Middle support construction for the underwater canopy cofferdam of multispan formula
Technical field
The present invention relates to canal for water conveyance side slope reparation cofferdam technical fields, underwater for multispan formula more particularly, to one kind
The middle support construction in canopy cofferdam.
Background technique
Large-scale canal for water conveyance (main channel of Water Transfer Project from South to North that such as design head is up to 7m) after a certain time of operation, can not keep away
It will appear that side slope liner plate is impaired to need the case where repairing with exempting from.Since general main canal is single line operation, do not have inspection of cutting off the water
The condition repaired mostly uses the method that cofferdam repair dryly under water of building.For canopy cofferdam as shown in Figure 1, including edge
Plug truss is arranged in the door shape steel truss of side slope setting, bottom, and top extends to the channel water surface or more, spreads on the outside of steel truss
Equipped with panel, and water sealing structure is set at panel splicing, so that it is guaranteed that it is mutually isolated with channel in cofferdam, it forms one and does not leak
The space of water is to meet construction requirement.When side slope impaired area is larger, such as along Parallel to the flow direction when being tens of meters, just
It needs for be designed in canopy cofferdam multispan structure, i.e., supports b in installation below the girder a of door shape steel truss, enclosed to share
Weir upper load.However, due to failure area inside lining plate there are crack, a variety of situations such as swell and collapse, side slope surface is not
Flatness is high, and support is unable to satisfy design requirement in existing fixed-size steel construction, cannot be formed with bottom liner plate well
Contact, be easy to cause stress to concentrate, destroy cofferdam panel between water sealing structure;Meanwhile the side slope of middle support bottom covering
Affected area can not be repaired, and cause liner plate to be repaired not exclusively, making channel, there are security risks, influence the long-term peace of channel
Full stable operation.
Summary of the invention
The present invention provides a kind of middle support construction for the underwater canopy cofferdam of multispan formula, it is therefore intended that solves existing middle branch
The problem of support installs not high matching degree and influence repairing quality with impaired side slope.
To achieve the above object, the present invention can take following technical proposals:
Middle support construction of the present invention for the underwater canopy cofferdam of multispan formula, including be arranged under door shape steel truss girder
The middle support of side, every middle support includes the support of winding up that is slidably connected on the girder, it is described wind up support it is logical
It crosses height adjustment mechanism and is connected with lower edge support.
Lower edge support bottom is provided with supporting plate.
Provided by the present invention for the middle support construction in the underwater canopy cofferdam of multispan formula, solves middle support and damaged not
The adaptability problem of smooth side slope, it can be ensured that the cofferdam structure in portion disposed thereon keeps certain flatness, and it is strong to meet cofferdam
Degree requires and sealing requirement, while can repair side slope liner plate whole in cofferdam by the position supported in movement, guarantees
Repairing quality makes channel safety and stability long-term operation.
Detailed description of the invention
Fig. 1 is the structural schematic diagram in existing canopy cofferdam.
Fig. 2 is structural schematic diagram of the invention.
Fig. 3 is change in displacement schematic diagram of the present invention when channel side slopes jump storehouse casting and constructing.
Specific embodiment
As shown in Fig. 2, the middle support construction of the present invention for the underwater canopy cofferdam of multispan formula, including be arranged in door
The middle support of the lower section of shape steel truss girder 1, supporting in every includes the support 2.1 and by 2.2 phase of height adjustment mechanism of winding up
Lower edge support 2.3 even.Specifically, which is made of I-steel, and support 2.1 of winding up is truss structure, by angle steel or L-type
Steel is welded, and top is equipped with pulley 2.5, is connected by the pulley 2.5 with the sliding of the flange plate of I-steel girder 1;Under
String support 2.3 is shorter, is the gridiron being welded by I-steel;In order to avoid stress concentration falls into lower edge support 2.3
In side slope, the beam lattice bottom of lower edge support 2.3 is welded with certain thickness steel supporting plate 2.4;And height adjustment mechanism 2.2 can
Select hydraulic cylinder, adjusting screw or linear motor etc..When installation, three kinds of components are both secured to support 2.1 of winding up, adjustable to stretch
Contracting part directly acts on lower edge support 2.3 by piston rod, screw rod and support rod.
In order to save the duration, concreting is carried out to slope surface usually using storehouse method is jumped.As shown in figure 3, first centering support
I, the slope surface region (area A, B, C as shown in shaded area in figure) other than II, III, IV carries out concreting and passes through later
Height adjustment mechanism 2.2 lifts the lower edge support 2.3 of each middle support, make middle support I to the area A mobile, middle support II, III to the area B
Mobile, middle support IV is mobile to the area C, reaches the region that concreting has been completed in target area) after, height is adjusted again
Regulating mechanism 2.2 contacts the whereabouts of supporting plate 2.4 with slope surface, forms support to girder 4 again, then, does not pour to original
It constructs in region.