SNFCC: CONSTRUCTION FACTS
In this section, we focus on the construction of the works, which are currently
progressing in full steam, transferring policies and plans to reality. We intend to
present some information on the specific technical methodologies applied in three
major sectors:
•
Quality of materials and workmanship
•
Environmental protection and respect to Community
•
New technologies
I.
Delivering Quality…
Quality of construction is the key factor in order to ensure lifetime integrity of the
project structures, minimum maintenance and maximum operational efficiency of its
facilities as well as preservation of its superior aesthetics.
Our approach is based on the following main applications:
Global Quality Plan: This defines the organization, the responsibilities, the lines of
authority and communication and the detailed procedures to be followed in every
project execution activity.
Subcontractors, materials and equipment: The approval by the SNFCC Consultants
of all potential subcontractors - suppliers, proposed materials and equipment is
required before the Contractor proceeds with any subcontracting or procurement
action.
Construction Drawings and Method Statements: The timely submission by the
Contractor and approval of these documents by SNFCC Consultants is a strict
prerequisite before any construction activity begins.
The Method Statements describe every step of the construction methodology to be
followed by the Contractor for each type of structure together with the relevant
inspection and testing procedures that need to be performed in order to verify that the
structure has achieved the quality standards required by the project specifications.
The key players in this laborious process are the SNFCC project managers and
inspectors, the Contractor’s construction and quality supervisors, and third party
testing agencies employed either by the SNFCC or the Contractor.
Page 1 of 22
Hundreds of traceable quality records are produced every day and stored directly to an
electronic Quality Data Bank, which is shared in real time by all participants. The
quality control procedures are supported by a site laboratory facility fully equipped with
advanced testing apparatus. The facility is operated by a certified third party testing
specialist and it is capable at present to perform and evaluate most of the quality tests
related to geotechnical and concrete structures.
The same quality observance and record keeping is ensured for the quality control and
testing performed off site either at the production – fabrication facilities (e.g. ready mix
concrete) or at recognized international testing institutions for special tests (e.g.
seismic isolators).
1. Site Laboratory Facilities
The Laboratory facilities, located at the NE corner of the site, support every day
construction activities for the big majority of commonly required tests, such as:
Earthworks: (Grain size analysis, Atterberg limits, Modified Proctor, in situ testing by
nuclear methods etc)
Page 2 of 22
Concrete: (Quality of aggregates, curing and compressive strength)
Ferro-cement mortar: (Workability, air content, curing and compressive strength)
From the commencement of the project more than 4,500 tests for the concrete
strength and 2,500 tests for the soil compaction have been performed by the site
laboratory with successful results.
2. Load tests on piles
Full scale ultimate load tests have been performed at representative locations at each
of the three buildings, which are founded on piles (Opera, Library and Car Park). All
tests have been successful and their results have been used for the verification of the
design assumptions and in fine tuning of the designed pile lengths
Page 3 of 22
3. Checking ready mix concrete supply
Each concrete mixer arrival is accompanied by the required production quality
documents, which are thoroughly checked upon arrival to verify the compliance with
the approved mix design and the special additives as well as the elapsed time after
production.
4. Checking ready mix concrete strength
Each batch of fresh concrete is tested for workability (slump) and temperature.
Samples are taken to the site laboratory for curing and testing the strength of
hardened concrete in numbers exceeding by far those required by the national
standards
Page 4 of 22
5. Integrity tests on piles
Integrity tests (sonic tests) have been performed successfully on all constructed piles,
barrettes and diaphragm walls in order to detect possible defects, variation in concrete
quality or change of section throughout the length of the element
6. Monitoring underground conditions during Hill construction
The rate of building up of the artificial Hill is closely controlled by continuous
monitoring of the underground conditions thru a sophisticated network of measuring
devices. The purpose is to maintain the bearing capacity of the under layers and to
Page 5 of 22
avoid long term settlements with detrimental effects to the neighboring structures and
to the finished landscaped park area covering the Hill
7. Testing the compaction of Hill bulk fill
The 14 m high Hill is formed by adding successive sloped soil layers of 40 cm
thickness. The soil material is derived partly from the project excavation and the
remaining quantities are imported from sources. Every layer is thoroughly checked for
the proper soil composition and the required degree of compaction
8. Testing seismic isolators
The seismic isolators are the most important elements for the structural behavior of
the Opera and Library buildings under strong earthquakes. These are sophisticated
devices which are placed under each building column.
