PROJECT: CONSTRUCTION OF AN OUTDOOR MUSEUM FOR THE CENTRAL SECTION OF THE ROMAN VILLA OF HEROD ATTICUS AT LOUKOU, KYNOURIA
The archaeological site of the Roman Villa of Herod Atticus at Loukou, Kynouria is located 4 kilometers to the northwest of the modern settlement of Mesogeiou Astrous, on the main Astrous – Tripoleos road. The excavations cover an area of approximately 12 stremma to the north of the Loukous Monastery (Transfiguration of the Saviour). The monument stands on a natural plateau south of the River Tanou, on the western edge of a vast olive grove that stretches from the valley of Paralio Astros to today’s Lower Doliana, which it overlooks.
BASIC PRINCIPLES OF DESIGN FOR THE SITE
With regard to the main shelter, given that the layout of the supporting columns is secure, we do not consider it worth following the lattice principle of construction since it is not required here. Our objective is to design a main frame supporting structure with a minimalist morphology which can be extended to connect with the lattice shells of future shelters.
This relationship to future shelters, which depends on the geometry of design grid outlines, is also determined by the respective heights, the individual rods, gradients, and coverage with purlins and composite thermally insulated galvanized sheet steel panels. Together with the circular cross-sections of the metal supporting columns (with a diameter of 70 cm), these elements ultimately combine to form a building code to cover the entire housing system for the site. This code will permit any changes in the size of shelters which may be required in the course of the project or modifications to supporting columns, and will facilitate the overall homogeneity of the system.
GENERAL ILLUMINATION PRINCIPLES FOR THE MONUMENT
The lighting of the covered monument is one of the most important factors in its exhibition.
First of all, adequate natural light must be secured for the site. Accordingly, provision is made for translucent materials to be installed in sections of the roofs of the shelters. In this way the requisite level of natural light can be ensured.
In addition, provision for suitable artificial lighting must also be made. This lighting must secure a satisfactory level of general lighting and slightly stronger lighting around the more important elements of the site. Artificial lighting is required for:
- lighting for night time exhibition and visiting.
- automatic enhancement of lighting by artificial means when particular conditions (such as overcast) result in reducing the level of natural light.
Finally, the capacity to increase the level of artificial light in the future must also be secured, in case that a reduction of overall natural light around important elements in the central section of the site is caused when the system of shelters as a whole is completed.
GENERAL PRINCIPLES OF CONSERVATION FOR THE MONUMENT SITE
The system of shelters, as described above, has the objective of preserving and protecting the site. Specifically, apart from rainwater which must be collected in an aesthetically acceptable manner and directed to a adjacent stream, the following must be ensured:
- protection from direct sunlight
- protection from erosion by wind
- adequate natural ventilation
- limitation of the range and rapidity of temperature fluctuations
- deceleration of atmospheric cycle of condensation - evaporation
- limitation of the effects of the average number of annual frosts
- avoidance of deterioration and aesthetic “harm” caused by bird droppings
It is also important that preventive measures should be taken in areas of the site which will remain uncovered for the time being, since the shelter program will be carried out in phases. Lastly, lightning protection of the structure is essential, as determined in accordance with the specifications.
These requirements may differ proportionally in individual shelters within the system, in accordance, of course, with the specific characteristics of the sections of the monument to be covered.
SHELTER CHARACTERISTICS ENSURING CONSERVATION OF THE SITE
The new shelter covering the central section of the site houses the areas which extend outwards around the ancient peristyle atrium. Construction of the new shelter must ensure:
BENEFITS EXPECTED OF COMPLETE PERMANENT COVERAGE OF THE MONUMENT
Complete coverage of the monument site is the first essential protective measure to be taken against the ongoing process of the aging of materials and structural decay. Specifically, the following benefits are expected to arise from coverage of the monument site:
- Protection of the monument from the erosive action of rain water
- Creation of milder microclimatic conditions
The main objective is the limitation of the effects of frosts, as well as limitation of the range and rapidity of fluctuations in temperature and humidity. This will also indirectly limit the erosive action of wind.
- Maximization of the beneficial effects of planned conservation, stabilization, restoration and repair interventions. Future 'restoration' interventions will become more effective over time than if the monument was left unprotected, especially since one of the most important elements are the particularly susceptible mosaic floors.
- Exhibition of the monument. The creation of a unified covered area is an inextricable part of exhibiting this important monument to the public, by securing the appropriate conditions for visitors.
MORPHOLOGY AND ADAPTATION OF SHELTER STRUCTURE & CONSTRUCTION TO THE CHARACTER OF THE MONUMENT AND THE NATURAL LANDSCAPE
With the objective of creating a peaceful, clean, simple, unified morphological structure, the basic starting point was the grid of the monument site as the infrastructure for the outlines of the system. The selected linear layout of the shelters is in three aisles, an arrangement which reflects the layout of the monument site and is in harmony with the incline of the land and the landscape in general.
