The excavation interval is from Hanxi Changlong Station to Hezhuang Station (now Wanbo Station), and the left and right lines of the interval are1738.86m.. The shield machine originating from the right line is S438 shield machine produced by Herrick Company in Germany. Get off at Hanxi Changlong Station, enter Hezhuang Station along the northeast of Hanxi Avenue, and finally hang out at Hezhuang Station. The whole section is expected to complete the excavation task before the end of 20 15.
The geological conditions of the tunnel from Hanxi Changlong Station to Hezhuang Station (now Wanbo Station) are very complicated, and it needs to cross 767 meters of weathered hard mixed granite stratum, in which the upper part is soft, and the lower part is about160m. The maximum rock strength during shield tunneling is107.3mpa, which is already very high in this stratum in Guangzhou. "The higher the rock strength, the more serious the tool wear of the shield machine, and it is necessary to open the warehouse more frequently to replace the tool. This requires us to strictly control the speed and various parameters of construction excavation, and at the same time strengthen safety precautions when opening warehouses to change tools, "said Wang Wei, a project engineer of Guangzhou Metro Construction Headquarters.
Millisecond blasting ensures safety.
It is understood that Zhongcun Station is located in Zhongcun Town, Panyu District, with Hanxi Avenue in the south and xie cun Industrial Park in the north. The station is equipped with parking lines and railway wells. The total length of the station is 468.6 meters. It is a two-story underground box frame structure and is one of the largest stations in the whole line.
Because the excavation depth of the station foundation pit is about 19 meters, weathered mixed granite develops in the station. The maximum thickness of basement rock is10m, and the rock hardness is 214mpa. The strength of bedrock is equivalent to that of ordinary steel. It is the most difficult station encountered in the construction of Line 7, which brings great difficulties to the continuous wall grooving and foundation pit excavation. In order to ensure the construction safety, Guangzhou Metro Company invited relevant experts to hold a technical seminar, and decided to adopt advanced millisecond blasting technology, which effectively controlled vibration, noise and flying stones, and the excavation of foundation pit did not adversely affect the surrounding ground and buildings.