Screw axial force construction method for cable clamp of suspension bridge

Abstract

The invention discloses a screw axial force construction method for a cable clamp of a suspension bridge and relates to the field of bridge engineering construction. The screw axial force construction method comprises the steps that the spreading time t0 of ultrasound in to-be-mounted screws under the non-stress state in the axial direction is measured, and a spanner is used manually to screw the screws and nuts; jacks are used for tensioning the screws to 60% of designed construction axial force Fn, the spanner is used manually to screw the nuts, and the jacks are dismounted; the spreading time t1 of the ultrasound inside the screws under the current stress state in the axial direction is measured, the current temperatures T of the screws are measured, and the current axial force F1 of the screws is calculated according to a formula, specifically, the rotating angle theta of the nuts relative to the screws when the axial force of the screws is between the current axial force F1 and the designed construction axial force Fn is calculated according to a formula; and the jacks are used for tensioning the screws to 110% of the design construction axial force Fn, the nuts are screwed by the angle theta in the screwing direction, and the jacks are dismounted. The screw axial force of the cable clamp can well meet the design construction requirement, axial force inspection after construction is facilitated, the cable clamp is prevented from sliding after being mounted, and the safety of a bridge in use is improved.

Description

technical field [0001] The invention relates to the field of bridge engineering construction, in particular to a cable clamp screw axial force construction method for a suspension bridge. Background technique [0002] The cable clamp of the suspension bridge is one of the main components of the superstructure of the suspension bridge. The main defect in the use process is that the cable clamp slips on the main cable. The reason is that the tightening force of the cable clamp screw is insufficient. ) Article 3.3.9 requires inspection of "whether the upper end of the suspender rod of the suspension bridge and the cable clamp of the main cable are loose, displaced and damaged". for serious defects. [0003] During the actual construction of the cable clamp screw rod at present, the screw rod is preliminarily tightened by the worker with a long wrench, then the hydraulic jack is used to stretch it to the construction axial force, and then the worker tightens it with a short wre...

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Problems solved by technology

[0004] However, it is difficult to accurately control the stress of the hydraulic jack to be consistent each time during on-site construction, and the one-time tension of the jack will lead to uneven stress redistribution of the structure; The torque coefficient during tightening is quite different, and the retraction of the nut after the construction is completed will also cause a large stress loss, which makes it difficult to accurately control the axial force tightening construction of the cable clamp screw; and after the construction is completed, the axial force of the screw is also Failure to conduct accurate and efficient inspections in time makes the cable clamps prone to slippage during use, which brings hidden dangers to the normal operation of the bridge

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