FinEst Link Feasibility Study Sub-report Alignment alternatives 12/2017

Transcription

1 FinEst Link Feasibility Study Sub-report Alignment alternatives 12/2017 1

2 Table of contents 1. Horizontal alignment of FinEst Link Vertical alignment of FinEst Link Horizontal alignment alternatives Alternatives in Finland Alternative A, North of Kerava Alternative B, North of Vuosaari harbor Alternatives C1 and C2, North of Airport - Separate freight tunnel Alternative D, North of Airport Alignment study at the coast of Helsinki Conclusion Alternatives in Estonia

3 1. Horizontal alignment of FinEst Link The basic concept of the FinEst link consists of a railway tunnel between Estonia and Finland connecting both capitals with a mixed train concept for both passenger and freight traffic. Currently, planned locations for tunnel portals are on the east side of Tallinn and near Helsinki-Vantaa Airport. From Tallinn, the tunnel starts at Iru junction and goes under the Gulf of Finland and city of Helsinki to Helsinki-Vantaa Airport. The planned construction concept requires two artificial islands which both will be built about 15 km from the coastlines of Estonia and Finland. The total length of planned tunnel is km. However, the final vertical alignment and exact portal locations will be studied in a later phase of the project. Figure 1.1 shows the planned alignment. Figure 1.1 Map of the FinEst link FinEst link international passenger stations are planned to locate in Ülemiste railway station, under Helsinki central railway station, under Pasila railway station and next to Helsinki-Vantaa Airport underground railway station of Ring railway. All those passenger stations are designed like Airport terminals (passport control, etc.). For cargo trains, additional bypasses have been planned for overtaking and safety reasons at stations in Finnish side. Figure 1.2 below shows a schematic picture of the station layout with cargo train bypasses. 3

4 Figure 1.2 Schematic picture of station layout with cargo train bypasses On the Estonian side, FinEst link development is directly linked with the Rail Baltic development by joined tracking as well as potential of sharing facilities in Estonian side. Figure 1.3 shows that freight facilities of the FinEst link are planned to share location with Rail Baltic facilities. Also on Estonian side, terminals and depots would locate in aircraft noise area. In addition, Rail Baltica could also connect FinEst link to Muuga harbor. Figure 1.3 Horizontal alignment and facilities in Estonia 4

5 The horizontal alignment plan of FinEst link starts from Ülemiste railway station close to Tallinn airport. The first 8-12 km, depending on tunnel portal location, from Ülemiste railway station is a surface section following the planned railway corridor in the Harju County Plan. The tunnel portal is located near Iru junction, southside of road #1. Other possible location for tunnel portal is approximately 4 km north from Iru junction (figure 1.3). In following studies, an exact location for tunnel portal needs to be planned. Despite which tunnel portal is chosen, the horizontal tunnel alignment follows the Harju County Plan beneath the Viimsi peninsula and island of Aegna. In the sea area, the planned tunnel alignment goes via shallow sea areas in Tallinnamadal (Estonia) and near Uppoluoto (Finland) where artificial islands are planned to be build. At the coast of Helsinki, the alignment is planned to avoid conflicts with an 8 km long deep sewage tunnel. Thus, the alignment is located on west side of it. Horizontal alignment curves smoothly to the central railway station of Helsinki and continues via Pasila station to the Helsinki-Vantaa airport. North of Pasila FinEst Link is planned to connect with Airport link. From that section to north, FinEst link and Airport link could run in a same expanded tunnel including both 1435 mm and 1524 mm gauges. Near airport, the planned alignment underpasses Ring railway close to the Aviapolis station and continues north-west side of Ring railway. Tunnel alignment ends to the north of airport area where railway is planned to continue as a surface section to the potential areas of depots, cargo and car/truck terminals. Exact location for tunnel portal needs to be studied more detailed in following planning phases. On the Finnish side, freight terminals and depots could be located north of Helsinki-Vantaa Airport mainly in aircraft noise area. That location is central from the logistic point of view. Hence, the terminal area would serve the entire Finland s freight transport. Planned ring road 4 and railway from terminal area to Hanko-Hyvinkää railway would provide both good road and rail connections to existing transport network. The schematic layout of alignment in Finland is presented in Figure 1.4 and Figure 1.5. In table 1.1, evaluation of pros and cons of FinEst Link and Airport link different gauge alternatives are presented. As a conclusion, separated 1435 mm and 1524 mm tracks in a same expanded tunnel was a chosen solution. The major reason to exclude dual gauge system was the susceptibility to interference. Please note that the double-track solution was not studied in detail. Table 1.1. Evaluation of gauge alternatives, FinEst Link & Airport Link 5

