地铁施工工法比较 英文版

Chapter3 Program comparison
3.1 summary
With the acceleration of the process of China's rapid economic development and urbanization, the existing road transport system has not meet the travel needs of the people.To ease the ever-increasing traffic pressure, China's major cities to speed up the construction of urban rail transit systempace. Comparative Analysis of rail transit and several other common way to travel, the rapid rail owns transit efficiency, energy saving, environmental protection, large volume, high speed, low pollution, low noise, low power, small footprint, safety, comfort, all-weather, etc.a unique advantage to solve urban traffic congestion, changing the urban layout. It has played a big role to achieve comprehensive management of urban environment and transport, and guide the city and take the road of sustainable development.
However, the tall buildings of the urban area-intensive, crowded, traffic, bus lines, subway station design is becoming increasingly narrow construction of space, around pipeline dense, close to existing buildings, ground with heavy traffic and many other constraints.
3.2 Several commonly used methods of subway station construction
Subway stations located in the city center, mostly, therefore,the selection of construction methods and structure type of subway station , mainly based on the
following aspects: (1)station function, station function mainly reflect from the station use effect and operation conditions, and the station use effect reflect from the capacity of the organization and distribution in passenger, equipment room decorate, operation management and utilization of underground space in comprehensive functions; (2) difficulty of construction, mainly from the difficulty of construction project itself, construction preparation of the implementation of the degree of difficulty, period and construction safety aspects of evaluation, embodied at the the maturity of construction technology and surface subsidence control, construct objects demolition, pipeline move and protection; (3) environmental impact of construction, environmental impact on the construction mainly embodied in the influence of urban traffic and urban living, the influence of the commercial activities, and pollution to the environment, etc. Subway station construction method has a lot kinds, commonly used in China are now open cut method, cut-and-cover method, cover excavation method and hybrid method,etc. Which cut-and-cover method consists of the bottom up and top down;
3.2.1 open cut method
Open-cut method is the traditional construction method of the ground frame structure.First of all, make the foundation pit on the ground, and then excave the soil from top to bottom, plus support when necessary to prevent the deformation of foundation pit,when excavation in the end facilities for the framework from the bottom up.The construction technique of open-cut method is simple, rapid, and economy, so the
subway station construction regarded open-cut method as the preferred solution. Construction of the open-cut method generally are used to cut-bottom up, cut-bottom up construction method in the construction sequence is as follows.
Fig A.1 Open-cut excavation procedure
3.2.2 cut-and-cover method
Cover and cut-bottom up method after completion of the retaining structure, the cover to the stereotypes of prefabricated standard structure (including the longitudinal beams and pavement slab) placed in a retaining structure to maintain traffic, be down repeated excavation and set up cross-hold until the design elevation.
Fig A.2 cut-and-cover method---bottom up method procedure
cover and cut-top down method steps: first to the ground surface down to do the pit of the envelope and intermediate piles the same with cover and cut-bottom up method, the foundation pit structure use of underground continuous wall or curtain pile.The intermediate support is more of the middle column of the main structure itself in order to reduce the project cost.
Fig A.3 cut-and-cover method---up dowen method procedure
3.2.3 Shallow depth of cover excavation method
In urban centers, ground transportation do not allow long-term interruption because of many buildings on the surface, a small ground construction site , the impact of a number of bridge pile in the city under the overpass, or pipeline complex,so it’s difficult to change the shift. So when the geological conditions allowed,it’s considered the tunneling method to subway station facilities
(1) the CD method.
Fig A.4 the CD method procedure
(2) the CRD method
Fig A.5 the CRD method procedure
(3) the double benching tunneling method
Fig A.6 the double benching tunneling method procedure (4)the middle hole method
Fig A.7 the middle hole method procedure
(5) the lateral hole method
Fig A.8 the lateral hole method rocedure (6)the PBA method
Fig A.9 the PBA method procedure
3.3 Comparison of the subway station construction method
Table A.1 The mainly construction method of subway station
3.4 several problems which should pay attention to the subway station construction 3.
4.1 Should pay attention to the optimization of the construction plans and construction methods
3.4.2 Should choose the right construction method.
3.4.3 Should take effective measures to control ground subsidence and structural deformation.
3.5 The Selection of Construction Method of the Youth Street Station
3.5.1 Youth Street station overview
(1) Geology and underground structures and pipelines
(2) Station site environment
(3) Construction project’s impact of environmental
3.5.2 Selection of Young Street subway station Construction Method
3.6 Conclusion。