China News Service, Guangzhou, July 17 (Cai Minjie Huang Xia) Guangdong Provincial Transportation Group announced on the 17th that the Guangdong-Hong Kong-Macao Greater Bay Area super project-the Shenzhen-Zhongshan Corridor project has another good news.
After nearly 3 hours of operation, the ultra-wide and variable-width steel shell immersed tube E29 section contracted by Poly Grow Guangzhou Salvage Bureau Consortium S08 Contract Section was recently twisted and moved out of the dock.
In order to realize the "streamlined" production of the steel shell assembly of the two pipe sections and the concrete pouring, the alternate drag operation of the E29 and E28 pipe sections was used for the first time in the undocking work. The harbor basin is temporarily moored to make way for the E29 pipe joint.
For the first time, two pipe joints were used for construction in dry dock at the same time, which greatly improved the construction efficiency of the project and promoted the prefabrication of pipe joints to a new level of efficient and streamlined production.
The deep-medium channel is a world-class cross-sea project integrating "bridges, islands, tunnels, and underwater intercommunication".
In order to realize the interconnection with the Guangzhou-Shenzhen Riverside Expressway and Shenzhen Bao’an Airport, the project has constructed an east artificial island and an underwater interchange. The steel shell concrete immersed tube tunnel connected to it has a variable width section of more than 620 meters on the east side. The section is gradually widened from 8 lanes in both directions to 10 lanes in both directions, and the section width of the corresponding pipe section gradually widens from 46 meters to 55.46 meters.
Among them, the E29 pipe section is the fourth ultra-wide, variable-width asymmetric structure pipe section on the curve axis of the deep and medium channel immersed tube tunnel. The average outer width of the pipe section is about 49.7 meters, and the length of the pipe section is 124.2 meters. About 60,000 tons.
The E29 immersed pipe section of the Shenzhen-Zhongshan Passage is undocked. Photo courtesy of Guangdong Transportation Group
In late May of this year, the project department started the prefabrication of concrete pouring for the E29 pipe section.
In June, the high temperature weather will have a greater impact on the concrete pouring work of the pipe joint roof and wall.
“In direct sunlight during the day, the temperature of the pipe surface of the E29 pipe section has exceeded 35 degrees Celsius. This is not only unfavorable for the operators to carry out fine work, long-term work affects their health, but also affects the flow performance of the self-compacting concrete. Reducing the quality of prefabrication brings greater risks.” said the person in charge of the pouring site at Poly Growth.
In order to avoid the influence of high temperature in summer on the pouring work of the pipe joints, the Polygrowth construction team adjusted the operation plan and on-site construction time in time, adopted continuous construction at night for pouring, and used the "golden sixteen hours" with suitable temperature to ensure that the E29 pipe The prefabrication work of section pouring was successfully completed.
Compared with the previous "interval" alternative construction method of pipe joints in the same station where the steel shell assembly was first implemented before concrete pouring, the construction team added a steel shell pipe joint assembly station in the dock, which is in progress. During the concrete pouring of the E29 pipe section, the general assembly of the steel shell of the next E28 pipe section was carried out at the same time.
When the E29 pipe section was prefabricated and released from the dock, the construction team moved the steel shell of the E28 pipe section from the main assembly station to the pouring station for concrete pouring, and at the same time proceeded to the next vacant assembly station. Section E27 pipe joint steel shell assembly, so as to realize the two pipe joint steel shell assembly and concrete pouring streamlined production, and improve construction efficiency.
"The tide level window left for us by this undocking is shorter than before, and the undocking operation requirements are more compact. In just 3 hours, we will use 38 shore control equipment, carry out 24 cable replacement operations, and coordinate and cooperate. It is extremely difficult. It requires very accurate operation of every action, very accurate calculation of every position, and very reliable twisting force of every equipment. Before undocking, we also test pull all shore control equipment and conduct a full analysis of the recent measured tide level. It is to ensure that the E29 pipe joint is completely undocked." said Jiang Zhibin, the construction manager of the S08 contract section of the Shenzhen Middle Passage of the Guangzhou Salvage Bureau.
After nearly 3 hours, the E29 pipe section was released from the dock.
After being undocked, the E29 pipe section will make a 180-degree turn around in the harbor basin and move it longitudinally to the storage area.
It is expected that in August this year, the Shenzhong Passage Project will carry out the floating, sinking and installation work of the first tube section on the east side of the immersed tube tunnel and the first ultra-wide variable-width tube section E32 tube section on the whole line.
(Finish)