Construction method of double-layer cast-in-place beam first up and then down

Abstract

The invention discloses a double-layer cast-in-situ beam support construction method adopting the sequence from the upper layer to the lower layer. In combination of comprehensive consideration of construction of upper-layer cast-in-situ beams and lower-layer cast-in-situ beams, the method that construction of two layers of cast-in-situ beams is met through one support is designed, that is, the upper-layer cast-in-situ beams and the lower-layer cast-in-situ beams share one support. After construction of the upper-layer cast-in-situ beams is finished, upper-layer support steel tubes are dismounted, bailey beams are lowered integrally to a lower-layer cast-in-situ beam support, an upper-layer cast-in-situ beam support is converted into the lower-layer cast-in-situ beam support directly, the high-altitude construction difficulty of the support is reduced, meanwhile, the use time of large hoisting equipment is shortened, the construction process is accelerated, and damage of the lower-layer cast-in-situ beam body due to construction of the upper-layer cast-in-situ beams is avoided.

Description

technical field [0001] The invention relates to a construction method of a bridge engineering foundation, in particular to a construction method for a cast-in-place beam support in which the upper-layer cast-in-place beam is constructed first and then the lower-layer cast-in-place beam is constructed according to the structural form that the upper layer is wider than the lower layer. Background technique [0002] With the increasing investment in infrastructure construction in our country, bridge construction is developing rapidly. In order to reduce construction costs and construction land, many cross-river and river-crossing bridges in China adopt a double-layer structure, and the upper cast-in-place girder is wider than the lower cast-in-place girder. form. [0003] The traditional double-layer cast-in-place beam support construction method generally adopts the construction of the lower floor cast-in-place beam first, and then erects the support according to the width of ...

AI Technical Summary

Problems solved by technology

[0003] The traditional double-layer cast-in-place beam support construction method generally adopts the construction of the lower floor cast-in-place beam first, and then erects the support according to the width of the upper floor cast-in-place beam. This method has the following disadvantages: 1. When the upper floor cast-in-place beam is wider than the lower floor cast-in-place beam The support of the cast-in-place beam on the upper floor will be affected by the cast-in-place beam on the lower floor. Part of the cast-in-place beam support on the upper floor needs to be supported on the top surface of the cast-in-place beam on the lower floor, and the other part needs to be supported outside the scope of the cast-in-place beam on the lower floor. When the steel pipe support is erected on the ground, there is often a large difference between the height of the support on the lower cast-in-place beam and the height of the support supporting the ground (generally a difference of tens of meters), resulting in mismatching of support stiffness, foundation settlement and beam deformation.

2. It is necessary to separately increase the layout of some upper cast-in-place beam support foundations and supports, which requires a large investment

3. The installation and removal of the bracket is cumbersome, the construction period is longer, and the construction cost of the whole bracket is higher

4. The construction of the upper cast-in-place beams is easy to cause damage to the lower cast-in-place beams

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