JP7484439B2 - Bridge deck replacement method - Google Patents

Description

This invention relates to a bridge deck replacement method in which an existing deck is replaced with a new precast deck while alternating between construction traffic restriction periods and traffic-free periods.

Traditionally, when carrying out renovation work on large road bridges that have bridges for inbound and outbound lanes to replace the existing bridge deck with a new deck, one of the bridges for the inbound or outbound lanes is closed to traffic while the renovation work is carried out, and traffic is restricted in both directions on the other bridge.

However, in heavy traffic roads in urban areas and mountainous areas sandwiched between long tunnels, restricting two-way traffic for long periods of time can have a negative impact on the traffic environment in the surrounding areas. For this reason, there is a need for a method of restricting lanes only at night while carrying out renewal work and opening up the entire area to traffic during the day. For example, Patent Document 1 discloses a bridge deck construction method in which road restrictions are implemented at night to replace the existing deck with a new one, in which workers are divided into a PC deck laying team and a concrete filling team.

Specifically, the PC deck laying crew will cut and remove the existing deck above the main girders, then lay the new precast deck parallel to the axis of the bridge, and cover the joints between adjacent precast decks with a temporary covering plate. After this, temporary paving will be applied to the top surface of the temporary covering plate, completing the work for one night. The PC deck laying crew will repeat this work every day until they have removed the deck from the section scheduled for replacement.

Meanwhile, the gap-filling concrete team begins work a few days later, removing the temporary pavement and temporary covering slabs from the newly constructed precast slabs that had been laid in parallel along the axis of the bridge, and pouring gap-filling concrete into the joints between the adjacent newly constructed precast slabs. Then, after the gap-filling concrete has been cured, temporary pavement is laid, completing the overnight work. The gap-filling concrete team repeats this work every day until they have poured gap-filling concrete into all of the joints between the adjacent newly constructed precast slabs that were laid in the section scheduled for replacement.

JP 2012-82622 A

As mentioned above, in Patent Document 1, it is assumed that the work up to laying the new precast deck, part of the series of work required to replace the existing deck with a new precast deck, will be carried out overnight. However, although this is not made clear in Patent Document 1, various processes such as scraping and installation of stud dowels are generally required on the top surface of the main girder that is exposed after the existing deck is removed.

Considering these complicated tasks, if any unforeseen incident occurs during construction, there is a risk that the work up to laying the new precast deck may not be completed overnight. Even if it were possible to complete the work overnight, the timing for reopening the road to traffic during the series of work processes for replacing the existing deck with a new precast deck would be limited to the period after the new precast deck is laid and immediately before the filling concrete is poured.

For this reason, it is difficult to adjust the progress of work within a single traffic control period depending on the site conditions and construction status. In addition, as mentioned above, it is assumed that the work up to laying the new precast deck will be done overnight, and there is no clear method for completing the series of work from laying the new deck to pouring filler concrete into the joints and laying the actual paving in one night.

The present invention was developed in consideration of these problems, and its main objective is to provide a bridge deck replacement method that can efficiently replace an existing deck with a new deck made of precast concrete.

In order to achieve this object, the bridge deck replacement method of the present invention is a bridge deck replacement method in which an existing deck installed on a steel main girder is replaced with a new deck made of precast concrete while alternating between construction traffic control time periods and traffic open time periods, and includes a first step of removing at least a portion of a plurality of existing deck pieces formed by dividing the existing deck of the bridge in the bridge axis direction to expose the main girder, a second step of installing stud dowels on the upper surface of the main girder before installing the new deck exposed by removing the existing deck pieces in the first step, and a second step of removing the stud dowels on the upper surface of the main girder before installing the new deck exposed by removing the existing deck pieces in the second step. and a third step of installing multiple new deck slabs on the main girders on which stud dowels are installed, joining the new deck slabs to the main girders, and then joining adjacent new deck slabs, wherein the first step to the third step are carried out during the traffic control time period for construction work, and include cases where two or more steps are carried out consecutively within one traffic control time period for construction work, and when the first step or the second step is carried out immediately before the traffic release time period arrives, a temporary covering deck slab is installed on the main girders, which are exposed at the time the work is completed, in place of the existing deck slab pieces that were removed.

