The shield elephant climbed a 12-meter-high building and dug 693 meters in 88 days.

Life News (Reporter Yu Yan) Recently, the right line of the shield section from Qunli Sixth Avenue to Gongnong Street Station in the second phase of Harbin Metro Line 3 runs through, which is one of the sections where the construction of Harbin Metro Line 3 is difficult. The groundwater level is high, and the shield machine "climbs" the shield up to 12 meters high. At present, the left line of this section is under excavation, and 75% of the engineering quantity has been completed. It is expected that the hole will be excavated at the end of this month to realize the double-line connection of this section.

Shield is like climbing stairs.

Completed 693m in 88 days.

At 17: 18 on the 3rd, in the rumble, the cutter head of the "Pioneer 1" shield machine of Harbin Metro Project of China Communications No.1 Bureau slowly broke ground. This marks the smooth connection of the right line of the shield section from Qunli Sixth Avenue to Gongnong Street Station in the second phase of Metro Line 3.

It is understood that two shield machines have been put into the 13th bid section of the second phase project of Harbin Rail Transit Line 3 of China Communications First Highway Engineering Group Corporation, and two shield sections from Qunli Sixth Avenue Station to Gongnong Street Station and Qunli Fifth Avenue Station have been completed in a single section. A total of four times of origination and four times of reception were carried out. This time, the right line of Qunli Sixth Avenue to Gongnong Street Station was connected for the first time. The "Pioneer 1" shield machine started from the sixth avenue of Qunli on May 8 this year. After 88 days, it excavated 693 meters and accumulated 577 rings.

Difficulties in construction

"In the flat construction, the EPB shield machine can dig more than 16 rings every day, while in our interval, it can only dig about 12 rings every day on average." Mao Chaojun, the chief engineer of the project at the site, told Life Daily that the biggest construction difficulty in this section is that during the tunneling process of the shield machine, it is equivalent to crawling to a 12-meter-high staircase, and the more forward the tunneling resistance, the greater the resistance.

At the same time, this section is located in Qunli New District, with many and complicated underground pipelines, close to the river, and the shield machine works in rich groundwater, and the geological layer through which it passes is sandy soil and silty clay, which is prone to the phenomena of gushing backward tunnel, overbreak disturbing stratum and ground subsidence.

It is estimated that by the end of the year, four shield sections of two sections and two lines will be fully connected.

During the interview, the reporter learned that after the "Pioneer 1" shield machine started to excavate, it pushed southward along Lijiang Road until it reached the receiving well at the northern end of Gongnong Street Station. After the shield machine came out of the hole, it was immediately dismantled and hoisted, and it was transferred to the northern end of Qunli Sixth Avenue for reassembly, and continued to excavate along Lijiang Road to the shield section of Qunli Fifth Avenue Station. At present, the "Pioneer 1" shield machine is being dismantled and hoisted. At the end of August, after the left line was connected, two shield machines were transferred to Qunli Sixth Avenue Station together, and the left and right lines were staggered for one month, and they were driven to Qunli Fifth Avenue Station in the same direction on September 10th and October 10th respectively.

In addition, the reporter learned that the left line between Qunli Sixth Avenue and Gongnong Street Station of Harbin Metro Line 3 is under intense shield construction, and at present, 75% of the engineering quantity has been completed. It is estimated that around December 2018, the four shield sections of the left and right lines of the two sections can be fully connected.