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CAREER: Decoding the Enigmas of U.S. Seismic Hazard Via Multi-Scale, Multi-Physics Approaches to Paleoliquefaction Analysis

职业：通过多尺度、多物理方法进行古液化分析，破解美国地震灾害之谜

基本信息

批准号：
1751216
负责人：
Brett Maurer
金额：
$ 50万
依托单位：
University of Washington
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1751216&HistoricalAwards=false
关键词：
CAREER Decoding Enigmas U.S.Seismic

项目摘要

This Faculty Early Career Development Program (CAREER) project will contribute knowledge that reduces the uncertainty of seismic hazards in the United States, thereby promoting scientific progress and the nation's prosperity and welfare. Nationally, there are many regions in which seismic hazards are especially uncertain because the return periods of earthquakes are longer than the historic record. In other words, it is known that earthquakes have and will continue to occur, but because prior earthquakes predate human records and/or the advent of seismic instruments, the expected characteristics of future earthquakes are highly uncertain. In these locales, soil liquefaction caused by past earthquakes, termed "paleoliquefaction," may provide the only evidence from which information about the seismic-hazard can be determined, including earthquake magnitudes, locations, and recurrence-rates. As a result, U.S. building codes are heavily influenced by paleoliquefaction evidence, and in turn, so too is public safety. This award supports fundamental research to improve the analysis of paleoliquefaction, which at present suffers from limitations that can lead to highly erroneous results. The findings will not only advance paleoliquefaction analytics, but will also benefit the understanding of liquefaction hazards in general, thus further reducing earthquake impacts on the built and natural environments. In addition, an educational research component will investigate links between seismic risk perception and socio-psychological bias, leading to more effective educational platforms in natural hazards engineering. This CAREER project aims to remove ubiquitous barriers to the accurate inverse-analysis of paleoliquefaction, which will be achieved by bridging fundamental knowledge-gaps at three distinct scales. The research includes: (1) micro-scale physical-numerical investigation of the mechanics controlling the formation and morphology of fluidized dikes and sand boils; (2) meso-scale formulation of a coupled, mechanically-consistent liquefaction triggering and manifestation model; and (3) a macro-scale approach to probabilistically geolocate seismic sources from paleoliquefaction and assess their rupture magnitudes. An analytical framework developed from the fundamental research will then be applied to paleoliquefaction evidence in regions where enigmatic seismic-hazards significantly impact society. These include the Cascadia Subduction Zone of the Northwest U.S.; the New Madrid Seismic Zone of the Central U.S.; the South Carolina Coastal Plain of the Eastern U.S.; and Coastal New England in the Northeast U.S. Aided by physical and numerical multi-scale modeling, field testing, and unprecedented case-history data, this research will advance both paleoliquefaction analytics and the understanding of liquefaction hazards in general, thus reducing future earthquake impacts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这一学院早期职业发展计划(CALEAR)项目将贡献减少美国地震灾害不确定性的知识，从而促进科学进步和国家的繁荣与福祉。在全国范围内，有许多地区的地震危险性特别不确定，因为地震的重现期长于历史记录。换句话说，众所周知，地震已经并将继续发生，但由于以前的地震早于人类记录和/或地震仪器的出现，未来地震的预期特征非常不确定。在这些地区，过去地震引起的土壤液化，被称为“古液化”，可能提供唯一的证据，根据这些证据可以确定地震危险的信息，包括地震强度、位置和复发率。因此，美国的建筑规范受到古液化证据的严重影响，公共安全也是如此。该奖项支持改善古液化分析的基础研究，目前古液化分析受到限制，可能导致高度错误的结果。这些发现不仅将促进古液化分析，还将有助于从总体上了解液化危害，从而进一步减少地震对建筑环境和自然环境的影响。此外，一个教育研究部门将调查地震风险认知和社会心理偏见之间的联系，从而形成更有效的自然灾害工程教育平台。这一职业项目旨在消除对古液化的准确反分析普遍存在的障碍，这将通过弥合三个不同尺度上的基本知识差距来实现。这项研究包括：(1)控制流态化岩脉和砂沸腾形成和形态的微观尺度物理-数值研究；(2)耦合的、力学一致的液化触发和表现模型的介观模型；(3)从古液化中概率地定位震源并评估其破裂强度的宏观尺度方法。根据基础研究建立的分析框架随后将应用于神秘地震灾害对社会产生重大影响的地区的古液化证据。这些地区包括美国西北部的卡斯卡迪亚俯冲区、美国中部的新马德里地震区、美国东部的南卡罗来纳州沿海平原和美国东北部的新英格兰海岸。借助物理和数字多尺度建模、现场测试和史无前例的案例数据，这项研究将促进古液化分析和对液化危险的总体理解，从而减少未来的地震影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。