Page 6 of 22
Each type of isolator undergoes a full scale dynamic test at specialized testing facilities
abroad (University of Pavia). Successful testing is the prerequisite for receiving the CE
certification by an independent European Union Authority
9. Testing of Micro-piles
The 60 cm thick concrete slab forming the bottom of the 14m deep stage pit at the
center of the Opera building is anchored to the underground by metal micro piles in
order to withstand the high uplift pressures applied from the groundwater surrounding
the pit.
Pull out tests have been performed on both preliminary and working micro-piles with
successful results.
Page 7 of 22
10. Mock-ups
Full scale mockups are produced for the major architectural elements to allow
preliminary inspection and eventual improvements by the project architects in order to
achieve best visual results of the final product. Examples:
Fair faced Concrete Walls
Soft and Hard landscaped areas
Page 8 of 22
Fencing
Opera Canopy
Page 9 of 22
11. Selection and Tagging of Trees
More than 1100 items of various species of trees have been carefully sourced from
various Nurseries in Greece and abroad. The trees have been securely tagged and
transported to a specially developed tree handling facility in Tragana – Viotia, where
they will remain and acclimatize before they are moved and planted to their final
position on the project.
Page 10 of 22
II.
Protecting environment – respecting community…
The overall project design is driven by the highest environmental goals and
international standards which are summarized in the following principles:
•
•
•
Strict Compliance with the Environmental Impact Study and Environmental
Terms approved by Greek Authorities
Achievement of Platinum LEED certification
Compliance with the highest international environmental standards
The same principles, which have already been applied in the design, are followed in
every day construction activities
Our approach is based on a comprehensive Environmental Project Plan in combination
with a LEED Strategy Plan describing the special organization, the responsibilities and
the detailed procedures to be followed in order to assess the risks during construction,
to implement the proper mitigation measures against any potential hazard and to
achieve the environmental targets of the project.
The key participants in this special task are the SNFCC consultants and auditors, which
include LEED specialists and third party environmental inspectors and the Contractor’s
LEED certified supervisors. Monitoring results are documented by a thorough and
systematic record keeping. The status of the environmental conditions on site is
constantly audited and evaluated thru periodical and ad hoc meetings and recorded in
monthly reports.
At the present stage of construction our efforts have been focused on the following
targets:
1. Initial clearance of site
The initial stage of works included clearance and removal from the site of big volumes
of domestic waste deposited over the past decades.
During the same period, the demolition of the pre-existing equestrian center facilities
took place.
Page 11 of 22
Any of excavation and demolition materials that could be re-used in future construction
have been salvaged and retained on site using screening and crushing techniques.
2. Construction Waste management
Based on relevant LEED requirements a specific waste management plan applies
covering:
•
•
•
•
•
Waste prevention
Sorting and selective storage of recyclable waste and direction for reuse
Hazardous material collection and removal by specialized subcontractors
Monitoring and documentation of recycling efforts
Continuing education of staff and labor
Page 12 of 22
3. Erosion , sedimentation and dust control
A great variety of measures have been installed and maintained in order to:
a. Protect existing public drainage networks and public areas from sedimentation
using:
• Sediments barriers and storm inlet protection
• Sedimentation Tanks cleaning site water before disposal to the public
networks
b. Prevent polluting the air with dust by:
• Dust control spray liquids on spoil heaps
• Watering and sweeping site roads
Page 13 of 22
c.
Keep the public road network by:
•
•
Cleaning facilities for outgoing vehicles
Concrete mixers wash out facilities
4. Noise control
Strict procedures apply to minimize noise disturbance to the neighborhood generated
from site activities such as
•
•
EEC noise limit certification is required for all construction equipment
Periodical noise measurements are taken at the vicinity of the site to monitor
potential violations
Page 14 of 22
5. Landscaping
Thousands of trees, shrubs and extensive green areas are to be planted as part of the
final project.
In the meantime the pre-existing trees are properly protected to avoid any harm
during construction activities.
6. Pedestrian Public Access Bridge
The construction works are extending to part of the “esplanade” the existing access to
the sea front. In order to restore any impact to the pedestrian traffic a steel bridge was
constructed that runs parallel to the esplanade. The bridge will provide clear and
comfortable access to the seaside for the public during the whole construction period.
Page 15 of 22
7. Visitors Center
The Visitors Center is a light temporary structure erected at the east border of the
project on top of the existing Esplanade corridor.
The architectural design is the result of a nationwide competition for undergraduate
students from the architecture schools at Greek Universities. Renzo Piano, the project
Architect, decided the winning design among the top ten competing proposals. The
team of Agis-Panagiotis Mourelatos and Spyridon Giotakis awarded the first prize.
