UNDERGROUND WORKS
22Pages

UNDERGROUND WORKS YOUR ROOFING AND WATERPROOFING PARTNER

Introduction 2 Flag’s experience in underground work 3 The manufacturing process 5 Elements and functional layers of the waterproofing system 8 Type of works 10 Natural tunnels 10 Man-made galleries and foundation 13 General installation guidelines 15 Checks 17 Detailed installation instruction: the FLAGON FAIL-SAFE SYSTEM 18 Index REV. 0 Ottobre 2002

INTRODUCTION Owing to the inherent complexity of construction, all underground works, whether tunnels or foundations, must have a life expectancy of several decades. All components of these works should have similar characteristics, especially the waterproofing system. The waterproof liner protects and makes the construction safer. Over its whole working life, it allows considerable cost savings in terms of maintenance and repair. Since the creation of the first tunnels, water seepage has been one of the main problems. Virtually no tunnel is ever bored into a completely dry substrate....

underground works FLAG’S EXPERIENCE IN UNDERGROUND WORKS Flag has been producing synthetic liners for underground works since the mid-60’s, when its materials were used in the construction of the first underground railway lines in Milan and Rome and in the first tunnels of the L’Aquila-Teramo motorway. Since then, some 50 million square metres of Flag waterproof liners have been applied all over the world, for the most prestigious road, motorway, railway and underground railway projects in the past 40 years. Today, Flag is one of the world’s leading manufacturers of synthetic liners for...

4 underground works MAIN CHARACTERISTICS The main characteristics of Flag liners for underground works are: - Excellent weldability; - Softness and flexibility; - High ultimate elongation (dimensional variation of the membrane when subjected to mechanical stress); - Tensile strength (the membrane can resist tensile stress without tearing); - Durability; - Adaptability to irregular substrates; - Maintains its integrity even in the case of structural movements or soil subsidence; - High electrical resistance; - Suitable for installation in humid places; - Resistance to static puncturing; -...

underground works 5 THE MANUFACTURING PROCESS FLAGON TPO LINERS The raw material used for manufacturing FLAGON TPO liners is actually a semi-finished product obtained from a mixture of synthetic polyolefins, softening agents (EPR) and various additives which, through a specific manufacturing process, are transformed into a melt mass and then into granules. The main advantage is the possibility of combining: • resistance to ageing and weathering with the softness and flexibility of EPR. • high chemical-mechanical characteristics with the excellent weldability of polyolefins. The exclusive...

FLAGON PVC LINERS CO-EXTRUSION In this process, the mixture of material components (resins, plasticisers, stabilisers, pigments, etc.) is introduced through a hopper into a cylindrical chamber. Here it is heated up and pressed by worm screws into a co-extrusion head, where the single extruders converge, and then it is laminated in a calender. The liner thickness is automatically adjusted by electronic equipment that controls the opening of the extrusion head and of the calender. The material thus obtained is a single-layer homogeneous, non-reinforced liner, with high tensile properties and...

underground works This spreading and gelation process is repeated four times. The liners manufactured by this system are therefore composed of four differently formulated layers. Between the second and third layers, an internal reinforcement is introduced, either in polyester mesh for tensile strength or glass mesh for stability. This manufacturing system establishes a molecular bond between the four layers creating a homogenous and flexible single-layer liner that can be combined with a thermally treated geotextile layer to improve its gripping characteristics when using adhesives or when...

APPLICATIONS The waterproofing of underground works is extremely complex and will not be dealt with in this document, as it would be difficult to examine their design in depth. Our technical offices and business partners who operate in specific sectors are at your service to design the waterproofing project and to draw up technical specifications. Contact the Flag S.p.A. offices (phone number +39.035.4940949 fax +39.035.4940649) or send an e-mail to info@flag.it to establish the details and characteristics of the specifications. SELECTING THE WATERPROOF LINER Selecting the correct...

underground works 3 - DRAINING LAYER This provides adequate drainage outside the waterproofing system; it is composed of materials with high drainage properties. 4 - WATERPROOF LAYER OR SEALING SYSTEM This makes the product durably waterproof. Either FLAGON PVC or FLAGON TPO liners can be selected according to their mechanical and performance characteristics, for instance: ultimate elongation, tensile strength, resistance to static and dynamic puncturing, chemical and biological resistance, compatibility with drinking water. 5 - SEPARATION LAYER This physically separates two adjacent...

a) FLAGON PVC or TPO PROTECTION, 1.6 to 2.1 mm thick, laid in dry conditions and welded onto the profiles of the compartmenting joints; b) Cement cap of adequate thickness. 8 - FASTENING ELEMENT (NATURAL TUNNEL) This supports the waterproof liner during installation. It is composed of rondels (washers) in PVC or TPO, fixed in place by shot-firing into the tunnel wall. 9 - WATER-STOP COMPARTMENTING SYSTEM This enables the waterproofing project to be divided into sectors, allowing future repair operations to be carried out by injection of water-reactive resins. It is composed of shaped joints...

underground works Once the correct preparation of the substrate has been verified, proceed to laying the adjustment/compensation layer. The fastening elements, i.e. rondels of the same material as the synthetic liner, are an essential part of the waterproofing system. The FLAGON rondel, besides keeping the sheet adhered to the substrate, is also a safety element in case of irregular tensioning of the waterproof liner before or during casting of the secondary lining in concrete. The rondels, fixed to the substrate by a shot-firing machine, support the waterproof liner. The latter is fixed to...