The bridge deck replacement method of the present invention is characterized in that the first to third steps are repeated in the bridge axis direction each time the construction traffic control period arrives.

According to the bridge deck replacement method of the present invention, the work process required to replace the existing deck with a new deck is divided into a first process, a second process, and a third process during which construction can be suspended. Then, when these processes are carried out during the traffic control period for construction work, the traffic control period for construction work and the traffic open period are repeated, including cases where two or more processes are carried out consecutively within one traffic control period for construction work. This allows the stage at which construction work is suspended to be appropriately selected according to the site conditions and construction status (for example, the progress of scraping work, stud dowel installation work, etc.), so that the progress of the work process carried out during one traffic control period for construction work can be adjusted while preparing for the arrival of the traffic open period, making it possible to efficiently carry out the replacement work for the new deck.

Therefore, by setting the traffic control hours for construction work to be at night, it is possible to open up traffic during the day. Even if the bridge on which the existing deck replacement method is to be implemented is located on a heavy traffic road in an urban area, or in a mountainous area sandwiched between long tunnels, construction can be carried out while minimizing the impact on the traffic environment in the surrounding area.

In addition, the bridge deck replacement method of the present invention is such that the cross section of the existing deck piece as viewed from the bridge axis direction is:
It is characterized in that it is formed into a half cross section by dividing the cross section of the existing deck in half.

According to the bridge deck replacement method of the present invention, the cross section of the existing deck is divided in half, and one of the half-sections of the existing deck is divided in the bridge axis direction to form multiple existing deck pieces, which are then removed and replaced with new deck pieces, making it possible to adopt the so-called half-section deck replacement method.
As a result, for example, in the case of a large road bridge that has a bridge for inbound and a bridge for outbound lanes, if one of the bridges is left open to traffic while the number of lanes on the other bridge is reduced at night, it will be possible to carry out replacement work on the existing deck while keeping the bridge fully open to traffic during the day.

Therefore, unlike conventional construction methods, there is no need to impose road restrictions such as completely closing one bridge to traffic while carrying out construction work and restricting two-way traffic on the other bridge. This not only ensures safety for passing vehicles, but also makes it possible to reliably carry out replacement work for existing decks even in road environments with various challenges, such as when two-way traffic restrictions cannot be implemented due to circumstances such as the road structure, or when long-term two-way traffic restrictions are difficult even if they are possible due to traffic conditions in the surrounding area.

In addition, in the bridge deck replacement method of the present invention, the adjacent new decks are replaced with the new decks in the third step.
It is characterized by being joined with a permanent plate that functions as part of the deck .

According to the bridge deck replacement method of the present invention, adjacent new decks are joined with a permanent plate that functions as a part of the new deck , and by placing this permanent plate on the upper surface of the joints formed by the adjacent new decks, the work of laying the permanent pavement can be carried out prior to the work of filling the joints with filler concrete. This allows the joints to be filled with filler concrete from the lower side of the new deck while traffic is opened after the permanent pavement is laid, reducing the amount of work carried out during traffic control hours and making it possible to significantly improve work efficiency.

The bridge deck replacement method of the present invention is characterized in that after the temporary lining deck is installed on the main girder, the upper and lower surfaces of the joints adjacent to the temporary lining deck are covered with opening cover plates, and the opening cover plates are fastened together using fasteners.

According to the bridge deck replacement method of the present invention, when a temporary lining deck is installed on the main girder, the gap filling process of the joints formed adjacent to the temporary lining deck can be easily carried out using an opening closing plate, which significantly improves the workability of installation and removal compared to when filling material is used, and contributes to shortening the construction period.

According to the present invention, the stage at which work is suspended can be appropriately selected depending on the site conditions, construction status, etc., so that replacement work for the new deck can be efficiently carried out while making effective use of lane closure periods in preparation for the arrival of traffic release periods.

