Following the worldwide recognized expectation and ideal aim to provide a modern society with high performance structures able to sustain a design level earthquake with limited or negligible damage, emerging solutions have been developed for high-performance, still cost-effective, seismic resisting systems, based on an efficient combination of traditional materials and available technology.
In this course, an overview of recent developments on innovative solutions for seismic-resisting prefabricated concrete and timber structures based on dry jointed ductile connections and tipically referred to as PRESSS-Technology, (PREcast Seismic Structural Systems) will be given. The combination of unbonded post-tensioning techniques and of additional sources of internal or external dissipaters leads to self-centering and dissipative systems, capable of undergoing major earthquake with minor damage when compared with traditional solutions.
The students will become familiar with the conceptual behaviour, design criteria and procedure as well as modeling aspects of these emerging systems. Updates on current trends in major international seismic code provisions will be provided along with real examples of on site applications as a further confirmation of the advantage associated to the easy constructability and speed of erection
Review of Force-Based (FBD) vs. Displacement Based Design (DBD) approaches. Role of residual deformations as additional damage indicator. Enhanced performance of self-centering systems. Alternative design philosophies and solutions for the seismic design of precast concrete structures. Introduction to PRESSS-Technology and the hybrid system concept.. Analysis and design criteria for frames and single or coupled walls. Simplified modeling techniques. Connection between floors and lateral resisting systems. Development of multi-storey long-span prestressed timber buildings using engineered wood materials. Extension to precast concrete or prefabricated timber bridges. Examples of on site applications worldwide in low-, medium- or high-seismic areas. Constructability aspects, sequence and detailing.
Afternoon Design Sessions:
In the design classes and as part of the assignment/projects requirements, students will be divided in groups and develop a preliminary design (using FBD and DBD) of a prefabricated PRESSS-type building consisting of seismic resisting frames and walls. Pushover and time-history analyses will be carried out using a suite of far field and near field events to confirm the design assumptions as well as the higher performance of these solutions when compared to traditional counterparts