6 Figure 1.4 A schematic layout of alignment in Finland Figure 1.5 Horizontal alignment and facilities in Finland According to design principles, the aim of the alignment planning and allocation process was to find alignment that enables passenger terminals to be located in Helsinki Central Railway station, Pasila railway station and Helsinki-Vantaa Airport. Other precondition was to allocate location for freight terminals as near Helsinki as possible. 6

7 During the planning process, five different alternatives for Finland and three for Estonia have been developed and evaluated. Alternatives have been discussed in FinEst Link planning workshops as well as in meetings with municipal leaders (Tuusula, Vantaa, Nurmijärvi, Järvenpää and Kerava). As a result, common approval is to go ahead with alignment alternative D. In section 3, all alignment alternatives are described and evaluated. 7

8 2. Vertical alignment of FinEst Link Several requirements were considered for the design of the vertical alignment, such as: the tunnel should be situated predominantly in geotechnical favourable geology meaning the crystalline bedrock (refer to chapter 5). a rock cover of 40m at any point of the tunnel s subsea section was set as a boundary condition in order to avoid weathered zones and geological disturbed zones which possibly could lead to hydraulic short circuits. a deeper tunnel alignment causes higher water pressure on the final lining of the tunnel and higher energy consumption of the trains to climb up the ramps to the surface. In order to have enough traction especially for heavy freight trains the max. gradient of the vertical alignment was limited to 10 while the minimum longitudinal gradient for a reasonable drainage of the inflowing ground water was set at 5. The vertical alignment of Finest link can be seen in Appendixes. At the deepest point the tunnel runs approx. 215m below sea-level. In total, there are 3 low points two at the intermediate access points and one in-between. Three low points are justifiable since a waterproof lining concept is designed for Finest (refer to chapter 6.3) and hence only a very small amount of water is expected in the tunnel. The low points coincidence with the positions of the rescue stations. The subsea tunnel section and the position of the 3 low points as well as those of the intermediate access points are shown in Figure 2.1 below. The bigger part of the tunnel is situated in the crystalline bedrock, while around 16 km of the tunnel on the Estonian side run in the Edicara sandstone or the blue clay formation. The tunnel portal on the Estonian side is located close to Iru junction right after passing the existing highway 1 Tallinn - Narva. Due to the high length of the inclined tunnel section on Estonian side (approx. 20km), the gradient of this ramp was reduced to 8.7 in order to lower the energy consumption and the brake loads. The other subsea tunnel sections have a gradient of 5. On the Finnish side Finest link is connected to underground stations therefore the difference in altitude between onshore and offshore sections is not that high and a design gradient of 5 is sufficient. The total tunnel length from one portal to the other is km. However, the final alignment of FinEst Link with the exact portal locations will be studied in detail in a later phase of the project. Tallinn / EST Helsinki / FIN Figure 2.1. Vertical alignment of subsea tunnel section with 3 lows Vertical alignment of FinEst Link under the Helsinki city is constrained by existing and reserve of underground infrastructures (Figure 2.2). Most of the existing tunnels and rock caverns are above the 8

9 z level 35. Deepest tunnels intersecting planned vertical alignment are YK tunnels ( m), planned underground railway line of Pisara ( m), district heat tunnel ( m) and Kehärata railway tunnel ( m) which is close to Helsinki-Vantaa Airport. Figure 2.2. Existing and reserve of underground infrastructures of Helsinki and Vantaa. Helsinki central underground railway station of FinEst Link ( m) have planned in this study to level 70 (rail level) to avoid conflicts and risks with Pisara and YK tunnels. Underground railway station of Pasila ( m) have planned to level 60. The platform levels of underground stations need to be review in next planning phase because it would be preferable if they would be closer to the ground surface (Figure 2.3). From Pasila to the north vertical alignment is planned slope gently upward and join the tunnel section of planned Lentorata railway line. Combination of planned FinEst and Lentorata tunnel 9

