UCD Project｜Shield Tunnel Construction Tasks for the Project of Shaoxing Metro Line 1 All Completed

On the morning of August 1, the cutterhead of the shield machine on the Chengfeng Right Line made an accurate stage pose, marking the successful completion of all 6 shield tunnels of the bid project No.12 of Shaoxing Metro Line 1 undertaken by UCD’s rail construction company, and the completion of all shield construction tasks. 

The bid project No.12 of Shaoxing Metro Line 1 consists of two stations and three sections, with a total of 6 tunnels. Shield tunneling method was adopted for the construction of all the sections, with 6 shield tunneling machines being used at the same time. The three sections stretch a total length of about 3.6km. The Tashan Station-Chengnandadao Station section, among others, is as long as 1.5km or so. In the course of tunneling, the complex stratum of full-section hard rock needed to be passed trough, and such difficulties as upper soft and lower hard soil conditions and weak soil needed to be overcome. At the same time, 31 risk sources including Shaoxing Yintai Commercial District, Fengzejiang River, and Chengnan Bridge, needed to be passed through underneath. Wait for 31 risk sources. At the same time, 4 shield machines were used on the construction site of Tashan Station, where space was narrow, and the location was in the downtown area of Shaoxing, making it difficult to coordinate. The section between Chengnandadao Station and Fenghuang Road Station stretches 1.2km or so in length and the whole section is situated under the Jiefang South Road with heavy traffic, where there are dense pipelines laid under and on either side of the street up above are moderately high or high-rise residential buildings and buildings for commercial use, being the shield interval for the latest arrival and last departure of metro trains in Shaoxing. At the same time, the shield tunneling also needed to pass through the upper-soft-and-lower-hard compound stratum, making the construction difficult. The total length of Fenghuang Road Station-Yushan Road Station is about 0.9km. Beneath the Jiefang South Road with heavy traffic and with the surrounding environment similar to that of the Chengfeng section, the Fenghuang Road Station-Yushan Road Station section, demolition and rebuilding of bridges needed to be done before construction.

Despite the difficulties in the construction, before using the shield machine to pass through the upper-soft-and-lower-hard sections, the project department had optimized the cutter head configuration  and the construction parameters on site in advance. Through careful organization and meticulous management, the shield successfully passed through the sensitive stratum of lower hard rock and upper water-rich and pressurized sandy silt. When tunneling at the soft soil section, through adjustment and optimization of muck improvement, backfill grouting, measures such as construction measurement and shield attitude control, etc., were strengthened, thus having effectively reduced the shield Technical problems such as deviation of the tunneling attitude, misalignment, damage of the formed segment, and the floating of the segment.

Faced with the severe circumstances of tight schedule and heavy tasks, under the correct leadership of UCD, all management personnel of the project department took turns to stay on duty around the clock for the bid project No.12 of Shaoxing Metro Line 1. They didn’t have rest during the Chinese Spring Festival and held fast to their posts at the production line regardless of difficulties. They spent nearly 8 months in the completion of 6 shield launches and 6 shield receiving tasks, laying an important foundation for winning the final victory on the whole in the construction of the bid project No.12 of Shaoxing Metro Line 1. All the staff of the bid project No.12 of Shaoxing Metro Line 1 will also continue to uphold the spirit of UCD as an construction iron army, make strenuous efforts with one heart, keep forging ahead in a devoted manner and, in a better state of mind, will ensure the successful completion of the subsequent projects, such as the inter-section communication channels, station attachments and internal structure of the station, under the premise of ensuring quality and safety.