Post-Earthquake Realignment and Repairs: A Novel Application for Structural Control and Health Monitoring

Abstract

Structural health monitoring and control (SHMC) for Post-earthquake realignment and repairs (PERR) is one of the most challenging issues facing earthquake engineers worldwide. Currently, neither SHMC nor PERR are parts of contemporary curricula and codes of practice. The ultimate aim of SHMC is to help achieve a viable degree of structural sustainability (SS) under predictable environmental conditions. In the present context SHMC refers to the effort that aims at achieving structural operability before and after severe earthquakes. SHMC is generally associated with the use of piezoelectric sensors to measure changes in stresses and strains of critical elements of important engineering structures. Regardless of the effectiveness of the SHMC systems no structure can lend itself well to PERR or remain seismically sustainable unless it has been designed specifically for the purpose, otherwise it would be disposable with no gains from the SHMC effort. A SS structure is one that can be designed to prevent actual collapse, overcome residual effects and lend itself well to PERR. All indications are that the use of multifunction design in conjunction with SHMC can lead to the evolution of viable SS archetypes. The purpose of the current article is to introduce a practical basis for efficient use of SHMC concepts in multi-objective earthquake resisting structures (ERSs). Replaceable energy dissipating moment connections (REDMC), rigid rocking cores (RRCs), high strength tendons, built-in stressing devices and support level grade beams have been introduced as natural instruments of structural control. The use of monitoring devices has been directed towards evaluation of the effects of formations or elimination of plastic hinges and the variations of the global drift of the system. The proposed methodologies impose and control the desired modes of lateral response and facilitate the PERR operations. Key words: Health monitoring; structural control; earthquakes; recentering; repairs.