Chengdu Leverages Digital Twins on Complex CNY 1.38 Billion Infrastructure Project

Incorporating BIM Methods into Every Part of Road and Pipeline Design Saved Time and Expense

Finding Space for New Roads in a Tight Environment

To address traffic congestion in the city of Chengdu, China, Chengdu Urban Construction Investment Management Group Co., Ltd. (CUCIMG) was tasked with designing a CNY 1.38 billion infrastructure redevelopment package. The centerpiece of the package is a 4.3-kilometer roadway system that will integrate 64 existing roads, with the main new road designed for speeds of 60 kilometers per hour and new auxiliary roads designed for 40 kilometers per hour. It would also include new and reworked intersections to optimize traffic flow and accommodate the varying road speeds. The organization would need to construct new bridges, tunnels, green spaces, and pedestrian paths, as well as redevelop existing pipeline networks and add a new tunnel for power distribution.

However, CUCIMG faced numerous challenges. Since the project was slated for a heavily developed commercial area, planning the best routes to optimize traffic became difficult. Overpasses could affect existing buildings, while underpasses had to be built around the Jin River, a subway system with two stations in the area, and the power tunnel. Ultimately, a 35-meter underpass would have to be constructed less than two meters from the subway, which required redeveloping the affected subway section. To accommodate new roads and belowground construction, various types of pipelines and cables—including those moving sewage, rainwater, electricity, gas, and data—would have to be either temporarily moved or permanently moved, or protected during construction. The design team also needed to design a safe pedestrian passage system near the highly trafficked roads.

Preliminary planning around the Jin River, dense buildings, pipelines, a subway line, and two subway stations became increasingly complex. Therefore, the project team determined that traditional 2D CAD drawings were not efficient enough to finish the design within the three-month deadline. Additionally, during previous CUCIMG projects, 2D design hindered coordination among contributors with varying specialties and produced many hidden clashes between design elements. Though CUCIMG created 3D models at the end of the design process, the organization discovered that the late-stage models produced limited value for planning, reporting, construction, and management.

Overcoming Challenges through Visualization

To overcome the project’s challenges and optimize designs within the tight timeframe, CUCIMG leveraged Bentley applications to incorporate BIM methodology into every step of the design process. The design team used unmanned aerial vehicles to capture images of the construction area, then created a reality mesh of the terrain, buildings, and underground elements using ContextCapture, as well as an existing digital model of the city of Chengdu. With the project surroundings visualized, the design team modeled potential designs with OpenBuildings, OpenRoads, and OpenBridge. By viewing plans in 3D, the design team could measure the effectiveness of each design and determine how to improve them.

CUCIMG used OpenRoads for multiple aspects of the project. In addition to laying out routes, determining intersections, and optimizing traffic flows for 64 different roads, the design team used OpenRoads to build subway tunnel sections, underpass tunnels, and underground utility models. The design teams automated many design details to greatly improve work efficiency and speed the evaluation of each iteration. Additionally, the design team used OpenRoads to label pipes as retained, removed, or newly built, which helped eliminate clashes in pipe placement and underground development. With OpenBridge, the design team strengthened the foundations of bridge piles, while OpenBuildings was leveraged to restore all aspects of the subway system affected by construction.

A Single Source of Truth Saves Time and Money

Teams from numerous disciplines collaborated in ProjectWise to ensure a single source of truth. Individual models were brought together in LumenRT to form a digital twin that visualized all elements of the project. Though design teams worked in different file formats, CUCIMG used the interoperability of Bentley applications to seamlessly combine all contributions into a single format. Compared to traditional 2D modeling, 3D visualization helped the design team improve designs and work efficiency. Additionally, the efficient visual twin presentation improved loading times and lessened hardware requirements compared to CUCIMG’s late-stage BIM presentations during past projects. The design team incorporated all necessary asset information for construction, operations, and maintenance into a digital twin, which is expected to extend the lifecycle of all assets.

By collaborating within ProjectWise, CUCIMG improved the design management process and increased internal work efficiency by 20 percent. ProjectWise also helped CUCIMG to detect and resolve 16 design clashes within the pipeline system. Automated design within OpenRoads reduced the construction drawing time by 120 resource hours. By using the digital twin to guide the construction process, the design team shortened the time required for planning, construction, and approval by 15 percent. Work with the digital twin determined that building the foundations of the elevated road and the underpass tunnel simultaneously would prevent problems during construction. In total, CUCIMG’s work with 3D modeling lowered design costs by 23 percent and construction costs by 10 percent.

Project Summary

Organization: Chengdu Urban Construction Investment Management Group Co., Ltd.

Solution: Digital Cities

Location: Chengdu, Sichuan, China

Project Objectives:

• To design a CNY 1.38 billion infrastructure package, including 4.3 kilometers of new roads.
• To improve efficiency by incorporating BIM techniques throughout the design process.

Products Used: ContextCapture, Descartes, gINT, LumenRT, MicroStation, OpenBridge, OpenBuildings, OpenRoads, ProjectWise

Fast Facts:

• The CNY 1.38 billion infrastructure redevelopment project included building 4.3 kilometers of new roads, pedestrian paths, and underground infrastructure.
• Building within the dense commercial area required minimizing the impact of overpasses on buildings and constructing tunnels two meters away from a subway line.
• To manage the complex project, CUCIMG leveraged 3D modeling throughout the design, which was a first for the organization.

ROI:

• 3D visualizations of all project assets helped determine where to place bridge supports and how to connect 64 roads designed for varying speeds.
• A connected data environment improved work efficiency by 20 percent, detected and resolved 16 design clashes, and reduced drawing time by 120 hours.
• Overall, 3D modeling applications helped lower design costs by 23 percent and construction costs by 10 percent.