10 concept has estimate continue roughly from chainage m to The plan is to cross Ring railway tunnel underneath of it ( m) close to the Aviapolis, which is underground station of Ring railway. Undergound station of FinEst Link & Airport Link in Helsinki-Vantaa Airport ( m) is planned to be on the north-west side of existing Ring railway station at level +7. From Airport station tunnel is planned to continue about 4 km with gradient 10 to the ground surface. Tunnel portal and horizontal alignment in the Airport area need to studied more detail in next design phase. The location of portal is depending several variables that are not clear to be able to justify exact location and horizontal alignment of tunnel in end. Figure 2.3. Vertical alignment under Helsinki city Figure 2.4. Vertical alignment at Helsinki Vantaa Airport 10

11 Recommendations & tasks for further studies concerning: More detail design o Underground stations design and location: Helsinki Central Railway, Pasila and Helsinki-Vantaa Airport. o How many stations are needed in Helsinki o How to cross Ring railway and underground station of Aviapolis o Depots, car/truck terminals and cargo areas o Tunnel portal location in Estonia side o Horizontal and vertical alignment of FinEst Link o Separations between freight and passenger tunnels in stations and if needed elsewhere o Combination of FinEst Link and Lentorata, junctions, tunnel profiles, concept etc. 11

12 3. Horizontal alignment alternatives 3.1. Alternatives in Finland Altogether, five spatial variants have been studied on Finnish side. All alternatives have same passenger station locations: Helsinki Central Railway station, Pasila railway station and Helsinki- Vantaa Airport. Helsinki Central Railway station is planned to locate -70 m below sea level, Pasila -60 and Airport +7 (-35 below surface). Instead, the alignment and location of depots and freight terminal varies between alternatives Alternative A, North of Kerava Figure 3.1. A schematic map of alignment alternative A 12

13 Figure 3.2. A schematic layout of alignment alternative A Description In alignment option A (Fig. 3.1 and 3.2), the FinEst Link tunnel connects to Airport Link after Pasila. FinEst Link and Airport link run in a common expanded tunnel. However, FinEst Link and Airport Link are separate systems having different gauges, FinEst 1435 mm and Airport Link It was also studied if FinEst Link and Airport Link could use a dual gauge system. With respect to limited information about dual gauge systems in similar context, separate systems in expanded tunnel was chosen. Separate systems give also more capacity and redundancy. This common tunnel section continues up to North of Kerava where both freight facilities are located and Airport Link connect to existing Finnish railway infrastructure. Thereafter, it branches to a surface rail heading to freight terminal and depot which are allocated to east of Oikorata and highway 4. Right after Helsinki-Vantaa Airport passenger station, a separate link to passenger train depots is planned. Evaluation In A-alternative, compared to other option, passenger trains, car/truck shuttle and cargo trains operate longer in a same tunnel which are not beneficial for train operation because different speed profiles. Hence, there will likely be a shortage of capacity without additional bypasses for overtaking. This alternative may also create a bottleneck effect. Any disturbance in a section where Airport Link and FinEst Link are together will possible close both systems. Running freight trains via passenger stations requires additional dedicated bypasses for cargo trains in stations due to train operation and safety reasons. This would also increase station costs. This alternative has the northernmost location for freight terminal and depot. Hence, car shuttle terminal would locate quite far from Helsinki. The allocated area is currently unbuilt and in agricultural use. Thus, the current land use don t set strict restrictions for planning terminal functions 13

14 in that area. However, close to the proposed area, there are groundwater areas as well as nature conservation areas. Hence, an optimal location would need more detailed planning Alternative B, North of Vuosaari harbor Figure 3.3. A schematic map of alignment alternative B. Figure 3.4. A schematic layout of alignment alternative B. 14

