Construction method of prefabricated corrugated steel web bent cap

Abstract

The application discloses a construction method of a corrugated steel web cover beam, which comprises the following steps: processing a corrugated steel web, welding a partition plate and a connecting structure; binding a bottom plate steel reinforcement framework and a top plate steel reinforcement framework, and installing prestressed tendons; installing a cover beam bottom formwork on a prefabrication pedestal, positioning transverse side formworks of a cover beam top plate and a cover beam bottom plate, and installing the transverse side formworks; pouring in layers, curing, once tensioning the prestressed tendons, and removing the side formworks. The corrugated steel web is used, the upper flange and the lower flange of the corrugated steel web are welded with shear keys pre-buried in the top plate and the bottom plate respectively, the upper edge and the lower edge of the partition plate are welded with shear keys pre-buried on the top plate and the bottom plate respectively, and the two vertical edges of the partition plate are welded with the corrugated steel web respectively, so that the structural strength of the corrugated steel web cover beam is ensured, and the weight of the cover beam is reduced under the premise that the structural strength meets the design requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to highway and urban road bridges, and in particular to a construction method of a prefabricated corrugated steel web cap beam. BACKGROUND

[0002] In a bridge construction project, the construction method of the bridge pier component (including the pier and the cap beam) mainly has a cast-in-situ method and a prefabricated hoisting method. The cast-in-situ method usually needs to close the road for a long time, thereby affecting the traffic condition of the road. The prefabricated hoisting method is to prefabricate the pier and the cap beam in a prefabrication plant and then install them by using a hoisting device or a bridge erecting machine. Compared with the cast-in-situ method, the prefabricated hoisting method has less on-site construction amount and relatively less impact on traffic, and thus is mostly used in the existing municipal bridge construction project.

[0003] The cap beam, also known as the hat beam, is a cross beam arranged on the top of the pier or the pier column and is mainly used for supporting the upper structure of the bridge and transmitting all loads to the lower structure, and is an important component of the bridge. At present, the bridge of the municipal bridge is relatively wide, which requires a wider cap beam (i.e., the transverse length of the cap beam is usually large), resulting in a large weight of the cap beam and a large hoisting difficulty. At present, the commonly used hoisting capacity in engineering is ≤300 tons, while the overall prefabricated cap beam usually exceeds the weight, and thus the separate prefabrication method is usually used in the actual engineering, and the prefabricated parts are poured together at the construction site, and the on-site assembly construction process is complex.

[0004] At present, the combined box beam using the corrugated steel plate to replace the left and right concrete webs of the traditional concrete box beam has been applied in bridge engineering. How to apply the corrugated steel plate to the cap beam, reduce the weight of the cap beam under the premise of ensuring that the cap beam meets the design requirements, and use the overall prefabrication to reduce the on-site assembly workload is crucial to the existing municipal bridge construction project. SUMMARY

[0005] The present application aims to provide a construction method of a prefabricated corrugated steel web cap beam. The present application applies the corrugated steel web to the prefabricated cap beam, greatly reduces the self-weight of the cap beam under the premise of ensuring that the structural strength meets the design requirements, reduces the hoisting difficulty and engineering cost, and improves the construction efficiency of the lower structure of the bridge.

[0006] To achieve the above-mentioned purpose, the present application can adopt the following technical solutions:

[0007] The construction method of the prefabricated corrugated steel web cap beam according to the present application comprises the following steps

[0008] Firstly, a corrugated steel web meeting the design requirements is processed, a plurality of partition plates are welded at intervals between the two corrugated steel webs, and a connecting structure is welded on the partition plates and the corrugated steel webs;

[0009] Second step, binding the bottom plate steel reinforcement framework and the top plate steel reinforcement framework, setting the lifting point and support pre-embedded parts in the top plate steel reinforcement framework, installing prestressed pipe in the reserved channel of the top plate steel reinforcement framework and the reserved channel of the bottom plate steel reinforcement framework respectively, and installing prestressed tendon in the prestressed pipe;

[0010] Third step, installing the cap beam bottom formwork on the prefabricated pedestal, rotating the top plate steel reinforcement framework, the bottom plate steel reinforcement framework and the corrugated steel web by 90° respectively and hoisting them onto the cap beam bottom formwork, so that the corrugated steel web corresponds to each other, the top plate steel reinforcement framework is located at the upper flange side of the corrugated steel web, and the bottom plate steel reinforcement framework is located at the lower flange side of the corrugated steel web;