FACTORS ARISING FROM RESTORATION ESTIMATES WHICH AFFECT THE PROPOSAL
1. Correlation of grid outlines to the monument
A key element of the proposal is the direct correlation between the construction grid of the supporting columns, trusses and load bearing beams of the shelter to the grid of columns of the peristyle. The average estimated radian distance of the peristyle is equivalent to 3,56 m and this is the unit used in the design grid.
2. Leveling of the gardens - elevation
The specifications indicate the need to create surface areas supporting traffic flow in the “garden”. Accordingly, the ground must be leveled. The chosen area presents the most construction and aesthetic advantages whilst offering a larger space for movement around the garden. In addition, it also provides us with greater flexibility in setting the foundations on piles and the anchoring of pillars to them.
The level to be fixed is dependent upon the highest remaining point of the retaining wall of the garden in combination with the surviving base of the pillars of the peristyle. Thus the level +151,50 is considered to be closest to the ancient level of the surface of the garden.
3. Correlation between the height of the ancient building and the shelter
The estimated height of the ancient building as a whole, is taken into account in order to determine the recommended height of the shelter, and is the major determining factor. The key advantage here is that the shelter will have a similar proportional volume to that of the ancient building. This factor is also taken into account in the proposals for subsequent extension of the shelter system.
4. Necessary height levels for restoration works
The height at which estimated restoration works will be carried out is also taken into account. The relationship between the height of the shelter and the highest part of the ancient building is not only determined by aesthetic considerations , but primarily by the need to ensure the necessary height allowance for use of lifting equipment and future restoration works. This factor is taken into account in the proposals for subsequent extensions to the shelter system.
5. Relative scale of the ancient buildings and the shelters
Lastly, the estimated scale of the respective volume of the ancient buildings actively contributes to determination of the relative scale volume of the proposed shelters. Thus by comparison with the taller central section which is to be constructed as part of this assignment, the shelters forming part of the subsequent extension will be correspondingly lower.
PROVISION FOR THE UNIMPEDED FUTURE CONSERVATION AND RESTORATION PROGRAMS FOR THE MONUMENT
Estimations of possible future restoration interventions at the monument site have an impact on our proposal. In addition to the basic design principles, factors associated with conservation work on sections of the monument are also taken into account, including mosaics, marble features and their pedestals, as well as the edges and masonry of the walls, not forgetting the sections with ceramic floors.
The requirements arising from the above, and accordingly the necessary provisions to be made, are summarized below:
A. Capacity for unobstructed movement of workers and technicians
B. Transport of small loads, including tools and small items of machinery
C. Transit and installation of utility supply services for works; and
D. Erection and operation of necessary lifting systems and equipment for the range of interventions.
Specifically, this includes:
A. The tender requires provision for access of visitors. Additional access of workers and technicians to cordoned-off areas of the monument without public access will be facilitated by temporary installations placed on the ancient structure and these will not be obstructed by the structural elements of the shelter.
B. Other requirements of the tender address issues pertaining to the transport of small loads using access ways which also provide for traffic of visitors. Transport of loads will involve utilization of these access routes.
C. The requirements of the tender also cover public utility supplies to the shelter (electricity supply, and water). Accordingly, arrangements can easily be made to provide these services for any works on the site as required.
D. The analysis of the restoration works of the sections of the monument determines both requisite height and estimated data specifications for lifting equipment requirements and corresponding systems. From the analysis of para. 1.4 and taking into account the maximum weight of monolithic columns ('3 tn for the peristyle and '4, '5 for the basilica), it is estimated that the minimum required height for the peristyle is 8.00 m from the level of the stylobate and 8.30 m for the colonnades of the basilica. This estimate is based on lifting equipment with a 5tn capacity requiring 2,00 m free height beyond the top of the ancient structure.
The height levels of the shelter system
The most important element affecting the proposal (apart from factors relating to the dimensions of the load bearing framework, technical specifications etc) concerns the height of the central shelter and its extensions. This element can be generally categorized as follows:
- The required height for unobstructed execution of restoration works
- The requisite height to create an aesthetically pleasing proportional relationship between the highest point of the restored section and the lowest point of the shelter structure roof
- The proportional relationship of the shelter to the estimated height of the ancient buildings of the monument site as a whole
- The incorporation of the structure within the surrounding environment
Positioning of supporting pillars and coverage boundaries for shelters
For future shelters, the selected positioning of supporting pillars on the monument site is determined by data available to date and on-site estimates carried out indicating the safest archaeological locations. In each case, further inspection will be carried out and in the event of any errors in calculation, the trusses can be repositioned to permit the necessary relocation.
Boundary of the central shelter
The boundary of the central shelter was determined on the basis of the design grid and its final dimensions, determined for the first phase with the objective of the best possible coverage of the monument and primarily of its mosaics, are 114,50 x 42,10m.
The central shelter can accommodate future extensions as it stands to the north and south. These are extensions foreseen by the design study for the maximization of protection of the monument along the entire length of the shelter and specifically in sections of 4,76m wide, as appropriate.
