Joist type cable arch bridge structure and its construction method

Abstract

A truss-type cable arch bridge structure is provided, whose last quarter main arch ring is composed of a plurality of arch steel pipes of the inner injecting concrete or the steel pipe to form the concrete truss-type main arch ring. The steel pipe concrete column is tightly fixed on the lower node of the last quarter main arch ring, while the upper end of the steel pipe concrete column is tightly fixed on the node of the first quarter driveway beam. The two ends of the inclined dragline equipped with an adjustable anchor nip are respectively fixed on the upper node and the lower node of the steel pipe concrete column adjoint the upper node. The construction method is that, the inclined dragline with the adjustable anchor nip is used to hoist the concrete truss-type main arch ring of the first unit, the steel pipe concrete column and the driveway beam from the bridge abutment on the two banks, and combined together; then to hoist the second unit, and the like, till the arch bridge folds, concrete is poured into each arch steel pipe or the steel box spar frame from the lower end; after forming a bridge, the inclined dragline at each node is adjusted for uniform stress on the entire arch. The invention can exert the cooperating combination, complementary advantages of different materials for the high strength steel cable, the steels and concrete etc, which is applicable for large span building the bridge in the V-shape valley of the a mountainous area.

Description

technical field [0001] The invention relates to an arch bridge structure and a construction method, in particular to a truss-type cable-arch bridge structure and a construction method suitable for inconvenient and difficult transportation conditions such as steep mountainous areas and V-shaped valley terrains. Background technique [0002] From the ancient stone arch bridge in my country --- Zhaozhou Bridge to the reinforced concrete arch bridge in the 20th century, it has gone through a thousand years of development. The cast-in-place reinforced concrete arch bridge needs to be made on site, which is only suitable for small arch bridges; Concrete arch bridges have gone through three stages of development: box arch, steel pipe concrete arch and truss composite arch. [0003] 1. Prefabricated thin-walled box-shaped concrete arch bridges—Before the 1990s, long-span arch bridges in mountainous areas in my country mostly used prefabricated thin-walled box-shaped arch bridges. It...

AI Technical Summary

Problems solved by technology

It is divided into 3-7 sections vertically, each section weighs 40-60t, and cable cranes are often used for erection. The installation of 200-500t of equipment and the erection of arch ribs take up to one year; A large amount of manpower is used, which increases the project cost. In addition, the mountainous terrain is steep, and there is no place for prefabrication and hoisting of long components, so that the maximum span of the box arch bridge stays at the level of L<150m

[0004] 2. Steel pipe concrete arch bridge--In 1990, Sichuan Wangcang Bridge built a steel pipe concrete arch. Its lower chord main arch ring is an arched steel pipe with concrete injected inside. Due to the light weight of the steel pipe, it can be used as both a support and a formwork. Great convenience Therefore, it has promoted the rapid development of long-span arch bridges in China. At present, the largest span is Wushan Bridge in Sichuan, which has reached 460m; According to the requirements, the large-scale cable crane equipment used in it uses as much as 500-800t of steel, and the construction facilities such as cables and buckle frames must be removed after the main arch ring is closed, resulting in high costs. Except for professional teams, general construction It is difficult for units to complete the construction task of long-span concrete-filled steel pipe arch bridges

However, after 20 years of operation practice, the weakness of the reinforced concrete material used in the truss composite arch has gradually been exposed; for example, the truss joints and the post-cast part of the main arch ring have cracks to varying degrees under repeated loads, which affects durability In addition, when the span increases, the weight of reinforced concrete prefabricated components is too large, which brings many technical difficulties to demoulding, moving, turning over, and hoisting

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