2009年-世界发展银行全球_Monitoring_and_Evaluation_of_Technical_Conditions_of_Seismic_Isolation_Systems_Implemented_in_Armenia___Institutional_Arrangements_for_Disaster_Risk_Management_and_Reduction_52页_5mb

Summary of "Monitoring and Evaluation of Technical Conditions of Seismic Isolation Systems Implemented in Armenia"

Core Content

This document provides a detailed analysis of the technical conditions of seismic isolation systems (SILRSBs) in eleven seismically isolated buildings located in Yerevan, Vanadzor, Gyumri and Spitak. The evaluation was conducted as part of a GFDRR-funded project aimed at promoting awareness and understanding of seismic isolation technologies in Armenia.

Main Objectives

• To assess the current technical condition of seismic isolation systems in Armenia.
• To identify violations and arbitrary alterations that may affect the functionality of these systems.
• To draw conclusions and make recommendations for improving the design, construction, and maintenance of seismic isolation systems.

Key Findings

1. Technical Condition of Seismic Isolators

• All seismic isolators (SILRSBs) are in good technical condition.
• Vertical deformations and rubber hardness values comply with design requirements and standards.
• The average height of loaded SILRSBs between the recess rings is approximately 159 mm, and the average rubber hardness is around 77.2.

2. Structural Elements Above and Below the Isolators

• The structural elements both above and below the seismic isolation systems are in good condition.
• No cracks, caving, or other types of deformations were observed in the structural elements adjacent to the joints.

3. Design and Construction Violations

• Some buildings have violations of design requirements during the construction phase.
• Arbitrary alterations by tenants have been made in the seismic isolation zones, such as filling gaps with construction waste, foam-plastic tiles, plywood, and concrete blocks.
• These alterations may impede the free movement of building parts during seismic events.

4. Lack of Legal and Technical Framework

• There is no legal framework for the maintenance and operation of seismically isolated buildings.
• Tenants, local self-government bodies, and developers have limited understanding of the maintenance and operation rules for seismic isolation systems.
• Construction supervision lacks quality control mechanisms, which may lead to non-compliance with design requirements.

5. Impact on Seismic Performance

• These violations could impede the full functionality of the buildings as seismically isolated structures.
• They may cause unpredictable deformations, damages, and destructions in the structural elements during earthquakes.

Main Recommendations

• Ensure strict compliance with design requirements during construction.
• Improve technical supervision and quality control during the construction process.
• Dismantle arbitrary construction elements that obstruct the seismic isolation systems.
• Develop and adopt a legal framework for the maintenance and operation of seismically isolated buildings.
• Distribute regulations and guidelines to local self-governments, private developers, and tenants.
• Conduct seminars and training sessions for tenants and construction companies to explain the principles and benefits of seismic isolation.
• Ensure access to the seismic isolators for regular inspections and measurements.

Technical Insights

• The design period of vibrations of the building is related to the initial stiffness of SILRSBs by the formula:
  $ \mathrm{T}{\text{design}} / \sqrt{10} \approx \mathrm{T}{\text{initial}} $
• In some buildings, the measured actual vibration periods are inconsistent with the design values, likely due to increased weight of the superstructure or obstructions in the seismic gap.
• The main advantages of seismic isolation technology in Armenia include:
  • High earthquake resistance.
  • Lower cost compared to traditional methods.
  • Possibility of retrofitting without evacuation.
  • Preservation of historical and architectural values.
  • Faster strengthening process.
  • Effective reduction of interstory drifts and floor accelerations.

Conclusion

Despite the successful implementation of seismic isolation technology in Armenia, several technical and operational challenges remain. These include design and construction violations, lack of legal and technical frameworks, and limited awareness among stakeholders. Addressing these issues through improved supervision, legal regulation, and education is essential to ensure the long-term effectiveness and safety of seismically isolated buildings.