[0011] Fourth step, positioning the transverse side formworks of the cap beam top plate and the cap beam bottom plate on the cap beam bottom formwork respectively, fixing each transverse side formwork on the cap beam bottom formwork, and connecting the inner form and the outer form of the transverse side formwork by a plurality of tension bolts; connecting the inner forms of the two transverse side formworks by a plurality of support members;

[0012] Installing longitudinal side formworks at both ends of the two transverse side formworks respectively, fixing the longitudinal side formworks on the cap beam bottom formwork, and connecting the inner form and the outer form of the longitudinal side formwork by tension bolts;

[0013] Fifth step, layering and pouring concrete into the transverse side formwork and the longitudinal side formwork and curing;

[0014] Sixth step, after the concrete is cured to the design strength, prestressed tendons in the top plate and the bottom plate are tensioned once respectively; after the tensioning is completed, the side formworks are removed, and a prefabricated corrugated steel web cap beam is obtained.

[0015] In the present application, the corrugated steel web is used to replace the traditional concrete web, and the prefabricated cap beam is a hollow structure surrounded by the corrugated steel web, the top plate and the bottom plate (concrete pouring), which greatly reduces the self-weight of the cap beam, reduces the lifting difficulty and improves the construction efficiency.

[0016] Compared with the existing block prefabricated cap beam, the present application applies the corrugated steel plate to the cap beam, reduces the self-weight, can be prefabricated as a whole, is convenient for transportation and hoisting, avoids the cumbersome process of on-site assembly after block prefabrication, reduces the scale of on-site personnel and speeds up the speed of on-site hoisting construction, and further reduces the influence on the existing line traffic blockage.

[0017] In the preferred embodiment of the present application, the connecting structure in the first step includes a plurality of shear keys, each of which includes a connecting plate and a plurality of connecting bolts fixed on the connecting plate. The connecting bolts of the shear key are pre-embedded in the top plate and the bottom plate of the cap beam during prefabrication, and are located in the side form during the setting of the side form, so as to ensure that the connecting bolts are poured into the top plate and the bottom plate of the cap beam.

[0018] In the preferred embodiment of the present application, the bottom plate of the prefabricated corrugated steel web cap beam is reserved with a manhole; the cap beam body corresponding to each pier is also poured with a concrete member, which connects the concrete top plate and the concrete bottom plate together, and the concrete member is provided with a hole. More preferably, the partition plates in the first step are longitudinally arranged, and each of the partition plates is provided with a through hole. The partition plates are provided with through holes, the bottom plate is reserved or provided with two or more manholes, the concrete member is also provided with a hole, which ensures the ventilation of the cap beam inner cavity, facilitates electrical wiring and maintenance, and improves the toughness of the cap beam body.

[0019] Compared with the traditional prefabricated cap beam, the present application has the following advantages:

[0020] The corrugated steel web is adopted in the present application, the upper flange and the lower flange of the corrugated steel web are welded to the shear keys embedded in the top plate and the bottom plate respectively, the upper edge and the lower edge of the partition plate are welded to the shear keys embedded in the top plate and the bottom plate respectively, and the two vertical edges of the partition plate are welded to the corrugated steel web, which ensures the structural strength of the corrugated steel web cap beam and reduces the weight of the cap beam under the premise of ensuring that the structural strength meets the design requirements.

[0021] The corrugated steel plate is adopted as the cap beam web in the present application, which greatly reduces the self-weight of the cap beam, facilitates transportation, and reduces the requirements for cranes and sites in the construction site, thereby reducing the hoisting difficulty; since the cap beam is prefabricated as a whole, the site wet work is also reduced, the risks encountered in the construction process are reduced, and the safety of the construction is improved.

[0022] The corrugated steel web is adopted as the web of the cap beam in the present application, which effectively reduces the temperature and shrinkage creep effect, improves the use efficiency of the prestressed tendon, and avoids the cracking problem of the traditional cap beam web; in addition, the corrugated steel web enables the tensioning prestress of the top plate tendon to be fully transmitted to the top plate, and the bottom plate does not appear tensile stress, which can be tensioned at one time during prefabrication, avoids on-site tensioning operation, greatly reduces the construction difficulty, and speeds up the construction progress. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a construction state diagram of the present application (the cap beam and the pier are π-shaped).

[0024] Figure 2 is Figure 1 a structural schematic view of the prefabricated corrugated steel web cap beam.

[0025] Figure 3 is Figure 2 an A-A view of the present application.

[0026] Figure 4 is Figure 2 a B-B view of the present application.

[0027] Figure 5 is Figure 2 a D-D view of the schematic diagram.

