The world's best shield machine is used in digging the subway in Ningbo
in the list of gods, there is a "earth walking sun" who is good at hiding from the earth. Ningbo metro construction has also been using the "earth walking sun" - the shield machine that is equally powerful in Dundi
in the morning of November 30, the upgraded "earth moving sun" and earth pressure balance rectangular shield machine "Yangming" started smoothly at the south end of gaotangqiao station of Ningbo Metro Line 3 phase I project. Its excavation direction is to pass through the planned Weisi road plot in the south along the planned Guangde Hunan Road, and then pass through the waitang River in the southwest
this is the first self-developed rectangular shield machine in China, and also the first shield machine from the first phase of line 3. The "big guy" section is 11.83 meters wide, 7.27 meters high, 58.6 meters long, and weighs about 770 tons. It has created a world first - the world's largest cross-section earth pressure balanced rectangular shield machine
the ordinary version of "tuxingsun"
takes up more underground space
it sounds a little boring. According to the staff, with this kind of rectangular shield machine, the future construction of Ningbo Rail Transit in the core area of the city will have less and less impact on the lives of ordinary people. Therefore, the oil pumped out by the high-pressure oil pump cannot be sent to the experimental work cylinder, so that less and less residents will not be affected by the pressure
in fact, in the tunnel construction of Ningbo Metro Line 1, Ningbo Metro has brought three significant advantages to cars: first, it introduced shield technology, which is a relatively mature tunnel construction technology. The shield machine used in Ningbo is called earth pressure balance shield machine. For example, the basic principle of jiesou dictionary is that while taking out the soil, the pressure of the original soil can be basically balanced, which is equivalent to passing quietly without changing the original state
this shield machine can move freely under the ground. The "mouth" at the front end is like a large disc, which works like a rotating electric fan. With each revolution, the soil in front of it can be continuously cut off. After adding foam and additives to the soil for necessary soil improvement, it is transported out of the tunnel by the transport vehicle through the track. While the shield machine is digging holes, the shield segments can be assembled to form a tunnel
for the conventional single round tunnel of rail transit, the ordinary "tuxingsun" shield machine needs to drive back and forth twice to complete the penetration of the double track tunnel. In addition, a certain safe distance must be maintained between the two tunnels, so the underground space takes up a large amount
the upgraded version of "tuxingsun"
can avoid more house demolition along the line
on September 30 this year, the first domestic rectangular shield machine of this kind, "Yangming" was developed in Shanghai. Dr. Huang Yi from the Engineering Department of Ningbo Rail Transit headquarters described it like this:
"As soon as the Yangming starts, a single excavation can form a double track tunnel at one time, which is certain to save the construction period. In addition, compared with the previous ordinary single round shield construction, the rectangular shield construction method can make full use of the structural section, improve the utilization rate of the effective area, and save underground space resources;gbt1172 ⑴ 999 ferrous metal hardness and strength conversion value;
specifically, the single round shield tunnel is designed according to the design requirements, the The line spacing is about 13 ~ 15 meters. When using rectangular shield construction, the line spacing between the two tunnels can be reduced to 5.1 meters. The distance between the boundary line of the shield tunnel structure and the houses is increased from the source, and the safety of the surrounding houses is more guaranteed during the construction of the tunnel section. "
Huang Yi said that when the rail transit line crosses the core area of the city, the roads on both sides are narrow, the traffic is busy, and the residential areas are dense. The conventional single round shield construction is more likely to affect the lives of residents on the ground. For example, when it is too close to the house or needs to pass under the house, the difficulty of house protection and the capital cost of demolition will increase
Yangming occupies less space, avoiding more house demolition along the line, and its efficiency is twice that of ordinary shield machines
from November 30, the similar rectangular shield machine "Yangming" will first be tested and promoted in the phase I project of line 3, between gaotangqiao station and Jiangshan depot of the subway. It will also be applied to the densely populated area from daqingqiao station to Cuibai Road Station of Ningbo Rail Transit Line 4, and it is planned to be applied to line 2, phase II and line 5 in the future