China News Service, Guangzhou, September 29 (Reporter Cai Minjie) On the 29th, at the construction site of the Guanghui Expressway reconstruction and expansion project, a smart device slowly drove to a predetermined location. After the operator presses the button, the mixing head automatically penetrates into the soft soil of the foundation and mixes the curing agent with the soil on the spot. The entire process is automatically completed by the system. This is the first large-scale application of fully automatic in-situ curing complete set of construction equipment on highways across the country.
Large-scale application of fully automatic in-situ curing intelligent construction equipment. Photo courtesy of Guangdong Communications Group
Previously, the project's first piece of shallow soft foundation solidification-in-place construction had passed uniformity and bearing capacity testing, marking a substantial step forward for this new technology.
The total length of the Guanghui Expressway reconstruction and expansion project is about 153.9 kilometers. Some sections of the shallow soft soil along the line have high moisture content and low bearing capacity, making construction organization difficult. If construction is carried out directly on it, the roadbed will continue to sink. The common methods are dredging and filling or in-situ solidification, that is, the weak soil layer is excavated and then backfilled with high-strength materials, or a curing agent is added to the soil layer to improve it.
Considering the large amount of waste along the line and the high environmental requirements, the project chose the in-situ solidification solution. However, the reinforcement effect of this process is closely related to the uniformity of the soil and groundwater conditions. Among them, whether the key parameter control is stable directly determines the reinforcement effect.
"We have introduced fully automatic, unmanned on-site solidification intelligent construction equipment, transforming the original manual judgment into intelligent control to improve the construction quality of soft foundation projects. This is the first time it has been used in the industry, and we are currently applying for a patent." Wen Jiandong, director of the Engineering Technology Department of the Guanghui Expressway Reconstruction and Expansion Project, said. This intelligent equipment configuration includes mixing machines and automatic control systems. Before construction, workers only need to input the construction scope and design parameters into the system, and the working lattice and three-dimensional trajectory can be automatically generated. Relying on Beidou Navigation's real-time dynamic differential positioning technology, the machine itself knows which point to work at and the depth to deliver the curing agent.
During construction, the equipment collects data such as rotation angle, inclination angle, pressure, and rotational speed in real time, dynamically senses the operating status, and completes walking, rotation, and mixing according to set parameters, and accurately controls the mixing depth, curing agent dosage, and mixing rate, so that the construction effect is more guaranteed. At the same time, it can also identify suspected hard objects, automatically stop, lift and provide early warning. Technicians can remotely monitor and deal with emergencies in safe areas, realizing unmanned and automatic operations.
In order to further ensure the quality of the project, the project also introduced a digital monitoring platform to completely record the implementation process of the process, so that each operation has its own "digital file".
During the operation, data such as equipment location, operation trajectory, mixing depth and speed, curing agent supply, and abnormal warnings are all written into this "file" through the digital platform. The platform then correlates and compares design parameters, execution status and job results. On this basis, technical personnel can carry out quality inspection, problem tracing and parameter optimization, forming a closed loop of construction, monitoring, early warning and archiving. Quality control will shift from post-event inspection to full-process control.
The Guanghui Expressway reconstruction and expansion project starts from Huangpu, Guangzhou, and ends in Huidong, Huizhou. Among them, the section from Xiaojinkou to Luogang was expanded from two-way six lanes to two-way ten lanes, and the section from Xiaojinkou to Lingkeng was expanded from two-way four lanes to two-way eight lanes. After the project is completed, it will strengthen the Guangdong-Hong Kong-Macao Greater Bay Area's ability to radiate and drive the eastern Guangdong region, and provide important transportation support for Guangdong's "millions of projects" and high-quality regional development. (over)