[0028] Figure 6 is Figure 2 an E-E view of the schematic diagram.

[0029] Figure 7 is Figure 2 a plan view (concrete roof omitted).

[0030] Figure 8 is a connection diagram of the corrugated steel web and shear key in the first step of the present application.

[0031] Figure 9 is a setting diagram of the side formwork in the fourth step of the present application.

[0032] Figure 10 is a second construction state diagram of the prefabricated corrugated steel web cover beam of the present application.

[0033] Figure 11 is a third construction state diagram of the prefabricated corrugated steel web cover beam of the present application.

[0034] Figure 12 is Figure 11 a schematic diagram of the prefabricated corrugated steel web cover beam. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below with reference to the drawings, which are implemented on the premise of the technical scheme of the present application, and the detailed implementation manner and specific operation process are given, but the protection scope of the present application is not limited to the following embodiments.

[0036] It should be noted that all the directional indications (such as up, down, left, right, front, back, etc.) in the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0037] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixing", etc. should be understood in a broad sense, for example, "fixing" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0039] This invention provides a construction method for prefabricated corrugated steel web cap beams. This method uses corrugated steel plates as the web of the cap beam, resulting in a hollow structure. While ensuring structural strength, this significantly reduces the self-weight of the cap beam, facilitating hoisting and reducing on-site work. Furthermore, the corrugated steel web allows all the prestressing stress of the top slab steel strands to be transferred to the top slab, preventing tensile stress in the bottom slab. Tensioning can be completed in one step during prefabrication, greatly reducing the complexity of on-site processes.

[0040] The following is in conjunction with the appendix Figures 1-12 To provide a more detailed description of the present invention, the precast corrugated steel web cap beam of the present invention includes a concrete bottom slab 1, a concrete top slab 2, a pair of corrugated steel webs 3, and a reinforcing support structure.

[0041] Combination Figures 4-5 It can be seen that multiple prestressed tendons 4 are pre-embedded in both the concrete base slab 1 and the concrete top slab 2 to ensure the structural strength of the main body of the cap beam.

[0042] Combination Figures 2-3 It can be seen that longitudinal web plates 12 are also poured at both ends of the concrete base plate 1 and the concrete top plate 2. The longitudinal web plates 12, the corrugated steel web plates 3, the concrete base plate 1, and the concrete top plate 2 form a hollow cavity, which greatly reduces the self-weight of the main body of the cap beam, enables overall prefabrication, reduces the difficulty of lifting, and improves construction efficiency.

[0043] Combination Figure 2 and 6 It is known that the load at the connection between the cap beam and the pier is often large. In order to improve the structural strength and load bearing capacity, a concrete reinforcing member 5 is also poured between the concrete bottom slab 1 and the concrete top slab 2 corresponding to the pier. The concrete reinforcing member 5 connects the concrete top slab 2 and the concrete bottom slab 1 together.

[0044] Combination Figure 2 , 5 As shown in section 7, the reinforced support structure includes multiple longitudinally arranged partitions 8 (made of steel plates) between the two corrugated steel webs 3. The two vertical edges of the partitions 8 are welded to the corrugated steel webs 3 respectively. The upper edge of the partitions 8 and the upper flange of the corrugated steel webs are connected to the concrete top slab 2 through upper shear keys 6 respectively. The lower edge of the partitions 8 and the lower flange of the corrugated steel webs are connected to the concrete bottom slab 1 through lower shear keys 7 respectively. This makes the corrugated steel webs 3, partitions 8, concrete bottom slab 1, and concrete top slab 2 connected to form a whole, further improving the structural strength of the main body of the cap beam.

[0045] The upper shear key 6 and the lower shear key 7 are identical in structure during actual prefabrication. The upper shear key 6 comprises a plurality of connecting bolts 6.1 embedded in the concrete top plate 2 and a connecting plate 6.2 connecting the plurality of connecting bolts 6.1 together, and the connecting plate 6.2 is made of a steel plate and can be welded with the upper flange of the corrugated steel web 3 during actual prefabrication, as shown in Figure 4 .

[0046] As can be seen from Figure 2 , 4 and 6-7, the manhole 1.1 is arranged on the concrete bottom plate 1 near the pier column; the maintenance hole 8.1 is arranged on the partition plate 8, and the hole 5.1 is also arranged on the concrete reinforcing member 5, and the manhole 1.1, the maintenance hole 8.1 and the hole 5.1 not only ensure the connectivity of the cover beam inner cavity, further ensure the ventilation of the cover beam inner cavity, but also facilitate the electrical wiring, the early maintenance and the later maintenance, and further improve the toughness of the cover beam main body.

