Carlos Baião Cenorgeo carlos.baiao@cenor.pt DESIGN AND CONSTRUCTION OF THE MACHICO-CANIÇAL CANIÇAL EXPRESSWAY TUNNELS
PRESENTATION LAYOUT Overall considerations Geological conditions Geological-geotechnical survey Caniçal Double Tunnel Conclusions Acknowledgments
OVERALL CONSIDERATIONS Geotechnical works in Madeira Island, in particular road tunnels, are greatly affected by: The extensive geological heterogeneity The structural and lithological complexity of the volcanic formations The rugged terrain
OVERALL CONSIDERATIONS This was overcome with the use of: Powerful means of earth removal with impressive production rates Sprayed concrete and soil nailing applied as temporary tunnel linings Large amounts of concrete as definitive tunnel linings using large-scale metallic formworks The jet-grouting technique at affordable costs
OVERALL CONSIDERATIONS This presentation will focus on the region of Machico, namely on the Machico- -Caniçal Expressway (about 8 kilometers long), located on the southeastern part of Madeira Island
OVERALL CONSIDERATIONS The Machico-Caniçal Expressway comprises six tunnels (all of which are double) and two access roads; Caniçal Double Tunnel is the longest of the six tunnels (2 x 2100 m) and remains the longest double tunnel in Portugal Fazenda Tunnel (and Access Road E) Piquinho Tunnel Caniçal Double Tunnel Portais Tunnel Palmeira Tunnel Queimada II Tunnel (and Access Road A)
OVERALL CONSIDERATIONS The table below lists the main characteristics of the six tunnels (and its road accesses, when applicable) included in the Machico-Caniçal Expressway DESIGNATION WIDTH (m) AREA OF EXCAVATED CROSS-SECTION SECTION (m 2 ) TOTAL LENGTH (m) MAXIMUM COVERING (m) Queimada II Tunnel 9,0 75 745 95 Access Road A 7,0 57 202 70 Piquinho Tunnel (double) 9,0 75 2 x 449 35 Fazenda Tunnel (double) 9,0 75 2 x 163 30 Access Road E 7,0 57 185 40 Caniçal Double Tunnel 9,0 75 2 x 2100 > 300 Portais Tunnel (double) 9,0 75 2 x 682 100 Palmeira Tunnel (double) 9,6 83 2 x 915 60
OVERALL CONSIDERATIONS Along the short stretch of expressway between Machico and Caniçal, tunnels account for a very significant part - 66% of the route corresponds to underground construction Total length of expressway (m) 7 770 Total number of tunnels (including double tunnels and access roads in tunnels) Total development of tunnels (including double tunnels and access roads in tunnels) (m) Total development of tunnel layout (including double tunnels and access roads in tunnels) (m) RELATIONSHIP BETWEEN THE DEVELOPMENT OF TUNNEL LAYOUT AND TOTAL DEVELOPMENT OF EXPRESSWAY (%) 14 10 493 5 096 66
GEOLOGICAL CONDITIONS The expressway crosses the volcanic complexes ß1 and ß2, as shown on the plant below: β1: comprises different pyroclastic materials, as well as intercalations of basaltic lava flow, always very weathered. The pyroclastic formations are coarse, chaotic, with great angular blocks, volcanic bombs, lapilli and ashes. Sometimes fine pyroclastic materials (tuffs with bombs) are predominant β2: very heterogeneous complex formed by alternate irregular layers of basaltic lava flow and breccia pyroclastic materials, generally interstratified, with less significant intercalations of compact tuffs. Sometimes alternate layers of disaggregate and compact breccias present significant thickness, but always variable and irregular
GEOLOGICAL CONDITIONS The following photos illustrate both complexes (ß1 and ß2): ß1 - Tuffs with volcanic bombs ß2 - Basaltic lava flow
GEOLOGICAL CONDITIONS The following photos illustrate both complexes (ß1 and ß2): ß2 - Pyroclastic lappili deposit ß2 - Pyroclastic fine tuffs
