At present, Suzhou Rail Transit Line 2 has begun trial operation, and Line 4 is also under accelerated construction. As the station with the “greatest construction difficulty” on Line 4, Beisita Station has attracted widespread attention because of its proximity to the national cultural relic Beisita.

　　Yesterday, the reporter learned from the construction unit that the station has recently successfully entered the main structure construction stage, with completion expected in mid-January 2014, and the shield machine is expected to be lowered into the shaft as early as February next year.

　　In addition, the "Beisita Building Protection Implementation Plan" specially formulated by the project department has also passed expert review. Every day, a third-party supervision unit sends professionals to monitor Beisita across six items to ensure its safety.

　　It is understood that Beisita Station is an interchange station between Line 4 and Line 5. The total length of the station is 204.1 meters, of which the standard section has an outer envelope width of 21.7 meters and a foundation pit excavation depth of 18.46 meters; the end section is 25.8 meters wide with a foundation pit excavation depth of 19.88 meters; the interchange section is 27.05 meters wide with a foundation pit excavation depth of 25.24 meters, and this section is three stories underground.

　　On-site project manager Tang Jianjun told the reporter that because Beisita Station is adjacent to Beisita, it is the most difficult station to construct in the main urban area along the entire Line 4. To protect Beisita, the project department specially formulated a plan, which has now officially passed expert review.

　　Tang Jianjun said that the closest distance between the main station body of Beisita Station and the physical building of Beisita is 89.5 meters, while the horizontal clear distance from the centerline of the "Railway Station—Beisita" shield tunneling section to Beisita is about 49.9 meters. How to carry out construction safely without affecting Beisita is a major challenge facing the construction unit.

　　Tang Jianjun said that according to on-site monitoring and calculations by the local cultural relic protection department, construction at these two distances is very safe for Beisita on the ground and will not cause any impact. At the same time, it is required to protect cultural relics, pipelines, and other surrounding structures at all times during construction to ensure orderly and reliable construction.”

　　It is understood that, just in case, the construction party has also invited a third-party supervision unit to monitor Beisita every day across six items, including whether it has settled, whether the surrounding groundwater level is uneven, and whether the nearby support axial forces meet requirements. In addition, once a week, the cultural relic protection unit and the construction party jointly re-inspect these monitoring items.