A prestressed design method for the anchorage area of ​​concrete towers of cable-stayed bridges

Abstract

The invention relates to a prestress design method for a concrete cable tower anchorage area of ​​a cable-stayed bridge, belonging to the field of prestress design for the cable tower anchorage area. The present invention comprises the following steps: Step 1: Determine the thickness-to-width ratio λ of the front wall of the cable tower; Step 2: Select the cable tower pull-strut model to be adopted according to the λ value, and calculate the geometric parameters; Step 3: Solve the maximum tie rod Internal force; Step 4: Calculate the required number of prestressed tendons according to the maximum internal force of the tie rods; Step 5: Arrange the prestressed tendons according to the direction of the tie rods in the model. The invention can be used for the quantitative design of the prestress in the anchorage area of ​​the cable tower, and proposes a tension-compression bar model in the anchorage area of ​​the cable tower with clear geometric parameters that can be directly used by engineers. The invention has strong versatility, high design efficiency, clear mechanics concept and high calculation accuracy, and avoids the blindness and low efficiency of relying on the experience of designers and a large number of trial calculations in the design of traditional cable tower anchorage areas.

Description

technical field [0001] The invention relates to a prestress design method for a concrete cable tower anchorage area of ​​a cable-stayed bridge, belonging to the field of prestress design for the cable tower anchorage area. Background technique [0002] The cable tower anchorage area is a key part of the cable-stayed bridge structure. Its complex structure, local stress concentration, and difficult design and construction have always been one of the key issues of bridge engineers. The concrete cable tower with box-section in the form of side wall anchorage, the huge cable force of the cable stays acts on the tower column, the vertical component is transmitted to the tower body through the anchor block, and the huge horizontal component acts on the relatively weak On the side wall of the tower column, the concrete of the tower wall and the structural steel bars arranged in it cannot bear it. Therefore, horizontal prestressed tendons must be set in the anchorage area to bear th...

AI Technical Summary

Problems solved by technology

This method has sufficient accuracy and is easy to apply in engineering. It is a low-cost and high-efficiency method to guide the design and optimization of the anchorage area of ​​the cable tower.

However, most of the published studies so far only focus on a specific case, which is not universally applicable, and this method requires the designer to have the basis of topology optimization, which limits its wide application. Compression bar model and prestressed structure analysis, Zhu Jingwei et al., Bridge Construction, 2017, vol.(05), pp.59-64" disclosed method

Document 2 "Research on key issues of prestressed concrete towers of long-span cable-stayed bridges, Tao Qiyu, Southwest Jiaotong University, 2012" proposed a prestressed quantitative design calculation formula based on the tension-compression bar model, but it is relatively rough, and the relationship between parameters is not good. It is clear that the calculation accuracy is low, and the tension-compression model that is convenient for engineering application is not given, and the position design of the prestressed tendons cannot be realized, which makes the designer fall into a "black box" operation, and loses the tension-compression model to reveal the internal transmission of the structure. The superiority of the force mechanism

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