Construction method of pouring concrete beams layer by layer on soft ground

Abstract

The invention relates to the field of bridge and culvert engineering in the transportation industry, and specifically discloses a construction method for layered pouring of concrete beams on soft ground. This construction method is based on the theory of elastic mechanics, deduces the stress function of the first layer concrete beam during the second layer concrete pouring process, and determines the first layer concrete beam according to the compressive strength test value of the same batch of concrete cube test blocks of the first layer concrete beam The elastic coefficient of the composite foundation under the stress safety condition. According to the elastic coefficient of the composite foundation, the elastic coefficient of the composite foundation is changed to a reasonable and safe range by partial replacement or direct grouting, thereby forming a safer composite foundation to improve its stability. This method can effectively guide the construction of layered concrete beams under soft foundations, and is beneficial to control the early strain of the beams and reduce the late creep, thereby reducing the probability of cracks in the concrete. It will also be more applicable in practice.

Description

technical field [0001] The invention relates to the field of bridge and culvert engineering in the transportation industry, in particular to a construction method for layered pouring of concrete beams on soft ground. Background technique [0002] Concrete bridges are widely used in bridge construction due to their good mechanical performance, serviceability and construction maturity. Most of the concrete beams are not casted in one time, especially the concrete beams with high beam height or complex detailed structure, generally need to be poured multiple times. For cast-in-place brackets, especially for concrete beams that are supported by full brackets and cast in layers, there are many reasons such as poor shrinkage of layered concrete, settlement of brackets, concrete hydration temperature drop, construction technology, etc. Cracks in the concrete will accelerate the carbonation of the concrete and reduce the corrosion resistance of the structure, and eventually reduce ...

AI Technical Summary

Problems solved by technology

For cast-in-place brackets, especially for concrete beams that are supported by full brackets and cast in layers, there are many reasons such as poor shrinkage of layered concrete, settlement of brackets, concrete hydration temperature drop, construction technology, etc. Cracks in the concrete will accelerate the carbonation of the concrete and reduce the corrosion resistance of the structure, and eventually reduce the strength and stability of the bridge structure and buildings, thereby reducing the service life of the structure and seriously affecting the safety and durability of the concrete. sex

However, for concrete beams cast in layers on soft foundations, there are often concrete cracks caused by excessive stress in the early pouring beams, causing safety and durability problems. Soft soil foundations mainly refer to deposits in still water or slow flowing water It is a kind of saturated cohesive soil in soft plastic to flow plastic state, which has high natural water content, high compressibility, low bearing capacity and poor water permeability.

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