FIG. 2 is a diagram illustrating a half-section deck replacement method according to an embodiment of the present invention. FIG. 2 is a diagram showing the flow of a half-section deck replacement method in an embodiment of the present invention. FIG. 2 is a diagram showing an outline of a half-section deck replacement method according to an embodiment of the present invention. FIG. 2 is a diagram showing the flow of a bridge deck replacement method in an embodiment of the present invention. 1 is a diagram showing an outline of a bridge deck replacement method according to an embodiment of the present invention. FIG. FIG. 2 is a diagram showing a temporary covering deck in an embodiment of the present invention. FIG. 2 is a diagram showing a newly constructed floor slab made of precast concrete in an embodiment of the present invention. FIG. 2 is a diagram showing a first step of a bridge deck replacement method in an embodiment of the present invention. FIG. 2 is a diagram showing the state of temporary filling in the deck replacement method of a bridge in an embodiment of the present invention. FIG. 11 is a diagram showing a second step of the bridge deck replacement method in an embodiment of the present invention. A figure showing a third step of the bridge deck replacement method in an embodiment of the present invention. FIG. 1 is a diagram showing the procedure for a permanent pavement when the first to third steps of the bridge deck replacement method in an embodiment of the present invention are repeated. 1 is a diagram showing the joint between a new deck slab of a travel lane and a new deck slab of an overtaking lane in an embodiment of the present invention. FIG. FIG. 1 is a diagram showing an example of a construction procedure for a driving lane and an overtaking lane in an embodiment of the present invention. FIG. 11 is a diagram showing another example of a bridge deck replacement method according to an embodiment of the present invention.

The bridge deck replacement method of the present invention is a method for replacing an existing deck with a new deck by alternating between construction traffic control periods, which include both lane control periods and road closure control periods, and traffic-free periods, and is a method that makes it possible to adjust the progress of work processes carried out within one construction traffic control period.

This type of bridge deck replacement method can also be used for full-section construction where the construction lane is closed to traffic, but in this embodiment, we will explain the details by taking as an example the case where the bridge deck replacement method is used for half-section deck replacement.

<<Half-section deck replacement method>>
The half-section deck replacement method, as shown in Figure 1(a), is a method in which, for example, in a road bridge B equipped with a bridge B1 for two lanes in the upward direction and a bridge B2 for two lanes in the downward direction, bridge B1 is restricted to traffic lanes and the existing deck slab 1 of one of the half-sections, either on the driving lane side or the passing lane side, is replaced with a new deck slab, and around the same time, the existing deck slab 1 of the other half-section is also replaced with a new deck.

The flow of the half-section deck replacement method will be explained below with reference to the flow diagram in Figure 2 and Figure 3. First, as shown in Figure 3(a), for bridge B1 with two up-bound lanes, the construction area is divided in the bridge axis direction and multiple sections are set (first step).

Next, as shown in Figure 3(b), each section is divided in a direction perpendicular to the bridge axis, and the driving lane side is set as work sections D1, D2, D3, etc., and the passing lane side is set as work sections O1, O2, O3, etc. (second step).

Once the work zones have been set, the deck replacement method is carried out on the work zone D1 on the driving lane side of the first zone (step 3-1). Next, the deck replacement method is carried out on the work zone O1 on the passing lane side of the first zone (step 3-1).

The following describes the deck replacement method, focusing on the work area D1. In this embodiment, as shown in Figure 1(b), the existing deck 1 in the work area D1 is successively replaced with a new deck 3 from the upstream side of the two upbound lanes (the right side in the bridge axis direction in Figure 1) to the downstream side (the left side in the bridge axis direction in Figure 1).

The flow of the deck replacement method will be explained with reference to the flow diagram of Figure 4 and the conceptual diagrams of Figures 1(b) and 5. First, as shown in Figure 1(b), multiple existing deck pieces 11 are formed in a work area D1 set up on the driving lane side (Step 1). In this embodiment, six existing deck pieces 11 are formed, and these are sized to be transportable by vehicle after removal.

Next, as shown in FIG. 5(a), two of the six existing deck pieces 11 are cut off and removed from the existing deck 1 (Step 2). Then, a part of the main girder 2 made of I-beam is exposed where the existing deck pieces 11 were removed, so preparatory work is carried out on the upper surface of the upper flange of this exposed main girder 2 (Step 3), and stud dowels 21 are installed as shown in FIG. 5(b) (Step 4).

