water. The detrimental effects of water in the backfill are to reduce strength and modulus, increase deformations (including creep deformation), and destabilize earth structures by increasing earth pressures and inducing seepage forces. When marginal backfill is used, use of geosynthetics for drainage as well as reinforcement becomes critical to the performance of embankments/walls. The researchers will be studying the following areas: 1) the drainage behavior of the geosynthetics, especially the long-term transmissivity of geosynthetics confined in marginal soil; 2) the consolidation behavior of marginal soil between layers of geosynthetics; 3) the interaction behavior between geosynthetics and marginal soil including direct sliding and pullout; and 4) the stability of embankments/walls using geosynthetic reinforcement with or without a drainage function. The project brings together the efforts of laboratories that have complementary expertise and research capabilities. The research will have an impact on the use of reinforcement-drainage geosynthetics in embankment/wall construction with marginal soil and provide guidance for the design of earth structures using these dual function geosynthetics. The project advances international human resources through the participation of a postdoc and a number of undergraduate students. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. Results of the research will be disseminated at scientific meetings and in scientific journals. The research will also be made available on the Internet.