By lyndamyer
On February 7, a significant breakthrough was achieved at the construction site of the Bang Pakong-south Bangkok power plant gas transmission pipeline project in Thailand. The first section of the initial phase of pipeline laying employed the laying and jacking machine with a diameter of 914mm, manufactured by CRCHI (China Railway Construction Heavy Industry), was successfully completed.
The first phase of the gas transmission pipeline project for the Bang Pakong-south Bangkok power plant is situated in the southern region of Bangkok. The longest stretch covers approximately 1 kilometer. The laying and jacking machine is specifically designed for constructing large slope V-shaped longitudinal curves. Notably, the entire pipeline must be installed amidst the foundations of high-voltage power line towers, spaced just 3.5 meters apart, with tower intervals of 200 meters. Given the extremely narrow space and the challenge of maneuvering an ultra-small diameter pipe over long-distance curved excavations, traditional optical guidance systems proved inadequate. The excavation process resembled threading a needle in the depths of the ground, presenting a fresh challenge for equipment reliability and measurement and guidance system accuracy.
To surmount these engineering challenges, CRCHI developed the ?914mm ultra-small diameter and ultra-long distance laying and jacking machine. This involved overcoming several key core technologies independently, including accurate long-distance curve guidance, equipment layout and heat dissipation within extremely limited spaces, long-distance power transmission, and rapid and safe propulsion. With the collaborative efforts of CRCHI’s service team and the construction team, the laying and jacking machine delivered exceptional performance with a zero failure rate for the main machine, achieved a stable excavation speed of 600 mm per minute, recorded a maximum footage of 48 meters in 2 hours, and accomplished a single-shift record of 86 meters during the initial 470-meter section of pipeline laying construction. The machine successfully navigated through the pile foundations of two power towers with precision, marking a technological breakthrough in the fast and reliable construction of ultra-small diameter, ultra-long distance, and ultra-high precision curves. This provided effective assurances for the smooth execution of subsequent projects in Thailand.
CRCHI has garnered notable success in various crucial underground pipeline network projects. On December 13, 2023, CRCHI’s jacking shield machine achieved a breakthrough in the raw water pipeline project of the Changsha Leifeng water plant in China. Covering a project section of 940 meters, with rock compressive strength exceeding 164MPa, and a maximum daily footage of 17.5 meters, this success marked a breakthrough in constructing long-distance pipelines through highly resistant rock formations.
Similarly, on December 28, 2023, a pressure-controlled hard rock pipe jacking machine deployed in Hong Kong, China, completed the initial section of a relocation project from Sha Tin Sewage Treatment Plant to a rock cave. This involved tunnelling along a curved route with a single jacking span of 320 meters. The rock strata throughout the section exhibited a maximum uniaxial compressive strength of 150 MPa. The successful execution of this project validated the equipment’s exceptional performance and directional correction control capability, marking it as the first domestically produced tunnel boring machine implementation case in Hong Kong. Following the Chinese New Year, the equipment will commence excavation for the second section.