[0047] The construction method of the prefabricated corrugated steel web cover beam comprises the following specific steps:

[0048] Firstly, the corrugated steel web 3 is processed (processed according to the design requirements to meet the design requirements), and a plurality of partition plates 8 are welded between the two corrugated steel webs 3, and the partition plates 8 are arranged longitudinally, and the two vertical edges of the partition plate 8 are welded with the corrugated steel web 3, respectively;

[0049] The upper shear key 6 is welded on the upper flange of the two corrugated steel webs 3 and the upper flange of the partition plate 8, respectively; the lower shear key 7 is welded on the lower flange of the two corrugated steel webs 3 and the lower flange of the partition plate 8, respectively; the upper shear key 6 and the lower shear key 7 are identical in structure, and both comprise a connecting plate 6.2 and a plurality of connecting bolts 6.1 fixed on the connecting plate 6.2, and the connecting bolts 6.1 are embedded in the concrete top plate 2 and the concrete bottom plate 1, as shown in Figure 8 ;

[0050] The connecting plates of the plurality of upper shear keys 6 at the top of the corrugated steel web 3 are preferably of an integral structure, and the connecting plates of the plurality of lower shear keys 7 at the bottom of the two corrugated steel webs 3 are preferably of an integral structure, and the connecting plates are welded on the upper flanges and the lower flanges of the two steel webs, respectively, which is simple in construction and improves the structural strength;

[0051] Secondly, the bottom plate steel reinforcement framework and the top plate steel reinforcement framework are bound according to the conventional method, the lifting point and the support pre-embedded part are arranged in the top plate steel reinforcement framework according to the conventional method, the prestressed pipe is installed in the top plate steel reinforcement framework and the reserved channel of the top plate steel reinforcement framework, respectively, and the prestressed tendon 4 is installed in the prestressed pipe;

[0052] Third step, install the bottom formwork 9 of the cap beam on the precast pedestal, rotate the top steel reinforcement framework, the bottom steel reinforcement framework and the corrugated steel web 3 by 90° and hoist them onto the bottom formwork 9 of the cap beam, the two corrugated steel webs 3 correspond to each other, the top steel reinforcement framework is located at the upper flange side of the corrugated steel web 3, and the bottom steel reinforcement framework is located at the lower flange side of the corrugated steel web 3, see Figure 9 ;

[0053] Fourth step, position the transverse side formwork 11 of the top plate and the bottom plate of the cap beam on the bottom formwork 9 of the cap beam respectively, fix each transverse side formwork 11 on the bottom formwork 9 of the cap beam, and connect the inner form and the outer form of the transverse side formwork 11 together by using a plurality of tension bolts 13; connect the inner forms of the two transverse side formworks 11 together by using a plurality of support members 10 (support rods arranged in a cross shape are selected);

[0054] Install longitudinal side formworks at both ends of the two transverse side formworks 11 respectively, fix the longitudinal side formworks on the bottom formwork of the cap beam, and connect the inner form and the outer form of the longitudinal side formworks by tension bolts; the inner cavities of the longitudinal side formworks and the inner cavities of the transverse side formworks 11 are sequentially connected in a head-to-tail manner to facilitate pouring the top plate, the bottom plate and the longitudinal web of the cap beam;

[0055] In actual construction, because the load at the connection between the cap beam and the pier column is often large, a formwork is arranged at the negative bending moment area corresponding to the pier column to improve the structural strength and load bearing capacity;

[0056] Fifth step, pour the concrete into the transverse side formwork 11 and the longitudinal side formwork in layers and cure according to the conventional method, and pour the concrete to obtain the concrete top plate 2, the concrete bottom plate 1 and the longitudinal web 12 of the cap beam;

[0057] Pour the concrete into the formwork at the broken part of the corrugated steel web 3 according to the conventional method to form the concrete reinforcing member 5, and the concrete reinforcing member 5 connects the concrete top plate 2 and the concrete bottom plate 1 together;

[0058] Sixth step, after the concrete is cured to the design strength, tension the prestressed steel bars 4 in the concrete top plate 2 and the concrete bottom plate 1 respectively at one time; after the tensioning is completed, remove the side formwork (by means of a lifting frame, etc.), and obtain the prefabricated corrugated steel web cap beam, see Figure 2 ; transport the corrugated steel web cap beam to the construction site, hoist it on the pier column by means of lifting equipment, connect the cap beam and the pier column together according to the conventional method, and see Figure 1 .

