The left line tunnel between Diejiao Station and Zhongshan Park Station of Foshan Metro Line 3 has been successfully completed

On July 28, blessed in the afternoon, with the noise of the shield machine broken wall, foshan metro line 3 engineering pile between beijiao station to zhongshan park station of the left line ", 68 "god save the shield construction machine smoothly into the steel sleeve, tunnel implementation, this 3205-2 standard (south China sea square station - fold kau station and zhongshan park station, railway station) of the left line of three interval tunnel have been well versed in, A new breakthrough has been made in the key point of shield tunneling in the northern section of Line 3 project.

The section from Diejiao Station to Zhongshan Park Station (hereinafter referred to as "Diezhong"), which was built by the Fourth Engineering Bureau of China Construction Construction, is an important passage connecting Foshan Metro Line 3 to the Zen-Gui area. Fold in the interval of the left line of shield in 2021 March 15, originating from the zhongshan park station, interval line along the wenchang road towards laying down in foshan waterway and the soy sauce factory, side wear sand bridge to fold the beijiao station receives, line is about 0.98 km long, line built on both sides, dense, interval lines to the left and right in to fold kau station about 260 meters of the cascading line up and down, The geological conditions are complicated, the pipelines along the line are dense, and the construction is difficult, which requires high level of construction technology and technology.

The strata traversed by the tunnel in the left line of the middle interval are mainly fine sand layer, medium coarse sand layer and strongly weathered argillaceous siltstone layer. More than 50% of the tunnel sections are upper soft and lower hard strata (the upper part is sand layer and the lower part is strongly weathered mudstone), and there are some loose stratum areas. Combined with the formation conditions, the mud-water balance shield machine of Tiejian Heavy Industry was used in the left line shield machine.

In the process of shield tunneling on the left line of the mid-stack interval, there were frequent cases of cutter folding mud cake and delay discharging in the warehouse, so the operation of opening and clearing mud cake and changing knives with pressure was carried out many times. The mud and water shield tunneling in the upper soft stratum and the lower hard stratum also appeared slurry pipe blocking, frequent blocking of the quarry box and so on, which are the factors that restrict the construction efficiency of shield tunneling.

For interval shield tunneling in the fold control risk, and prompted the tunnel safely, smoothly foshan iron cast group brainstorming, organize the contractors have held expert consultation and commenting to thrash out of shield construction efficiency is low, the knife the intertwining mud cake, in a belt to wear under pressure, open channel and other high risk during the operation, in conjunction with the construction and supervision units for 24 hours on duty, The risk of shield construction is effectively controlled. At the same time, in order to ensure the safe reception of the left line shield machine in the middle of the stack interval, the steel sleeve receiving process was used for the first time in the bidding section 3205-2.