The cross-sea underground comprehensive pipeline gallery project with the longest length and the largest pipe jacking diameter in China has been completed

On May 28, the second cross-sea project of the underground comprehensive pipe gallery in the new airport area of Xiamen Xiang'an Airport - the cross-sea section of the airport expressway, which is 130 meters away from the receiving well of Dadeng Island and 20 meters deep, the workers of the 3th Engineer., LTD of China Railway 22nd Bureau Group operated the mud-water balance pipe jacking machine to reach the head well of the receiving point. At this point, the cross-sea project of the underground comprehensive pipeline gallery project with the longest length and the largest pipe jacking operation pipe diameter in China has been completed, laying the foundation for the smooth progress of the first pipeline gallery PPP project in Xiamen, which is the first batch of comprehensive pipeline gallery pilot cities in the country.

The underground integrated pipe gallery helps ensure the safe operation of the "urban lifeline" such as power and communications, and enhance the level of scientific, refined and intelligent urban management. As the only dual pilot city in China for the construction of underground comprehensive pipe corridors and sponge cities, Xiamen actively promotes the construction of urban underground pipe corridors. The underground comprehensive pipe corridor project in the Xiang'an New Airport area is its first municipal project constructed in the PPP mode. After the project is completed, it will effectively avoid problems such as repeated excavation of the road surface and dense overhead line network, and improve the disaster resistance of the pipeline, providing an important guarantee for the construction of the new Xiang'an Airport and the economic and social development of the region along the line.

Wen Chunrong, project manager of China Railway 22nd Bureau Group, introduced that the underground comprehensive pipeline gallery project in the area of Xiamen Xiang'an New Airport is the largest pipeline gallery project in Xiamen at present. As far as we know, the pipeline gallery will include power, communications, water supply, reclaimed water, gas, rainwater, sewage and other pipelines, and set up management systems for fire fighting, drainage, ventilation, information, electrical, monitoring, and identification. Among them, the gas pipeline is included, which is the first time in the construction of Xiamen Pipe Gallery.

The sea-crossing project is the focus and difficulty of the underground comprehensive pipeline gallery project in the Xiamen Xiang'an New Airport area. Its geology is complex, with all kinds of residual sandy cohesive soils everywhere, as well as fully weathered granite and high-strength boulders on the seabed. Underground pipe jacking must overcome the poor geological treatment of the seabed, precise positioning of the long-distance pipe jacking axis, and zero discharge of waste mud. Multiple problems. Deputy project manager Han Linjun said, “There is no precedent for this kind of jacking operation of large-section concrete pipe gallery in a subsea environment.”

To this end, the project department established a technical team to vigorously carry out scientific and technological research, and organized expert demonstrations for many times. They developed high-precision geological detection technology, realized accurate exploration of underground boulders, and developed and designed a composite cutterhead mud-water balance pipe jacking machine, successfully overcoming the problem of large underground boulders. The technical team also innovated the laser precision guidance system to solve the problem of positioning and measuring the long-distance pipe jacking. The actual error of the passage of this pipe corridor through the sea is within 5 cm.

In response to the many challenges caused by the direct burial of underground pipelines such as water, electricity, gas, and communications, the project department applied the "prefabricated prefabricated laminated board" process to the construction of underground comprehensive pipe corridors, which is the first case in Fujian Province. "Assembled prefabricated laminated board" pipe gallery, that is, through the splitting of the pipe gallery wall panel nodes, the pipe gallery structure is decomposed into several panels for prefabrication, and then assembled on site, so that the wall panels are cleverly connected to form a good integrity , Assembled integrated pipe gallery whose structural strength and waterproof performance can meet the design requirements. Compared with the traditional cast-in-place concrete technology, the "prefabricated prefabricated laminated slab" has many advantages such as obvious green and environmental protection benefits, greatly reduced construction costs, strong controllability of wall quality, and effective shortening of construction periods.

In the construction of the cross-sea section, 50 cubic meters of mud will be produced for every 1 meter of the jacking pipe. Workers in the project department adhere to green construction and adopt technologies such as multi-stage waste mud separation to effectively concentrate the volume of waste mud and discharge it in the form of circulating water, realizing zero discharge of waste mud in the sea.

In order to further improve the pipeline disaster resistance capability, the construction unit has integrated the "3D modeling + GIS visualization management", robot inspection system, wireless sensor system and other technologies on the integrated pipe gallery intelligent management and control platform independently developed by China Railway Construction. Through comprehensive integration and high data integration between various monitoring systems, more than ten subsystems such as security, fire warning, voice communication have realized efficient and intelligent pipe gallery operation management.