[0059] In actual prefabrication, the partition plate 8 is made of steel plate, each partition plate 8 is provided with a maintenance hole 8.1, the bottom plate of the bent cap near the pier is provided with at least one manhole 1.1, and the concrete reinforcing member 5 is provided with a hole 5.1, so that the internal cavities of the corrugated steel web 3 are connected with each other, not only having a ventilation effect, but also facilitating electrical wiring, early maintenance and later maintenance, and also improving the toughness of the bent cap body.

[0060] The lower flange of the corrugated steel web 3 and the lower edge of the partition plate 8 are respectively welded on the connecting plate of the lower shear key 7, and the upper flange of the corrugated steel web 3 and the upper edge of the partition plate 8 are respectively welded on the connecting plate of the upper shear key 6, thereby connecting the corrugated steel web 3 and the partition plate 8 with the top plate 2 and the bottom plate 1 of the bent cap together, thereby forming an integral structure and ensuring the structural strength of the corrugated steel web bent cap. The two vertical edges of the partition plate 8 are respectively welded with the corrugated steel web 3, so that the corrugated steel web 3, the partition plate 8, and the bottom plate 1 and the top plate 2 are connected to form an integral whole, further improving the structural strength.

[0061] It should be emphasized that the prefabrication method of the present application can not only prefabricate the bent cap shown in the figure Figures 1-2 The "π" shaped bent cap shown in the figure is also applicable to Figure 10 The door-shaped bent cap shown in the figure (i.e. the bent cap body and the pier are in a door-shaped structure) can also be Figures 11-12 The T-shaped bent cap shown in the figure (i.e. the bent cap body and the pier are in a T-shaped structure).

[0062] Finally, it should be emphasized that the above description is only for the preferred embodiments of the present application and is not intended to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments without creative labor, or make equivalent replacement of some technical features. Thus, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A construction method for a precast corrugated steel web cap beam, characterized in that, Includes the following steps: The first step is to process corrugated steel webs that meet the design requirements, weld multiple partitions between two corrugated steel webs at intervals, and weld connecting structures on the partitions and corrugated steel webs. The second step is to tie the bottom slab reinforcement cage and the top slab reinforcement cage, set up lifting points and support embedded parts in the top slab reinforcement cage, install prestressed pipes in the reserved channels of the top slab reinforcement cage and the bottom slab reinforcement cage respectively, and install prestressed tendons in the prestressed pipes. The third step is to install the bottom formwork of the cap beam on the precast platform, rotate the top slab reinforcement cage, bottom slab reinforcement cage and corrugated steel web by 90° and hoist them onto the bottom formwork of the cap beam, so that the corrugated steel web is aligned with the top and bottom, the top slab reinforcement cage is located on the upper flange side of the corrugated steel web, and the bottom slab reinforcement cage is located on the lower flange side of the corrugated steel web. The fourth step is to position the transverse side formwork of the top plate and bottom plate of the cap beam on the bottom formwork of the cap beam, fix each transverse side formwork to the bottom formwork of the cap beam, and connect the inner and outer formwork of the transverse side formwork together with multiple tie bolts; connect the inner formwork of the two transverse side formworks together with multiple support members. Longitudinal side formwork is installed at both ends of the two transverse side formworks respectively. The longitudinal side formwork is fixed on the bottom formwork of the cap beam, and the inner and outer formworks of the longitudinal side formwork are connected by tie bolts. The fifth step is to pour and cure concrete in layers into the transverse and longitudinal side formwork to obtain the concrete top slab, concrete bottom slab and longitudinal web of the cap beam. Step 6: After the concrete has cured to the design strength, tension the prestressing tendons in the top slab and bottom slab at one time. After tensioning, the side formwork is removed to obtain the precast corrugated steel web cap beam.

2. The construction method of the precast corrugated steel web cap beam according to claim 1, characterized in that: The connection structure in the first step includes multiple shear keys, each of which includes a connecting plate and multiple connecting bolts fixed to the connecting plate.

3. The construction method of the precast corrugated steel web cap beam according to claim 1, characterized in that: The precast corrugated steel web cap beam has a pre-reserved manhole on its bottom plate; a concrete component is also cast on the main body of the cap beam corresponding to each pier column, the concrete component connects the concrete top plate and the concrete bottom plate together, and the concrete component has holes.

4. The construction method of the precast corrugated steel web cap beam according to claim 3, characterized in that: The partitions in the first step are arranged longitudinally, and each partition has a through hole.

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