SGER: Critical Appraisal of Research Needs for SMF Connections in Steel Buildings

SGER：钢结构SMF连接研究需求的关键评估；CMS建议0335718 PI：宾夕法尼亚州立大学的琳达·哈纳根1994年北岭地震后，钢结构弯矩连接被发现意外损坏。为了解决这一重大安全问题，联邦紧急事务管理局(FEMA)资助了SAC合资企业，该合资企业制作了FEMA 350系列指南文件、最新报告和其他出版物。随后，这些调查结果被纳入了新建筑的建筑规范要求。自这些指南文件发布以来，美国钢结构协会(AISC)通过不断制定协商一致的标准《钢结构建筑抗震规定》(AISC，2002)，将钢结构建筑设计和施工的许多建议正式化为要求。通过这种方式，将从北岭地震中吸取的教训纳入新建筑规范要求的工作正在进行中。由于FEMA 350系列文件不是共识标准，其中包含的建议必须经过采纳过程。目前，《钢结构建筑抗震规定》(AISC，2002)将梁柱连接要求归类为特殊弯矩框架。这些要求的实质是不仅要提供足够的强度，而且要提供足够的延性。符合这一要求可以通过两种方式之一来满足：通过测试或使用符合《抗震规定》附录P的“预鉴定”的连接。为了减少对基于项目的测试的需求，AISC正在通过其连接资格预审小组(CPRP)制定一项共识标准。该标准预计将仿效FEMA 350，因为它将概述几个连接的设计、细节和制造程序，这些连接被认为是预审的，而不需要进一步的测试。前提是对一系列典型连接进行了充分的测试和评估，以便将它们纳入协商一致标准。事实上，当时的希望是，联邦应急管理局350号的建议可以全部通过，但稍作修改。自从FEMA 350发布以来，其中包含的许多建议都受到了加州结构工程师协会(SEAOC)和其他机构的质疑。除RBS连接外，其他所有连接(WUF-W、FF、WFP、BFP)在SEAOC的评论中都获得了负面评级。CPRP将认真考虑SEAOC和其他方面提出的关切。目前，CPRP内的任务小组正在审查联邦应急管理局350号建议和支持数据，以确保符合《地震规定》(AISC 2002)中规定的资格预审要求。如果不立即对一些关键问题进行调查，预审连接标准的第一版很可能只包含RBS连接，该标准将有效地管理地震区的所有钢框架结构。在如此多的资源被投入到这个主题上之后，这对建筑业来说将是一个非常不幸和不必要的结果。PROPOSED研究由于SAC合资企业的大部分研究是平行进行的，对个人联系的研究没有回溯分析的好处。有了一些探索性的资金，PI作为CPRP成员的作用可以扩展到实现三个额外的目标：1)审查现有的文献和测试数据，以了解将连接的具体结果外推到其他连接的可能性。实现这一目标可能会导致更多连接被包括在AISC连接资格预审标准中。2)制定一套通过CPRP和PI的工作确定的当前研究需求。作为CPRP的成员之一，PI在确定扩展AISC标准以包括更多FEMA 350推荐连接所需的研究方面处于某种独特的地位。3)制定一项研究提案，在NEES联盟方案下提交，以满足目标2下确定的一些关键研究需求。SGER JUSTIFICATION他的研究可以说具有“严重紧迫性”，因为实现这些目标有赖于已经开始的CPRP的审议。预计在拟议研究举措下开展的工作将对制定鞍钢集团资格预审标准产生近乎立竿见影的影响。如果没有拟议研究提供的切线重点，在进行进一步调查之前，CPRP可能会使RBS以外的许多关于连接的工作变得毫无用处。

SGER: Critical Appraisal of Research Needs for SMF Connections in Steel Buildings; CMS proposal 0335718 PI: Linda Hanagan, Penn State UniversityFollowing the 1994 Northridge earthquake, unexpected damage was discovered in steel moment connections. To address this substantial safety issue, the Federal Emergency Management Agency (FEMA) funded the SAC Joint Venture, which produced the FEMA 350-series guideline documents, state of the art reports and other publications. Subsequently, theses findings have been incorporated into the building code requirements for new buildings. Since the publication of these guideline documents, the American Institute of Steel Construction (AISC) has formalized as requirements many of the recommendations made for steel building design and construction through the ongoing development of the consensus standard Seismic Provisions for Structural Steel Buildings (AISC, 2002). In this way, work is ongoing to incorporate the lessons learned from the Northridge earthquake into the building code requirements for new buildings.Because the FEMA 350-series documents are not consensus standards, the recommendations contained therein must undergo an adoption process. Presently, the Seismic Provisions for Structural Steel Buildings (AISC, 2002) define the beam-to-column connection requirements for classification as a special moment frame. The essence of these requirements is to provide not only adequate strength, but also adequate ductility. Conformance with this requirement can be satisfied in one of two ways: by testing or by using a connection "prequalified" in accordance with Appendix P of the Seismic Provisions. To alleviate the need for project based testing, AISC, through its Connections Prequalification Review Panel (CPRP), is in the process of developing a consensus standard. This standard is expected to be modeled after FEMA 350 in that it will outline design, detailing, and fabrication procedures for several connections that are considered prequalified without further testing. The premise is that adequate testing and evaluation has been conducted for a range of typical connections such that they can be included in the consensus standard. In fact, the hope was that the recommendations of FEMA 350 could be adopted in their entirety with some minor modification. Since the publication of FEMA 350, many of the recommendations contained therein have been brought into question by the Structural Engineers Association of California (SEAOC) and others. With the exception of RBS connection, every other connection (WUF-W, FF, WFP, BFP) have received an unfavorable rating in the SEAOC Commentary. The CPRP will seriously consider the concerns raised by SEAOC and others. Currently, task groups within the CPRP are reviewing the FEMA 350 recommendations and the supporting data for conformance with prequalification requirements set forth in the Seismic Provisions (AISC 2002). Without immediate investigation into some of the critical concerns, it is very possible that the first edition of the prequalified connections standard, which will effectively govern all steel moment frame construction in seismic areas, will contain only the RBS connection. After so many resources were dedicated to this topic, this would be a very unfortunate and unnecessary result for the building industry.PROPOSED RESEARCHBecause most of the SAC Joint Venture research was done in parallel, the research on individual connections did not have the benefit of retrospective analysis. With some exploratory funding the PI's role as a CPRP member can be extended to accomplish three additional objectives: 1) Review existing literature and test data for the possibility of extrapolating connection specific results to other connections. Accomplishing this objective may have the result of more connections being included in the AISC connection prequalification standard. 2) Develop a set of current research needs as identified through the work of the CPRP and the PI. As one of the members of the CPRP, the PI is in a somewhat unique position to identify research required to expand the AISC standard to include more of the FEMA 350 recommended connections. 3) Formulate a research proposal, to be submitted under the NEES Consortium program, to address some of the critical research needs identified under goal #2. SGER JUSTIFICATIONThis research can be characterized as having "severe urgency" in that accomplishing the objectives is dependant on the deliberations of the CPRP, which have already begun. It is expected that the work conducted under the proposed research initiative will have a nearly immediate impact on the development of the AISC prequalification standard. Without the tangential focus afforded by the proposed research, it is possible that much of the work on conections other than the RBS will be rendered useless by the CPRP until further investigation is conducted.