Become case variable cross-section continuous rigid frame aqueduct single box single chamber case beam and method for designing
Technical field
The present invention relates to a kind of change case variable cross-section continuous rigid frame aqueduct single box single chamber case beam and method for designing, belong to hydraulic engineering technical field.
Background technology
Along with developing rapidly of China's hydraulic engineering, the application of Long span defeated draining continuous rigid frame aqueduct is more and more extensive, and existing continuous rigid frame aqueduct single box single chamber case beam base plate curve parameter adopts parabola, circular arc line and broken line etc., simultaneously, for guaranteeing smooth in water flow in groove body and being connected with two casees box girder with variable cross section smoothly, single box single chamber case beam base plate upper limb generally adopt longitudinal gradient be 1/1000 ~ 1/3000 straight line, single box single chamber case beam is in the process transitting to two casees box girder with variable cross section cross sections, its base plate thickness sharply increases, result in single box single chamber box section area and the increase of bending resistance moment of inertia, significantly reduce the type heart position in cross section, obviously weaken the prestressing effect (referring to CN202450427U) of single box single chamber case beam region base plate longitudinal prestressing reinforcing bar, add the use amount of the base plate longitudinal prestressing reinforcing bar of whole continuous rigid frame aqueduct, simultaneously, single box single chamber case beam needs the distance of 15 ~ 20m just can transit to two casees box girder with variable cross section cross sections, result in the difficult arrangement of base plate longitudinal prestressing Bar Anchorage tooth plate, moreover, base arrangement concrete contacts generation 2 unfavorable factors with water body: 1. single box single chamber case beam base plate will produce an additional temp gradient effect, its maximum positive temperature difference is 14 DEG C, maximum subzero temperature difference is-6.5 DEG C, the positive compressive stress that the positive temperature difference will cause case beam base plate to increase about 4MPa, subzero temperature difference will cause the positive tensile stress of case beam base plate increase about-2MPa, seriously unfavorable to structure stress, further increase the use amount of base plate longitudinal prestressing reinforcing bar, 2. water body directly will corrode base arrangement concrete and top layer reinforcing bar, have impact on the durability of structure.
Summary of the invention
The object of the invention is: for the defect of prior art, there is provided a kind of and become case variable cross-section continuous rigid frame aqueduct single box single chamber case beam and method for designing, both baseplate temp gradient effect had been reduced, base plate longitudinal prestressing Bar Anchorage tooth plate can be solved again arrange, to overcome the deficiency of existing slope retaining technology.
Technical scheme of the present invention
A kind of change case variable cross-section continuous rigid frame aqueduct single box single chamber box beam casting method, the method is being built in variable cross-section single box single chamber case beam process, single box single chamber case beam is progressively becoming its base plate lower edge formation ogive curve in large process along with cross section, its base plate upper limb adopts the Changing Pattern identical with curve parameter, base plate is made to form the equal ogive curve entirety of a thickness, a gradually-changed space is formed between Water space in the case of base plate upper limb and single box single chamber box beam concrete, in gradually-changed space, fill full bed course makes gradually-changed space upper surface smooth, and make gradually-changed space upper surface and single box single chamber box beam concrete both sides form Water space in smooth case, thus realize the construction becoming case variable cross-section continuous rigid frame aqueduct single box single chamber case beam.
Aforesaid one becomes in case variable cross-section continuous rigid frame aqueduct single box single chamber box beam casting method, bed course in described gradually-changed space comprises waterproofing course two, light weight concrete construction bed course, gas concrete insulation layer and waterproofing course one from bottom to up successively, vertical height adjustable case beam base plate longitudinal prestressing steel bundle anchoring tooth plate is laid in light weight concrete construction bed course both sides, light weight concrete construction bed course and case beam base plate longitudinal prestressing steel bundle anchoring tooth plate improve constantly greatly its thickness along with the change of gradually-changed space, make the gas concrete insulation layer above being positioned at and waterproofing course one keep smooth.
Aforesaid one becomes in case variable cross-section continuous rigid frame aqueduct single box single chamber box beam casting method, and the thickness of waterproofing course one, gas concrete insulation layer and waterproofing course two is consistent building in variable cross-section single box single chamber box beam concrete process.
A kind of change case variable cross-section continuous rigid frame aqueduct single box single chamber case beam, comprise the single box single chamber case beam that cross section is gradual change, the base plate of this section of single box single chamber box beam concrete is the ogive curve structure that one section of thickness is consistent, and the bottom of Water space is linear structure in single box single chamber box beam concrete, form gradually-changed space between base plate and Water space, in gradually-changed space, fill bed course make maintenance level bottom Water space.
Aforesaid one becomes in case variable cross-section continuous rigid frame aqueduct single box single chamber case beam, the described bed course of filling in gradually-changed space comprises waterproofing course two, light weight concrete construction bed course, gas concrete insulation layer and waterproofing course one from bottom to up successively, vertical height adjustable case beam base plate longitudinal prestressing steel bundle anchoring tooth plate is laid in light weight concrete construction bed course both sides, light weight concrete construction bed course and case beam base plate longitudinal prestressing steel bundle anchoring tooth plate improve constantly greatly its thickness along with the change of gradually-changed space, make the gas concrete insulation layer above being positioned at and waterproofing course one keep smooth.
