Contenido Structural Restoration of Masonry Monuments: Arches, Domes and Walls

Historic structures need to be restored in line with international guidance and charters developed by architects and archaeologists, but technical understanding of structural engineering and materials is crucial, particularly with respect to response to earthquake loading.

This guide to structural assessment and restoration of masonry monuments and historical buildings outlines the techniques, materials and design procedures used. It begins with principles, theory and practice and then presents case studies.

The assessment focusses on

- Building materials and construction techniques used in the past

- The mechanics of masonry

- The structural behaviour of masonry monuments and historical buildings

-  In-situ investigation and laboratory tests for existing and restoration materials.

The restoration elaborates on

- Techniques and materials available for structural restoration

- Structural analysis and design

- Deciding on the restoration scheme

- Emergency measures and protective measures.

INDEX

Table of Contents

1. Introduction

General
Restrictions under consideration for the structural retoration
Authenticity and life safety
The Structure of this book

2. Building Materials and Construction Techniques of Monuments

General
Materials
 - Stones
 - Bricks
 - Mortars
   - General
   - Mud mortars
   - Lime mortars
   - Pozzolanic mortars
   - Aggregates
   - Additives
   - Case studies
- Timber
-  Iron,cast-iron and steel
- Construction techniques
  - Walls and piers of mortared stone and brick
  - Timber-framed walls
  - Timber and steel floors
  - Timber and steel roofs
  - Ancher and barrel vaults
  - Groined and domical vaults
  - Domes and related forms
  - Columns
  - Foundations
    - General
    - Case studies

3. Masonry mechanics

- General
- Mechanica properties of masonry considered as a homogeneous material
   - Introduction
   - Compressive strength and deformation
     - Failure theory based on elastic analysis
     - Failure theory based on the strength of brick and mortar under multiaxial strength
     - Semiempirical formulas for the compressive strength of masonry
     - Compressive strength  of masonry
     - Compresive strength of three-leaf masonry walls
     - Compresive deformations
- Tensile strength
-  Shear strength and deformation
    - Shear strength
    - Deformations
- Axial comprenssive load combined with cyclic shear loading
  - Introduction
  - Mechanical properties
     - Strength
     - Displacements
- Mechanical properties of masonry under biaxial loading
   - Introduction
   - Experimental results
   - Analytical results

4. Structural behaviour of masonry monumental buildings

- General
- Conceptual approach to the structural behaviour of masonry elements
- Masonry structural elements
  - Masonry walls
    - Axial compressive loading
    - Axial compressive load combined with horizontal out-of-plane seismic action
    - Axial compressive load combined with in-plane horizontal seismic action
    - Masonry walls subjected to foundation settlements
- Arches and barrel vaults
- Groin vaults
- Domes
- Masonry structurel systems-vulnerability
  - General
  - Free masonry walls
  - Timber-roofed basilicas
  - Cross-domed central nucleum
  - Secular building
    - The two main residential masonry structural systems
    - The transfer of seismic action in the case of diaphragmatic action of the floors
- Bell towers and minarets
    - Axail compressive load combined with in

5. Techniques and materials in use for structural restoration

- Techniques
   - Introduction
   - Classification of techniques
   - Local types of repair
     - Masonry walls and  pirtd
     - Strengthening of walls by applying skins of reinforced concrete ( R/C )
     - Strengthening of free- standing columns
     - Strengthening of arches and barrel vaults
     - Strengthening of domes
     - Repair and strengthening of timber decks
- General type of strengthening in structures adove the ground
   - Introduction
   - Mass grounting of masonry walls
   - Removal of masses
   - Improvement of the distribution of mass and stiffnes
   - Improvement of structural response of basilicas with nonthrusting timber or steel roofs
   - Improvement of the structural response of multistorey residental  buidings
   - Improvement of structural response in arched vaulted and domed structures
- Strengthening of foundations
  - Introduction
 - Consolidation of soil by means of injections
 - Underpinning with additional foundation
 - Underpinning with micropiles
-  Seismic isolation and energy dissipation systems
-  Materials
   - Introduction
   - Monmetalic materials
     - Stones and bricks
     - Mortars and grouts
     - Concrete
     - Timber
   - Metallic materials
     - Introductory remarks
     - Conventional steels
     - Stainless steel
     - Titanium
     - Case studies from Greece
  - Fibre-reinforced plastics ( FRPs)
     - Introduction
- Conclusion

