Collaborative Research: Engineered Earth Masonry for Affordable Seismic Resistant Low-Rise Buildings

合作研究：经济适用的抗震低层建筑的工程土砌体

• 批准号: 1537078
• 负责人: Michele Barbato
• 金额: $ 16.5万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1537078&HistoricalAwards=false
• 关键词: Collaborative; Research; Engineered; Earth; Masonry

There is a continuing demand in the United States for sustainable and hazard-resilient but highly affordable low-rise buildings for households and businesses. The goal of this research project is to investigate the feasibility of high-quality reinforced earth masonry (REM) for seismic resistant low-rise buildings. This goal will be achieved by transforming sustainable and locally appropriate but brittle unfired earth masonry into a stronger and more ductile system by using non-biodegradable recycled plastic fibers combined with internal steel reinforcement. This research will investigate REM as a low-cost option for low-rise industrial buildings and sheds, with a vision of fostering the development of small plants and warehouses by reducing construction and maintenance costs, thus promoting economic development. The technical objectives of this research are the following: (1) to engineer, prototype, and verify an affordable and high-quality REM system for seismic resistant low-rise buildings, and (2) to formulate, verify and implement a new numerical model to accurately and efficiently predict the structural response of REM walls. The hypotheses are:v(1) engineering of earth blocks and mortar stabilized with nine percent or less cement, and reinforced with one percent or less volume fraction of recycled plastic fibers, combined with internal steel reinforcement, will change the strength and ductility of REM, making it suitable for seismic resistant buildings, and (2) computationally efficient numerical models based on newly developed nonlinear macroelements (MEs), whose kinematics are described by the smallest possible number of degrees of freedom, will enable the accurate prediction of the response of REM structures subject to static and dynamic loads. This research will be conducted in three phases. First, selected prototype block-mortar combinations (unreinforced, fiber reinforced, and fiber reinforced with grouted steel bars) will be characterized through load testing of materials and assemblages. A candidate reinforced system will be selected for the second phase. Three-dimensional (3D) digital image correlation (3D-DIC) will be used to measure full-field deformation maps and inform the development of numerical models. The resulting constitutive models for materials, mortar joints, and REM assemblages will serve to formulate detailed finite element (FE) models. Second, performance data will be obtained through large-scale testing and 3D-DIC monitoring of REM walls subject to quasi-static cyclic loading. The results will inform the formulation and validation of new structural ME models and their FE code implementation. Third and final, ME-based FE models of the large-scale specimens will be developed based on the comparison between numerical and experimental results. The resulting first-generation ME models will be used for a preliminary estimate of seismic design coefficients and factors to establish feasibility. In addition, a preliminary quantification of sustainability-related parameters and construction cost for representative REM materials and buildings will be performed to provide a basis for comparison with alternative systems, for example, light-framed wood, as well as life-cycle cost analysis.

在美国，家庭和企业对可持续的、抗灾的、价格合理的低层建筑有着持续的需求。本研究项目的目的是探讨优质加筋土砌体（REM）在抗震低层建筑中的可行性。通过使用不可生物降解的再生塑料纤维与内部钢筋相结合，将可持续的、适合当地的、易碎的未燃土砌体转化为更坚固、更延展性的系统，从而实现这一目标。这项研究将调查REM作为低层工业建筑和棚屋的低成本选择，通过减少建筑和维护成本来促进小型工厂和仓库的发展，从而促进经济发展。本研究的技术目标如下：(1)设计、原型和验证一种经济实惠、高质量的低层建筑抗震REM系统；(2)制定、验证和实施一种新的数值模型，以准确有效地预测REM墙的结构响应。假设是：v(1)土块和砂浆工程用9%或更少的水泥稳定，并用1%或更少的再生塑料纤维体积分数进行加固，结合内部钢筋，将改变REM的强度和延性，使其适用于抗震建筑；(2)基于新发展的非线性宏单元（MEs）的计算效率高的数值模型。其运动学由尽可能少的自由度来描述，将能够准确预测REM结构在静、动载荷作用下的响应。本研究将分三个阶段进行。首先，选定的原型砌块-砂浆组合（未增强、纤维增强和纤维增强与灌浆钢筋）将通过材料和组合的负载测试来表征。第二阶段将选择候选加固系统。三维（3D）数字图像相关（3D- dic）将用于测量全场变形图并为数值模型的开发提供信息。由此产生的材料、砂浆接缝和REM组合的本构模型将用于制定详细的有限元（FE）模型。其次，对准静态循环荷载作用下的REM墙体进行大规模试验和3D-DIC监测，获取性能数据。结果将为新的结构ME模型的制定和验证及其有限元代码的实施提供信息。第三步也是最后一步，基于数值结果和实验结果的对比，建立大型试件的有限元模型。由此产生的第一代ME模型将用于初步估计地震设计系数和因素，以确定可行性。此外，将对代表性REM材料和建筑物的可持续性参数和建筑成本进行初步量化，以便为与其他系统（例如轻框架木材）进行比较以及生命周期成本分析提供基础。

项目成果

Feasibility Study of Affordable Earth Masonry Housing in the U.S. Gulf Coast Region

美国墨西哥湾沿岸地区经济适用土砌体住房的可行性研究

• DOI: 10.1061/(asce)ae.1943-5568.0000311
• 发表时间: 2018
• 期刊: Journal of Architectural Engineering
• 影响因子: 2
• 作者: Kumar, Nitin;Barbato, Michele;Holton, Robert
• 通讯作者: Holton, Robert

Multihazard Interaction Effects on the Performance of Low-Rise Wood-Frame Housing in Hurricane-Prone Regions

多灾害相互作用对飓风多发地区低层木结构房屋性能的影响

• DOI: 10.1061/(asce)st.1943-541x.0001797
• 发表时间: 2017
• 期刊: Journal of Structural Engineering
• 影响因子: 4.1
• 作者: Unnikrishnan, Vipin U.;Barbato, Michele
• 通讯作者: Barbato, Michele