GEOLOGICAL-GEOTECHNICAL SURVEY The geotechnical investigation carried out was based on detailed geological surface surveys and geological prospecting using trenches and boreholes comprised basically of rotation boring A total of 146 borings were made along the expressway, making up 3071 meters of drilling Considering the average costs of the investigation works, the following conclusions can be drawn: To each kilometer of expressway corresponds an average of 100 000 of prospecting work Each tunnel has associated an average of 40 000 of prospecting work These costs correspond to around 0.5 to 1.0% of the total cost of the construction network
QUEIMADA II TUNNEL Year of opening 2004 Total length (m) 745 Lay-bys - Connecting galleries for vehicles Pedestrian evacuation galleries - - ACCESS ROAD A Total length (m) 202 VIEW OF THE SOUTHERN PORTAL
QUEIMADA II TUNNEL Year of opening 2004 Total length (m) 745 Queimada I Tunnel Lay-bys - Connecting galleries for vehicles - Access Road A Queimada II Tunnel Pedestrian evacuation galleries - ACCESS ROAD A Total length (m) 202 VIEW OF THE NORTHERN PORTAL
PIQUINHO TUNNEL Year of opening 2004 Total length (m) 2x449 Lay-bys - Connecting galleries for vehicles Pedestrian evacuation galleries - 2 VIEW OF THE SOUTHERN PORTAL
PIQUINHO TUNNEL Year of opening 2004 Total length (m) 2x449 Lay-bys - Connecting galleries for vehicles Pedestrian evacuation galleries - 2 VIEW OF THE NORTHERN PORTAL
FAZENDA TUNNEL Year of opening 2004 Total length (m) 2x163 Lay-bys - Connecting galleries for vehicles - Access Road E Fazenda Tunnel Pedestrian evacuation galleries - ACCESS ROAD E Total length (m) 185 VIEW OF THE SOUTHERN PORTAL
FAZENDA TUNNEL Year of opening 2004 Total length (m) 2x163 Lay-bys - Connecting galleries for - vehicles Fazenda Tunnel Access Road E Pedestrian evacuation galleries - ACCESS ROAD E Total length (m) 185 VIEW OF THE NORTHERN PORTAL
CANIÇAL DOUBLE TUNNEL Year of opening 2004 Total length (m) 2x2100 Lay-bys 3 Connecting galleries for vehicles Pedestrian evacuation galleries 1 8 VIEW OF THE WESTERN PORTAL
CANIÇAL DOUBLE TUNNEL Year of opening 2004 Total length (m) 2x2100 Lay-bys 3 Connecting galleries for vehicles Pedestrian evacuation galleries 1 8 VIEW OF THE EASTERN PORTAL
PORTAIS TUNNEL Year of opening 2004 Total length (m) 2x682 Lay-bys 1 Connecting galleries for vehicles Pedestrian evacuation galleries - 4 VIEW OF THE WESTERN PORTAL
PORTAIS TUNNEL Year of opening 2004 Total length (m) 2x682 Lay-bys 1 Connecting galleries for vehicles Pedestrian evacuation galleries - 4 VIEW OF THE EASTERN PORTAL
PALMEIRA TUNNEL Year of opening 2004 Total length (m) 2x915 Lay-bys 1 Connecting galleries for vehicles Pedestrian evacuation galleries 1 4 VIEW OF THE WESTERN PORTAL
PALMEIRA TUNNEL Year of opening 2004 Total length (m) 2x915 Lay-bys 1 Connecting galleries for vehicles Pedestrian evacuation galleries 1 4 VIEW OF THE EASTERN PORTAL
CANIÇAL DOUBLE TUNNEL The Caniçal Double Tunnel figures as the most representative and emblematic tunnel constructed along the Machico-Caniçal Expressway The tunnel comprises two galeries 15 m apart in a straight direction with an average distance of 2100 m and a constant inclination of 3,5% in the northern gallery and 3,65% in the southern gallery West Portal is located at level 70 on Machico side and East Portal is located at level 140 on Caniçal side The opening of this tunnel, in 2004, set an alternative to the Old Caniçal Tunnel to get from Machico to Caniçal
CANIÇAL DOUBLE TUNNEL Eastern Portal of the Old Caniçal Tunnel Old Caniçal Tunnel tansverse type cross-section Location of the Western Portals of the Old Caniçal Tunnel (in light blue) and of the Double Caniçal Tunnel (in yellow)
CANIÇAL DOUBLE TUNNEL The transverse type cross-section of each gallery of the Caniçal Double Tunnel has a working width between walls of 9,0 m and a maximum height of 7,75 m, ensuring a minimum clearance of 5,0 m The roadway profile is comprised of a two-lane carriageway (2 x 3,25 m), an outer shoulder of 0,75 m wide and an inner hard shoulder of 0,25 m wide, plus two passing places which form the limits of the platform
