Gilbert A. Hegemier - US grants

In this project, an experimental laboratory will be upgraded during the construction period to enhance and improve the capability of the facility to conduct research projects on full- or large-scale five-story buildings of masonry, steel or reinforced concrete. The long strong floor will provide a capability to perform research on multi-span continuous bridges, not now available in the United States. The laboratory will be the only one of its type in the United States capable of full- or large-scale experiments on buildings and small- or large-scale projects on bridges. It will provide the United States with a unique experimental laboratory. Experiments on buildings and bridges will be performed using sophisticated loading devices and instrumentation.

Masonry construction comprises a large portion of building construction in the U.S. and the world. Reinforced masonry construction use is increasing in moderate to higher seismic zones because of its apparent features of economy, fire safety, architectural flexibility, and ease of construction. The present state of masonry structural analysis and design and materials and construction technologies do not enable an accurate prediction of building behavior under lateral loads such as seismic loads. This research project will examine the behavior of floor-to-wall and wall-to-wall intersections of structure components. The research will utilize existing data in this analytical research effort. This will provide conclusions relative to monotonic and hysteretic behavior of planar intersection response and formulation of a viable analytical and numerical model of intersection behavior.

This research will provide equipment for outfitting the new University of California-San Diego (UCSD) Structural Systems Laboratory. This facility will provide unique capabilities in that it is designed for full-scale experimental testing of buildings up to five stories by using a massive 50 foot high reaction strong wall. The equipment will include hydraulic actuators, control systems, data collection systems, and support systems. This laboratory will have four main functions. First, it will serve as the focal point for the Structural Engineering Program at UCSD. Second, it will serve as a regional laboratory and complement other structural and earthquake engineering laboratories. Third, it will support international research programs such as the US-Japan Coordinated Earthquake Program in Masonry Research. Fourth, it will encourage interaction between academic researchers, practicing engineers, and the construction industry.

This research project will conduct integrated experimental and analytical studies on simple components, main subassemblages, and finally a complete multistory masonry building (Masonry Research Building). These studies will be conducted using small, medium, and full scale specimens. The objective of the studies is the development of a reliable methodology for investigating the in-plane behavior of multistory reinforced hollow unit masonry wall elements when a building is subjected to earthquake ground motions. Emphasis will be given to the development of the experimental methodology which will be used as a basis for studying the earthquake behavior of the full scale Masonry Research Building. Results from the two and three story in-plane wall tests will be used to verify the analytical models developed by others.

Masonry construction comprises a large portion of building construction in the U.S. and the world. Reinforced masonry construction use is increasing in moderate to higher seismic zones because of its apparent features of economy, fire safety, architectural flexibility and ease of construction. The present state of masonry structural analysis and design, and materials and construction technologies does not enable an accurate prediction of building behavior under lateral loads such as seismic loads. In the U.S., masonry buildings are designed and built with methods, codes and standards that rely upon a mixture of working stress methods, empirical rules, and questionable methods for determining allowable stress values. Masonry is also a complex building material because of the large number of design and construction variables which influence the final product configuration and its response under seismic loads. In order to describe the seismic response of masonry buildings it is necessary to develop the fundamental knowledge base to determine basic design methodologies consistent with safety and economic requirements. This research project will construct an advanced analytical model for reinforced masonry and associated numerical algorithms to simulate the monotonic and hysteretic planar response of 1-, 2-, and 3-story shear walls. The model is nonphenomenological in the sense that the global response can be synthesized from the constitutive relations of the masonry, steel and steel-concrete interfaces together with the steel geometry. The research provides direct support to other masonry researchers where the results will be used to plan experiments, interpret experimental data, and extend the experimental data base. This project is part of the U.S.-Japan Coordinated Program for Masonry Building Research and the Technical Coordinating Committee for Masonry Research (TCCMAR) Program.

Within the framework of the joint U.S.-Japan masonry research program, the specific objective of the U.S. program is to develop an experimentally verified design and analysis methodology that will ensure satisfactory performance of reinforced masonry buildings under a wide range of seismic loadings. In particular, under severe earthquake loadings such buildings must exhibit ductile behavior. A key aspect of the philosophy adopted by the U.S. program is to support the design and analysis development by an increasingly complex set of experiments culminating with the study of a five-story full-scale masonry building. This experiment is essential to achieve the objectives of the program in that it will provide the final validation of the analytical and computational models developed, and thus will form the basis for the design recommendations to be made at the culmination of the overall project. This research project is a full-scale building test conducted at the Charles Lee Powell Structural Systems Laboratory at the San Diego campus of the University of California. The experiment is performed using a reaction wall concept, in which the building is subjected to generated displacement histories at the floor levels via hydraulic actuators in a manner that simulates the displacements during an actual seismic event.

