International Concrete Abstracts Portal

SP-174 Innovative design applications and advanced research has led to widespread use of steel and concrete composite and hybrid systems in the construction of buildings, bridges, and many other types of civil structures. The state of the art in this field continues to move forward today. Extensive research programs and field testing have yielded efficient, reliable, and safe procedures, incorporating these two dissimilar materials for overall improved construction. This publication presents an overview of the latest developments in behavior and design of composite and hybrid structures. In 1995 ACI Committee 335 sponsored two technical sessions in Montreal, Quebec on the current practice of the composite and hybrid construction and the state of the art in the field. Researchers and practicing engineers from the United States, Europe and Japan gave presentations encompassing topics related to design and construction of composite and hybrid systems and the advancement of research in three continents. The twelve papers appearing in this volume include topics presented in Montreal, along with additional manuscripts. The breadth and depth of the material covered make this publication a useful resource to practicing engineers, educators and researchers.

Existing design criteria for composite steel-concrete construction are fragmented among several different sources and are incomplete for some types of composite construction. This paper reviews the coverage of composite design provisions of major standards in the United States including the ACI-3 18 Code, the AISC-LRFD Specification, and the 1994 NEHRP Recommended Provisions for seismic design. Areas where design criteria is lacking or can be improved are discussed, and strategies for developing such information are proposed. Suggestions are made for where more coordination between the existing AISC-LRFD Specification and ACI-3 18 Code is needed.

The earthquake that shook southern Hyogo Prefecture in Japan on January 17, 1995 (also known as the Kobe earthquake) measured 7.2 on the Richter Scale. This event was the most devastating earthquake to strike Japan since the Kanto earthquake of 1923. This paper focuses on the performance of a particular composite system, referred to as Steel Reinforced Concrete (SRC). This type of structural system comprises approximately 10 percent of all square meters of construction in Japan. A major factor contributing to the collapse of many SRC buildings, known to Japanese researchers prior to the earthquake, could be said to be the lack of adequate confining steel and cross ties, especially for large columns. Additionally, the use of 90 degree hooks, even with close tie spacing, was shown to be undesirable.

Composite and Hybrid Structures (CHS) provide many advantages over those employing conventional systems. Since the available design codes in Japan do not cover these systems, the current Japanese Building Standard Law requires detailed experimental and/or analytical studies before the building permit for a structure with CHS can be issued. As part of the U.S.-Japan Cooperative Earthquake Research Program on Composite and Hybrid Structures, three major types of composite and hybrid systems are being studied. These include concrete-filled tubular columns (CFT), reinforced concrete columns with steel beams (RCS), and reinforced concrete cores with steel perimeter frames (HWS). Among other objectives, these studies are expected to lead to design guidelines which can be incorporated in the Building Standard Law. The availability of these guidelines are expected to encourage the Japanese designers to use CHS more frequently. This paper provides an overview of the ongoing studies in Japan. After a brief historical review of each system, the important issues related to each system are summarized. Planned and ongoing studies for each group of composite systems are also described.

Diagonal Mar Centro Comercial is a 350,000 square meter (3.75 million square foot) mixed use commercial development in Barcelona, Spain. It is located at the terminus of the premier boulevard in Barcelona, avenida Diagonal and will be known as Diagonal Mar - the avenue by the sea. The project is located only two hundred meters from the shores of the Mediterranean Sea and approximately ten kilometers east of the Olympic Village - home to the athletes in the 1992 Olympic Games. A commercial venture of Diagonal Mar S.A., the first phase consists of a 165,000 square meter (1.75 million square feet) retail mall and hypermarket (the largest in Spain) and six levels of underground parking for 5,100 automobiles in 185,000 square meters (2.0 million square feet) of space. Construction cost for Phase I is estimated to be $180,000,000 US dollars. Residential housing and office buildings are planned for later phases of the project. The site is a very large triangular plot bounded by the extension of avenida Diagonal on the northwest, avenida Josep Pla on the west and avenida Taulat on the south. The sides of the triangle are approximately 333 meters (1,072 feet) along avenida Diagonal, 285 meters (935 feet) along avenida Taulat and 236 meters (774 feet) along avenida Joseph Pla. The 24 meter (79 feet) deep excavation required for the underground parking, located 18 meters (59 feet) below the shallow water table, will create the largest basement substructure in the world and will remove more than 1 .O million cubic meters (1 .3 million cubic yards). The sheer size of the project and its location so close to the sea posed a whole host of enormous engineering challenges for the design and construction planning team as follows: (1) Excavation retention method; (2) Foundation system selection and design; (3) Excavation/substructure construction method and sequence, (4) Substructure system selection and design.