Support-free and opposite pull rod combination construction method for concrete triangular rigid frame in consideration of restraint action of inclined legs

Abstract

The invention discloses a support-free and opposite pull rod combination construction method for a concrete triangular rigid frame in consideration of a restraint action of inclined legs. The method is mainly characterized in that firstly, the inclined legs on two sides provide counter force for each other by using opposite pull rods, are balanced mutually and are poured in a layered way, so that the distribution of a complicated huge support system below the inclined legs is avoided; secondly, a main longitudinal beam support between the inclined legs is supported on the inclined legs, an arch seat or a carrying platform, and a main longitudinal beam support outside the inclined legs is supported on a supporting layer, so that the consumption of a driven precast pile or a cast-in-situ bored pile can be reduced to the greatest extent, the construction period can be shortened, and the cost is reduced; thirdly, a simple computation method for an effective pre-stress value which actually acts on the main longitudinal beam when a pre-stressed tendon of the main longitudinal beam of the triangular rigid frame is tensioned is provided, the restraint action of the inclined legs is taken into full consideration, a pouring mode of the main longitudinal beam can be determined by simple computation, and a guiding significance is provided for design and construction.

Description

technical field [0001] The invention relates to the field of bridge engineering construction, in particular to a combined construction method of a concrete triangular rigid frame with few supports and paired tie rods considering the restraint effect of oblique legs. Background technique [0002] Concrete triangular rigid frames are widely used, such as mid-supporting arch bridges, V-shaped rigid frame bridges, partial beam-arch composite bridges, etc. During construction, most of them need to form a stable triangular rigid structure first, and then carry out the construction of other parts, which is very critical in some bridges. The construction progress, quality, and safety of the triangular rigid frame have a profound impact on the entire bridge. However, there are two main problems in the construction of triangular rigid frames: [0003] (1) Traditional construction methods are expensive, slow in progress, and difficult to control in quality and safety. [0004] The t...

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Problems solved by technology

[0003] (1) Traditional construction methods are expensive, slow progress, difficult to control quality and safety

[0004] The traditional construction technology usually adopts the full support method. Due to the existence of "V" shaped oblique legs, the support system is complex and huge, the construction period is long, and the cost is high. If the details are not carefully considered, it may cause instability and collapse, resulting in unpredictable Similar accidents are not uncommon; in addition, the support system has certain requirements on geological conditions, which are greatly affected by geological conditions or water level depths. It is often difficult to drive in sufficient depth with prefabricated piles, resulting in insufficient friction or end bearing force. Larger settlements will cause quality and safety accidents. If bored piles are used, the cost will be high and the economy will be lost; moreover, the support system needs heavy preloading, which is expensive and takes a long time; finally, the deformation of the support system is difficult to estimate. In the finite element calculation, the boundary conditions cannot be simulated well, so it also brings difficulties to the calculation and analysis

[0005] (2) Part of the design and construction is not considered, ignoring the restraint of the oblique legs, and insufficient understanding of whether the main longitudinal beam is constructed in sections

However, due to the formation of the triangular rigid structure, the oblique legs will "offset" part of the load, and the prestress of the main girder is actually difficult to be fully and effectively applied to the main girder, and it will change the force of the oblique legs. Without detailed calculation and judgment , could have serious consequences

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