6. In-situ investigations and laboratory test

- Introduction
- Investigation
  - Visual inspection
  - Geometrical and constructional survey
  - Survey of damages and deformations
    - In situ DTs
    - In situ NDTs
- Laboratory tests of original masonry materials
  - Introduction
  - Physical,chemical and mineralogical tests
  - Mechanical test
- Laboratory test of mortars and grouts in use for masonry restoration
- Laboratory test on models
- Soil tests

7. Structural analysis and design

- Task of analysis and design
- Historical notes
- Modelling
  - General
  - Geometry
  - Internal morphology of structural elements
  - Mechanical properties of masonry
  - Modification of the structural systems in the past
  - Cracks and damage of the past
  - Actions
       - Dead and live loads
       - Imposed deformation
       - Seismic action
   - The behaviour factor ( q-factor )
   - M-0 diagrams
- Linear elastic analysis and design
- Limit-state analysis
  - General
  - Nonlinear analysis of an equivalent frame model
  - Isotropic-orthotropic homogeneous,nonlinear material macromodels,for 2D structures
  - Heterogeneous nonliar microelement models for 2D structures
- Design
  - Distinction between conventional and seismic loading
     - Conventional loading
     - Seismic loading
  - Displacement based design for seismic loading
     - Inelastic dynamic analysis and design
     - Force  based design
  - Design considerations
- Conclusions

8. Assessment

- Introduction
- The successive steps of structural restoration
- Diagnosis
- Quantitative safety evaluation
- Assessment-structural restoration scheme

9. Case studies

- The Rotunda of Thessaloniki
  - Introduction
  - Description
  - Pathology
  - Energency measures
  - Structural restoration
    - General
    - Documentation
    - In situ investigations
    - Laboratory tests
    - Evaluation of the mechical characteristics of the structure
    - Analysis and design of the Roman part of the monument
    - Analysis,design and assessment of the Christian part of the structure
    - Proposals for repair and strengthening
    - Reanalysis and redesign
  - Execution
- Structural restoration of the Acheiropoietos basilica in Thessaloniki
   - Introduction
   - Historical background and structural form
   - Pathology
   - Static and dynamic behaviour of the monument
   - Proposal of intervention scheme
   - The type of chosen diaphragms
   - Structural analysis and design
     - Basic assumptions
     - Evaluation of results  
   - Intervention materials
   - Conclusions
- The structural  restoration of the National Library of Greece in AtHENS
   - Introduction
   - Description
   - Bulding pathology
   - Site investigations and laboratory tests
   - Analytical models
     - Dynamic finite element analysis
     - Nonlinear static analysis
- Proposed intervention scheme
- Conclusions
- Strengthening of the minaret of Rotunda in Thessaloniki
  - Introduction
  - In situ and laboratory research
    - Geometry of the structure
    - Pathology-emergnecy interventions
    - Mechanical characteristics of brick,mortar and masonry
    - Fundamental period of the minaret
    - Geotechnical and seismological study of the territory
- Bearing capacity at virgin state
   - Analytical model and verification
   - Bearing capacity at virgin state
- Alternative strengthening proposals
  - Internal concrete jacket
  - External steel strips nailed to the masonry
- Hagios Andreas church in Peristera,Greece
  - Introduction
  - Description
  - Structural condition
  - Detailed investigations
    - Architectural and constructional survey
    - Survey of the damage
    - Test on materials
    - Static analyses
  - Repair and strengthening
    - Specifications
- Restoration of the Mar Girgis church and the Roman Tower underneath in Cairo
  - Introduction
  - General information
  - Historic context
  - Project I.D
  - Pathology
    - Roman Tower
    - St George´s  church
 - In situ and laboratory investigations
 - Restoration works
   - Roman tower
   - Church of St George
- Theofilou mansion,Thessaloniki,Greece
   - Introduction
   - Description
   - Structural condition
   - Investigations-materials
   - Restoration
   - Structural analyses
     - General
     - Static approach
     - Dymamic approach
- Restoration of St.Irine Square Townhouse Athens
  - Introduction
  - Description
  - Structural condition
  - Investigations-materials
  - Restoration
  - Structural analysis
References
Index