The Center construction has been completed. The equipment installation is currently
under way. The Center will open to the public late September 2013 and will remain in
place until the scheduled opening of the SNFCC in late 2015 serving multiple functions.
It will give the visitors the opportunity to overview the construction site and learn
about the SNFCC, its history, role, scope and organization and its future plans. It will
also function as a space for exhibits and other public events.
Page 16 of 22
III.
New Technologies…
1. Information Management
Before the commencement of any procurement or construction activity all technical
documents produced by the Contractor (Construction Drawings, Method Statements,
Material submittals etc.) are subject to the review and approval of SNFCC specialists.
Such a procedure coupled with the everyday general and contractual correspondence
necessitates the exchange of enormous amounts of documents within and between the
three main participating entities i.e. the (a) Project Designers, (b) Employer and its
Representatives and (c) Contractor and its Consultants/ Subcontractors.
All this communication is achieved thru a web based electronic system with project
customized software, which connects in real time about 18 organizations and 145
engineers / key consultants located in Greece and all over the world and allows a
paperless but formal exchange of thousands documents every month.
The system automatically streamlines each type of document according to a predefined
workflow and develops, by default, document registers and archives, whilst warrants
confidentiality and neutrality to all participants
Traditional communication
WEB management system
Page 17 of 22
2. Building Information Modeling (BIM)
The benefits of BIM technology used from the initial stages for the design development
stage are extended to the production of construction drawings. The intelligent 3D
modeling continues to be used serving now the purposes of project constructability. It
facilitates the efficient coordination between different trades, the incorporation of
various elements added by specialist subcontractors and the accurate detailing of the
complex engineering systems. At the end, the “as built” drawings produced by BIM will
reflect the detailed picture of how the project was actually constructed and will offer
the best background for the next stage, which is the facilities management i.e. the
operation and maintenance of the project
Page 18 of 22
3. The “Hill” construction
Although it appears to be a simple process of adding successive layer of soil layers, in
reality the building up of the 14m artificial Hill is one of the most sensitive and
sophisticated construction procedures. As the soil structure rises, the construction is
continuously monitored recording three very critical parameters: the underground
water’s pressure, the rate of settlement and the degree of compaction achieved. The
sloping Hill Area will be finally developed to a great park, one of the biggest landscaped
green areas in the city extending to the south continuously from the Hill over the
neighboring concrete roofs, which will be constructed with the same slope.
The retaining structure around the Hill is not made of structural concrete walls. An
innovative eco-friendly technology is used called “reinforced earth” i.e. successive
layers of crushed aggregates reinforced by embedded synthetic nets. Underneath the
reinforced earth 3.500 gravel piles (underground stone columns) have been installed,
Page 19 of 22
which are designed to act as a natural foundation of the reinforced earth and to
prevent ground liquefaction during strong seismic activity.
4. Seismic Isolation
Both, the Opera and the Library will be based on seismic isolators. These are special
devices, which are placed between the vertical bearing elements and the foundation of
the buildings absorbing much of the destructive seismic energy before it is transmitted
to the superstructure. The seismic isolation does not only provides additional safety to
the structural building frame but also reduces earthquake movements protecting from
damage e.g. the expensive architectural fittings and finishes and the sensitive
electromechanical networks and equipment.
Page 20 of 22
5. Tower Cranes - non collision and zoning control
There are more than 100 special construction lifting equipment, excavators, and other
construction machinery, including 10 tower cranes (soon to become 11) serving the
works with overlapping working ranges. This makes the SNFCC site the most intensive
construction site in Greece. The working population is currently more than 600 people,
soon to exceed 1.500. Such intensity necessitates for safety reasons the installation of
an electronic system, which monitors all tower crane movements preventing them from
collision and other accidents by automatic controls and breaking. It is the first time
that such a system is ever installed on a construction site in Greece.
Page 21 of 22
6. Sustainable Urban Drainage Systems
The storm water drainage design strategy of the project is based on the following main
criteria - objectives:
a) To avoid overloading the existing public networks with increased storm water
runoff from the project area.
b) To protect sufficiently the project area from internal flooding
One of the basic means to achieve such objectives is the installation of Sustainable
Urban Drainage Systems (SUDS) inside the project area in compliance with the
relevant LEED requirements. SUDS consist of a combination of traditional infiltration
trenches with the new technology of “geo-cellular boxes”. The role of the geo-cellular
boxes is to provide a final infiltration step, buffer storage and release of excess storm
water to the public networks at controlled and significantly reduced rates
Page 22 of 22