Yuangang Station of Guangzhou Metro Line 6 is located in Tianyuan Road, Guangzhou. There is a turn-back line behind the station, which is also used as a parking line (that is, a parking line). It is mainly used to store spare trains, temporarily store faulty trains, and maintain lines and operating equipment at night. The site is basically surrounded by public facilities such as culture and education, rural development and industrial land in the southwest, and educational, military, residential and sports land in the northwest. The planning area focuses on education and scientific research, and the rest areas have been developed and constructed, with dense houses, mostly 2-6-storey buildings. The station line is arranged along the east-west direction of Tianyuan Road, and the red line width of each section is 60m, with a relatively stable trend. As Tianyuan Road has two viaducts across the planned road, the station is mainly arranged along the south side of the road.
2 Analysis of engineering design conditions
2. 1 design features
This project is an underground station, and there are turn-back lines and parking lines behind the station. The station is long, the platform length is 10m, the line spacing is 13m, and the center line of the line is 2. 15m away from the side wall, which determines that the width of the station is only 2 1.6m, resulting in a long and narrow space. From the architectural point of view, it is quite difficult to reasonably arrange all kinds of management rooms and equipment rooms in a narrow space, and the room layout is often unreasonable or impractical because of poor design. At the same time, there are many municipal pipelines in the construction area, and the traffic flow on the road section is also large. The influence of traffic relief and pipeline relocation on the planning and implementation should be considered in the design.
2.2 design focus
The architectural design of this project focuses on the following issues, including: the relationship between station site and planning, rational layout of entrance and exit passages, wind wells and wind pavilions in combination with surrounding conditions and planning requirements; Handle the relationship between internal management rooms and equipment rooms; Handle the relationship between underground pipeline and station layout, buried depth and station scale; Handle the relationship between station scale and turn-back line and parking line; Minimize the influence of station construction on traffic relief.
2.3 Other issues that need to be considered include reasonably controlling the scale of the station to reduce the amount of house demolition, and at the same time paying attention to the rational use of the open-cut space on the turn-back line. This station is a signal interlocking station with traction substation, and pedestrians should be fully considered when crossing the street.
3 Analysis and comparison of architectural design schemes
3. 1 Contradictions to be considered and design guidelines
(1) Main Contradictions in Design
The design of subway station architecture scheme is influenced by many factors. According to the above analysis of the characteristics and key points of this project, it can be concluded that the main contradiction to be solved in the design is how to design a reasonable station scheme (including parking lines) and control the total project cost in a narrow area. Among them, the problem of parking line should be considered. Stations with parking lines must be longer and larger than ordinary stations, and the scale and form of stations will directly affect the project cost. Relevant statistics show that the cost of rail transit project is about 400-800 million RMB per kloc-0/km. Designers must consider the feasibility of implementation and the rationality of cost when considering the architectural scheme. On the premise of meeting the needs of passengers, operation management and traffic safety, the scale of the station should be reduced as much as possible, so that the station design can reflect the comprehensive optimal effect.
⑵ Design guiding ideology
In the design of ordinary subway stations, the equipment management rooms can be evenly designed on both sides of the public area of the station hall according to the needs, which is easy to achieve the purpose of smooth movement of various professional pipelines and convenient use by staff during operation. In the architectural design of this project, the surrounding environment and planning requirements should be considered first, and the location of the station plane, entrance and exit and wind pavilion should be arranged. Secondly, by adjusting the plane, station and buried depth of the station, it can attract passengers to the maximum extent, reduce the amount of demolition of buildings and the migration of underground structures and pipelines, facilitate construction and minimize the impact on ground traffic. On the premise of meeting the use function of the station, the general layout of the station should be reasonably arranged, the scale should be reduced, and the buried depth should be reduced, so as to reduce the boarding height of passengers, the project cost and the operating cost. The first two aspects are the same as other station designs, but in terms of reducing the scale and cost of the station, this project needs to be realized by compressing the distance from the starting point of the platform to the starting point of the station and using the space above the parking line as much as possible.
3.2 Preliminary design scheme
The initial focus of the design is whether the space above the stop line is backfilled or utilized. Because the geological surrounding rock in the parking line area does not have the conditions for underground excavation, the whole station, including the parking line, should be excavated. As far as the parking segment is concerned, if it is backfilled after excavation, its budgetary estimate is roughly equal to setting the upper part as a utilization space. In contrast, when choosing backfill, it is necessary to increase the thickness of the structural roof. Therefore, the space above it can be considered as the station equipment room, even as an underground parking lot or warehouse, which is more economical. After comprehensive consideration, it is decided that this space is more economical.
