US-Korea Cooperative Research on Nonlinear Behavior and Marginal Safety of Low-Rise Reinforced Concrete Shear Wall Systems Against Interacting Ground Motions

该提案请求拨款，以允许密苏里大学罗拉分校土木工程系Franklin Y.Cheng博士与韩国高级科学技术学院(KAIST)土木工程系Chang-Koon Choi博士进行为期24个月的研究，低层钢筋混凝土剪力墙体系在相互作用地震动作用下的非线性行为和边际安全性的合作研究计划。在美国和韩国，低层民用建筑占建筑建设的压倒性比例。对于有钢筋混凝土墙的这类结构，高宽比较小。在地震荷载作用下，这些墙经历的是剪切变形，而不是较高结构中的墙所经历的弯曲。目前流行的研究主要涉及高层结构在弹性极限范围内的弯曲变形。另一方面，本次合作研究将考虑低高宽比墙体的弹性极限和破坏之间的储备强度。在这一范围内的结构行为是非线性的，必须开发新的分析模型来预测新结构和修复结构的行为。这些模型将根据实验结果进行测试和验证。损伤研究将基于实验行为和计算结果。此外，还将评估建筑规范规范。在预测高层结构在多分量地震作用下的行为方面已经取得了很大进展。要预测低层结构的行为，提高其抵御地震荷载的能力，以及修复后的结构的强度，还有很多工作要做。这个项目的合作者非常适合承担这样的工作。美国PI之前的工作涉及一个宏观单元公式模型，该模型可以可靠地预测结构体系的响应，但没有提供关于个别墙的局部变形的详细信息。韩国的PI在微量元素分析方面有经验，可以用来观察局部变形。他们的模型在检验系统变形和元素变形之间的关系方面是互补的。该项目所解决的问题的解决方案将有利于美国和韩国。该项目与美韩合作科学计划的目标相关，该计划旨在通过交流科学信息、想法、技能和技术以及通过在互利问题上的合作来提高美国和韩国科学家和工程师之间的合作水平。

This proposal requests funds to permit Dr. Franklin Y. Cheng, Department of Civil Engineering, University of Missouri-Rolla, to pursue with Dr. Chang-Koon Choi, Department of Civil Engineering, Korea Advanced Institute of Science and Technology (KAIST) for a period of 24 months, a program of cooperative research on nonlinear behavior and marginal safety of low-rise reinforced concrete shear wall systems against interacting ground motions. Low-rise civilian buildings comprise the overwhelming percentage of building construction in the U.S. and Korea. For such structures with reinforced concrete walls, the height-to-width ratios are small. Under seismic loads, these walls experience shear deformation rather than the bending experienced by walls in taller structures. Research currently in vogue deals mainly with bending deformation of high-rise structures within the elastic limit. The present cooperative research, on the other hand, will consider the amount of reserve strength between the elastic limit and failure for walls of low height-to-width ratios. Structural behavior in this range is nonlinear, and new analytical models must be developed to predict the behavior of new and repaired structures. These models will be tested and verified against experimental results. Damage studies will be based on experimental behavior and calculated results. In addition, building code specifications will be assessed. Considerable progress has been made in predicting the behavior of high-rise structures subjected to multicomponent seismic input. Much remains to be done toward predicting the behavior of low-rise structures, improving their ability to withstand earthquake loads, and the strength of rehabilitated structures. The collaborators on this project are well suited to undertake such work. The U.S. PI's previous work has dealt with a model of macro-element formulation which reliably predicts the response of structural systems but does not yield detailed information on localized deformations of individual walls. The Korean PI has experience in micro-element analysis which can be used for observing localized deformations. Their models are complementary for examining the relationship between system and element deformations. The solution to the problems addressed by this project would be beneficial to the United States and Korea. This project is relevant to the objectives of the U.S.-Korea Cooperative Science Program which seeks to increase the level of cooperation between U.S. and Korean scientists and engineers through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit.