30results about How to "Reduce mid-span deflection" patented technology

The invention discloses a welding type slab crack joint for a precast concrete floor system used in a building. The welding type slab crack joint comprises an X-shaped connection piece, a cover slab type connection piece, a support plate side overhanging platform and a supported plate side overhanging platform, wherein the X-shaped connection piece consists of anchor bars, panels and panel strips; the cover slab type connection piece consists of reinforcing steels arranged at the bottom of a slab, an embedded steel plate and a cover plate; the upper ends of the support plate and supported plate sides are provided with metal embedded pieces which consist of the anchor bars and the panels; the panels of the support plate is fixedly connected with the panels of the supported plate by the panel strips to form the X-shaped connection piece; the lower ends of the support plate and the supported plate sides are embedded with metal plates which are welded with the reinforcing steels at the bottom of a precast slab; the embedded metal plates of the support plate and the supported plate are fixedly connected by a metal cover plate to form a cover plate type connection piece; and after being overlapped with each other, the support plate side overhanging platform and the supported plate side overhanging platform are fixedly connected by the X-shaped connection piece at the top of the slab and the cover plate type connection piece at the bottom of the slab.

The invention relates to an anti-shearing reinforcement device and method for a concrete box girder web. In order to solve the problem that in existing engineering technologies, the concrete box girder web has cracking inclined cracks and insufficient anti-shearing bearing capacity, an external vertical prestressing tendon reinforcement device and method are provided. The device comprises groove-shaped steel, L-shaped steel, vertical prestressing tendons, wedge-shaped steel cushion blocks and an anti-corrosion coating at the outer side of the web. The groove-shaped steel is horizontally fixedto the junction of the upper end of the web and a top plate in the girder length direction. The L-shaped steel (6) is horizontally fixed to the lower end of the web in the girder length direction andis parallel to the groove-shaped steel (5). The vertical prestressing tendons are vertically mounted on the groove-shaped steel and the L-shaped steel, and it is ensured that the vertical prestressingtendons are parallel to the plane of the web. According to the anti-shearing reinforcement device and method, the web is connected with the top plate and a bottom plate through finish rolling twistedsteel, the force transmission path is definite, the risk that web concrete is pulled broken is reduced, and meanwhile, midspan deformation is reduced; the problem of insufficient main tensile stressof the web concrete is effectively solved, and the situations of continuous extension of the inclined cracks of the web or new inclined cracks are prevented.

The invention provides a slab end slotted hole SP hollow laminated slab-steel beam connecting structure and a construction method thereof. The slab end slotted hole SP hollow laminated slab-steel beam connecting structure is composed of an SP prestressed hollow slab with a slab end core hole slotted hole and a slab top hole, a steel bar net rack, a shearing force connecting piece and a post-pouring concrete layer. The slab end of the prefabricated SP prestressed hollow slab is provided with an elongated slot, the slab top hole is formed, the steel bar net rack is placed in the slot, the shearing force connecting piece is welded to a steel beam, and the slab end elongated slot and core hole are filled when the concrete post-pouring layer is poured. The effective width of slab ribs can be increased by filling the slab end core holes with the concrete, the slab end shear bearing capacity can be improved, the weak part of the slab is reinforced, the longitudinal continuity and integrity of the floor slab can be guaranteed through the steel bar net rack, part of hogging moment can be borne under the vertical load, the midspan deflection of the composite floor system is reduced, the vertical bearing capacity is improved, the steel bar can be used as a longitudinal shear-resistant steel bar of a composite beam and a slab-end shear-resistant steel bar to enhance the slab-end shear-resistant bearing capacity, and a wide application prospect is achieved.

A new prestressing system for bamboo and wood continuous beams is suitable for prestressed bamboo and wood beams in the field of civil engineering. It solves the phenomenon of limited beam span and material waste caused by excessive mid-span deflection of bamboo and wooden beams at present. The invention includes a double U-shaped steel backing plate, a bottom steel backing plate, a groove arc steering block, a screw rod, a prestressed tendon, an anchorage and the like. During the specific construction, the prestressed tendons are anchored at the end of the beam, and the position of the prestressed tendons is fixed through the grooved arc-shaped steering block set on the beam to ensure that the steel bars are close to both sides of the beam body, and the steering block is turned up and down by rotating the screw Move, so as to drive the prestressed tendon connected with the steering block and the beam to produce lateral relative displacement to control the application of prestress. In actual processing, the intermediate support can be added according to the specific situation, and the shape of the steering block can be changed to achieve the purpose of remarkable effect, economy and safety.

The invention provides an external prestressing overall reinforcement power station boiler large plate beam structure and a reinforcement method thereof. The large plate beam structure comprises a power station boiler large plate beam, anchor boxes, supporting beams, prestressed pull cables, hanging rods, connecting beams and the like. The supporting beams comprise vertical supporting beam bodies and horizontal supporting beam bodies, and the vertical supporting beam bodies and horizontal supporting beam bodies are connected through cover plates by adopting high-strength bolts; the horizontal supporting beam bodies make contact with the lower edges of lower flanges through cushion plates; the supporting beams are connected through the connecting beams to form a combined member; and the pull cables are symmetrically arranged on the two sides of a web of the large plate beam and directly or indirectly connected with the supporting beams through the hanging rods by adopting cable clamps. In order to reduce the prestress loss in the pull cables, arc-shaped rotation devices can be arranged between the hanging rods and vertical supporting beam top plates to enable the hanging rods to rotate by small angles; and through external prestressing overall reinforcement of the boiler large plate beam, the large plate beam lower flange tensile stress is reduced, the internal force state of the large plate beam structure is optimized, and surface crack propagation at a lower flange splicing weld seam is effectively inhibited.

