Construction Supervision

Summary from Contractor

In the month of December 2003, the excavation of EP No.2 was completed breakthrough on 2nd of December 2003 and reached to the station 0+078.6 with a length totaling 71.5 m for North Side (fr. Inlet Side) and 66.1m on South Side (fr. Outlet Side)

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 3,096.44m (progress 80.28%).

As of December 31, 2003, the face No.4 excavation length for this month was 5.1m. the distance from the tunnel portal gives a total length of 3,406.9m until station 5+049.9 from the North Side and South Side giving 450.1m, overall total length 3,857m for 100% completed.

Construction Supervision by Engineer

Main Tunnel 

• Excavation

Main Tunnel Completed (bench excavation 14th of Nov.03)

Electrostatic Precipitator No. 2

In the month of December 2003, the excavation of EP No.2 was completed breakthrough on 2nd day of Dec. 2003 and reaching station 0+078.6 with a length totaling 71.5meters for North Side (fr. Inlet Side) and 66.1meters on South Side (fr. Outlet Side).

• Niche Excavation:

Sixty-eight (67) Niches - sixteen (16) Emergency Call Niches and Fifty-one (51) 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+817.5 to 5+026.5, totaling 209m 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.

ntil the end of this month, a total length of 3,268.5m (Station 1+664~4+846.5/5+065.5~5+151.5) 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 2,848.44 meters. The Concrete Lining works for Lay-by Left Nos. 1, 2, 3, 4 and Lay-by Right Nos. 1, 2, 3,4 in Main Tunnel, totaling eight lay-bys with a length of 248.00m, were 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 from previous month. For its middle block (8-2), which connects with the Clean Air Supply Section of the Ventilation Adit was completed this month.

The Main Tunnel Concrete Lining completed up to the end of this month totaled to 3,096.44m (Progress: 80.28%).

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 December 2003, the concrete works for the cable duct bank was temporary stop due to the completion of MT lining concrete which connection to VA Exhaust Shaft and Supply Section. The total length poured from previous month of November 2003 with manholes, including the installation of two (2) lines of embedded conduit pipe with a diameter of 110mm each, reaching to 2,501.00m up to station 4+170.

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 4+119.55, totaling a length of 2,449.10m while for pre-cast catch basins, 101nos (to station 4+170) starting from no. 2 to no. 102 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 4+145.5, giving a length of 2,447.57m.

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 4+144.55 with a total length of 2,475.0m. The setting/installation of pre-cast catch basins were from no. 2 ~ 102, totaling 101nos. (to station 4+170).

• 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+883.9m, totaling a length of 2,214.40m. Concreting of sidewall was also started on the same station and reached to station 3+686.5 with a total length 1,977.7m. 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+835.9 a totaling 2,166.40m.

On December 22, 2003, a joint site inspection no. 3 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+815.5 Lay-by No.3 to station 3+205.5 Lay-by No.4 by Package IA to Package III/IV and including East Side Duct Bank for PKIII at same station. 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+460 this month with total length of 1,750.6meters including setting/connection of pre-cast concrete manhole nos. 1~9 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 excavation of Face No. 4 was completed breakthrough on the 1st December 2003 with south side excavation at station 5+049.9 1st of December 2003.

The Face No. 4 excavation length for this month was 5.10m. The distance from the tunnel portal gives a total length of 3,406.90m until station 5+049.90 from North Side and South Side giving 450.1m, over all total length 3,857meters for 100% completed.

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 1,353.12m (station 0-135.11~1+201) on left side and 1,341.29m (station 0-135.11~1+189.17) 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 ~ 1+039.52 with a total length of 1,111.58m (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 982.99meters from block no.17 to 110 (0-055.05 ~ 0+913.97) and including block no.180 to 181 for Cut and Cover Section. Concrete lining from block 14 to 1 (0-065.05 ~ 0-135.11) of the Enlargement Section (Supply Sect.) was also completed, giving a total length of 74.56meters. The Exhaust Shaft Section Lining Concrete consist 5blocks that connects both side of VA and MT were completed this month of Dec.2003.

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 1,057.55m (Progress: 56.03%).

On December 15, 2003, a joint site inspection between the Consultant and contractors of Package IA, III and IV E and M was handing over at the bottom VA. The contractor PKIA completed the concrete lining works, concrete pavement including cable pit and duct bank from block no.12 station 0-077.10 to Supply Section station 0-132.70. The handing over by Package IA to Package III/IV E and M, even though have minor items were needed to correct, part of the cable pit for PKIII, however, agreed and handed over to E and M for their works' access only

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+829.00 with total length of 896.83meters 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+519.45, totaling 565.5meters. The second lift center wall was commencing at the bottom VA station 0-019.05~0-010.05 with a length total 9.0m.

Cable Duct Bank:

This Month of December 2003, the pouring of concrete for cable duct bank began according to the revised design and location approved by the Engineer's from the station 0-077.05 ~ 0-106.49 with total length 29.44m Enlargement Section. On the Standard Section was also started at station 0-046.05 ~ 0+151.5 giving a length 197.6m.

Major Events and Issue

Monthly Meeting

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

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