Construction Supervision

Summary from Contractor

After the final breakthrough completed at Station 5+019.3, the excavation of the bench was continued and completed on Noveber 14, 2003.

Sixty eight (68) niches (16 emergency call niches and 52 Firefighting Niches) were completely excavated inside the Main Tunnel.

The Main Tunnel Concrete Lining completed up to the end of this month totaled to 2,898.00m (progress 75.14%).

As of November 30, 2003, 111.60m were excavated in the Evacuation Tunnel this month, giving the total length of Evacuation Tunnel excavation reached to 3,401.60m, (progress 88.19%) from the Tunnel Portal.

Construction Supervision by Engineer

Main Tunnel 

• Excavation

In the month of November 2003, after the final breakthrough ceremony was celebrated, bench excavation for the Main Tunnel was continued.

The Final Breakthrough Ceremony was successfully held on November 7, 2003, with the presence of the JBIC, Minister of Transportation, Danang City Delegates, PMU85 Director, Consultant's President, Contractors' and Subcontractors' Managers, and other guests.

After the final breakthrough has been completed at Station 5+019.3, excavation of the bench was continued and was completed on the 14th of this month.

Bench excavation was accomplished from station 4+962.0 to station 5+019.3, with a total length of 57.30m.

Electrostatic Precipitator No. 2

After completing the bench excavation for the Main Tunnel, the MT group proceeded with the excavation of the Inlet Side of the EP No. 2, reaching station 0+066.8 with a length totaling 61meters. The contractor scheduled to reach station 0+078.9 and breakthrough with the excavation of EP No. 2 from the south side 1st week of December 2003.

• Niche Excavation:

Sixty-eight (68) Niches - sixteen (16) Emergency Call Niches and Fifty-Two (52) Firefighting Niches - in the Main Tunnel were completed until this month.

• Lay-by Left No.1, 2, 3, 4 and Right No.1, 2, 3(connected to EP Outlet), 4

Excavation of all lay-bys (Lay-by No.1~10), which has a length of thirty-two (32) meters each, was completed in previous months as per original plan.

• Main Tunnel Rear Works (Concrete Works)

The pouring of Class D concrete for the Foundation Beam of the Lining Concrete continued this month from Station 4+577.5 to 4+817.5, totaling 240m on each side.

Installation of Mole Drain Pipes, together with filter cement aggregate, on both sides of the tunnel continued simultaneous with the foundation beams.

Cutting of Rock bolt heads and installation of geo-textile covers were done on areas with rock bolts.

Installation of EVA Waterproofing Membrane was also continued following the covering of rock bolts. Until the end of this month, a total length of 3,100.5m (Station 1+664~4+764.5) was completely covered with waterproofing membrane. The Engineer continued to require testing of the welded joint sheets using air pressure test, as per procedure stated on the method statement, before continuation of the installation.

Pouring of Concrete Lining was also carried out as per approved design segment. The Engineer carefully checked, during the joint survey with the contractor, the setting of the form for both bulkhead sides and the thickness as per design requirements.

The Concrete Lining for Standard Section of the Main Tunnel completed until the end of this month totaled to 2,662.50 meters. The Concrete Lining works for Lay-by Left Nos. 1, 2, 3, 4 and Lay-by Right Nos. 1, 2, 3 in Main Tunnel, totaling seven lay-bys with a length of 217.00m, were also completed. For Lay-by No.8 (Lay-by Right No.4), which consists of three (3) blocks, two blocks (8-3 and 8-1) were already concreted. For its middle block (8-2), which connects with the Clean Air Supply Section of the Ventilation Adit, preparation for concrete has been going on until end of this month.

The Main Tunnel Concrete Lining completed up to the end of this month totaled to 2,898.00m (Progress: 75.14%).

For cross passages, only the concrete lining for the blocks connected to the Main Tunnel are being executed. Concrete lining completed until the end of this month includes the Pedestrian Cross Passage No. 1~4 (Station 2+000, 2+400, 3+190, 3+688) and Vehicular Cross Passage No. 1~2 (Station 2+800, 4+100), totaling six (6) Cross Passage with a length of 20.10m.

Cable Duct Bank:

In the month of November 2003, the concrete works for the cable duct bank with manholes, including the installation of two (2) lines of embedded conduit pipe with a diameter of 110mm each, has been completed to station 4+170, the total length poured reaching to 2,501.00m.

Side Drainage/Catch Basin:

This month, the pouring of side drain and setting of pre-cast catch basins has been going on. Pouring of side drain, which was started from station 1+670.45, reached to station 3+969.55, totaling a length of 2,294.84m while for pre-cast catch basins, 92nos (to station 3+945) starting from no. 2 to no. 93 have been installed.

• West Side: (Right Side)

Cable Duct Bank:

The conduit duct bank concreting under the walkway structure has been commenced from station 1+691.55 and reached to station 3+864.12, giving a length of 2,195.12m

Side Drainage/Catch Basin:

Casting on-site of side drainage on the west side of the Main Tunnel began at Station 1+670.45 and reached to Station 3+882.95 with a total length of 2,212.5m. The setting/installation of pre-cast catch basins were from no. 2 ~ 95, totaling 94nos. (to station 3+995).

• Walkway Structure:

This month, the pouring of walkway structure was continuing. The base concreting works has been completed from station 1+669.70 to station 3+379.5m, totaling a length of 1,809.80m. Concreting of sidewall was also started on the same station and reached to station 3+274.5 with a total length 1,604.8m. The casting concrete of hydrant pipe saddle inside the walkway structure was also simultaneously executed with a base concrete starting from the same station and reaching to station 3+419.5 a totaling 1,749.80m.

On November 25, 2003, a joint site inspection no. 2 between the Consultant and contractors of Package IA, III and IV E and M was held prior to handing over. The walkway structure from station 2+384.5 Lay-by No.2 to station 2+815.5 by Package IA to Package III/IV and Duct Bank for PKIII from station 1+670.00 Portal East Side to station 2+815.5 Lay-by No.3. Although some minor items were needed to correct, part of the walkway structure and duct bank were, nevertheless, agreed and handed over to E and M for their works' access only.

• Main Drainage:

The installation of 400mm-dia Perforated Concrete Pipe had been started at station 1+709.4 and reached to station 3+023 this month with total length of 1,313.6meters including setting/connection of pre-cast concrete manhole nos. 1~6 and connection of cross drain from PVC mole drain.

• EP No. 1 Concreting Works:

The Electrostatic Precipitator No. 1 was turned over to PKIII/PKIV on October 10, 2003.

Evacuation Tunnel

The rock encountered in the Evacuation Tunnel was in good condition, although, on some rounds, installation of safety rock bolts became necessary due to slickensides with white clay band. Geologically, the rock condition encountered was stable on Class B. On some portion, it was classified as class A.

The excavation of the Pedestrian Cross Passage No. 6 (CP No. 8) at station 4+870 had commenced first day of the month from the ET side and was completed on the 10th from the MT side.

The excavation of Face No. 4 continued through CP No. 8 and the contractor targeted to reach the breakthrough with south side excavation at station 5+049.9 1st of December 2003.

The Face No. 4 excavation length for this month was 111.60m. The distance from the tunnel portal gives a total length of 3,401.60m until station 5+044.60 (Progress: 88.19%).

The Temporary Transformer Niches No. 1~11 were completely excavated as per approved plan submitted by the Contractor.

The Enlarged Pedestrian Cross Passageway Nos. 1 to 6 and the Vehicular Cross Passageway No. 1, 2 have been completed

Ventilation Adit Tunnel

• Concreting Works:

Cut and Cover Section / Connection Lining Concrete at Portal:

The Concrete Lining for Cut and Cover Section, with Portal Wall, and two (2) blocks of Normal Section of Lining Concrete connected to the Cut and Cover Section were completed with a total length 13.97m from Station 1+738.54 to 1+752.51.

Normal Section Lining Concrete:

Pouring of Class D concrete for the Foundation Beam of the Normal Section as well as for Enlargement Section of Lining Concrete has been continuing and reached a total length of 1,113.91m (station 0-135.11~0+961.79) on left side and 1,101.95m (station 0-135.11~0+949.83) on the right side at the end of this month including Cut and Cover section. Exhaust Shaft Section was completed in previous months.

Installation of Mole Drain Pipes, together with filter cement aggregate, on both sides of the tunnel continued simultaneous with the foundation beams.

Cutting of Rock bolt heads and installation of geo-textile covers were done on areas with rock bolts.

Installation of EVA Waterproofing Membrane for Normal Section has been continuing this month from station 0-055.05 ~ 0+850.0 with a total length of 922.10m (included Cut and Cover Section). The installation waterproofing membrane on the Enlargement Section to Clean Air Supply and Exhaust Sections was also completed.

Pouring of Concrete Lining was also carried out as per approved design segment. The Engineer carefully checked, during the joint survey with the contractor, the setting of the form for both bulkhead sides and the thickness as per design requirements.

The Concrete Lining for Normal Section of the Ventilation Adit completed until the end of this month totaled to 815.62meters from block no.17 to 96 (0-055.05 ~ 0+746.60) and including block no.180 to 181 for Cut and Cover Section. Concrete lining from block 14 to 2 (0-065.05 ~ 0-130.44) of the Enlargement Section (Supply Sect.) was also completed, giving a total length of 75.54meters.

The Ventilation Adit Concrete Lining completed, including Cut and Cover Section together with its connection to the normal section and enlargement section, up to the end of this month totaled to 891.16m (Progress: 47.21%).

Main Drainage:

The installation of 300mm dia. Perforated Concrete Pipe had been started at station 0-066.83 and, this month, reached to station 0+731.00 with total length of 797.83meters including setting/connection of pre-cast concrete manhole no. 1 at the bottom part of VA intersection of Exhaust Shaft Section.

Center Wall Concrete:

Construction of foundation together with the first lift 0.60m of the center wall had been started at station 0-055.05 and this month reached to station 0+327.60, totaling 272.31meters.

Grouting Works:

In the month of November 2003, the chemical injection using Denka ES mixed with Setter D-100 and cement milk for the secondary holes between sections D and A including some additional areas with water seepages has been completed.

A joint inspection among the Employer, the Consultant and the contractor was held on 28th of November 2003. The Employer decided to continue the grout injection on the areas with water seepages on the Portal Side and the contractor continued the injection until the end this month.

Major Events and Issue

Monthly Meeting

Monthly Meeting: Monthly Progress Meeting was held at the Employer/Engineer South Office on November 03, 2003.

On October 30, 2003, breakthrough of the Main Tunnel was witnessed by the Employer, the Engineer and Contractors.

Breakthrough Ceremony:

On November 7, 2003, official breakthrough ceremony was held at the North Portal attended by MOT Minister, JBIC Representatives, Japan Embassy Representatives, Officials from Hue Province, Officials from Danang City, Officials from Government, the Employer, the Engineer, Contractors of Hai Van Pass Tunnel Project, Mass Media, and other guests from various government agencies

Joint Site Inspection of Duct Bank (West and East Side) for Hand-over:

On November 25, 2003, a Joint Site Inspection of Duct Bank (west and east) for Hand-over was conducted by the Engineer, Package I, Package III and Package IV.

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