Anchor device of first sliding and then fixing type combined steel anchor boxes of cable stayed bridge and construction method thereof

Abstract

The invention discloses an anchor device of first sliding and then fixing type combined steel anchor boxes of a cable stayed bridge and a construction method thereof. The anchor device comprises multiple anchor box segments continuously arranged in the vertical direction, wherein each anchor box segment is provided with an anchor box side pulling plate, a bolting end and a fixed end; the anchor box side pulling plate is positioned in the middle; the bolting end and the fixed end are respectively arranged at the left and right ends of the anchor box side pulling plate; the bolting ends and fixed ends in the adjacent anchor box segments in the vertical direction are arranged in a staggered manner; sliding pairs are arranged between the bolting ends and fixed ends in the adjacent anchor box segments in the vertical direction; and both the bolting ends and fixed ends of the anchor box segments are provided with connection structures combined with concrete in the tower wall of a cable stayed bridge tower. The device can give full play to the tensile strength of anchor box steel, simultaneously avoids transferring excessive horizontal pull to the tower wall, avoids that the steel anchor boxes prevent contraction of the tower wall, and avoids that the concrete tower wall is unilaterally stressed when the stay cables are replaced or broken. The invention also provides a construction method of the anchor device.

Description

technical field [0001] The invention relates to an anchoring structure of an anchor box of a cable-stayed bridge and a construction method thereof, in particular to an anchoring device of a combined steel anchor box of a cable-stayed bridge that slides first and then solidifies and a construction method thereof. Background technique [0002] The cable anchorage structure of the cable tower is an important force-bearing structure that safely and evenly transmits the local concentrated force of a cable stay to the tower column. For long-span cable-stayed bridges, there are mainly three anchoring methods: tooth block plus tower wall prestressed anchorage, steel anchor box anchorage and steel anchor beam anchorage (there is generally no prestressed anchorage in the tower wall when the steel anchor box and steel anchor beam are anchored). stress). The tooth block plus prestressed anchor generally adopts the "U" shaped prestressed beam or "well" shaped prestressed beam, and the p...

AI Technical Summary

Problems solved by technology

The tooth block plus prestressed anchor generally adopts the "U" shaped prestressed beam or "well" shaped prestressed beam, and the prestressed force is applied to ensure that the concrete tower wall does not crack. The tower is small, with a large space for jacking in the tower, but there are many anchoring tooth plates in the tower, the construction is cumbersome, the positioning accuracy and quality of the cable anchor pipes are difficult to control, the steel bars in the cables and prestressed tooth plates are dense, and the concrete is difficult to compact. Larger; the bending radius of the hoop prestressed bundle is small, the loss of prestress is large, the number of bundles is large, and there are many vertical and horizontal steel bars cut at the anchor notch, which is unfavorable for resistance; and all processes require on-site high-altitude operations, and the overall construction Quality is not easy to guarantee

The steel anchor box is manufactured in the factory, and the position of the anchor point and the angle of the anchor pipe are easy to control; the disadvantage is that the horizontal force of the cable must be borne by the tower wall and the steel anchor box, and the steel anchor box prevents the contraction of the tower wall, causing the tower wall to collapse. The horizontal force shared by the wall is enough to crack the concrete. If prestressing is used to prevent the tower wall from cracking, the steel anchor box prevents the application of prestress, and the steel anchor box only bears a small part of the horizontal force of the stay cable, which cannot exert the steel anchor box. Tensile properties of the anchor box

The main advantages of the steel anchor beam anchorage structure are: the horizontal force of the cable is basically only borne by the steel anchor beam during the operation stage, the tensile stress of the concrete tower wall is small, and the force is clear; The horizontal force of the cable is only borne by the tower wall on one side corresponding to a single steel anchor beam. At this time, the concrete of the tower wall will crack. , the positioning accuracy of the cable anchor points and anchor pipes is also difficult to control, the construction is cumbersome, and the space construction is difficult

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