Rail transit and urban spatial structure optimizat

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Rail transit and urban spatial structure optimization Shanghai

75n12 / person, motorcycle l1.66n12 / person, bus 1m / person, car 14m / person, a taxi 1O. 5m / person; rail transit built in the underground or overhead, do not take urban roads. Hourly 5 million needed to transport width of the road, the car is 180m, the bus is 9m, integrated area of rail traffic for the road 1 / 3 (subway and elevated light rail covering less). In fact, Shanghai in the years after the 9O 2O century, road construction has developed very rapidly, but due to excessive growth of motor vehicles, the situation has not been effective in relieving traffic congestion,[link widoczny dla zalogowanych], major new roads were car occupied. The car's total traffic volume is only the l1%, the marginal benefit weak. Bus due to the impact of road congestion, slow traffic, and other means of transport less competitive, competitiveness and transport efficiency by the dual impact of the total traffic volume in urban areas is 24%,[link widoczny dla zalogowanych], compared to just 17 in the city %. (2) run fast. Shanghai downtown space is almost saturated, suburban cities,[link widoczny dla zalogowanych], although the urban population of the strategy are ease, but the attractiveness of the central business district in a short time can not be dispelled. People living in the suburbs, trip distance will be extended, and thus travel speed is very important. Shanghai Metro is divided into R, M, L three: R (City in line) speed of 6O ~ 80km / h, the suburbs run at speeds up to 120km / h; Bear on Bridge of Lions in the design of the vehicle braking force Cao Xueqin Jin-Long Zhu 2 (1) Department of Bridge Engineering, Tongji University, 200092, Shanghai; 2) Department of Engineering Mechanics and Technology, Tongji University, 200092, Shanghai ∥ first author, professor) a train on the bridge the basic mechanism of the emergency braking system of the train braking points generally Activity (or normal braking) and the emergency brake two. The emergency brake on the train tracks, cross the bridge structure, bearings and the role of a longitudinal force pier,[link widoczny dla zalogowanych], bridge design in the urban rail transport must be considered. 1.1 coefficient of friction between the brake shoe and wheel () A single wheel in the braking, the brake shoe to beat the law to the rim, wheel and axle load rail asking longitudinal forces N and B (Figure 1). By dynamic balance are: Chi r-Br a = 0 (1) is B = (r a blog) / r (2) where: B is the wheel and rail longitudinal force Q; as brake friction coefficient with rim question ; a deceleration of the wheel angle; for the wheel edge radius; c, moment of inertia for the wheels turning. One. Ⅳ Figure 1 aB a single round of the mechanical braking Schema decision from the train brake cylinder pressure in the braking process, basically unchanged. Before the speed and braking. And the instantaneous velocity during braking on the train. Figure 2 shows that,[link widoczny dla zalogowanych], during braking with the speed reduced, and gradually increased. Moment when the wheels stop rolling, reaching the maximum. Equation (3), (4) that the value of subway cars: = 0.25 +8 / (100 +20 v) (73 = 0 ~ 45km.h-1; R> 450rf1) (3) = 30 / (100 + 73) (73> 45km.h-1; R> 450rf1) (4) brake brake (= 0), equation (3), equation (4) equal. 1.2 adhesion coefficient between wheel and rail () v / (km · h) Figure 2 Relationship between a V curve M (subway) the rate of 60 ~ 80km / h; L (light) mainly through promoting the city as a space for rural restructuring Shanghai Urban Spatial Structure of the promotion. Areas of transport, speed is also 60 ~ 80km / h. Space compared to other pay and to promote adjustment of industrial structure optimization, communication tools should be the Shanghai city, the only rail transportation to meet people's travel needs, guiding the development of strategy. Take the inch in the day. , Base Suoshi Zhanlakunqi