RU2817590C1 - Method for construction of monolithic bridge supports in sliding formwork - Google Patents

Abstract

FIELD: bridge construction.

SUBSTANCE: construction of bridges with supports made of monolithic concrete. A method for constructing monolithic bridge supports in sliding formwork includes the construction of its first tier, consisting of a supporting frame, onto which a jacking frame is secured with four hydraulic jacks placed on it symmetrically relative to the axis of the support, carrying sliding formwork panels of the second tier, which are secured by closed connections along the perimeter of the formwork to the supporting frame with gripping legs, as well as hanging the third, fourth and fifth tiers to the second tier. In this case, gripping legs are used, having end parts tapering in their longitudinal section in the shape of a trapezoid, with horizontal flange platforms supporting the frame are installed on the upper part, and the lower ones are connected from the inside to form-building crossbars covering the shields at two levels, and the lower of them are installed on screw jacks. On the outer side of the gripping legs, a screw stop is hinged to the middle of the lower end part, the upper end of which is hinged from below to the supporting frame. In hydraulic jacks, jack pipes coated on the outer surface with lubricant are placed with emphasis on the base, load-bearing vertical and connecting horizontal reinforcement are installed, and the concrete mixture is laid in layers in the formwork and compacted with the help of deep vibrators, preventing them from touching the vertical reinforcement. As the laid mixture approaches the upper edge of the shields, the jack grips on the jack pipes carry out vertical movement of the supporting frame with the formwork panels attached to it, and set the permissible amount of sliding of the grips when compressing the jack pipes coated on the outer surface with lubricant to no more than 2-3 mm.

EFFECT: increasing the reliability of bridge supports constructed in sliding formwork by reducing the deviation of the vertical axis of the support from the design position.

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Description

The invention relates to the field of construction of bridges with supports made of monolithic concrete.

There is a known method for constructing monolithic reinforced concrete supports, in which a formwork closed around the perimeter, a supporting frame with racks and a drive are organized, and horizontal support frames are installed on the racks of the supporting frame with the possibility of vertical movement along them, on each of which spring-loaded levers connected to the formwork panels are mounted , and when the upper frame moves upward, the levers rotate, which leads to the separation of the panels from the concrete surface and lifting them to a new height, at which the concrete mixture is laid (SU 327310, publ. 01/26/1972).

There is a known method for constructing monolithic reinforced concrete bridge supports, in which formwork panels with upper and lower sections are used, which are alternately torn off the concrete by a drive, so that when the sliding formwork operates, one of the formwork sections moves upward, resting on the other, which is held motionless by forces friction between the shields and the structure being constructed, created by jacks, while the load is removed on the jacks of the moving shields (SU 1650888, published 01/26/1972).

The closest known method is the method of constructing monolithic reinforced hollow supports in sliding formwork, in which a formwork closed around the perimeter is assembled from panels, on which a supporting frame-platform is assembled from two tiers of channels, hydraulic jacks are installed, into which jacking rods are inserted, supporting them with their ends in concrete, assemble a U-shaped frame, each leg of which is attached to the longitudinal beams of the supporting frame by means of locking pins, install vertical external and horizontal distribution reinforcement to the height of one grip, the concrete mixture is initially laid to a height of 0.6-0.7 m in two layers , then continuously - 0.25 m thick, and each subsequent layer is laid before the previous one begins to set, the laid concrete mixture is compacted with deep vibrators, reinforcement is increased as the formwork rises (Technological map, Construction of monolithic hollow supports in sliding formwork, Central Institute for Normative Research and scientific and technical information "Orgtransstroy" of the Ministry of Transport Construction, 1977).

Known technologies for constructing supports do not exclude deviations of the vertical axis of the supports from the design position despite the use of control means.

Currently, sliding formworks are used for the construction of supports up to two hundred meters, where, according to data from the PSK company (https://psk-holding.ru/products/opalubka_mostovykh_opor_gidravlicheskaya_skolzyashchaya/), the deviation is 15 mm, which requires reliable technical solutions to ensure this.

The objective of the present invention is to improve the technology for constructing bridge supports, allowing for a reduction in the deviation of the vertical axis of the support from the design position.