The boundaries of future shelters 3 & 4
It is intended that shelters 3 & 4 shall comprise a continuation – extension to the central shelter to the west and east respectively.
Though the proposed locations of their supporting columns are considered to be secure, it is also possible for independent shelters to be constructed on the same principles as the central shelter, in order to create the appearance of a unified whole.
Shelter 3 to the west covers a section greater that the size of the western basilica. It also secures the capacity to house the areas of the existing entrance and educational stands. The dimensions of this shelter are 42,10 m in length, equivalent to the width of the central shelter without extensions, and 14,24 m wide.
Shelter 4 to the east fully covers the monument in that position, and has a length equivalent to the width of the central shelter plus its extensions of (42,10 + 4,76 + 4,76) = 51,62 and 14,24 m wide. Shelters 3 and 4, together with the central shelter, form a central united aisle (as previously mentioned).
Shelter 5 will comprise the southern aisle of the shelter system, and it is proposed that it will incorporate 9 metal supporting pillars in positions estimated to be relatively safe and secure. These pillars will support trusses in a horizontal grid 3,56 Χ 3,56 with a height of 1,78m bearing purlins covered with composite thermally insulated sheet steel panels with a single sided incline of 2%.
The external dimensions of the shelter boundary are 73,65 Χ 22,13 m.
Furthermore, this achieves the best possible convergence of the three shelters (central, 5 and 4) without duplicate coverage, offering the solution to a serious problem arising from the preliminary study delivered to us.
Future shelter 6 will be supported by 8 pillars located in positions which do not infringe on the three aisles of the northern basilica. These pillars will be incorporated within the usual grid and support trusses with the same geometric detail as shelter 5.
Coverage with purlins determines a final boundary for the shelter with dimensions of 33,38 Χ 61,86 m.
MORPHOLOGICAL AND FUNCTIONAL ADAPTATION OF THE ENTIRE PROPOSED CONSTRUCTION PROJECT TO THE NATURE OF THE ARCHAEOLOGICAL SITE - CONSTRUCTION DESIGN AESTHETICS OF THE SHELTER SYSTEM AT FULL DEVELOPMENT
The grid layout of the monument site as infrastructure for the development and geometric form of the shelter system
Clear indications have arisen supporting the estimation that the geometry of the supporting columns of the peristyle of the monument is based on a grid unit with dimensions of 356 Χ 356 cm.
It is considered that this grid is appropriate to determine the positions of supporting columns and the outlines of the central shelter in its entirety.
It is also desirable that this grid should govern the entire system of proposed shelters to follow in subsequent phases, in consideration of the contribution this will make to the achievement of the desired morphological continuity and simplicity.
Linear layout of shelters
Using this design grid, and with the objective of creating a clean minimalist structural form for the shelter system, it is suggested that the proposal delivered to us for 7 + 1 shelters in total should be modified to eventually create a complex of 3 basic shelters with a common direction: the direction from east to west as arising from the layout of the monument site.
The proposed system is composed of a central main aisle and two parallel aisles on each side following the same linear direction from East to West. The center aisle is created by the central shelter, which is the basic subject of this design study, and for which two future extensions are proposed, to the east and the west, with the aim of covering the entire monument along its full length.
The future south side aisle/shelter will cover the southern bath houses, the Sarapeio – Kanopos and the Antineio.
The future north side aisle/shelter will cover the pillared hall of the northern basilica.
This linear layout of the three shelters is in harmony with the peaceful surrounding landscape and their arrangement on different levels contributes to a reduction of the overall size of the system, following the natural incline of the ground, as well as the different sections which comprise the layout of the monument site as a whole.
The structure of shelters with the aim of creating morphological homogeneity
Given the integration of the design grid within the archaeological site, the entire system should provide flexibility in relation to the positioning of columns, to the extent that any existing provisions may be altered by potential archaeological finds.
This flexibility can be secured only through use of space frames. Under current conditions all the shelters should be able to offer such flexibility, apart from the central shelter where the supporting pillars located in the garden area are archaeologically secure.
It should also be noted that although the use of space frames may often leave a neutral impression, on the other, as a whole, they may create a rather dense and fiddly construction over an archaeological site. Consequently, it is considered appropriate that they should only be used where absolutely necessary within the planned shelter system.
In the case of the central shelter where the layout of supporting columns is secure, we consider it appropriate to avoid the principle of space frames, since here it is unnecessary. Our objective is to design a main load bearing structure with a minimalist morphology which can be extended to connect with the space frames of future shelters.
This relationship to future shelters, which depends on the geometry of design grid outlines, is also determined by the heights, the individual rods, gradients, and coverage with purlins and composite thermally insulated galvanized sheet steel panels. Together with the circular cross-sections of the metal supporting columns (with a diameter of 70 cm), these elements ultimately combine to form a building code to cover the entire shelter system for the site. This code will permit any changes in the size of shelters which may be required in the course of the project or modifications to supporting columns, and will facilitate the overall homogeneity of the system.