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Project

Background

In many regions with high seismic risk, such as Portugal and many other countries, a significant number of buildings do not have adequate resistance to seismic actions they may be subjected to. Earthquakes in these areas can cause a high number of fatalities. In Portugal, as in several other countries, the problem is particularly serious due to the large number of existing old buildings that have not undergone rehabilitation or strengthening works for several decades, making them highly vulnerable. The ideal solution to this problem would be a widespread intervention in all vulnerable buildings to provide them with the required seismic resistance. However, due to economic and other reasons, this generalized solution is practically unfeasible.

Motivation and Objectives:

The objective of the SHELTER project is to develop a seismic shelter solution for portions of existing buildings (houses, offices, health centers, tourist apartments, etc.) that can be completely integrated individually and autonomously, without requiring structural reinforcement of the buildings, resulting in an expedited installation with reduced costs. The design of this shelter takes into consideration all aspects related to preserving human life during the potential collapse of the building and ensuring survival in the post-collapse period. Since Teixeira Duarte (TDEC) and IST have always been involved in seismic construction, the main motivation for the development of the SHELTER project arose from the intention to strengthen TDEC's competencies and international recognition in the field of seismic construction.

Strategy and Methodologies:

The development of a seismic shelter solution involves studying its mechanical and structural behavior, construction aspects, architectural integration, operational capabilities, design, and ergonomics. The project development is based on a multidisciplinary team (co-promoters and subcontracted institutions) assembled to address the multitude of involved problems.

The project began with bibliographic research related to situations where some of the encountered problems have already been studied, such as people's resistance to rapid and violent mechanical actions and survival in confined spaces. Examples include conventional and atomic war shelters, underground mines, cockpits of racing cars, aircraft, submarines, and spacecraft.

The mechanical behavior was evaluated through experimental tests, and numerical models were developed to simulate situations that vary from the base model studied in the tests. The shelters are designed to be compatible with existing construction and to be easily and quickly installed, using accessible technology and common labor, while minimizing architectural impacts with integrated and adaptable solutions for existing spaces.

To ensure operability, the inclusion of 'early warning' seismic alarms, already commercially available, was studied, which could provide some extra time. Although the time between the start of an earthquake and the eventual collapse of buildings is not sufficient for evacuating a building, it should be enough to reach the shelters installed in houses or offices. A training program will be developed to accompany the shelter installation.

Design and ergonomics aspects were also developed to ensure psychological and physiological well-being in a confined space until rescue, which may take days. Functionality of the space was optimized, and equipment and support systems for food, hydration, and other physiological and psychological needs were defined.

The team at the IADE laboratory.

Innovation:

The proposed solution is innovative in terms of protecting human lives in the event of an earthquake. The scientific and technical community has been trying to ensure the protection of human lives by focusing on the overall protection of heritage through seismic reinforcement and protection of entire buildings.

Although there is already sufficient know-how to provide buildings with resistant capacity compatible with regulatory seismic actions, these interventions require significant financial resources, preventing their widespread implementation.

Some seismic shelter solutions have been presented, but they generally consist of autonomous equipment that is difficult to architecturally integrate into easily accessible locations, where they need to be installed to become functional. With this study, a seismic shelter has been developed that is cost-effective, 'embedded in the construction, i.e., architecturally 'discreet,' and therefore capable of being installed in a central location in any apartment, allowing for the rescue of occupants in the event of a severe earthquake.

Results:

The project's development has resulted in a shelter solution to be installed in existing buildings that can save human lives in the event of an earthquake, with the following characteristics:

  1. Mechanical resistance to seismic actions, including the global collapse of the building and the ability to withstand and absorb diverse, multidimensional, dynamic, and complex forces associated with an earthquake;
  2. Capability to preserve human life during the collapse of the building;
  3. Human survival capability and assurance of adequate levels of physical and psychological comfort for victims until rescue is provided;
  4. Construction and architectural integration into buildings, with minimal impact on existing space;
  5. Reduced costs compared to the costs of structural rehabilitation of entire buildings, allowing for immediate implementation in any location (house, office, health center, tourist apartment, etc.);
  6. Installation with reduced intervention, not requiring evacuation of the premises.