Xi'an, the ancient capital of the thirteen dynasties and the largest city in the northwest, is currently making every effort to build a national central city. Behind the dazzling development achievements, there is also a vibrant green that cannot be ignored. In the ranking list of China's urban greening rate in 2020, Xi'an ranks tenth in the country, with an urban greening rate of 42.5%, which is comparable to Jiangnan and is the only northwestern city on the list.

As a key supporting project for the 14th National Games, CSCEC’s China State Construction Silk Road (China State Construction Northwest Regional Headquarters) invested in the construction of the PPP project on the right bank of the Bahe River in Xi’an Chanba Ecological Zone. The Bahe Greenway Project is the implementation of the project. The concrete practice of the concept of green development, an important part of Xi'an's "three rivers and one mountain" greenway construction, and an important measure to promote Xi'an's "global water management, clear waters, and urban prosperity". The construction length of the project is about 9 kilometers, and the total area of upgrading and renovation is about 1.8 million square meters. The implementation content mainly includes urban greenways, node squares, upgrading and renovation of existing docks, pedestrian landscape bridges, and green planting.

On September 12, the Bahe Greenway served as the starting point for the final station of the 14th National Games Torch Relay, providing an ecological oasis for the National Games Torch Relay.

Design first ▪ Build a quality greenway with proven ingenuity

The Bahe Greenway Project is built along the river, with complex terrain and wide coverage. At the same time, it is also restricted by intricate underground pipelines, park vegetation protection and riverside gabions. It is necessary to build this patchy and rugged area into a green, With a casual, modern slow-moving system, the design of the "pioneer" has faced an uphill battle from the very beginning.

After receiving the project construction task in July 2020, the project design team immediately took action to investigate the status quo and characteristics of the Chan River along the Bahe River, follow the requirements of the upper planning, from the overall to the partial, layered and implemented in stages, and carried out in an orderly manner. "Immersive design" including deepening design, preliminary design, construction drawing design, and follow-up operation.

In terms of design concept, the project insists on giving priority to ecology, respecting the original appearance of the ecological environment of the site, and avoiding major demolition and construction; insisting on being people-oriented, and providing citizens with abundant water space. In the section from Eurasia Avenue to the North Third Ring Road, the greenway connection point of the port area is designed on the front water surface, the current greenway in Chanba area is on the back water surface, and there are multiple water source wells, high-voltage lines, and management between the two ends of the greenway. Housing, etc., cannot be removed in the near future. The project held a meeting to discuss the design of barrier-free greenways, and formulate multiple plans such as streamer bridges and box culverts. After comparison and selection of various indicators, the plan for designing box culverts to connect the water-facing slope and the back-water slope greenway was determined. It not only avoids damage to the original ecological environment and infrastructure, but also guarantees the construction period.

After nearly a month of discussion and verification, it was repeatedly modified and improved according to the current situation of the site, and finally formed the Bahe Greenway design of the four major systems of road traffic system and slow-moving system, blue-green sponge system, open space system, and supporting service facility system. It connects ecological zone parks, scenic spots, landmark buildings, cultural relics, etc., creating an ecological network pattern of 1.8 million square meters.

Overcome Difficulties ▪ Responsibility Greenway

On July 15, 2020, the project officially started construction. Faced with multiple constraints, the project department carefully analyzed the status quo, integrated resources in a timely manner according to the actual situation, started at the same time from the aspects of staffing, transportation vehicle supplementation, and logistics support services. schedule.

On July 30, 2020, Manshuiqiao soil cofferdam; September 30, Bahe East Road opened to traffic; during the Spring Festival of 2021, more than 600 builders actively responded to the call and devoted themselves to construction; March 30, Manshuiqiao The main bridge was closed; on April 3, the main bridge of the streamer bridge was closed; on April 20, the starting point square was completed and the garden road was opened; on April 30, the Bahe Greenway was completely opened and officially opened to the outside world... From the research structure diagram, Beginning with architectural drawings and pipeline drawings, starting from docking with gardens, transportation, power grids, water supply and drainage and other units... The project team insists on thoroughly understanding every drawing, every node, and every process, while maximizing innovative thinking and finding various points. The optimization points of the Ministry of Engineering have formulated a detailed construction answer sheet for the follow-up of the project.

Careful selection and breeding

Xi'an has a warm temperate semi-humid monsoon climate, with cold winters and hot summers, with four distinct seasons, which are good for plant growth, but for urban greening, it has become a major problem: evergreen plants that are resistant to extreme low temperatures are difficult to grow, leading to landscaping The greening plant species used in the landscape is not rich enough, objectively there is a problem of less flowers in spring and summer and less green in winter. To solve this problem, seedling selection and breeding has become a key link.

In order to ensure that after the completion of the project, there will be lush greenery and scenery everywhere. The project adheres to the requirements of “selection and optimization”, carries out the selection and planting and maintenance of seedlings with high standards. A beautiful landscape that showcases the city’s natural features and humanistic features. At the same time, the project also fully considers the experience of citizens and tourists. When selecting and breeding, the vegetation form and function are taken into consideration, so that big trees can provide shade in summer, some special smelling small plants are used to repel mosquitoes, and low shrubs are used as spectacles. Through reasonable planting methods, a landscape pattern that contrasts high and low and complements each other is formed.

In order to ensure the quality of seedlings, in October and December 2020, the project department will select a seedling breeding team to go to Sichuan and Shandong for on-site inspections in two trips. According to the actual growth status of the seedlings, the standards are determined, and the selection plan and checklist are revised and adjusted to ensure that the selected seedlings meet the requirements of "success in the same year" and long-lasting survival.

Water is controlled throughout the region, the city is rejuvenated by clear water, and rivers are turning into scenic lines. China State Construction Silk Road actively implements the concept of green development, actively integrates into urban development planning, fulfills the mission of a central enterprise, gives full play to the advantages of the entire industry chain of "investment, design, construction, and operation", and participates in all aspects of regional urban construction and ecological environment improvement. Regional economic and social development provides China Construction Wisdom and Silk Road solutions, strives to create a green, ecological, and well-equipped livable place, and uses green development to help the region play a "concerto" of economic ecology. Editor/Sang Xiaomei