Construction case of double-wheel groove milling machine | Construction of Xixiang Park Station of Shenzhen Metro Line 15



Overview of Saigo Park Station:Xixiang Park Station of Line 20 is a two-story underground single-column double-span reinforced concrete structure, an island station, with a foundation pit length of 355m, a standard section width of 22.3m, and an excavation depth of 18.9m. Xixiang Park Station of Line 15 is a three-storey, three-column and four-span reinforced concrete structure with a side station, with a foundation pit length of 271m, a standard section width of 30.1m, and an excavation depth of 26.2m. 5 entrances and exits, 5 groups of wind pavilions, and two lines are planned and constructed at the same time.

Main strata:Plain fill, silty clay, silty sand, silty sand, medium coarse sand, gravel sand, sandy clay, fully weathered granite, soil-like strongly weathered granite, massive strongly weathered granite, moderately weathered granite, slightly weathered granite, and the roof cover in the later stage of the station is about 3.2~4.2m.

Construction Method:Line 20 adopts the open cut method, and Line 15 adopts the open cut + cover cut method.

Shield origination/reception:The end of the small mileage of Line 15 is the shield receiving site between Liutang Station ~ Xixiang Park Station, and the end of the large mileage is the shield receiving site between Xixiang Park Station ~ Pingzhou Station. The end of the small mileage of Line 20 is the shield receiving site of Shangchuan 1st Road Station ~ Xixiang Park Station, and the end of the large mileage is the shield starting site of Xixiang Park Station ~ Hangcheng Station.

Description of major difficulties:

1. Before the demolition of the Liutang pedestrian bridge above the Guangzhou-Shenzhen Highway, a new pedestrian bridge needs to be built, and the demolition span and weight of the pedestrian bridge are large, and the traffic of the Guangzhou-Shenzhen Highway is busy, and the demolition construction is difficult and risky.

2. Guangshen Highway and Baomin No. 2 Road involve rain and sewage, water supply, gas, 110kV electricity, communication and other pipelines, and the pipeline relocation and modification workload is large and the cycle is long.

3. The excavation of hard rock in the foundation pit of Line 15 station is large and the intensity is high, and the blasting excavation has a great impact on the surrounding hospitals, residential buildings, industrial parks and office buildings.

Construction Risks:

1. The construction risk of excavation of the main body of the station and the attached deep foundation pit.

2. The construction risk of pipe jacking method for the entrance and exit channel of Subsidiary A.

3. The construction risk of the main body of the station and the attached deep foundation pit near the buildings and pipelines.

At present, it has entered the construction stage of the enclosure structure, and there are about 200 underground diaphragm walls in the main body, with a groove section and wall thickness of 6 meters and 1 meter respectively, a depth of 28.4 meters, and a depth of about 10 meters in rock socketing.

Construction Equipment:Sany SDC120 double-wheel groove milling machine, SR415R rotary drilling rig