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

该提案要求资金允许密苏里大学罗拉分校土木工程系Franklin Y. Cheng博士与韩国科学技术院（KAIST）土木工程系Choi chang - kwon博士进行为期24个月的研究。地震动作用下低层钢筋混凝土剪力墙系统非线性行为及边际安全性合作研究。在美国和韩国，低层民用建筑占据了压倒性的比重。对于这种带有钢筋混凝土墙的结构，高宽比很小。在地震荷载作用下，这些墙体经历剪切变形，而不是高层结构墙体所经历的弯曲。目前流行的研究主要针对高层结构在弹性极限内的弯曲变形。另一方面，本合作研究将考虑低高宽比墙体弹性极限与破坏之间的储备强度。在这个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，还将对建筑规范进行评估。在预测高层结构在多分量地震输入作用下的性能方面已经取得了相当大的进展。在预测低层结构的性能、提高它们承受地震载荷的能力和修复结构的强度方面，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先前的工作处理了一个宏观元素公式模型，该模型可靠地预测了结构系统的响应，但不能提供单个墙壁局部变形的详细信息。韩国PI在微元素分析方面有经验，可以用来观察局部变形。他们的模型在考察系统和单元变形之间的关系方面是互补的。这个项目所解决的问题将对美国和韩国有利。该项目与美韩合作科学项目的目标相关，该项目旨在通过科学信息、思想、技能和技术的交流以及在互利问题上的合作，提高美韩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.