The building scheme adopts two-story design, and the soil covering is controlled in the 3m line required by the planning. The center mileage of the effective platform of the station is YAK24+0 15, starting point YAK23+954.25 and ending point YAK25+297.7, with a total length of 343.45m, including the parking line of 234.7m m. The advantages of this scheme are that the environmental control load is concentrated at one end, the power distribution is convenient, and the centralized layout of the station control room and communication signal room is more reasonable. However, the shortcomings are also obvious, including: ① Because the total length of the effective platform is 72m, the left end of the platform is only equipped with rooms for piston wind and related equipment according to the air conditioning professional system, which fails to shorten the length of the left end of the platform and is uneconomical; ② The streamline of the public area of the station is not smooth, and passengers need to turn around when entering or leaving the station; (3) As the station needs to be equipped with traction substation, in order to save area and facilitate equipment transportation, the traction substation is located at the bullet formed by two branch lines on the negative second floor, and the station management room is located near the public area, which limits the air conditioning room on the negative 1 floor from being far from the public area, resulting in too long air ducts and chilled water pipes and excessive energy loss; Although the station itself is relatively large, the public space used by passengers is relatively small. Of course, if we simply pursue the spatial effect, we can make the middle transparent, that is, the hall floor and the platform floor can achieve intervisibility, and the spatial effect of the whole building will be improved a lot. However, due to the restriction of fire-fighting factors, this scheme was not adopted in the end.
3.3 Several modification schemes
Through the evaluation of the original scheme, on this basis, we readjusted and designed three reference schemes (sketches), which are introduced as follows:
[Scheme 1] This scheme optimizes the layout of the left machine room, and intercommunicates the positions of the low-voltage machine room and the environmental control room. Its advantages are that the environmental control room is close to the public * * * area, and the ventilation and air conditioning pipeline of the large system has a short stroke, which is convenient for air supply and exhaust in the public * * * area and the equipment area, and does not need to pass through the low-voltage electrical room. The disadvantage is that the communication signal room is too far from the car control room, comprehensive control room, AFC and other majors, and too far from the station hall and platform public area; The substation is far away from the load center, and the cable and bridge are long; The dislocation between the station hall and the platform ground is large, and the opening position of the air conditioner is not reasonable enough, which leads to the scattered layout of the ground wind pavilion.
[Scheme 2] In this scheme, the annular engine room is adjusted to the left. Its advantage is that the ventilation and air conditioning pipeline of large system has the shortest stroke and does not pass through any room in the equipment area; The environmental control load is evenly distributed, which is convenient for air supply and exhaust in public areas and equipment areas, and the air duct is short. The disadvantage is that most of the environmental control loads are located at the west end, and the substation is located at the east end, with a long distribution distance; The number of ground wind pavilions must be increased from 2 to 4, and the area occupied by the ground part will also increase; Because the station provides cooling for the substation, the chilled water pipes of large-scale systems need to pass through public areas.
[Scheme 3] In this scheme, a management room is set at the left end. The advantage is that the ventilation and air conditioning pipeline of the large system has the shortest stroke and does not pass through any equipment area room; Environmental control load is concentrated at one end, which makes power distribution more convenient. The disadvantage is that the air conditioning room and ventilation room of the system need to pass through the public area, and the larger air duct needs to pass through the public area. The equipment management room is concentrated at the left end, and the substation is located at the east end. The wiring distance is long, and there are more cables that need to pass through the public area, which is bound to increase the floor height.
3.4 Final Scheme
As the above three adjustment schemes failed to make a substantial breakthrough, based on the principle of making the layout of management rooms and equipment rooms more reasonable, using the space above the parking line as much as possible, and minimizing the scale of the station, the final scheme adopted the way of changing the position of the left piston ventilation system and the right mechanical air system, which shortened the length of the station from the original 343.45m to 335m and optimized the flow line of people in public areas, as shown in Figure 3. The problems discussed above are basically solved in the final scheme, and the effective platform center mileage is changed to YAK24+004, which is convenient for traffic relief, indicating that the final scheme is obviously reasonable and applicable compared with the above scheme, and the only disadvantage is that the problem of long air conditioning pipeline has not been well solved.
The author has studied other design schemes of station buildings with turn-back lines, and found that although the design conditions are similar, none of them can completely solve all the problems. For example, in the design of Tian Ping Frame Station of Guangzhou Metro Line 6, most of its management rooms are arranged far away from public areas, which will bring inconvenience to the future use of operating units, so Yuangang Station finally did not consider adjusting according to this plan. Of course, if some design conditions can be changed, the design and selection of the scheme may become easier. For example, Yuangang Station is not equipped with traction substation or water chiller, so the more restrictive conditions in design, the more comprehensive the problems to be considered, and the more ideal scheme can be made by comprehensively weighing all aspects.
4 conclusion
The scheme design of subway station including stop line (or turn-back line) is still a subject worthy of discussion and practice. With more and more cities in China building subway projects, it is believed that there will be more and more subway stations of this type, because the existence of parking lines increases many restrictions in the design process. How to find out the best treatment method in the process of modifying the design many times, how to find out the contradictions and weaknesses in many aspects to design a relatively reasonable scheme, I hope that through the design example of this paper,
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd