Progress Report > Package IA - North Tunnel Section

Physical Progress | Photographs | Construction Supervision

Physical Progress

Contractor	JV of Hazama and Cienco 6
Commencement of the Works	1st October 2000
Time Elapsed (days)	848 of 1460 (58.08%) Remaining 612 days
Progress
Main Tunnel(3857m)	99.50m in this month; 2,099.60m in total (54.44%)
Evacuation Tunnel(3857m)	85.40m in this month; 2,084.10m in total (54.03%)
Ventilation Tunnel(1810m)	117.70m in this month; 1,823.01m in total (96.12%)
Others

 

Photographs

	North Portal
	Ventilation Adit Portal
	Mucking in Main Tunnel
	Shotcrete Spraying in Main Tunnel
	Concrete Pouring on Foundation Beam
	Waterproofing Works
	Setting Form for Concrete Lining
	Mole Drain Installation
	Completed Lining Concrete at Main Tunnel
	WaterProofing Work (As of Jan. 03) at Main Tunnel Station 3+265; L=1,601 meters
	Installation of Safety & Pattern Rockbolts at Main Tunnel Station 3+738.9 under Supporting Type II
	Completion for Concreting Lining of Layby No.3-3 at Main Tunnel Station 2+805.9~2+815.5 Vehicular Cross Passage No.1 Lining Concrete Connection to Layby No.3 Completed
	Concreting Works of Layby No.3 and Setting Steel Rib Form and Form Panel for Vehicle Cross Passage No.1 at Station 2+800
	Hauling of Blasted Materials to Temporary Stockpile Area in Evacuation Tunnel
	Explosive charging in Evacuation Tunnel
	Evacuation Tunnel After Blasting; Geological Condition w/Fracture Zone under Supporting System Type II w/ Pattern Rockbolts +t=10cm Shotcrete at Station 3+720.6
	Tunnel Face Drilling at Ventilation Adit
	Explosive Charging in Ventilation Adit
	Starting Excavation for Enlargement Section (for Exhaust Shaft & Clean Air Section) at Ventilation Adit Station 0-005
	Ventilation Adit Enlargement Section Cutting Face Station 0+067.5 Geological Condition Classified as Class B~A (in Good Rock Condition)
	Driling at Electrostatic Precipitator
	Loading of explosive at Electrostatic Precipitator
	Electrostatic Precipitator Face Condition; Class B~A (Support Type I) at Station 0+115.5
	Site Visit of MOT Minister, Politburo Member & PMU85 General Director at North Portal
	MOT Minister / Politburo Member / PMU85 General Director Warmly Welcome by Consultant Engineer Project Manager, Mr. Ishimoto at North Portal

Construction Supervision

Summary

As of January 31, 2003, the total length of Main Tunnel Excavation reached to Sta. 3+742.6 or 2,099.6 meters (including six (6) laybys) from the Tunnel Portal.

Thirty nine niches (10 Emergency and Call Niches and 29 Firefighting niches) were completed the excavation inside the Main Tunnel.

Concreting of the Foundation Beam and Concrete Lining Works at the Main Tunnel were carried out. As of January 31, 2003, Concrete Lining construction reached to 1,489.5 meters.

As of January 31, 2003, total length of Evacuation Tunnel excavation reached to Sta. 3+727.1 or 2,084.1 meters from the Tunnel Portal.

Four Cross Passageways were completely excavated across the Evacuation and Main Tunnel. An approved Additional Cross Passage was also excavated connecting the Main and Evacuation Tunnel.
As of January 31, 2003, total length of Ventilation Adit excavation reached to Sta. 0-70.5 or 1,823.01 meters from the Tunnel Portal.

Excavation for the 1st Electrostatic Precipitator was started on January 16, 2003 and as of Januray 31, 2003, total length of excavation reached to Sta. 0+144.69 or 32.6 meters from Main Tunnel connection.

Main Tunnel 

• Excavation

For the month of January 2003, although the rock condition was classified as Class B on the first half of the month, which is under support type I, slickensides, joint planes and some joints on the cutting face were encountered which develop into fractures on the right hand side of the Main Tunnel. Some safety rockbolts were instructed on site by the Engineer. After the blasting on 27^th of January 2003, a big geological over-break occurred. The Engineer also observed that the fracture have soft filling and some joints appeared. Due to this condition, the RE gave instruction to change the supporting system from type I to type II which continued until the end of this month.

This month, no big rock mass deformation in the Main tunnel was encountered.

Overall, the rock condition encountered this month was classified as Class B.

