The application effect of prestressed fish-belly type foundation pit steel support technology in open-excavation tunnel engineering is remarkable. The total length of the tunnel is 1244m, the excavation depth of the foundation pit is 3m to 15.4m, and the steel support consumption is about 9000 tons. Prestressed fish-belly foundation pit steel support and undisturbed soil filling concrete pile technology are adopted.
Project Overview:Total length of tunnel under Section 2 of Huzhou Inner Ring (North Line) Rapid Transformation Project1244m, foundation pit excavation depth3mto15.4m, steel support consumption about9000Tons of
Supporting form of foundation pit:Prestressed fish-belly steel bracing for foundation pit+Undisturbed soil is filled with concrete pile
Commencement Date:2020years12month01day
Project Location:The intersection of Huzhou Erhuan North Road, Light Textile Road and Qingtang Road is southwest to northeast.
The background conditions of this project are relatively complex, mainly manifested as:
1The project is located in the downtown area, high environmental requirements;
2, the surrounding environment is complex, customs warehouse, sewage plant, high voltage cable, subway planning section, etc.;
3The field investigation shows that the stratum of the proposed project is thick with silty and silty clay, and the excavation of the foundation pit is easy to lead to pit wall instability, basement uplift, soil flow, and inrush, etc.
4In order to reduce the impact on local traffic, the project time limit is strict.
In view of this situation, the project adopted the prestressed fish-belly type foundation pit steel support technology, mainly because:
1The steel support is made of standardized steel members connected by bolts, and the construction is noiseless; Components can be recycled, no construction waste generation, green environmental protection;
2High prestress can be applied to improve the strength and stiffness of the fish belly beam, effectively control the displacement of the foundation pit, protect the surrounding buildings and roads;
3The support of long-span fish belly beam makes the support and enclosing purlin form a whole through the tension of steel strand, and the force is uniform, so that the deformation of foundation pit can be controlled evenly;
Comparison of steel bracing force between traditional bracing and prestressed fish-belly bracing
4, steel components site splicing, disassembly, flexible construction; Large construction space, high efficiency, shorten the construction period.
In addition, the project from the construction scheme, quality management, personnel arrangements to do a careful design, to ensure the quality and safety of the construction.
The foundation pit of the project has now been completed45%, the construction period is shorter than expected30%The left and right sides. The project team will concentrate its efforts, continue to maintain the construction pace of high efficiency and high quality, and strive to deliver satisfactory results to Party A.
View of prestressed fish-belly foundation pit steel support construction site
Shanghai Qiangqiang Foundation Engineering Co., Ltd. has completed more than 1,000 projects in the fields of housing construction, underground space, subway, railway, highway, bridge, tunnel, airport, sea reclamation, and so on. Hundreds of projects it has participated in have won the "Luban Award of China Construction Engineering" or the "Magnolia Award of Shanghai Construction Engineering".Contact Number: 400-100-2850
