Xingtai Transportation Construction Group Co. Ltd is no stranger to incorporating advanced infrastructure design tools into its projects. In their recent project, the East Lake Bridge in Handan, China, they opted to use ALLPLAN’s cutting-edge bridge design software. The East Lake Bridge, a stunning double-deck, cable-stayed composite bridge with a main span of 150 meters, showcases Xingtai's ingenuity and skill. The intricacies of this modern marvel of engineering, the complex process behind its construction, and the invaluable role of ALLPLAN and BIM in bringing the East Lake Bridge from conception to completion make an interesting read.
Project Background
The project background is rooted in the shift towards digital transformation in infrastructure design. Since 2021, when China introduced a unified standard for highway engineering information models, the importance of accurate and comprehensive BIM models has been at the forefront of design and construction methodology. These unified standards not only emphasized accuracy but also defined its applications at every stage, from preliminary design and construction drawing to the actual construction process and final acceptance.
This new mandate necessitated the development of BIM models that met an LOD of L4.0 according to the new standard, which is a model suitable for construction. Xingtai embraced these standards and chose ALLPLAN for their design tool. ALLPLAN enabled Xingtai to create a high-precision BIM model that accurately represented every facet of the bridge, from its corrugated steel web composite sections to its double tower cable stayed structure.
This approach allowed for an interactive, highly detailed, and accurate model that could be easily manipulated and analyzed, providing invaluable insights at each phase of the project. From the foundation's drilled piles to the installation of pedestrian passage components, the BIM model guided each step. Furthermore, this detailed digital representation made it possible to pre-empt potential challenges, optimize resource allocation, and execute complex construction processes such as the four-stage lower pylon pour and the nine-segment upper pylon pour.
A Complex Challenge
The East Lake Bridge project presented several intricate design and construction challenges, all of which required precise planning, complex detailing, and rigorous analysis to overcome.
One of the initial hurdles was the detailed reinforcement modeling for both the upper pylon and the composite girder decks. Precise simulation was required to estimate the construction feasibility and the exact quantity of rebars needed. With ALLPLAN’s powerful reinforced concrete modeling tools, a detailed reinforcement model was constructed, which allowed for an accurate evaluation of construction feasibility and calculation of rebar amounts.
ALLPLAN's parametrized modeling function, based on the alignment route and bridge cross-section, enabled quick location and updates to the cross-sections and bridge piers based on route images. This functionality proved essential in modeling the connection between the bridge deck reinforcement and the steel web and in considering the reinforcements in the steel anchor box.
The software was also used to model shear nails for the bridge deck and connection keys at the edge of the web. With this, it was much easier to plan, model, and visualize the layout of reinforcement and pre-stressing tendon holes in the steel structures. Through detailed simulation and design optimization, a safety analysis of the large temporary structures required was performed for the upper pylon templates.
Despite the precision of initial design processes, several unanticipated details for the lower pylon were discovered. ALLPLAN allowed for precise simulation and correction of these details, ensuring the smooth progress of construction. Even elements like the bridge deck hanging baskets, disk-type scaffolding, and rigid structural framework during pylon construction were simulated and modelled accurately.
A crucial component of this project was the modeling of repetitive and standardized components, such as corrugated steel webs, steel structures for pedestrian walkways, truss decorative structures, connection components between the main tower and steel cables, and steel templates. Through secondary development based on ALLPLAN, the efficiency and accuracy of modeling these components was significantly improved.
Intelligent Planning for Robust Results
The team was also able to convert ALLPLAN data into 3D-printed large-scale models of the bridge and other components, providing a tangible representation of the project. Furthermore, it was possible to convert ALLPLAN models into not only truss beam elements but also frame and solid elements, facilitating complex stress structures or hydration heat analysis for mass concrete.
As part of the intelligent construction approach, ALLPLAN was combined with other technologies for intelligent processing of reinforcements, including parametric models, segmentation of bridge components for easy assembly, and automatic optimization of reinforcement cutting. All these processes were automatically transferred to the MES system, ensuring accuracy and efficiency in processing and installation.
Despite the challenges encountered during the East Lake Bridge project, the powerful modeling functions, convenient secondary development capabilities, and open data compatibility of ALLPLAN contributed to the successful application of intelligent construction techniques and the smooth completion of this project.