15 Description In this alternative, the FinEst Link tunnel diverges into a separate freight tunnel to Vuosaari Harbor area (Fig and 3.4). FinEst passenger rail connects to Airport Link after Pasila. In this section, the FinEst passenger link and Airport Link are separate systems running in a common expanded tunnel until north-east of Helsinki-Vantaa Airport where passenger train depot would be located. A separate FinEst cargo train tunnel branches near the coast of Helsinki and runs to north of Vuosaari harbor area. The freight tunnel has the same tunnel system as the rest of FinEst link. After terminal and depot area north of Vuosaari harbor, the FinEst Link connects to existing Savio-Vuosaari freight rail tunnel. Proposed location for freight facilities would be approximately 3 km north from Vuosaari harbor. Right after Natura 2000 area, the FinEst freight tunnel would surface to existing agricultural area where terminals and depots would be located. Evaluation Alternative B has rail-rail/road terminal, truck loading terminal, depot and maintenance activities north of Vuosaari. Allocating facilities (loading/unloading area, train depot and maintenance etc.) to that area would be beneficial because of existing logistic infrastructure. Thus, this alternative would be the best from logistic point of view. However, there is ongoing land use planning together with cities of Helsinki, Vantaa and Sipoo. Land use plans and alternative B are in conflict with this proposal for Östersundom joint masterplan (Fig. 3.5) arising from Natura 2000 areas, other environmental aspects and the need of ecological connection from south to north. Figure 3.5. Extract of the proposal for Östersundom joint (Helsinki, Vantaa, Sipoo) masterplan and approximate areas needed for FinEst facilities in Vuosaari. Shifting cargo trains from the FinEst and Airport Link section would help the tunnel concept (gradient) and shorten the FinEst tunnel about 12 km compared to alternative A. However, total tunnel length would increase because of the additional freight tunnel. It would also simplify a passenger station concept but on the other hand add a complex branch construction under seabed 15

16 Alternatives C1 and C2, North of Airport - Separate freight tunnel Figure 3.6. A schematic map of alignment alternatives C1 and C2. Figure 3.7. A schematic layout of alignment alternatives C1 and C2. 16

17 Description Both C alternatives, 1 and 2, have approximately same tunnel and train operation concept as alternative B has (Fig. 3.6 and 3.7). The FinEst Link tunnel diverges into a separate freight tunnel to north of Airport where freight facilities are located. A new surface rail from freight terminal to Hanko-Hyvinkää rail connects FinEst Link freight traffic to the existing Finnish railway network. In alternative C1, the freight tunnel branches at the coast of Helsinki before the Central Railway station and in alternative C2 north of Pasila. The FinEst passenger rail connects to Airport Link after Pasila. In this section, the FinEst passenger link and Airport Link are separate systems running in a common expanded tunnel until north-east of Helsinki-Vantaa Airport where passenger train depot would be in aircraft noise areas. In both C alternatives, also all other FinEst facilities (loading/unloading area, rail to rail terminal, train and maintenance depot) are located mainly in aircraft noise area, workplace and logistics area and area allocated for handling and storage of excavated material, clean rubble and soil. Evaluation In alternative C1, separate freight tunnel would be longer than in alternative C2 but freight trains don t run via passenger stations when additional bypasses are not needed. Otherwise, C alternatives have same advantages and disadvantages as B alternative has considering train operation and safety. Location for terminal and depot facilities is as good as alternative B has from logistic point of view. However, aircraft noise area north of Helsinki-Vantaa Airport would offer a feasible location for FinEst facilities in contrast to Vuosaari area. Separate freight tunnel, as in alternative B, would rise costs due to increased total tunnel length. C2 would require less additional tunnel but it won t have benefits compared to option D. C alternatives might also conflict with Päijänne fresh water tunnel and Vantaa river valley 17

18 Alternative D, North of Airport Figure 3.8. A schematic map of alignment alternative D. Figure 3.9. A schematic layout of alignment alternative D. 18

