Construction method of lowering double-wall special-shaped steel cofferdam

Abstract

The invention relates to a construction method for lowering a double-wall special-shaped steel cofferdam, and belongs to the technical field of steel cofferdam construction. The invention provides a construction method for lowering large-scale double-walled special-shaped steel cofferdams suitable for complex hydrological conditions, adopting the construction technology of piles first and then weirs, and adopting double-wall special-shaped steel cofferdam structures at the same time, and the bottom elevation of the steel cofferdams According to the topography of the bottom of the river bed, special-shaped structures are used for matching. Supporting corbels are fixed on the outer wall of the supporting piles, and the supporting corbels are used as the assembly platform for the first segment of the steel cofferdam. The steel cofferdam adopts a diamond hanger system and a continuous jack. Decentralization can meet the decentralization requirements of large steel cofferdams under complex hydrological conditions, greatly increasing the safety factor of the system; at the same time, a positioning system is installed to ensure accurate devolution of steel cofferdams. The invention not only has the advantages of improved construction period, simple operation, cost saving and high safety, but also enriches the new technology of steel cofferdam construction.

Description

technical field [0001] The invention relates to a construction method for lowering a double-wall special-shaped steel cofferdam, and belongs to the technical field of steel cofferdam construction. Background technique [0002] In the field of infrastructure construction such as buildings and bridges, steel cofferdams, as a temporary maintenance structure, play an important role in preventing water and soil from entering the interior of the cofferdam and excavating foundation pits. The steel structure has many advantages, which promote the wider application of the steel box cofferdam. The commonly used steel cofferdams usually include single-wall steel cofferdams and double-wall steel cofferdams. Under complex hydrological conditions, the structural rigidity and safety of single-wall steel cofferdams are difficult to guarantee, so double-wall steel cofferdams have been more widely used in large bridge construction. At the same time, under complex hydrological conditions, the...

AI Technical Summary

Problems solved by technology

The advantage of this solution is that the processing efficiency is high, and the damage to the steel cofferdam wall can be avoided by cutting. Under the environment, the horizontal load is reduced, and the safety is difficult to guarantee

Patent Publication No. CN107761751A discloses "A Double-walled Steel Cofferdam and Its Construction Method". By setting pulling lugs on the outer wall, the cables exert tension on the double-walled steel cofferdam from multiple points to limit the steel cofferdam. The movement of the weir after launching improves the construction accuracy of the steel cofferdam; however, this method of positioning using a hoist increases the number of operating steps in the lowering process, occupies limited operating space, and increases the overall cost of construction

Patent Publication No. CN107237338A discloses "Double-wall steel cofferdam block-by-block construction method". First, the construction of the island cofferdam is carried out, and then the cofferdam foundation pit is cut out, and then the base is leveled and the steel cofferdam is hoisted; the method passes The steel cofferdam with a special structure of male and female locks is used for construction to ensure the tightness and accuracy of the connection, but this method is not suitable for the construction method of piles first and then the cofferdam, especially the impact of water flow cannot be considered

Patent Publication No. CN107288140A discloses "Construction Device and Construction Method for Active Sinking and Correction of Steel Cofferdam", which forces the steel cofferdam to actively sink by tightening the tie rods to increase the pressure, reduces the amount of mud suction, and speeds up the construction period. However, this method It is not suitable for large-scale cofferdams, because more tie rods need to be added and more jacks must be installed at the same time, which is difficult to implement in terms of increased cost and lifting effect

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