KR20050026470A - Method of manufacturing and construction melthod of preflex composite beem by division mode - Google Patents

Abstract

A manufacturing and installing method for a preflex composite beam by division is provided to prevent the overturn and crack in support when placing upper slab concrete and to prevent a bridge from falling off at an earthquake. The preflex composite beam is manufactured by installing a PC beam(100) and an anchor plate(110) on both ends of an I-beam member while applying preflex load(Pf) on an I-beam member manufactured with planned bending moment by applying live load, placing prestress on a PC beam(100) using a hydraulic jack, and placing lower casing concrete while keeping preflexion, then releasing, and installed by carrying, connecting and re-assembling on a bridge, and releasing the prestress of the PC beam(100).

Description

 Preflex beam split fabrication installation method {METHOD OF MANUFACTURING AND CONSTRUCTION MELTHOD OF PREFLEX COMPOSITE BEEM BY DIVISION MODE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing and installing a preflex beam composite beam, and more particularly, to a method for splitting and installing a preflex beam of a continuous beam of short span and two spans or more. In the conventional method of splitting short beams and continuous beams of a preflex beam composite beam (FIG. 1), a prefabricated beam type I beam is divided by a design bending moment, and the split type I steel beam is assembled and connected. Loading the reflection load, assembling the reinforcing bars in the lower casing, placing and curing the concrete, releasing, disassembling and transporting the assembled assembled preplex beam splitting member to the alternating piers, and reassembling and connecting Introducing the partial prestress into the beam splitting member, assembling the reinforcing bars of the casing connection and curing the concrete, disassembling the partial prestressing placing hypothesis, and assembling the reinforcing bars into the abdomen and slab and curing the concrete. In order to introduce partial prestress into the preplex beam splitting member assembled in the conventional preflex beam splitting fabrication method as described above, in the short span, the insulated portion of the lower flange casing concrete at the junction of each preflex beam member is There are IN CABLE METHOD, OUT CABLE METHOD, and counterweight method. For continuous beams of two spans or more, I-shaped section of the negative moment section is increased with the haunting part and height. The technique of installing oil jacks at both ends and raising and lowering to introduce prestresses, and the method of placing high strength concrete on upper slabs in the negative moment section and installing and lowering oil jacks at the branch to introduce prestresses. have.

In the conventional split fabrication method, the preflex beam is manufactured and preflection stress consumption begins as time passes after the release of the preflection. After 30 days, a sudden loss begins and the camber value decreases. Due to process delays, long-term loads of more than 30 days are frequently required, such as transport-mounted assembly connections and slab concrete casting in alternating piers.Partial prestress is introduced at the joints of the lower part of the joints after the assembly of the preflex beam splitting members. By introducing partial prestress, prestress is distributed unevenly over the entire assembled parts. Excessive input of partial prestress equipment consumes a lot of manpower and expense. Is generated.

 In addition, in the conventional preflex beam composite beam splitting fabrication, the preflex beam is divided into a positive moment portion and a negative moment region in a continuous beam having two or more spans, and then divided into an upper slab of the negative moment region. The construction of high-strength concrete or augmenting the rigid cross section, the installation of oil jacks at the joints or points at both ends of the splitting member, and raising and lowering the preflex beam causes excessive installation and air delay in the process of introducing partial prestress.

According to the present invention, a preflex beam type I rigid member is divided into three sections for short spans, and a continuous beam having two or more spans is divided into two or more sections. Pre-stressed beam splitting member is prepared by installing PC steel in the abdomen and prestressing to maintain the preflex load by hydraulic jack, and assembling reinforcing steel and pouring concrete into I-type lower flange casing. Transported by alternating piers Assembly Prefab beam which prevents loss of pre-flection, maintains camber value and makes additional corrections even after long-time loading up to concrete casting, and releases prestress introduced by hydraulic jack to PC steel Integrate the divided assembly member by introducing a uniform prestress to the entire assembly member It is intended to provide a method of manufacturing a preplex beam splitting fabric.

In addition, in the continuous beams of two spans or more, the two-stage internal beams with the point where the bending moment becomes zero at the time of the bending moment at the time of the live load load are replaced with equivalent spans. Divided into simple beams with the point of zero moment as a point, the stress of internal and external forces is replaced by the equal intervals, and the I-shaped steel is manufactured by dividing it into positive (+) moment and negative (-) moment sections. Pre-stress is introduced into PC steel with hydraulic jack under the condition of preflex load.Preflex beam splitting member is manufactured to reduce the cross-section due to stress and split the length of beam to increase the efficiency of manufacture and transportation. Negative reaction bearing is installed at the pier point of the moment section and pre-assembled composite beams are assembled and mounted with hydraulic jacks on the negative reaction bearings and the lower casing of the preflex composite beams. By introducing a force peuriseuteuresing up to the sub-unit to attenuate the moment () (-) to minimize the cross-section of the moment interval, and the upper slab concrete when the sub-aims to to prevent the moment interval fulcrum portion cracks ().

According to the present invention, in the method for manufacturing and installing a preflex beam, the preflex beam I type steel is divided into three sections for short spans and continuous beams for two or more spans divided by design bending moments according to loads for live loads (W). When explaining the case using the accompanying drawings in the manufacturing process as follows. Preflex load (Pf) loading diagram according to the bending moment diagram (Fig. 2 (a)) according to the live load load on the simple beam during the short span preplex beam split fabrication installation (Fig. 2 to 4) (b)) to prepare the I-shaped steel in three segments to introduce prestress (PS) into the upper flange (11 in FIG. 3) at both ends of the central portion (L / 2 section of FIG. 2) and in the I-shaped steel (10 in FIG. 3). A step of drilling a high tension bolt hole (14 in FIG. 3) to temporarily fix the fixing plate (110 in FIG. 11) (FIG. 3 (a)). Step 11 (13 of FIG. 3) by adding a high tension bolt (15 of FIG. 3) by adding (11), loading the pre-flex load (Pf) to the connected assembled I-shaped steel (Fig. 3 (c)), the PC bolts (100 in Fig. 11) and the fixing plate (110 in Fig. 11) are attached to the central axis (neutral shaft NN) on the upper flange of the central I-shaped both ends in the state where the preflex load is loaded. PC Steels with Fixed Installation (111 in Figure 11) Introducing prestress (PS) corresponding to the preflex load with the hydraulic jack and assembling reinforcing steel and pouring concrete into the lower flange casing (Fig. 3 and Fig. 11) (Fig. 3 (d)), the loaded pre Releasing the flex load Pf (Fig. 3 (e)), unscrewing and dismantling the connecting plate of the connected preflex beam member and the high tension bolt (Fig. 3 (f)), the divided preflex beam member To the bridge (40 in FIG. 4) to carry and reassemble and connect the connecting plate (13 in FIG. 3) and the high tension bolt (15 in FIG. 3) (FIG. 4 (a)). 3 and 11, the prestress (PS) of 100) is released to disassemble the prestress temporary equipment of the fixing plate and the PC steel to introduce the preflection (Fig. 4 (b)), and the preassembled split member assembled and connected PC steel JACKING consisting of the step of casting concrete (Fig. 4 (c)) of the connection portion and the slab (30 of Fig. 4) Prestressed introduction preflex beam split fabrication installation method,

Left and right symmetry of bending moment diagram (Fig. 5 (a)) due to the load according to the live load (W) during two-split splitting (Figures 5-7) Segmented part (-) moment (MB) (B) in Fig. 5 is segmented, and the stress of internal and external forces is replaced by equivalent beams (Fig. 5 (b)), and the bending deflection according to the live load (W) load. The moment of bending moment of the equally substituted simple beam, and the bending moment according to the live load, which is equivalently substituted for the internal stress by the internal beam at the point (E, F in Fig. 5). (A method of loading a pre-flection load according to (c) of FIG. 5 (FIG. 5 (d)) is a positive moment section (i.e. F-G) are loaded with two preflex loads (Pf), a flange fixing plate (110 in Fig. 12) and PC steel (100 in Fig. 12) are installed to introduce prestress (PS) into the hydraulic jack. of mine At the end of the beam (B in Fig. 5), a negative reaction pre-flexion (PfRB) is loaded and a flange fixing plate (110 in Fig. 12) is installed, and the starting point (E, F in Fig. 5) neutral axis (center) Axial mounting plate (115 in FIG. 12) is installed at the intersection of axis NN) with high tension bolt (111 in FIG. 12) and connected to PC steel (120 in FIG. 12) to connect prestress (PS) to PC steel with hydraulic jack. Equivalent displacement of the maximum negative moment (Mpf) Preflex beam splitting fabrication and installation method of pre-beam beam splitting member installation after carrying out pre-assembled beam splitting member by releasing and lowering the lower casingcrete after casting The production method is as follows. Producing I-shaped steel with a deflection curve due to two-segment two-segment internal beam bending moment (Fig. 6 (a)), to both ends of the positive moment section (A point and E point in Fig. 5). Preload (Pf≥3WL / 8) After loading the load, negative reaction force pre-flection (PfRB≥3WL / 2) is applied to the end (B) of the negative moment section (Point E to B in Fig. 5). Step (Fig. 6 (b)), the PC steel and the fixing end in the upper flange of the positive moment section I-shaped steel (10 in Fig. 6) in the state of pre-loading Introduce prestress (PS) with JACK,

Installing the PC steel and the fixing end on both sides of the I-shaped abdominal section of the negative moment section and introducing prestress (PS) by hydraulic jack to pour casing concrete to cure (FIG. 6 (c)), Step of releasing the preflex load (Pf) (Fig. 6 (d)), the negative reaction force bearing at the point portion (point B of Fig. 7) of the negative moment section of the bridge (200 in Fig. 7) Step) to install a prestressed PSPS-induced span-split preflex beam, and then install it on the bridge (Fig. 7 (a)). Step of dismantling the temporary facility (Fig. 7 (b)), the negative reaction force prestress (PfB) is applied to the negative moment bearing section B by the hydraulic jack on the lower casing and the preflex composite beam lower casing. Introducing step (Fig. 7 (c)), slab (40 in Fig. 7) and connection of the preflex beam Preflex beam split fabrication and installation method installed by curing concrete

In addition, in the split beam fabrication of continuous beam preflex beam composite beams of two or more spans, two-span and three-split manufacturing installations (Figs. 8 to 10) have the right and left bending moments (Fig. 8 (a)) according to loads in the live load (W). The point where the bending moment becomes zero at symmetry is the point (E, F in Fig. 8) and the positive (+) moment section (A-E, F-C in Fig. 8) and the negative (-) moment section (Fig. 8). E-F) of 8 is divided into equivalent beams (Fig. 8 (b)) by the simple bore due to the stress of internal and external forces, and the equivalent positive and negative moment sections Calculation of bending moments (MD, MB, MG) according to live loads (W) loads on separate simple beams and fabricating segments loading preflection loads (Pf) according to bending moment diagrams (Fig. 8 (c)) The production method is as follows. Two-segment three-segment The step of producing a positive (+) moment section and a negative (-) moment section I-shaped steel with the deflection curve by the simple beam bending moment (-) in the negative (-) The central point portion of the moment section (B in Fig. 8) attaches the lower flange cross (+) reinforcement base plate (16 in Fig. 9), and the positive moment section is at both ends (A point in Fig. 8). Load the pre-flexion (Pf≥3WL / 8) with the point E, and the negative moment section (points E to F in Fig. 8) is the center cross-shaped reinforcement base plate (16 in Fig. 9). ) (F) load negative reflection pre-flexion (PfRB≥WL) (Fig. 9 (b)), and load the pre-flexion (f) to form a reverse camber in the I-shaped steel (Fig. 9 ( c), In the state of pre-loading, the positive moment section is divided into PC steel and the fixing stage (110 in FIG. 13) on the I-type upper flange with the central axis (neutral shaft NN) high tension bolt (111 in FIG. 13). ) Prestressed by hydraulic jack In the negative moment section, PC steel (130 of FIG. 13) and fixing stage (115 of FIG. 13) are installed on both sides of the I-shaped abdominal abdomen, and prestressing (PS) is introduced with a hydraulic jack. Step 9 of pouring the curing of Fig. 9 (Fig. 9 (d)), releasing the preflection (Pf) load (Fig. 9 (e)), the point of the negative moment section of the bridge Installing a negative reaction force bearing (200 in FIG. 10) at the part (point B of FIG. 9) and carrying a span-divided preflex beam in which prestress (PS) is introduced to construct a temporary connection to the bridge (in FIG. 10). (a)) Release the prestress (PS) introduced into PC steel, remove the PC steel and fixing plate temporary equipment, and attach the negative reaction force bearing at the point B of the negative moment section and the upper flange of the preflex composite beam. Introducing a negative reaction prestress (PfB) into the hydraulic jack (step (b) of FIG. 10), the connection of the slab and the preflex beam Pouring concrete curing by the method comprising: making ((c) of FIG. 10) PC steel JACKING prestress introduced Preflex beam splitting method for manufacturing installation and

In continuous beams of two spans or more, a negative reaction force is supported after the sheath pipe (212 in Fig. 14) of PC steel is buried in the pier point of the negative moment section (50 in Fig. 14). 14 (200 in FIG. 14) and the preflex beam splitting member (10 in FIG. 14) are connected to the carrying base and mounted on the negative reaction bearing, and then the sheath pipe embedded in the piers in the upper flange (10 in FIG. 14). (212 in Fig. 14), the PC steel (211 in Fig. 14) is pulled out in the opposite direction to insert a negative reaction prestress (PS in Fig. 14) with a hydraulic jack on the flange using a fixing cone (211 in Fig. 14). By minimizing the maximum negative moment by minimizing the cross section of the negative moment section, preventing the fall of the upper slab concrete and preventing the crack at the point, and free fall prevention in the event of an earthquake Flex beam split fabrication installation method.

