A connecting bridge is under construction outside the Chestnut Hill Tunnel of the Ziyi High-Speed Railway. Photo by Liu Zhongjun
Yibin, China, January 20 (Reporter Liu Zhongjun) On the morning of the 20th, with the completion of the excavation of the last 1 meter of surrounding rock on the steps, the Chestnut Mountain Tunnel, a key project of the Sichuan Zigong-Yibin high-speed railway (hereinafter referred to as the Ziyi high-speed railway), was successfully penetrated, which marked the construction of the Ziyi high-speed railway into the sprint stage and laid a solid foundation for the full line of the Ziyi high-speed railway.
Located at the foot of Qixing Mountain in Nanguang Town, Xuzhou District, Yibin City, Sichuan Province, the Chestnut Mountain Tunnel is a control project of the whole line of the Ziyi High-speed Railway, designed by the Second Hospital of China Railway and built by the Third Bureau of China Railway, which is a single-hole double-line high-risk tunnel with a total length of 1732 meters and a design speed of 350 kilometers per hour, and the undesirable geology mainly includes coal seams, gas, goaf areas, smooth layers and dangerous rocks.
Aerial photo of a bridge under construction in the canyon outside the Chestnut Mountain Tunnel of the Yi high-speed railway. Photo by Liu Zhongjun
"The construction conditions of the Chestnut Mountain Tunnel are extremely complex, and the tunnel inlet spans the Nanguang Tunnel of the existing railway Yijue Branch Line, which was built in the 1960s and 1970s, with an angle of about 76° in the middle of the line, and a net distance of only 3.37 meters at the intersection." Wang Xiaoping, commander of the Ziyi Railway Headquarters of the Third Bureau of China Railway, said that the tunnel shizhong adopts a special bottom plate type lining structure, uses the pile raft foundation to achieve leapfrogging, implements mechanical excavation, controlled blasting, and general blasting in sections, optimizes the excavation method from the step method to the middle and next door method, and adds temporary arches to some sections, effectively controlling the tunnel settlement and ensuring the safety and stability of the existing railway tunnel.
It is understood that the Chestnut Mountain Tunnel is located near the upper tributaries of the Yangtze River, the natural environment requirements are extremely high, the construction unit has taken measures such as the combination of plugging and drainage, cleaning and diverting sewage, etc., effectively solving the problem of construction sewage pollution of natural water bodies. At the same time, the construction cave body crossed more than 200 meters of coal seam goaf section, adopted the pile raft foundation span, supplemented by comprehensive remediation measures of backfilling and grouting reinforcement, and also crossed the water-rich section of more than 13,000 cubic meters of daily water inflow.
The Chestnut Mountain Tunnel of the Ziyi High-speed Railway runs through the site. Photo by Liu Zhongjun
"The start is a decisive battle, and the beginning is a sprint." The relevant person in charge of Chenglan Railway Company said that the company has launched a labor competition with the theme of "working hard for 100 days and making new contributions" to improve the level of construction management and promote project construction. "During the Spring Festival, the construction of the Chenglan Railway, the Chengzi High-speed Railway, the Ziyi High-Speed Railway, and the Chengdawan High-Speed Railway did not stop working."
It is reported that after the completion of the Zigong Yibin high-speed railway, it will further improve the high-speed railway network in Sichuan Province, promote the integrated development of the southern Sichuan and western Chongqing regions and the construction of shipping hubs in the upper reaches of the Yangtze River. (End)
On the left, above the Nanguang Tunnel of the Yijue Branch Line of the Railway, there is the Lilishan Tunnel and Bridge of the Ziyi High-Speed Railway under construction. Photo by Liu Zhongjun
Source: China News Network