Changsha metro line 3 star sand section of double penetration

Today, with the "pioneer" shield machine cutting through piles, it marks the smooth opening of the shield tunnel from xianglong station to xingsha station in line 3 of changsha metro line 14, and it also declares that all the tunnels in the xingsha area of line 3 of changsha metro line are through. It is reported that this is the first time for zeng to run a medium-high speed railway tunnel in China.

According to reports, changsha metro line 3 no.14 project starts at yuehu park north station in kaifu district and ends at xingsha station. The total length of the two-line tunnel is nearly 8 kilometers. Between xianglong station and xingsha station, subway line 3 is the "throat" connecting downtown changsha and county district, which is very difficult to construct. It needs to run down liuyang river tunnel of beijing-guangzhou high-speed railway and through beijing-hong kong-macau high-speed separated three-dimensional intersection bridge, with dense buildings along the line and large tunnel slope.

According to the introduction of technicians on the project site, in addition to ensuring the "zero uplift" of the high-speed rail track, the settlement must be strictly controlled within 1.4mm during the construction of the shield tunnel. In order to control the excavation quantity, the construction side should weigh the dregs for every 1.5 meters of excavation, no more, no less. Measures such as enhancing secondary grouting and tracking reinforcing grouting are taken synchronously when assembling the pieces to ensure no leakage of the pieces and real-time adjustment of tunneling parameters.

Project constructed by bureau of China railway twenty-five five companies, according to project director Zou Shitao across the surface settlement control is difficult to overcome, shield attitude control difficulty higher technical problems, through the process, the project department real-time adjust the driving parameters, through the construction organization, to ensure that people take machine, 24 hours emergency disposal plan, equipment maintenance and emergency response teams on standby, and select the test section of a similar construction environment to test many times, tunneling parameters, ultimately achieve zero uplift under wear.

According to the introduction, during the tunneling of high-speed railway tunnel, the shield tunneling machine reached the high efficiency of tunneling one ring in 60 minutes, which was 16.7% less than the original plan of tunneling time for each ring, and completed the tunneling construction safely and quickly in 10 days. After the inspection, the accumulated settlement of liuyang river tunnel is controlled within the range allowed by the regulations, and the rail elevation of the high-speed railway line is 0 mm, far higher than the requirement of the general shield construction precision, ensuring the safety of the beijing-guangzhou high-speed railway train. The project has twice successfully traversed the middle and high speed railway tunnel in operation, marking a breakthrough of zero for the domestic urban rail transit project to run through the high-speed railway tunnel in operation.