Tension construction method of steel strand cable with anti-skid key as locking device

Abstract

The invention discloses a steel strand inhaul cable tension construction method by taking a slip-resistant stud as a locking device. When one side, with the slip-resistant stud, of each steel strand is tensioned, the side, without the slip-resistant stud, of the steel strand is tensioned as well, the tensioning force applied on the side with the slip-resistant stud is always kept larger than that applied on the side without the slip-resistant stud, and the difference between the tensioning force on the two sides is as 1-2 times as actually measured frictional resistance; when the side, with the slip-resistant stud, of each steel strand is tensioned to reach monitored target cable tensioning force fc, anchoring is performed firstly, the tensioning force fk of the side, without the slip-resistant stud, of the steel strand is decreased to target cable tensioning force, and then anchoring is performed again to finish the tension construction of the steel strand inhaul cable. The steel strand inhaul cable tension construction method by taking the slip-resistant stud as the locking device has the advantages that a mounting method is optimized, cable force, on two outer sides of a tower column, of each steel strand is enabled to be identical, the slip-resistant stud is enabled to be tightly attached to the tower column and to be provided with enough pressure storage, internal force, on two sides of the tower column, of each steel strand is enabled to be identical, safety of the integral inhaul cable is improved, locking force of the slip-resistant stud is more reliable, on-site construction is facilitated and less prone to going wrong, and ultra-tensioning-force is prevented from affecting the integral structure largely.

Description

technical field [0001] The invention relates to the technical field of cable-stayed bridge cable construction, in particular to a steel strand cable tensioning construction method using an anti-skid key as a locking device. Background technique [0002] Tower-through steel strand cable-stayed cables are mainly used in short-tower cable-stayed bridges. The concept of this type of bridge was proposed by the Frenchman JacguesMathivat. Japan built the world's first low tower cable-stayed bridge. So far, Japan is the country that has built the most bridges of this type. Since 2000, China has successively built the Wuhu Yangtze River Bridge and the Zhangzhou War Preparation Bridge in Fujian, accumulating a certain amount of design experience. [0003] saddle (such as figure 1 (shown) is the key structure of the tower column of the cable-stayed bridge with short towers. Its basic function is to allow the stay cables to pass through the tower column in an uninterrupted manner, and...

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Problems solved by technology

[0004] Among them, the article "Cable Cable Design of Main Bridge of Zhangzhou War Preparedness Bridge" published in "Bridge Construction" No. 1, 2002 discusses the relevant double casing structure (such as figure 2 As shown), the shortcomings were found in the application: 1) Due to the processing deviation and deformation after operation, it is difficult to replace the inner pipe of the saddle; 2) The contact surface between the double sleeves is narrow and the stress concentration under the tube is serious; 3) The double sleeves The gap between the pipes is narrow so that the grout is not compacted and the mortar body is cracked and damaged

[0006] However, some problems are also exposed after the anchor tube is used: 1) The mortar in the tube is bonded to the exposed steel strand, and the cable system cannot replace a single steel strand, which is not economical; 2) The anchor tube transmits the unbalanced force to the tower column through the anchor plate at the end of the saddle, so that the surface area of ​​the tower column is locally tensioned, and there is a pulling fatigue effect in the anchorage between the anchor plate and the tower column; The torsion makes the cable appear a small corner near the tower column, and the anchor tube restricts the free rotation of the cable. The joint between the anchor tube and the anchor plate, and the anchor structure of the anchor plate and the tower column will all suffer from bending fatigue effect.

From a certain section of the whole bundle of cables (except the saddle and the anti-skid key), the tension of each steel strand is different, and the on-site operation is prone to errors, and it is difficult for the construction monitoring personnel to determine whether the deviation of the whole bundle of cable force meets the requirements

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