Deepwater steep fluctuating rock surface steel cofferdam construction process

Abstract

The invention relates to a deepwater steep fluctuating rock surface steel cofferdam construction process. The deepwater steep fluctuating rock surface steel cofferdam construction process comprises the following construction steps that 1, a foundation trench is excavated in a deepwater steep rock surface; 2, drilling piles are constructed in the foundation trench at intervals; 3, a steel cofferdam is accurately lowered into the foundation trench; 4, gravels are filled on the outer side slope of the foundation trench; 5, stiffening section steel is placed in the drilled piles, and concrete is poured into the sandwich walls of the steel cofferdam; 6, a steel casing is lowered, bottom sealing concrete is poured, and a cast-in-place pile is constructed; and 7, water is pumped in the cofferdam and the steel casing is cut off. According to the deepwater steep fluctuating rock surface steel cofferdam construction process, the foundation trench is adopted for fixing the steel cofferdam, leakage during concrete pouring of the compartments of the cofferdam is avoided through filling the gravels in the outer side slope of the foundation trench, connection between the steel cofferdam and a riverbed is enhanced through the drilled piles arranged in the foundation trench at intervals, the pouring amount of bottom sealing layer concrete can be effectively reduced, and the situation that the anti-buoyancy force of the steel cofferdam cannot meet the design requirement is avoided.

Description

technical field [0001] The invention relates to the technical field of bridge construction, in particular to a construction technique for a steel cofferdam on steep and undulating rock faces in deep water. Background technique [0002] At present, large-scale steel cofferdams have been widely used in the construction of deep-water bridge projects, but when they are applied to deep-water steep rock surfaces without overburden layers, the location of the cofferdam sinking is not accurate, and the cofferdams are prone to slipping under external forces. There is a large gap between the bottom and the rock surface, which causes technical problems such as poor pouring of the back cover concrete, which makes the construction of the bridge foundation engineering more difficult, the risk factor increases, and the influence of the depth and flow velocity of the river increases, and the construction quality cannot be guaranteed. [0003] In order to solve the technical problems existin...

AI Technical Summary

Problems solved by technology

Due to the relatively undulating rock surface of the river bed and no covering layer, it is difficult to locate the occlusal pile drilling, and the position accuracy of the top of the pile is relatively small. After the steel cofferdam sinks, it cannot be guaranteed that the stiffening steel is exactly inside the steel cofferdam; The innovation is to take advantage of the better leakage resistance of the occlusal piles. If the pore forming accuracy of the occlusal piles is poor, there may be gaps between the piles, and the permeability resistance will be greatly reduced; since the concrete surface after pouring is still There is a phenomenon of unevenness, which makes the concrete leak under the impact of the river water when the sandwich wall concrete is poured

Images