Prefab beam composite beam fabrication method, which prevents the loss of preflection and prevents the camber from being lost for a long time until the pre-assembled beam splitting member manufactured in the division of short span and two or more spans is manufactured by carrying out alternating pier. The value can be maintained and further corrected, and uniform prestress is introduced to each connected preplex beam, thereby integrating the divided assembly members, and the construction cost can be reduced by the partial prestress introduction temporary equipment and air shortening.

In addition, the negative moment is attenuated to minimize the I-shaped cross section of the negative moment section, and the fall prevention facility is unnecessary when placing the upper slab concrete. It can prevent falling out when it happens.

1 is a diagram illustrating a process of splitting a conventional preplex composite beam

2 is a live load and bending moment of the present invention

Figure 3 is a short span preflex beam splitting manufacturing process of the present invention

Figure 4 is a short span preflex split beam fabrication installation of the present invention

FIG. 5 is a diagram showing two-stage two-segment preplex beam splitting stress diagram for continuous beams of the present invention; FIG.

Figure 6 is a continuous beam two-span two-segment pre-plex beam splitting fabrication of the present invention

7 is a view showing the installation of the continuous beam two-span two-division preplex split beam of the present invention

Figure 8 is a two-stage three-segment pre-plex beam split stress diagram of the present invention

Figure 9 is a continuous beam two-span three-segment preplex beam splitting fabrication of the present invention

10 is a view illustrating the installation of a continuous beam two-span three-division preplex split beam of the present invention;

Figure 11 is a detailed view of the short-span preflex beam splitting fabrication of the present invention

12 is a detailed view of a continuous beam two-span two-segment pre-plex beam splitting of the present invention

Figure 13 is a detailed view of the continuous beam two-span three-part preflex beam splitting fabrication of the present invention

Figure 14 is a detailed view of the negative reaction pre-stressing introduction of the present invention

Claims (4)

In the split fabrication method of preflex beams, PC steel and fixing plates are installed on both ends of the I-shaped steel member under the condition that the pre-flex load is loaded on each of the I-shaped steel members manufactured by the design bending moment according to the live load. Pre-stress is introduced into PC steel by hydraulic jack. After pre-stressing and releasing the lower casing concrete while maintaining the pre-flexion, the pre-flex beam splitting member is manufactured.The transport connection is reassembled and installed on the bridge, and the pre-stress of PC steel is released. Preflex beam split fabrication installation method. For continuous beam preflex beam composite beams with spans of more than two spans, the central point of the negative moment, which is the symmetrical of the bending moment diagram due to the load due to the live load, is segmented to replace the stress of internal and external forces with equivalent beams, and is equivalent I was manufactured by dividing the stress of internal and external forces into internal beams at the point where the bending moment of the substituted simple beams became zero, and by the bending moment diagram loaded with the live loads on the internal beams replaced by equivalent sections. Load the pre-flection load on the positive moment section of the steel member and install fixing plates on both ends to introduce pre-stress to the PC steel with hydraulic jack, and then add negative reaction pre-flection load on the end of the inner beam. And the negative moment was converted into the prestress of PC steel by installing prestressing plate on the PC steel with hydraulic jack by installing fixing plate at the intersection and end of the neutral shaft at the time of in Method release after curing the poured concrete to produce a lower casing Preflex beam splitting member, and carrying connection assembly installed on the bridge and install free flex beam splitting produced to release the prestress of the PC steel material from. In the production of continuous beam preflex beam composite beams with two or more spans, the positive moment and negative moment sections are defined as the point at which the bending moment becomes zero at the symmetry of the bending moment diagram according to the live load. Segmented by, and replaced by the equivalent beams by the stress of internal and external forces, and the angle of flexural moments according to the simple beam loads of the positive and negative moment sections The pre-loaded load of the positive moment section and the negative reaction preflection were loaded on the central point of the negative moment section and then prestressed to PC steel by hydraulic jack. The pre-cast beam splitting member is manufactured by placing and curing the lower casingcrete while maintaining the pre-fraction.The pre-beam assembly is installed on the bridge, and the pre-stress is released. Flex beam split fabrication installation method. In the production of continuous beam preflex beam composite beams with two or more spans, a sheath pipe for inserting PC steel is embedded at the pier point of the negative moment section, and after the pier is completed, a negative reaction bearing is installed and the preflex beam is installed. Preflex beam that carries the member and mounts it on the negative reaction bearing, and then pulls the PC strand into the opposite direction from the upper flange hole to the sheath pipe embedded in the piers and introduces the negative reaction prestress into the hydraulic jack. Production installation method.