This month, the excavation of Main Tunnel extended by 99.50m (station 3+643.1 ~ 3+742.6) only due to simultaneous excavation of the Electrostatic Precipitator No. 1.  This gives a total length of 2,099.60m (Progress: 54.44%) from the tunnel portal.

• Electrostatic Precipitator No.1 (Excavation)

This month, the excavation of the Electrostatic Precipitator No. 1 started from the outlet side based on the new approved location on station 3+643.04 along the centerline of MT and is currently executed simultaneous with the excavation of the Main Tunnel.  The sequence of excavation and the supporting system are based on the approved sequence and support system submitted by the contractor. The geological condition encountered was in good condition and was classified as class B to A.

The excavated length of EP on the side Lay-by Right No. 3 side at Main Tunnel was 32.6m  (station 0+144.69 to 0+112.1).

• Niche Excavation:

Forty (40) Niches – Ten (10) Emergency Call Niches and Thirty (30) Firefighting Niches – in the Main Tunnel were already excavated. Excavation of niches continues according to the designed niche distribution plan.

• Lay-by Left No.1, 2, 3 and Right No.1, 2, 3

The Lay-by Left No. 1, 2 and Lay-by Right No. 1, 2, in the Main Tunnel, which has a total length of thirty-two (32) meters each, were completed as per original plan. The excavation of Lay-by Right No. 3 (Lay-by No. 5) and Lay-by Left No. 3 (Lay-by No. 6) were also completed this month.

• Behind Works (Behind Tunnel Excavation)

The pouring of Class D concrete for the Foundation Beam of the Lining Concrete continued this month from Station 3+184.5 to 3+323.5 with a total length of 139m 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 random/safety rock bolts.

Installation of EVA Waterproofing Membrane also continued following the covering of random rock bolts. The completed laying/installation of membrane reached to station 3+234, totaling a length of 1,570m. The Engineer continued to require testing of the welded joint sheets using air pressure test, as per procedure stated on 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 1,408.50 meters. The completed Concrete Lining includes twenty-one (21) Fire Fighting Niches and five (5) Fire Fighting with Emergency Call Niches.

The Concrete Lining works for Lay-by Left No. 1, 2 and Lay-by Right No.1 in Main Tunnel, totaling a length of 93m on station 1+984.5 ~ 2+015.5, station 2+384.5 ~ 2+415.5, and station 2+784.5 ~ 2+815.5 including one (1) Fire Fighting Niche and two (2) Fire Fighting with Emergency Call Niche, were also completed.

The Main Tunnel Concrete Lining completed up to this month totaled to 1,489.50m (Progress: 38.62%).

For the Pedestrian Cross Passage No. 1 (station 2+000), No. 2 (station 2+400) and Vehicular Cross Passage No.1 (station 2+800), concrete lining works for the blocks connected to the Main Tunnel Lay-by Section, which has a total length of 10.5m, were completed.

Evacuation Tunnel

In the beginning of January 2003, the fracture zone and slickenside on the left-hand side continued. The support type III, which was instructed in December 2002, continued until 16^th of January 2003 at station 3+682.8. The crushing zone with soft filling on the left hand side was moving outside the profile line from shoulder part until it disappeared but the fracture zone and some joints on the cutting face still remained. Due to this condition, the RE gave an instruction to change the supporting system from type III to II-A with random wiremesh and steel fiber shotcrete. An instruction was also made for 10cm-thick shotcrete and pattern rockbolts. Generally, the rock was classified as class CII to CI.

The excavated tunnel length for the month of January 2003 was shorter compare to last month progress due to poor geological rock condition. The excavated length this month was 85.40m (station 3+568.3 ~ 3+727.1), giving a total length of 2,084.10m  (Progress: 54.03%) from the tunnel portal.

The Temporary Transformer Niches No. 1~10 were completely excavated as per approved plan submitted by the Contractor.

The Enlarged Pedestrian Cross Passageway Nos. 1, 2 and 3 and Vehicular Cross Passageway No. 1 were totaling four (4) Cross Passage completed.

The Temporary Cross Passage (CP N0.5) at station 3+450 was also completed.

Ventilation Adit Tunnel

In the month of January 2003, the rock condition encountered was in good condition. Geologically, the rock condition was stable on class B. On some portions, it was almost classified as class A.

The excavation of the Enlarged Section was on-going with the supporting system approved by the Engineer for the inner part and connection to Main Tunnel of Exhaust Shaft Section and Supply Clean Air section.

The excavated length for the month of January 2003 was 117.70m (station 0+047.2 ~ 0-070.5), totaling to 1,823.01m (Progress: 96.12%) from the tunnel portal. The progress percentage includes the 144m-tunnel length extension for modification of ventilation system approved by the Employer.