The technical result is to increase the reliability of bridge supports constructed in sliding formwork by reducing the deviation of the vertical axis of the support from the design position

The technical result is achieved by the fact that in the method of constructing monolithic bridge supports in sliding formwork, including the construction of its first tier, consisting of a supporting frame, onto which a jacking frame is attached with four hydraulic jacks placed on it symmetrically relative to the axis of the support, supporting closed connections along the perimeter of the formwork panels of sliding formwork of the second tier, which is fixed to the supporting frame with legs-grippers, as well as hanging from the second tier of the third, fourth and fifth tiers, while using legs-grippers having end parts tapering in their longitudinal section in the shape of a trapezoid, on the upper ones in which horizontal flange platforms supporting the supporting frame are installed, and the lower ones are connected from the inside to form-building crossbars covering the shields at two levels, and their lower part is installed on screw jacks, and from the outside of the gripping legs, a screw is hinged to the middle of the lower end part a stop, the upper end of which is hingedly connected from below to the supporting frame, in hydraulic jacks, jack pipes coated on the outer surface with lubricant are placed with a stop at the base, load-bearing vertical and connecting horizontal reinforcement are installed, and the concrete mixture is laid in layers in the formwork and compacted with the help of deep vibrators, preventing them from touching the vertical reinforcement, and as the laid mixture approaches the upper edge of the panels, the jack grips on the jack pipes carry out vertical movement of the supporting frame with the formwork panels attached to it, and set the permissible amount of sliding of the grips when squeezing the jack pipes coated on the outer surface with lubricant, no more 2-3 mm.

The invention is illustrated by the following drawings:

in fig. Figure 1 shows gripping legs connected through form-building crossbars to sliding formwork panels;

- in fig. 2 shows the connection of the gripper legs with the supporting frame;

- in fig. Figure 3 shows the axisymmetric arrangement of hydraulic jacks.

The method of constructing monolithic bridge supports in sliding formwork includes the construction of its first tier, consisting of a supporting frame 1, onto which a jacking frame 2 is attached with four hydraulic jacks 3 placed on it symmetrically relative to the axis of the support. Construction of the second tier, supporting closed connections along the perimeter of the formwork panels 4 sliding formwork. The second tier is secured to the supporting frame 1 with legs-grippers 5. Next, the third, fourth and fifth tiers are suspended (sequentially and/or parallel) to the second tier for carrying out technological operations. In the process of constructing monolithic supports, gripping legs 5 are used, having end parts tapering in their longitudinal section in the shape of a trapezoid (see Fig. 1), on the upper of which horizontal flange platforms 6 are installed supporting the supporting frame, and the lower ones are installed on the inside are connected to the form-building crossbars 7 covering the shields at two levels, and their lower part is installed on screw (regulating) jacks 8. From the outside of the gripper legs 5, a screw stop 9 is hinged to the middle of the lower end part, the upper end of which is hingedly connected from below to the carrier frame 1. Screw supports ensure the rigidity of the structure and its adjustment, both during installation and during the working process. In hydraulic jacks 3, jack pipes 10 are placed with emphasis on a pre-prepared rigid base, coated on the outer surface with lubricant. In the space limited by the formwork, load-bearing vertical and connecting horizontal reinforcement are installed and the concrete mixture is laid in layers in the formwork, compacted with the help of deep vibrators, preventing contact them vertical reinforcement. Next, as the concrete mixture laid in layers, preferably 25 mm, approaches the upper edge of the boards, the grips of the jacks 3 for the jack pipes 10 carry out vertical movement of the supporting frame 1 with the formwork panels attached to it, and the permissible amount of sliding of the grips when compressing the coated ones on the outer surface is set lubricating the jacking pipes no more than 2-3 mm.

Compliance with this technology of work, as well as taking into account the amount of sliding of the grippers, makes it possible to increase the reliability of the monolithic bridge support constructed in the sliding formwork due to additional measures to control the possibility of deviation of its vertical axis from the design position.

Claims (1)

A method for constructing monolithic bridge supports in sliding formwork, including the construction of its first tier, consisting of a supporting frame, onto which a jacking frame is attached with four hydraulic jacks placed on it symmetrically relative to the axis of the support, carrying sliding formwork panels of the second tier, closed by connections along the perimeter of the formwork, which secured to the supporting frame with legs-grippers, as well as hanging the third, fourth and fifth tiers from the second tier, using legs-grippers that have end parts tapering in their longitudinal section in the shape of a trapezoid, on the top of which horizontal supports for the supporting frame are installed flange platforms, and the lower ones, from the inside, are connected to form-forming crossbars covering the shields at two levels, and their lower part is installed on screw jacks, and from the outside of the gripping legs, a screw stop is hinged to the middle of the lower end part, the upper end of which is hingedly connected from below with a supporting frame, in hydraulic jacks, jacking pipes coated on the outer surface with lubricant are placed with an emphasis on the base, load-bearing vertical and connecting horizontal reinforcement are installed, and the concrete mixture is laid in layers in the formwork and compacted with the help of deep vibrators, preventing them from touching the vertical reinforcement, and As the laid mixture approaches the upper edge of the boards, the jack grips on the jack pipes carry out vertical movement of the supporting frame with the formwork panels attached to it, and the permissible amount of sliding of the grips when compressing the jack pipes coated on the outer surface with lubricant is set to no more than 2-3 mm.