 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Welcome to Our Site! |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Progress Report > Package IA - North Tunnel Section
Main Tunnel
In the month of August, the rock condition encountered in the Main Tunnel was classified as B until the end of this month. Small fracture zone was observed and some slicken side rock appeared, so the Engineer instructed to install some safety rock bolts. Geologically, the condition was stable on Class B. A total
length of 141.30m (station 3+045.0 ~ 3+186.3) was excavated in the
Main Tunnel this month, giving a total length of 1,1540.30m (Progress:
40.01%) from the tunnel portal.
Twenty-nine (29) Niches - Seven (7) Emergency Call Niches and Twenty (22) Firefighting Niches - in the Main Tunnel were already excavated. Excavation of niches continues according to the designed niche distribution plan.
The Layby Left No. 1, 2 and Layby Right No.1 in the Main Tunnel, which has a total length of thirty-two (32) meters each Layby, were completed as per original plan. The on-going excavation of the Layby Right No. 2 was based on the original station/location, which was along the connection of the Main Tunnel and Electrostatic Precipitator No. 1.
The pouring of Class D concrete for the Foundation Beams of the Lining Concrete continued this month. The placing of concrete continued from Station 2+451.5 to 2+583.5 on both sides with a total length of 132.5m 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 continued 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 2+547, totaling a length of 883m. 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 also continued as per design segment approved. 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 715.5 meters. The Lining Concrete were poured using Shutter No. 1 from Segment No. 2 to No. 27 (Sta. 1+665 to Sta. 1+977), Segment No. 30 to No. 58 (Sta. 2+027.5 to Sta. 2+375.5) and from Segment No. 61 to No. 64 (Sta.2+427.5 to Sta.2+475.5). Shutter No.2 was first used on the pouring of Segment No. 28 (Sta.1+977 to 1+984.5), which connects the standard section of the Main Tunnel to Layby Left No. 1. The completed Concrete Lining includes twelve (12) Fire Fighting Niches and three (3) Fire Fighting with Emergency Call Niches. The Concrete Lining of Layby Left No. 1 in Main Tunnel, totaling a length of 31m on station 1+984.5 ~ 2+015.5m, including one (1) Fire Fighting with Emergency Call Niche, was also completed. The Main
Tunnel Concrete Lining completed up to this month totaled to 746.5m
(Progress: 19.35%). Evacuation Tunnel For the Evacuation Tunnel, the rock encountered was in good condition. Generally, the classification of rock was steady on class B and some portion was classified as class A. The excavated tunnel length for the month of August 2002 was 125.10m (station 3+019.7 ~ 3+144.8), giving a total length of 1,501.80m (Progress: 38.94%) from the tunnel portal. This month the excavation of Evacuation Tunnel was shorter compare to previous month's progress because of the breakdown of Shovel loader (tam rock) used for mucking of blasting rock. The contractor used the wheel loader for mucking of blasted rock but it took longer time mucking, so the cycle time round was affected for more than one week. The Temporary Transformer Niches No. 1~7 were completely excavated as per approved plan submitted by the contractor. The Enlarged Pedestrian Cross Passageway Nos. 1 and 2 has been completed. The Vehicular
Cross Passage No.1 was completely excavated from Evacuation tunnel
and Main Tunnel side with a total length of 19.4m. Ventilation Adit For Ventilation Adit this month of August, the rock encountered was classified as Class B until the middle of this month. From 18th of August, the rock was classified as C1 due to some fracture zones that appeared with soft white filling and water seepage from joint plane that were observed on almost every cutting face of the tunnel. Therefore, the Engineer issued an instruction to change the supporting system from type I to type II until 28th of this month. The Engineer also instruct to the contractor to carry out one exploratory drilling hole on cutting face at station 0+498.10m to investigate the rock and water condition ahead. The result of exploratory drilling, which was jointly inspected with the Consultant's Geotechnical Engineer, were: from 0~4m medium to hard (Class C1 ~ B) and 4~7 hard to very hard (Class B) and no water was encountered along the seven (7) meter length drilled hole. After three (3) blasting rounds, reaching more than the exploratory drill length, the rock became hard and the supporting system was changed again into type I to end of this month. The excavated
length for the month of August was 128.70m (station 0+603.5 ~ 0+474.8),
totaling to 1,277.71m (Progress: 72.91%) from the tunnel portal. Ventilation Adit - Access Road Paving of Asphalt had commenced and the 5cm-thick first layer from Culvert No.2 to the connection of the access road with NH1 was completed on 31st of August 2002. The second layer to complete the 10cm-thick asphalt pavement will executed on the following month. Major Events and Issue
Activities for Coming Month
Main
Tunnel Excavation Evacuation
Tunnel Excavation Concrete
Lining Works Niche
Excavations Drainage
Works Foundation
Beam at Main Tunnel Waterproofing
Works at Main Tunnel Ventilation
Adit Excavation
Continuous operation of the Waste Water Treatment Plant. Operation & Maintenance of Primary Water Control System. Operation of Primary Control System in Main Tunnel, Evacuation Tunnel and Ventilation Adit will be continued. Dewatering inside the three tunnels will be continued. Installation and Operation of Ventilation Systems and Lighting System in Main Tunnel, Evacuation Tunnel and Ventilation Adit will be continued. Maintenance and Operation of all equipments will be continued. Maintenance of Contractor's office & camps will be continued. Maintenance
of all constructed temporary facilities will be continued. This homepage is presented by the Consultant Team Any further question should be forwarded to Webmaster or Consultant Team
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||
Progress To Date
