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Following the 23 June, 1977 Tonga earthquake, the authors were made available by the New Zealand Ministry of Works and Development (through the Ministry of Foreign Affairs Bi-lateral Aid Programme) to the Tongan Government to help survey building damage and to recommend repairs and strengthening necessary to protect the structures from future earthquakes. The authors were also required to supervise government reconstruction teams. Recommendations are at present being prepared for structural design requirements for future building work in the Kingdom.

This paper is the result of deliberations of the Society's discussion group on seismic design of ductile moment resisting reinforced concrete frames.

A procedure is presented in step by step form for designing and detailing a reinforced concrete frame building to the requirements of DZ4203 (Draft New Zealand loading code). Consideration is given for adequate ductility by means of a capacity design approach to all members to obtain a large number of plastic hinges which are detailed to dissipate energy without brittle failure. Further ductile detailing is given for all other locations where accidental hinges could occur and to limit excessive deflections that may result from deterioration of beam column joints. OBJECT: The object of the procedure is to design a structure which will perform in a predict­ able and ductile manner when lateral earth­ quake loads exceed the nominal code require­ ments , with a large number of plastic hinges being generated in order to provide adequate energy absorption. Such plastic hinges will, in general, form in the beams and thus enables the building to be subsequently repaired. The Draft New Zealand Standard Code of Practice D.Z.4203 "General Structural Design and Design Loading" 1973. Draft N.Z. Code of Practice applies.

A comprehensive review of the state of the art in the design of earthquake resisting ductile structural walls is presented. The material has been compiled from the technical literature, the deliberations within the New Zealand National Society for Earthquake Engineering and research efforts at the University of Canterbury. The paper attempts a classification of structural types and elaborates on the hierarchy in energy dissipation. After a review of available analysis procedures, including modelling assumptions, a detailed description of capacity design procedures for both cantilever and coupled shear wall structures is given. The primary purpose of capacity design is to evaluate the critical design actions which can be used in the proportioning and reinforcing of wall actions which can be used in the proportioning and reinforcing of wall sections. An approach to the estimation of structural deformation is suggested. To satisfy the ductility demands imposed by the largest expected earthquake, detailed design and detailing recommendations are given and the application of some of these is presented in an appendix.

Following the 17th November 1979 Taveuni earthquake, the authors were sent by the Fiji Government to inspect earthquake damage. The damage was assessed at $0.75m. This paper is based on their reports and makes recommendations relevant to Pacific Island construction.

This paper examines the application of capacity design methods to foundations. Results of research on foundation rocking are reviewed, and their implications included in the formulation of a rational design procedure.

Amendments to "Procedure for the Analysis and Design of Ductile Reinforced Concrete Frame Buildings of Moderate Height" - R. L. Williams, published Bulletin of the N.Z.N.S.E.E. Vol. 8, No. 4, December, 1975.