"Subgrade bearing capacity: 150 kPa (standard: 100 kPa), permeability coefficient of 10 to the minus 5th power...... Meets the standards for silt solidification subgrade. On the morning of March 17, in the Hetang section of the Yuhuan Urban Connection Line Project of Provincial Highway 226, after the on-site inspection of the expert group, the new process of in-situ solidification and repair of silt was unanimously recognized by experts, and this new process was in the forefront of Zhejiang Province.
It is understood that the silt in-situ solidification and remediation process refers to the injection of a special ratio of soil solidifier into the soft soil, so that the silt under the soft soil can be quickly dehydrated and solidified in situ to form a composite and stable base layer, so as to achieve the effect of silt in-situ solidification and repair, which is not only environmentally friendly, but also reduces costs and improves efficiency.
At the scene, the reporter saw that the construction section was undergoing double-width operation: on one side was the newly completed brand-new roadbed, with a smooth and hard surface; On the other side, an excavator is "loosening" the soft foundation, while the other excavator is injecting a curing agent into the sludge under the soft foundation by manipulating a powerful mixing head.
"This area was originally a fish pond, and after we drained the water in the fish pond, we went through the in-situ solidification and repair process, and now it has reached the hardening standard, saving more than 30 million yuan in cost."
In terms of materials, according to the original process, the soft foundation should be backfilled with gravel, and now the silt reclaimed by the tidal flat is directly solidified in situ, breaking through the material limitations and reducing the use of mineral resources.
It is worth mentioning that such a "big project" is also very economical in terms of labor and time. "One day, we can complete 3,000 cubic meters with a team of 3 people, even if it rains lightly, we can continue to construct as usual, and the roadbed can walk normally after 7 days." Zhang Hengxu said that according to the traditional process, it takes at least 6 to 8 months to settle, and then backfill, which takes at least 10 months to a year.
At present, the process is not only piloted in the construction project of S226 Provincial Highway Yuhuan Urban Connection, but also in the road construction and sewer pipe gallery curing support project of Yuhuan Ganjiang Bingang Industrial City, the construction project of Yuhuan Digital Economy Industrial Park in Nanwan Zhigu ·, the road construction project of Donghai Avenue in Yuhuan City, a first-class highway, and the roadbed construction project of Toumengang Industrial Park, and the ecological restoration project of infrastructure and environment improvement of the eastern coastline of Tianjin Dongjiang, and other key projects inside and outside the province, and the results are obvious.
Experts said that the silt in-situ solidification repair process is a technological innovation in the field of subgrade construction, especially now the country advocates the concept of "no solid waste" city, this new process in terms of green and environmental protection, embodies the concept of renewable utilization of resources, and has great promotion significance in the southeast of Zhejiang.
"Originally, it was also very costly to transport the silt waste soil to the concentration point for unified incineration and landfill, as well as soft foundation treatment and reinforcement. Now, through in-situ curing technology, waste soil is used as roadbed filler, which can be said to be 'turning waste into treasure' and achieving the purpose of environmental protection. Zhang Liqi, director of Taizhou Traffic Engineering Management Center, said.
It is reported that the process can also be widely used in the grassroots construction of new (reconstructed) highways, airports, tunnels, bridges, and heavy factory projects, and has a wide range of application prospects in municipal, transportation, water conservancy and other projects.
