Improve the energy dissipating method of arch bridge bearing capacity
Technical field the present invention relates to the method that old bridge is reinforced, improved the arch bridge bearing capacity, is specifically related to improve the energy dissipating method of arch bridge bearing capacity.
Background technology is in order to adapt to the needs of transport development, and the large quantities of arch type bridges that built up are suddenly treated reinforcement and strengthening because former design load grade is low, improve bearing capacity.The existing method that improves the arch bridge bearing capacity has two big classes: the first improves its moment of inertia and resistance to compression, resistance to tension by increasing the main arch ring cross-section, reaches the purpose that improves former bridge bearing ability.As shown in Figure 1, usually the approach of taking is earlier former bridge main arch circle 1 to be cut a hole hair, clean, holed, anchor pole and steel mesh reinforcement are set, thicken one deck reinforced concrete floor or wrap one deck steel concrete cuff 2 all around at former bridge main arch circle hogback, soffit by the mode of cast-in-situ concrete or sprayed mortar then, working procedure is many, and technical difficulty is big, and material usage is big, reinforcing expense height accounts for and rebuilds new bridge 20~40%; Long in time limit, construction adds about 2 months phases of concrete curing at least; Traffic there is certain interference, even will suspends traffic.Its two be adopt as shown in Figure 2 " mounting method " by on former bridge main arch circle 1 with high-strength materials 3 such as epoxy rubber cement affixing carbon fabric, steel plate, glass fiber reinforced plastic or reinforcing bars, to improve the intensity of main arch circle, reach the purpose that improves bearing capacity.This method difficulty of construction is big, and technical sophistication, material expensive, reinforcing expense are higher than preceding a kind of method, account for build again 30~50%, particularly the carbon cloth cost is the highest.Duration is than pouring concrete short approximately (mainly be that curing time is short, but engineering time and technical difficulty being greater than pouring concrete).
The deficiency that summary of the invention exists at above-mentioned prior art, it is little to the purpose of this invention is to provide a kind of difficulty of construction, and the duration is short, does not influence or suspends traffic, and free from environmental pollution, the energy dissipating method of arch bridge bearing capacity is reinforced, improved to the old bridge that the reinforcing expense significantly reduces.
The object of the present invention is achieved like this: the energy dissipating method that improves the arch bridge bearing capacity, affixed at the main arch pressure zone, crack in promptly former bridge main arch circle and abut junction, and the perfusion flexible material, the tensile region is separated, can fine rotation, discharge the internal force of arch springing, reduce hogging moment, adjust arch axis line and pressure line, carry out full arch circle internal force and heavily distribute, improve the force-bearing situation of former bridge main arch circle, improve supporting capacity.Described flexible material is polyurethane foam resin or composite asphalt.
The present invention is for by changing the form that connects of former bridge main arch circle and abut, by original whole affixed, can not rotate that to be converted to the pressure zone part affixed, adjust arch axis line and pressure line, carry out full arch circle internal force and heavily distribute, improve the force-bearing situation of former bridge main arch circle, reach the purpose that improves supporting capacity.
The present invention has following advantage:
(1) compares traditional reinforcement means engineering cost and reduce cost saving 60~70% significantly;
(2) do not need original bridge arch ring cutter hair, polishing, clean and boring, add anchor pole, reinforcing bar, formwork, pouring concrete or affixing steel plate, carbon cloth, glass fiber reinforced plastic etc., only need original bridge arch ring and abut junction are handled, difficulty of construction is little, workload is little, duration shortens greatly, and reinforcement material is saved more than 90%;
(3) single span arch bridge and the not high bridge of abut are not needed to set up scaffold, only the higher bridge of arch springing is taken a small amount of scaffold or workbench, need full-bridge or large tracts of land spanning zone need take full hall formula scaffold than traditional reinforcing technique and can save built time and scaffold expense;
(4) construction period does not influence traffic and uninterrupted traffic;
(5) environment is not polluted.
The invention will be further described below in conjunction with the drawings and specific embodiments for description of drawings.
Fig. 1 reinforces the method schematic diagram that improves bearing capacity with steel concrete or sprayed mortar
Fig. 2 is that affixing steel plate or glass fiber reinforced plastic are reinforced the method schematic diagram that arch ring improves bearing capacity
Fig. 3 is the method schematic diagram that the present invention improves the arch bridge bearing capacity
Preferred forms
Referring to Fig. 3, step of the present invention is:
1, sets up a little scaffold (the not high arch of single span or abut is scaffolding not) at the arch springing position;
2, crack with abut 4 junctions at former bridge main arch circle 1, form flat hinge;
3, with the hinge seam of flexible material 5, get final product as polyurethane foam resin or composite asphalt perfusion main arch circle and abut junction.
4, reduce and discharge former bridge arch pin hogging moment 30~40%, improve 1~2 grade of class of loading of former bridge bearing ability.
The open web type arch bridge that least significant end spandrel arch cross wall is had certain distance or pillar spandrel construction apart from springing line, tensile region (more than the neutral axis) opens a finedraw at main arch circle hogback springing line place, and opposite joint perfusion flexible material, main arch circle tensile region and abut kept apart getting final product.
Real abdomen formula arch bridge or least significant end spandrel arch cross wall are needed, all to separate with tensile region, abut springing line place until the main arch circle with its pressure zone of Materials with High Strength cementation from down and upper edge springing line section gap is cracked to the arch ring end face near the open web type arch bridge of springing line; The isolation of perfusion flexible material gets final product.