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Wave-induced Liquefaction and Sediment Transport in Coastal Environment

沿海环境中波浪引起的液化和沉积物迁移

基本信息

批准号：
13450192
负责人：
SEKIGUCHI Hideo
金额：
$ 10.69万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

This research project aims at developing an integrated framework by which to describe consistently the processes of wave-induced liquefaction, fluidization and sediment transport that have profound practical implications in coastal environment. The principal results obtained may be summarized as follows :1)Effect of wave-loading history upon liquefaction resistance of sandy sediments ; A series of centrifugal wave tests with carefully designed wave-loading histories showed that re-liquefaction resistance increased significantly due to marked densification that had occurred through "solidification" in the preceding wave-loading stage.2)Development of a computational model for sediment gravity flow ; A three-dimensional analysis procedure for sediment gravity flow (3D-LIQSEDFLOW) has been developed in the research project. The liquefied soil is modeled as a heavy viscous fluid and a soil domain undergoing solidification is described in terms of elastoplastic consolidation theory. The free and solidification surfaces during flowage are traced using a VOF technique, facilitating analyses of a range of moving-boundary problems such as underwater sediment-dam breaking problems.3)Mechanisms of sediment gravity flow and ensuing re-deposition ; The way in which liquefied sediment flows out and comes to a rest, was investigated in laboratory flume tests with a PIV technique introduced. The results clearly demonstrate how the initially fluid-like body of sediment with a high concentration underwent solidification in the course of flowage, eventually coming to an abrupt stop or "freezing".

该研究项目旨在开发一个综合框架，通过该框架一致地描述在沿海环境中具有深刻实际意义的波浪诱导液化、流化和沉积物输运过程。本文的主要研究结果如下：1）波浪荷载历史对桑迪沉积物抗液化强度的影响：一系列离心波浪试验表明，由于波浪荷载作用前一阶段沉积物的“固化”作用，使沉积物的再液化强度显著提高。本研究开发了一套泥沙重力流三维分析程序（3D-LIQSEDFLOW）。液化土被模拟为一种重粘性流体，并根据弹塑性固结理论描述了一个正在进行固化的土域。流动过程中的自由表面和固化表面的跟踪使用VOF技术，便于分析一系列的移动边界问题，如水下泥沙溃坝问题。3）沉积物重力流和随后的再沉积的机制;在液化泥沙流出和到达休息的方式，在实验室水槽试验中引入PIV技术进行了研究。结果清楚地表明，最初的高浓度流体状沉积物如何在流动过程中凝固，最终突然停止或“冻结”。