19 Description In the figures 3.8 and 3.9, yellow line from North of Pasila indicates the section where FinEst Link and Airport Link could run in a same expanded tunnel as separate systems including both 1435 mm and 1524 mm gauges. FinEst Link can follow that alignment whether the Airport Link will be built or not. However, there will be some synergy advantages to FinEst Link if Airport Link will be built. At the coast of Helsinki, alignment is planned to avoid conflict with 8 km long deep sewage tunnel and for this reason alignment must locate on west side of sewage tunnel. Alignment turn smoothly to the central railway station of Helsinki and continue via Pasila station to station of Helsinki Vantaa airport. Tunnel alignment end to the north of airport where railway continues as surface section to the areas of depots, cargo and car/truck terminals. After area of terminals and depots, new one track surface rail to Hanko-Hyvinkää rail is planned to connect FinEst Link to existing Finnish railway infrastructure. FinEst Link passenger stations are planned to locate under Helsinki main railway station, under Pasila railway station and next to Helsinki-Vantaa Airport underground railway station. For cargo trains, additional bypasses have planned for overtaking and safety reasons. Terminal area for freight trains and truck/bus/car shuttle trains including loading and unloading areas are located north of Helsinki- Vantaa Airport mainly in aircraft noise area. That area also includes depots for passenger and cargo trains as well as other needed infrastructure and power supply. In total, area reservation is approximately m². Evaluation Alignment alternative D, which is the suggested solution, can be seen as a compromise of all other alternatives. It is a shorter version of alternative A and it use the same location for terminal and depot area as C-alternatives. This alternative does not have additional freight tunnel which keeps the cost estimation lower compared to option with additional freight tunnel. However, it causes a need for additional bypasses for overtaking in passenger stations due to train operation (schedule) and safety reasons. At this alternative, construction of complex branch under seabed can be eliminated. The most important benefit of alternative D is a feasible location for FinEst facilities. Land use plans concerning these areas are Vantaa master plan (Fig. 3.10) and general plan of Ruotsinkylä-Myllykylä, Tuusula (Fig. 3.11). Compared to these plans, FinEst Link facilities are located mainly in aircraft noise area, workplace and logistics area and area allocated for handling and storage of excavated material, clean rubble and soil. C-alternatives have also same location for facilities but those also include separate freight tunnel which increase the total length of FinEst tunnel compared to alternative D. However, alternative D has also some additional costs compared to alternative C1 because of the need for bypasses in passenger stations. In the end, this additional cost for stations is much lower than having separate freight tunnel. Thus, alternative D is the most feasible of studied alignment options. 19

20 Figure Ruotsinkylä-Myllykylä general plan in Tuusula Figure North-west part of Vantaa master plan Note that Vantaa has started to make new master plan. 20

21 Alignment study at the coast of Helsinki Figure Different alignment options studied at coast of Helsinki and between stations in Helsinki. Different alignment options were studied at the coast of Helsinki and between Helsinki Central and Pasila station. Option A was first chosen alignment, but it was found risky when crossing vertically too close of Sewage tunnel. Sewage tunnel is old tunnel, which is not done based on latest rock support standards. There has been stability problems and safety distance is needed. Option B is alternative with only one station in Helsinki, Pasila station. Alternative C was chosen in this study. Table 3.2. Evaluation of alignment alternatives at the coast of Helsinki 21

22 Conclusion Alt-A Problematic train operation concept (different speed profiles - long tunnel) Longer tunnel compared to Alt-D Less favorable loction for facilities compated to Alt-D Alt-B Allocating facilities is problematic Conflict: Master plan of Östersundom, Natura 2000 and environmental aspects The best option from logistic point of view Complex branch construction Additional cost: separate freight tunnel Alt-C1 Approx. Same tunnel and train operation concept as Alt-B Aircraft noise areas can be used for FinEst facilities Additional cost: separate freight tunnel Alt-C2 Compromise between Alt-A and C A shorter separate cargo tunnel compated to Alt-C1 Additional cost: separate freight tunnel Alt-D Shortest overall tunnel length No complex branch construction Aircraft noise areas can be used for all Finest facilities on Finnish side As a result of the alignment study, alternative D has been considered as the most feasible option for FinEst link in Finland. Evaluation process started when alternative A were considered to have disadvantages related to train operation concept, unfavorable location for freight terminals and rather high cost estimation due to a long tunnel section. Due to the problematic train operation concept, idea of separated freight tunnel was invented in an advisory board meeting. However, the alternative B collided to environmental aspects as well as ongoing land use plan at Vuosaari area. As a result, C alternatives were invented. Both C alternatives emerged from same premises as alternative B, a separate cargo tunnel. Aircraft noise area next to Helsinki-Vantaa Airport prove to be feasible location for FinEst facilities. Thus, the B alternative transformed to C alternatives having approximately same train operation concept and tunnel concept but a different location for FinEst freight terminals and depots. However, separate tunnels running rather close each other were considered an expensive solution. Hence, alternative D was created having same location for facilities but without need for separate, expensive, cargo tunnel. In these circumstances, additional bypasses for cargo trains have been planned for overtaking and safety reasons at passenger stations in Finnish side. 22

