tunnelling-journal (1)
tunnelling-journal (1)
  • Home
  • Print
    • Subscribe
    • Tunnelling Journal
    • Breakthrough
    • ITA Activity Report
    • A&NZ Journal
    • WTC Preview
    • Media Kit
  • Digital
    • Newsletter
    • E-Shots
    • TJ Digital edition
    • Products Page
    • Media Kit
  • Conferences
    • BTS Conference and Exhibition
    • Cutting Edge 2023
  • Buyer’s Guide
  • Events Diary
  • Jobs
  • About Us
  • Contact Us
  • Podcast

Home > First tunnel complete on Guangxi Province North Line Water Irrigation Project

First tunnel complete on Guangxi Province North Line Water Irrigation Project

Tris Thomas

Written by Tris Thomas on 05/03/2020 in News

Tagged:

In January 2020, contractor Guangdong No. 2 Hydropower Bureau Co., Ltd successfully broke through its Robbins 5.97m diameter Main Beam TBM in Guangxi Province, China, following the excavation of the first of two tunnels, an 11.9km long conduit for Lot 1 of the North Line Water Irrigation Project, Letan Water Reservoir, Drought-Relief.

Image 1

The tunnel was marked by a gauntlet of challenges, from karst cavities to fault zones and water inflows. The contractor and the owner, Construction Management Bureau for the Letan Water Reservoir, had much to celebrate after completion of what is widely regarded as the most complex and longest tunnel on the North Line project.

Boring with the TBM and continuous conveyor system began in summer 2015. “There was no precedent in this province for using a Main Beam TBM to excavate a tunnel longer than 10km. We didn’t have relevant local experience to use for reference,” explained Yongjiu Jin, Deputy Manager of the Project for Guangdong No. 2 Hydropower Bureau Co., Ltd.The machine did encounter a number of difficult geological obstacles as it bored through limestone rock, but was still able to achieve advance rates up to 40m per day in good ground.

Much of the geology consisted of lightly weathered limestone in rock class II to III, with some sections in class IV to V rock that required the heaviest amount of ground support, ranging from rock bolts to ring beams and mesh. “Our team encountered a coal seam, gasses in the tunnel, two large water inrushes, three fault zones up to 103m long, 11 karst cavities, and more. In order to solve the ground problems, there were more than 160 special technical research meetings held,” said Yongjiu.

While the completion of the first tunnel—the longest single-heading construction on record for water tunnels in Guangxi—is a milestone, there is more to do. The Robbins machine will be inspected and relaunched to bore a second tunnel 4.2km (in length. The ground conditions are predicted to be equally challenging, but the tunnelling operation has some help from ground prediction methodology. Tunnel Reflection Tomography (TRT)—consisting of ground prediction using seismic waves—is being used to detect changing conditions ahead of the TBM. The method can predict the distribution and scale of joints and fissures, allowing the crew to plan ahead.

Located near Laibin City, the North Line project provides much needed drought relief using a network of tunnels totaling 29.4kk. “This tunnel will realize the dream of drought control that people in Central Guangxi have had for many years. The breakthrough is the most important milestone event in this first phase of the North Line project,” said Yongjiu.

 

Robbins

With more than 65 years of innovation and experience, The Robbins Company is the world’s foremost developer and manufacturer of advanced, underground construction machinery. Robbins has been involved in hundreds of tunnel boring projects around the world.

More Information | sales@robbinstbm.com | +1 440 248 3303

Comments:

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Search

Digital Edition

More Like This

22/08/2023

PUB completes tunnelling on DTSS Phase 2

PUB completes tunnelling on DTSS Phase 2

PUB, Singapore’s National Water Agency, has concluded tunnelling works on the second phase of the Deep Tunnel Sewerage System (DTSS)….

25/07/2023

First breakthrough on Sydney Metro – Western Sydney Airport project

First breakthrough on Sydney Metro – Western Sydney Airport project

TBM ‘Eileen’ has broken through at the Airport Terminal metro station site, marking the first tunnel breakthrough on the $1.8bn…

04/04/2023

TERRATEC EPBMs launched for Surat Metro

TERRATEC EPBMs launched for Surat Metro

TERRATEC has announced the launch of another EPBM for the Surat Metro in India. This unit is a refurbished 6.61m…

  • Contact Us
  • Media Kit
  • Magazine Archive

Newsletter

The latest from the Tunneling Journal direct to your inbox.

Social



Enquiries

TGS Media Ltd
The Old Library
Webster House
Dudley Road
Tunbridge Wells
TN1 1LE
United Kingdom

© Tunnelling Journal. All Rights Reserved. Privacy Policy / Terms & Conditions. Admin

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.OkRead more