The invention relates to a railway pier and triangular bracket cross-brace rockfall prevention structure. Triangular supports are arranged on the two sides of a railway beam; each triangular support comprises two inclined rods, the bottom ends of the two inclined rods are fixed to the pier tops of two longitudinally-adjacent railway piers respectively, and the top ends of the two inclined rods intersect and are fixed to the beam bottom of a horizontal longitudinal beam arranged above the triangular supports. A plurality of vertical rods are connected between the horizontal longitudinal beam and the inclined rods of the triangular support, and a vertical protective net is hung between the inclined rods of the triangular supports and the horizontal longitudinal beam. According to the rockfall prevention structure, the middle connecting position of the two triangular supports is located in the midspan of the beam, the supporting force is strong, the stress characteristic of the triangularsupports is equivalent to the fact that the long span of a longitudinal hole is divided into two longitudinal short spans, so that the rigidity of the upper anti-falling stone structure is enhanced,and problems that an ordinary anti-falling stone structure is supported by longitudinal piers, and midspan deflection is large are solved.

The double-amplitude four-cable-plane multi-tower cable-stayed bridge with the annular row support stump flowerpot-shaped bracket has the advantages of being good in structural rigidity, attractive inmodeling, convenient to construct, economical, reasonable and the like. A single-blade double-curved-surface thin-shell stump flowerpot-shaped bracket is arranged on a bridge foundation, an annular row support is arranged at the top of the stump flowerpot-shaped bracket to support a double-amplitude main beam bridge deck, the annular row support system can restrain relative rotation between a main beam and a cable bent tower, and the structural rigidity of the multi-tower cable-stayed bridge is improved. Unbonded prestressed steel strands are uniformly arranged in the variable cross-section concrete-filled steel tube hollow column type bridge tower column, prestressed steel bars are tensioned to extrude concrete, the compactness of concrete in a tube is improved, the problem of interfaceseparation of a large-diameter steel tube and a core concrete column body is solved, and the structural rigidity of the variable cross-section concrete-filled steel tube bridge tower column is improved. Simulated bark is adhered to the periphery of the variable cross-section prestressed concrete-filled steel tube bridge tower column, and the artificial leaf tower crown is arranged at the top of the variable cross-section prestressed concrete-filled steel tube bridge tower column, so that the landscape effect is improved.

The invention discloses a deck type beam-arch combined rigid frame bridge for double-layer traffic. The deck type beam-arch combined rigid frame bridge comprises an upper chord box-shaped beam arranged in the longitudinal direction of the bridge, a lower chord box-shaped arch for supporting the upper chord box-shaped beam and bridge piers; urban road traffic is located on the bridge surface of theupper chord box-shaped beam, and urban rail traffic is located in an upper chord box chamber of the upper chord box-shaped beam; a double-layer traffic function can be achieved, the characteristics of reducing the construction cost, being convenient and fast to construct, convenient to maintain, capable of reducing noise, saving energy, environmentally friendly and the like are achieved, the excellent mechanical property of the beam-arch combination is brought into full play, the span of the road-rail dual-purpose concrete bridge is boosted to be within the range of 200-300 m, and the spanning capacity is greatly improved.

The invention provides a pre-stress cable-stayed bailey beam combined bearing system. The system comprises a bailey beam, beam end supports, a mid-span jointing support seat, stay cables, beam end anchoring ends and a pre-stress tension system. The bailey beam is formed by combination of bailey trusses; the beam end supports with supporting effects are arranged on two sides of the bailey beam; themid-span jointing support seat serving as a mid-span supporting structure is positioned under the middle of the bailey beam; the stay cables are connected with two ends of the bailey beam and the mid-span jointing support seat and capable of generating supporting reaction force; the beam end anchoring ends have a function of anchoring the pre-stress stay cables; the pre-stress tension system is used for tensioning of the stay cables. By combination of a cable-stayed stress structure of the stay cables and a simply-supported stress structure of the bailey beam, material consumption increase isavoided, clearance is slightly affected, stress advantages of two systems are given into full play, a span of the bailey beam is increased, material consumption is reduced, and under-beam clearance influences are reduced. The system has advantages that defects of failure in span increasing of a traditional bailey beam structure and lack of terrain conditions in adoption of floor stands are avoided, and stress system clearness, convenience in construction operation, structural safety and sharp reduction of material consumption are realized.

The invention provides a large-span prestressed box-shaped simply-supported steel beam column structure. The large-span prestressed box-shaped simply-supported steel beam column structure comprises steel columns, a simply-supported steel beam, a corbel, an anchoring plate, a sleeve pipe and a prestress rib, wherein the corbel is welded and fixed to the right flange of a left steel column, the leftend of the steel beam is fixed to the upper surface of the corbel through a bolt, and the right end of the steel beam is welded and fixed to the left flange of a right steel column; a cover plate iswelded to the left end face of the steel beam, wherein a lower positioning plate is welded to the lower portion of the cover plate, an upper positioning block is welded to the cover plate, and the anchoring plate is clamped between the lower positioning plate and the upper positioning block; and the two ends of the prestressed rib are anchored on the anchoring plate and the left flange of the right steel column. The large-span prestressed box-shaped simply-supported steel beam column structure is large in rigidity, high in elastic bearing capacity, capable of effectively reducing midspan deflection of the steel beam and reducing the section height of the steel beam, high in safety performance, simple in structure, low in cost, good in durability, small in prestress loss and capable of being widely applied to large-span structures.