CN-116479770-B - Main tower vertical rotation method of single-tower double-layer steel truss cable-stayed bridge

CN116479770BCN 116479770 BCN116479770 BCN 116479770BCN-116479770-B

Abstract

The invention relates to the technical field of main tower vertical rotation of a cable-stayed bridge, and discloses a main tower vertical rotation method of a single-tower double-layer steel truss cable-stayed bridge, which is characterized by comprising the following steps of S1, erecting a temporary assembly platform on a bridge deck, wherein the main tower structure assembly is 5 degrees with the bridge deck, and completing integral assembly on the bridge deck; S2, assemble vice tower, installation both sides cage, depression bar, flexible pull rod, cable anchor point, back of the body cable anchor point, steel strand wires jack etc. with vice tower door frame installation on the main tower, set up the front anchor point on the main tower, set up the back anchor point on the bridge floor, set up the main tower and assemble at the bridge floor, construction conditions is better, welding quality is easier to control, shorten main tower installation time by a wide margin, saved temporary equipment input, construction machinery cost greatly reduced, the structure safety is easier ensured, main tower structure is assembled and is 5 with the bridge floor simultaneously, like this is easier pulling than direct horizontal direction.

Inventors

ZHENG MINGJUN
CHEN JIANWEI
XUE WEN
SHI LEI
XIE BO
ZHU YIMIN
XU YIFAN
WANG GAOKE
YU HAIWEI

Assignees

宁波通途投资开发有限公司
宁波城建投资控股有限公司
宁波市城建设计研究院有限公司
宁波市基础设施运营管理有限公司

Dates

Publication Date: 20260508
Application Date: 20230418

Claims (1)

1. The main tower vertical rotation method of the single-tower double-layer steel truss cable-stayed bridge is characterized by comprising the following steps of: s1, erecting a temporary assembly platform on a bridge deck, and assembling a main tower structure to form 5 degrees with the bridge deck, so as to complete integral assembly on the bridge deck; S2, assembling an auxiliary tower, mounting hanging cages, compression rods, flexible pull rods, stay rope anchor points, back rope anchor points and steel strand jacks on two sides, mounting an auxiliary tower door frame on a main tower, wherein a front pull anchor point is arranged on the main tower, and a rear pull anchor point is arranged on a bridge deck; S3, threading steel strands through the steel strand traction cable and the back cable, synchronously pre-tightening the steel strand traction cable and the steel strand pull rod steel strands, pre-tightening each steel strand of the steel strand pull rod by about 1t, and enabling the lengths of the steel strands to be equal; S4, noticing weather conditions in advance, preparing for vertical rotation, and selecting windless weather for vertical rotation; s5, pre-tensioning the anchor cable to enable the auxiliary tower to be tensioned to form a stable triangular structure, removing the compression bar assembly bracket, then debugging the synchronous vertical rotation system equipment of the steel strand jack, and then testing vertical rotation; S6, the front end of the main tower is separated from the assembly platform by about 5cm, is statically observed for about 1 hour, and is inspected for a temporary vertical rotation structure, a stable rope system, a vertical rotation system, a foundation, a hanging point and a bottom hinge point, and the formal vertical rotation is started on the premise of confirming the absolute safety of the whole vertical rotation working condition S7, gradually tensioning the anchor cable by using a continuous steel strand jack to enable the main tower to vertically rotate, monitoring each structure while vertically rotating, closely monitoring the tension force of the traction cable in the rotation process when the main tower vertically rotates to 45 degrees, and if the cable force of a single steel strand is smaller than 4t, stopping rotation operation in time and reporting to a commander; S8, turning the main tower to a 60-degree state, suspending traction of the turning, tensioning the back rope, turning the main tower to a 75-degree state, and adjusting the back rope to a specified rope force; S9, vertically rotating the main tower to a position close to a design position, measuring and controlling, slowing down the vertical rotation speed, finely adjusting the main tower in the vertical direction, accurately positioning, welding a main tower opposite interface, and dismantling a rotating body structure to finish the rotating body of the main tower; The pre-tensioned anchor cables are loaded step by using continuous jacks, synchronization is kept, the pre-tensioned difference value among the jacks cannot exceed 10t, the anchor cables are tensioned step by step, each anchor cable is pre-tensioned by 350t, and the total of four anchor cables is pre-tensioned by 1400t; In the step S2, the guy anchor points are divided into a front anchor and a rear anchor, the front anchor is a pretension anchor point and consists of a special tensioning steel strand, a front anchor ear plate and tensioning slings, 2 tensioning anchor points are correspondingly arranged on one side of the main tower respectively, and 2 tensioning slings are adopted for the single tensioning anchor point; In the step S2, the auxiliary tower door frame vertical column adopts a round pipe of P420x16, and the transverse web member is P180x6.

