T-frame closure pouring method for long-span continuous rigid-frame bridge with high pier in mountainous area

Abstract

The invention discloses a T structure closure pouring method for a mountainous-area high-pier large-span continuous rigid-frame bridge. Before T structure closure pouring, weights are loaded at the cantilever ends of T structures to enable the cantilever ends of the two sides of T structure mid-span enclose sections to generate large longitudinal horizontal displacement towards to the two side-span directions so as to compensate shrinkage and creep and horizontal displacement generated due to later-period whole temperature reduction; the high-pier large-span characteristics are combined, adverse influence, on the continuous rigid-frame bridge internal force and deflection, of concrete shrinkage, creep and the temperature effect which are caused due to the effect of long-term load is reduced, and mid-span mid span bottom bending caused due to the influence of concrete shrinkage and creep is avoided; and weight bodies can obtain materials from local sources, pushing is not needed, simple and feasible effects are achieved, construction is convenient, safety is high, original side span cast-in-situ sections and enclose sections adopt hanging baskets for pouring till pouring is conducted to supporting seats, supporting engineering is reduced, after mid-span enclosure, in side span cast-in-situ, the whole rigidity is large, deformation control is good, and construction is easy.

Description

technical field [0001] The invention relates to a construction method of a continuous rigid-frame bridge, in particular to a T-structure closing method for a continuous rigid-frame bridge with high piers and large spans in mountainous areas. Background technique [0002] Long-span continuous rigid-frame bridge with high piers is a prestressed rigid-frame bridge with long span. In terms of force, it has similar characteristics to ordinary rigid frame bridges, but with the increase of span and pier height, it also has its own unique characteristics in force. Continuous rigid-frame bridges with high piers and large spans in mountainous areas usually adopt the side spans first and then the middle spans for closing and pouring, and the cast-in-place sections of the side spans are cast-in-place with brackets or brackets. For the construction environment of high piers and large spans in mountainous areas, it means a large amount of engineering. The risk is high and there are great...

AI Technical Summary

Problems solved by technology

Continuous rigid-frame bridges with high piers and large spans in mountainous areas usually adopt the side spans first and then the middle spans for closing and pouring, and the cast-in-place sections of the side spans are cast-in-place with brackets or brackets. For the construction environment of high piers and large spans in mountainous areas, it means a large amount of engineering. The risk is high and there are great safety hazards. Due to environmental and structural factors such as cliffs or cylindrical piers or pier body strength is not enough, it is not suitable to use floor supports and brackets, and the use of floor supports or brackets requires a large amount of work and a high risk factor ; while the side span closure section adopts the hanger, and generally adopts the counterweight; and for the closure construction of the middle span, due to concrete shrinkage, creep, temperature change, etc., some additional internal forces will be generated on the structure, especially the sensitivity to temperature is relatively high. High, during the construction process of the closing section, the actual temperature during closing may deviate from the design temperature, and the temperature difference will cause the beam body to displace, cause the main pier to produce horizontal displacement, and generate secondary stress

Similarly, shrinkage and creep in the later period will also cause vertical deflection, horizontal displacement and additional internal force of the beam body, resulting in the deviation of the main pier, affecting the beauty of the bridge and the comfort of driving, and at the same time adversely affecting the stress of the main pier influences

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