This project will develop an anlytical numerical method to predict the response of existing reinforced concrete and reinforced concrete masonry buildings subjected to wind and/or earthquake forces. The method will be used to ascertain the safety of the buildings before and after repair or retrofit.

An Institute of Mechanics and Materials (IMM) is being established at the University of California at San Diego to integrate research and industrial applications in mechanics and materials. The Institute will foster interdisciplinary communication and liaison between academia, industry and governmental organizations. The principal activities will include short courses on frontier, interdisciplinary areas; workshops on specific industrial problems and innovative materials; and short and intermediate length visits of graduate students, post-doctoral fellows, faculty members, and scientists and engineers form government laboratories and industrial organizations. The Institute will not conduct extensive research projects, per se, but will aim to serve as an intellectual forum to catalyze the formation of research groups when new areas or methods of approach are identified. This will include novel techniques for materials development, synthesis and processing; characterization and identification of properties-microstructure relations; physically-based micromechanical and computational modeling; and constitutive relations for nonlinear response and failure analysis; as well as design and performance analysis of complete structural entities. Timely topics will be discussed in think-tank-style workshops which will also be used for periodic assessments of long-term goals in mechanics and materials science and engineering. An external Board of Governors of prominent senior scientists and engineers will direct the Institute activities through action subcommittees and regularly assess the Institute's progress. The educational efforts of the Institute will include all levels of engineers and scientists in academia, industry and government (both national and international); and a strong outreach program to high school students and their teachers on a nationwide basis wherever there is interest, with a deliberate effort to reach minorities and under-represented segments of the population, as well as the gifted.

The first U.S. 5-story full-scale research building which was tested at UCSD under simulated seismic loads to 1-1/2 to two times the seismic design and deformation levels, provides in its damaged state a unique opportunity to develop and experimentally validate new repair technologies. The proposed repair measures consist of epoxy injection, advanced composite wall and floor overlays as well as ceramic foam applications in the hollow core plank floors, with particular emphasis on materials and technologies originally developed and applied in the defense industry to show their potential for application in the civil sector. It is proposed to use loading sequences in the retest which correspond closely to the original seismic load test, in order to get a direct experimental seismic behavior comparison for the verification of the effectiveness of the proposed repair measures. The test results will provide important information about the repairability of damaged reinforced masonry structures and about the expected behavior of repaired structures under future seismic loads.

Abstract
The objective of this Major Research Instrumentation (MRI) project is to procure instrumentation and equipment specifically for an Explosive Loading Laboratory (ELL), which is currently under construction. The ELL will allow for one-of-a-kind real time blast and impact testing of structural components, assemblies, and systems of critical infrastructure such as buildings and bridges in a controlled environment. The testing laboratory is the first facility in the world that can accurately and repeatedly performs simulated explosive loading tests and characterize their effects on structures for use in developing retrofit and hardening optimization technologies without creating actual explosions.
During large- or full-scale testing of structural systems or assemblies at the ELL, a large array of sensors will be distributed in specific locations such that precise measurements can be obtained to investigate the development of non-linear failure mechanisms. A vital element in the development of the ELL is the procurement of robust, state-of- the-art instrumentation and sensors that can be operated in an outdoor environment, data acquisition systems and high performance networking capabilities. The key components are: real-time distributed data-acquisition systems, a high-speed digital camera, camera measurement systems, a range of conventional sensors such as DCDTs.
The vision is to provide the ELL with sufficient instrumentation that can be used to integrate state-of-the-art blast engineering experimental and computational research into educational curriculum using internet-based technologies. The equipment requested for the ELL can be leveraged to promote research being conducted at the Scripps Institute of Oceanography (SIO) at UCSD, for further development of ROADNet, a network and information management system that will deliver data to a variety of end users in real-time.
The state-of-the-art ELL facility, will add a significant new dimension and capabilities to existing United States testing facilities and promote research in Structural Engineering, Dynamic Systems and Control, and Information Technology.