Description

Main tower vertical rotation method of single-tower double-layer steel truss cable-stayed bridge Technical Field The invention relates to the technical field of main tower vertical rotation of cable-stayed bridges, in particular to a main tower vertical rotation method of a single-tower double-layer steel truss cable-stayed bridge. Background Over the years, new technologies, new materials, new technologies have emerged. Bridges of various new structures are also constantly emerging. For the vertical rotation method of the main tower of the cable-stayed bridge, most of the methods are completed by adopting a cut-off assembly construction method. The method saves a large number of special mechanical equipment, but has a plurality of defects, namely high temporary support requirement, high temporary support installation height, large consumption, large risk hidden danger, long construction period, difficult control of welding quality, difficult linear control, more uncertain factors and the like, high-altitude welding risk, difficult control of welding quality, large welding task amount, difficult control of high-altitude installation operation precision and longer construction period. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention provides a main tower vertical rotation method of a single-tower double-layer steel truss cable-stayed bridge, which solves the problems proposed by the background art. (II) technical scheme In order to achieve the purpose, the invention provides the technical scheme that the main tower vertical rotation method of the single-tower double-layer steel truss cable-stayed bridge is characterized by comprising the following steps of: s1, erecting a temporary assembly platform on a bridge deck, and assembling a main tower structure to form 5 degrees with the bridge deck, so as to complete integral assembly on the bridge deck; s2, assembling an auxiliary tower, mounting hanging cages, compression rods, flexible pull rods, stay rope anchor points, back rope anchor points, steel strand jacks and the like on two sides, mounting an auxiliary tower door frame on a main tower, arranging a front pull anchor point on the main tower, and arranging a rear pull anchor point on a bridge deck; S3, threading steel strands through the steel strand traction cable and the back cable, synchronously pre-tightening the steel strand traction cable and the steel strand pull rod steel strands, pre-tightening each steel strand of the steel strand pull rod by about 1t, and enabling the lengths of the steel strands to be equal; S4, noticing weather conditions in advance, preparing for vertical rotation, and selecting windless (or wind speed is less than four levels) weather for vertical rotation; s5, pre-tensioning the anchor cable to enable the auxiliary tower to be tensioned to form a stable triangular structure, removing the compression bar assembly bracket, then debugging the synchronous vertical rotation system equipment of the steel strand jack, and then testing vertical rotation; S6, the front end of the main tower is separated from the assembly platform by about 5cm, is statically observed for about 1 hour, and is inspected for a temporary vertical rotation structure, a stable rope system, a vertical rotation system, a foundation, a hanging point, a bottom hinge point and the like, and the formal vertical rotation is started on the premise of confirming the absolute safety of the whole vertical rotation working condition S7, gradually tensioning the anchor cable by using a continuous steel strand jack to enable the main tower to vertically rotate, monitoring each structure while vertically rotating, closely monitoring the tension force of the traction cable in the rotation process when the main tower vertically rotates to 45 degrees, and if the cable force of a single steel strand is smaller than 4t, stopping rotation operation in time and reporting to a commander; S8, turning the main tower to a 60-degree state, suspending traction of the turning, tensioning the back rope, turning the main tower to a 75-degree state, and adjusting the back rope to a specified rope force; s9, vertically rotating the main tower to a position close to the design position, measuring and controlling, slowing down the vertical rotating speed, finely adjusting the main tower in the vertical direction, accurately positioning, then welding a main tower butt joint port, dismantling a rotating body structure, and completing the rotating body of the main tower. Preferably, the pretensioned anchor cables are loaded step by using continuous jacks, synchronization is kept, the pretension force difference value among the jacks cannot exceed 10t, the anchor cables are tensioned step by step, each anchor cable is pretensioned by 350t, and the total of four anchor cables is pretensioned by 1400. Preferably, in the step S2, the cable anchor point is divided into a front anch