23 3.2. Alternatives in Estonia Alternative railway tunnel alignment has been developed to enable direct connection between Tallinn city center and Helsinki. In this context, three different scenarios have been developed during process of prefeasibility study and current feasibility study (figure 3.12.) The first one is an alignment (A) where the tunnel exit is at Naissaar Island. In this case a bridge connects the island with the mainland in Kopli. From Kopli the railway section would continue the surface via Tallinn city center to Ülemiste (airport). The second option (B) for the tunnel alignment is below Tallinn Bay, under Kopli and with the tunnel exit to the ground level in Tallinn city center or in Ülemiste. Due to lack of space in the city center an underground station would likely be needed. In this option, there is no really benefit going via (under) Naissaar (A). The third option (C) will surface in Viimsi peninsula close to the Rail Baltica corridor. Figure Alignment alternatives in Tallinn. Red color indicates a need for a bridge. In the first option (A), the rock conditions are extremely difficult to build a tunnel exit in Naissaar. The tunnel would penetrate the quaternary sediments (buried valley) all the way up to the surface (from depth 120 m below sea level). Island of Naissaar is a nature conservation area and it is considered to belong to the Natura 2000 program. The authorization to build a tunnel exit, TBM base, railway tracks and bridge might prove to be very challenging. The length of the bridge would be over 12 km and the height above the sea level should be sufficient to allow undisturbed sea traffic. It should also be considered that the TBM (tunnel boring machine) installation base needs a large land area and a proper harbor, which causes extra disturbance for the nature on the island. Transporting millions of tons of crushed rock cause lot of traffic in this valuable nature area (noise and pollution). It is very demanding to connect/build railway on surface through the existing Kopli, Tallinn and Ülemiste town structures. 23

24 Figure Building tunnel exit in Naissaar would mean penetrating very difficult rock conditions In the second option (B), there will be lack of space in the city center for a surface station, tunnel exit area and TBM base. Thus, the station in the city center should be underground and the possible tunnel exit in Ülemiste. Tunnel would need to penetrate deep buried valley between city center and Ülemiste. It would be very challenging to reach the design gradient of tunnel. The elevation of the underground station locates in the Blue Clay layer. The Blue Clay is a soft stone however very dense and impermeable. Building an underground station in city center with cargo train bypasses and tunnel to Ülemiste in option (B) would in these circumstances be very challenging and expensive. In alternative C, alignment goes under Aegna Island and follows Viimsi peninsula. Tunnel portal would be located at the Iru junction or approximately 4 km north, alternatively. This alternative has more suitable construction conditions compared to other options. The alignment can avoid deep fracture zones and it can be built without underground station. It also connects FinEst Link directly to Rail Baltica, Muuga harbor and Ülemiste. The C alternative is justified as it has a corridor reservation in Harju county plan (Figure 3.14). Option C gives possibility to design tunnel with lower gradient, which is Figure Extract of Harju County plan Revision A red dotted line indicated FinEst Link reservation. 24

25 preferable for freight traffic in long upward slope, in other options gradient would be too steep when taking account of geological limitations. Table 3.1 Evaluation of alignment alternatives in Estonia. Alternatives A and B are excluded from this feasibility study due to challenging and expensive rock conditions around Tallinn city center, due to environmental values in Naissaar and lack of space in city center. Thus, this study follows alignment alternative C: Viimsi. This option has more suitable rock conditions compared to others. It also connects FinEst Link to Rail Baltica and Muuga harbor better than options A or B. Also, the Harju county plan underpin this decision since there is a reserved corridor for FinEst Link. Thus, the alignment in Estonia follows that corridor presented in Harju county plan. 25