Aforesaid one becomes in case variable cross-section continuous rigid frame aqueduct single box single chamber case beam, it is characterized in that: the thickness of waterproofing course one, gas concrete insulation layer and waterproofing course two is consistent building in variable cross-section single box single chamber box beam concrete process.
Owing to have employed technique scheme, compared with the prior art, the single box single chamber case beam floor combination structure that the present invention adopts, the structure solving existing change case variable cross-section continuous rigid frame aqueduct only case single cell box girder is not enough, specific as follows: to solve case beam backings thickness and sharply increase (in case beam cross section progressively increase process, under case beam internal water body space remains unchanged condition, the base plate thickness be positioned at bottom case beam can only increase) a series of unfavorable result brought, significantly enhance the prestressing effect of longitudinal prestressing reinforcing bar, solve the Layout Problem of case beam base plate longitudinal prestressing steel bundle anchoring tooth plate, reduce single box single chamber case beam base plate additional temp gradient effect, the maximum positive and negative temperature difference reduces nearly 50%, waterproof slab ability strengthens nearly 2 times, enhances the durability of structure, compared with former technical scheme, base plate longitudinal prestressing steel bundle saves 40%, and achieve the safety stock being better than former technical scheme, in addition, invention also reduces the deadweight in continuous rigid frame aqueduct span centre region, improve the bulk deformation of structure, good economy performance.
Accompanying drawing explanation
Accompanying drawing 1 is structure structural representation of the present invention;
Accompanying drawing 2 is A-A sectional views of accompanying drawing 1;
Accompanying drawing 3 is structural representations when not filling bed course in the present invention in gradually-changed space.
Detailed description of the invention
Below in conjunction with accompanying drawing to the present invention with being described in further detail, but not as any limitation of the invention.
Embodiments of the invention: a kind of change case variable cross-section continuous rigid frame aqueduct single box single chamber box beam casting method, the method is being built in variable cross-section single box single chamber case beam process, single box single chamber case beam is progressively becoming its base plate lower edge formation ogive curve in large process along with cross section, its base plate upper limb adopts the Changing Pattern identical with curve parameter, base plate is made to form the equal ogive curve entirety of thickness (so in practice of construction work, if bridge span is too large, in order to meet design strength, suitably progressively should thicken base plate thickness, the upper limb of right base plate and the curvilinear trend of lower edge keep similar, make the reinforcing bar binding in construction in base plate and mixed earth easy construction, also can ensure that base sheet stresses change can not be undergone mutation, ensure its intensity), a gradually-changed space is formed between Water space in the case of base plate upper limb and single box single chamber box beam concrete, in gradually-changed space, fill full bed course makes gradually-changed space upper surface smooth, and make gradually-changed space upper surface and single box single chamber box beam concrete both sides form Water space in smooth case, thus realize the construction becoming case variable cross-section continuous rigid frame aqueduct single box single chamber case beam, bed course in this gradually-changed space comprises waterproofing course two from bottom to up successively, light weight concrete construction bed course, gas concrete insulation layer and waterproofing course one, vertical height adjustable case beam base plate longitudinal prestressing steel bundle anchoring tooth plate is laid in light weight concrete construction bed course both sides, light weight concrete construction bed course and case beam base plate longitudinal prestressing steel bundle anchoring tooth plate improve constantly greatly its thickness along with the change of gradually-changed space, the gas concrete insulation layer above being positioned at and waterproofing course one is made to keep smooth, and waterproofing course, the thickness of gas concrete insulation layer and waterproofing course two is consistent building in variable cross-section single box single chamber box beam concrete process.
Case variable cross-section continuous rigid frame aqueduct single box single chamber case beam is become according to the one that said method is formed, as shown in drawings, comprise the single box single chamber case beam 1 that cross section is gradual change, the base plate 2 of this section of single box single chamber box beam concrete 1 is that the ogive curve structure that is consistent of one section of thickness is (so in practice of construction work, if bridge span is too large, in order to meet design strength, suitably progressively should thicken base plate thickness, the upper limb of right base plate and the curvilinear trend of lower edge keep similar, make the reinforcing bar binding in construction in base plate and mixed earth easy construction, also can ensure that base sheet stresses change can not be undergone mutation, ensure its intensity), and the bottom of Water space 3 is linear structure in single box single chamber box beam concrete 1, gradually-changed space 4 is formed between base plate 2 and Water space 3, in gradually-changed space 4, fill bed course make maintenance level bottom Water space 4.
The bed course of wherein filling in gradually-changed space 4 comprises waterproofing course 25 from bottom to up successively, light weight concrete construction bed course 6, gas concrete insulation layer 7 and waterproofing course 1, vertical height adjustable case beam base plate longitudinal prestressing steel bundle anchoring tooth plate 9 is laid in light weight concrete construction bed course 6 both sides, light weight concrete construction bed course 6 and case beam base plate longitudinal prestressing steel bundle anchoring tooth plate 9 improve constantly greatly its thickness along with the change of gradually-changed space 4, the gas concrete insulation layer 7 above being positioned at and waterproofing course 1 is made to keep smooth, and waterproofing course 1, the thickness of gas concrete insulation layer 7 and waterproofing course 25 is consistent building in variable cross-section single box single chamber box beam concrete process.