CANIÇAL DOUBLE TUNNEL At the eastern end of its stretch the tunnel galleries have a widened section whose working width between walls at the start of the stretch varies from 9,0 m to 12,25 m, remaining constant at 12,25 m until the end of the stretch The widening of the section was performed in order to enable the construction of an additional traffic lanes which comprise the exit and the entry lanes to the Caniçal road junction
CANIÇAL DOUBLE TUNNEL Given its large extension, the tunnel was equipped with 3 emergency parking lay-bys in each gallery (in yellow), 1 connecting gallery between the two central lay-bys which enables light vehicles to reverse in the event of an accident (in blue) and 8 pedestrian evacuation galleries (in red) FUNCHAL KM 2+780 KM 2+980 KM 3+180 KM 3+380 KM 3+580 KM 3+780 KM 3+980 KM 4+180 KM 4+380
CANIÇAL DOUBLE TUNNEL Layout of the central emergency parking lay-by and its connecting gallery:
CANIÇAL DOUBLE TUNNEL Overall view of the lay-by during the application of the waterproofing system (on the left) and after the completion of the secondary lining (on the right)
CANIÇAL DOUBLE TUNNEL Based on the lithological and structural characteristics of the formations crossed by the tunnel, geotechnical zoning of the rock mass was carried out 4 zones were defined, covering all foreseeable situations, each corresponding to a level of rock mass quality and behaviour: ZG1 zone: essentially comprised of compact basalts and compact breccia ZG2 zone: comprised of resistant rocks (faulted basalts) ocasionally intercalated with layers of materials of poorer characteristics ZG3 zone: comprised of rocks of weak resistance and compacted or loosely consolidated soils, such as disaggregated breccia, compact tuff and compact tufa with volcanic bombs ZG4 zone: encompassed all the formations of geotechnical zone ZG3 but was associated with stretches of shallow covering or with an important presence of water
CANIÇAL DOUBLE TUNNEL Primary and secondary linings were defined for each geotechnical zone as follows: ZG1 ZG2 ZG3 and ZG4 (1) PRIM. LINING Occasional 4 m Swellex rock bolts and 5 cm of shotcrete 4 m Swellex rock bolts at 2 m intervals in the vault and 5 to 10 cm of shotcrete with metallic fibers HEB160 steel ribs, AQ50 electro-welded steel mesh and 10cm of shotcrete SEC. LINING Reinforced concrete layer 0.25 m thick Reinforced concrete layer 0.4 m thick (1) ZG4 differs from ZG3 in the spacing of steel ribs: at 1m intervals in ZG3 and 0.70m intervals in ZG4
CANIÇAL DOUBLE TUNNEL Safety concerns were given great emphasis and an evolved system, comprising the installation of the following control and safety equipments, was implemented: Power supply Lighting Ventilation Signalization Communications Control systems CCTV Auscultation Fire detection and fire extinguisher systems Fire hydrants
CONCLUSIONS Tunnels play a major role in the development of road networks under conditions such as the ones found in Madeira Island; the percentage of tunnel length of the Machico-Caniçal Expressway is unique (66%), mainly due to the vigorous relief of the island Concerning the design, although considering the significant limitations associated with the nature of the volcanic rock mass of Madeira Island, it is possible to improve the geological recognition in order to obtain the necessary guidelines to define the geotechnical zoning and the primary and secondary linings The construction of expressways in geotechnical and topographical conditions as unfavorable as those of this case can only be successful if, from the initial design stage, the geological and geotechnical constraints are exhaustively incorporated
ACKNOWLEDGMENTS The authors are greatly indebted to Estradas da Madeira of the Região Autónoma da Madeira for authorizing the publication of this paper, as well as all the entities involved in the construction of the Machico-Caniçal Expressway tunnels THANK YOU VERY MUCH FOR YOUR ATTENTION