Above: Assembling TBM 1 in Shaft 9B-1
proximity to the bridge foundation, only some 0.90m away. The short section of tunnel had to be designed with curves, resembling an S-curve, requiring an experienced operator and a TBM with an effective copy cutter system. The tunnel has successfully passed this critical
section, alleviating concerns for the project team. Additionally, work conducted under the flyover
presented further challenges due to space constraints, requiring a gantry crane for lifting segments and muck cars to be specially designed for optimal functionality in the limited area.
TBM 3 TBM3 (S102 machine, 4.80m-diameter) will begin at Shaft 9B-1 to bore approximately 2.2km.
CURRENT PROGRESS As of now, TBM2 (S105) has excavated approximately 200m through Shaft 9B-4. TBM1 (S106) was launched from Shaft 9B-1 and, as noted above has passed the critical section of the
S-curve tunnelling at the bridge foundations to reach (Shaft 9B-2). The contractor will relocate facilities to Shaft 9B-2 to continue boring toward Shaft 9B-3. TBM3 (S102) is currently in the process of being
lowered into vacated Shaft 9B-1 to commence boring approximately 2.2km in the opposite direction, to connect with Shaft 9A-5 of another contract.
CONCLUSION The G-TN-9B tunnelling project presents significant challenges in both management and engineering, particularly with its proximity to the flyover’s foundation and the need to operate in constrained areas, such as low headroom zones. Additionally, the geological conditions along the alignment, which consist of high- pressure sandy layers, require careful planning and execution. Effective collaboration among all parties involved
in the project - including the project owner (MWA), consultants, contractors (Italianthai-Nawarat JV), and the TBM manufacturer (Terratec) - is essential for successfully achieving the project’s challenging goals.
Far left:
TBM 1 breakthrough at Shaft 9B-2
Left:
Assembling TBM 2 for launch in Shaft 9B-5
November 2024
| 21
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49
