Design and Practice of Green and Low-Carbon Urban Rail Transit Planning

Objective To achieve cost efficiency and low-carbon transformation in rail transit, the planning, design, and implementation of green and low-carbon urban rail transit systems is investigated. Method Aiming at life-cycle sustainable development, through comprehensive route selection and laying methods optimization（mainly elevated）, Shenzhen Metro Line 6 innovatively applies systematic technologies such as comprehensive vibration and noise reduction technology for elevated lines, prefabricated and assembled green construction（such as U-shaped beams and floating plate tracks）, distributed photovoltaic power generation, regenerative braking energy feedback, ecological sponge vehicle depot design, intelligent cloud platform and TOD（transit oriented development） model intensive land utilization, etc., to explore green and low-carbon planning, design and practice paths. Result ＆ Conclusion The green and low-carbon technology system of Shen-zhen Metro Line 6 has demonstrated remarkable outcomes: construction costs are reduced by approximately 45%（10.9 billion yuan） compared to a fully underground scheme, with a 2.4 million-ton carbon emission reduction in construction-phase. The operational energy consumption is decreased by 40%（annual electricity savings of 33.6 million kW·h）, with accumulated carbon emission reduction of 580 000 tons in 25 years. The annual power generation and energy saving by using photovoltaic and regenerative braking technologies are 6.78 million kW·h; the land development income is expected to reach 30 billion yuan（RMB）. This case provides a replicable technology integration solution for urban rail transit to achieve the carbon peak and carbon neutrality（shorten as "dual carbon"）goals, proving that the green, low-carbon and high-quality sustainable development can be collaboratively achieved through systematic innovation.