After this, as shown in Figure 5 (c), a new precast concrete deck 3 is installed on the upper flange of the main girder 2 (Step 5), and the new deck 3 is joined to the main girder 2 using stud dowels 21 by pouring non-shrink mortar 4 (Step 6). Then, a permanent plate 52 is installed across the horizontal joint J1 (a joint extending perpendicular to the bridge axis), and the upper edges of the new deck 3 are joined together (Step 7).

After that, the work of laying the permanent pavement 6 on the top surface of the new deck 3 to make it passable for vehicles (Step 8) and the work of pouring the filler concrete 51 into the horizontal joint J1 located on the underside of the permanent plate 52 (Step 9) are carried out simultaneously or before or after this. Note that the permanent pavement 6 refers to the grade of pavement called the permanent pavement in the half-section deck replacement method.

The above steps from Step 2 to Step 9 are repeated until all existing deck pieces 11 are removed from the work section D1, completing the deck replacement work for the half cross section that corresponds to the travel lane side of one section of the bridge B1 for two up-bound lanes in the work section D1. In this embodiment, two of the six existing deck pieces 11 are removed in Step 2, so Steps 2 to 9 are repeated three times, but any number of existing deck pieces 11 can be removed in Step 2.

The process of Step 1, in which multiple existing deck pieces 11 are formed in the work area D1, and the process of repeating the work of Steps 2 to 9 on the multiple existing deck pieces 11 in the work area D1 after Step 1 is completed, constitute one cycle. Therefore, the construction period required for one cycle can be appropriately adjusted depending on the distance range in the bridge axis direction set in the work area D1.

The replacement method for the existing deck using the above procedure shows a case where lane restrictions can be implemented day and night for a certain period of time (several weeks to several months). However, if daytime traffic release periods are to be set during this construction period, construction would have to be carried out during lane restriction periods set at night, and not only would construction have to be suspended before the traffic release periods arrive, but each time construction is suspended, work section D1 would have to be made passable for vehicles.

For this reason, the above-mentioned Steps 2 to 9, which are repeatedly performed in the work area D1 after Step 1 is completed, are divided into the first to third steps during which construction can be interrupted, as shown in the flow in Figure 4. The first step is the process of removing the existing deck piece 11 and preparing the top surface of the main girder 2 (Steps 2 and 3), and the process of creating the existing deck piece 11 in Step 1 is a preliminary operation before carrying out the first step.

The second step is a step (Step 4) of installing the stud dowels 21 on the upper surface of the main girder 2. The third step is a step (Steps 5 to 9) of installing the new deck 3, joining the adjacent new decks 3, and laying the main pavement 6.

In this case, it is advisable to alternate between the construction traffic control period and the traffic release period, including cases where two or more of the first to third steps are carried out consecutively within one construction traffic control period.

Any combination is acceptable, but for example, the first step may be carried out during the preceding lane restriction time period, and then the second and third steps may be carried out consecutively during the following lane restriction time period. Or, the first and second steps may be carried out consecutively during the preceding lane restriction time period, and then the third step may be carried out during the following lane restriction time period. In these cases, two traffic-free periods can be secured, one after the end of the first or second step, and the other after the end of the third step.

Alternatively, steps 1 to 3 may be carried out consecutively during the preceding lane restriction time period, and two of the six existing deck pieces 11 in the work area D1 may be removed, a new deck 3 may be laid, and a permanent pavement 6 may be applied, as shown in Figures 5(a) to 5(c). After this, steps 1 to 3 may be carried out consecutively during the succeeding lane restriction time period, and two of the remaining four existing deck pieces 11 in the work area D1 may be removed, a new deck 3 may be laid, and a permanent pavement 6 may be applied. In this case, a traffic-free time period may be secured each time the third step is completed.

The combination of steps performed during the lane restriction time periods described above does not have to be the same every time. For example, the first step may be performed during the preceding lane restriction time period, the second and third steps may be performed consecutively during the following lane restriction time period, and then the first through third steps may be performed consecutively during the next lane restriction time period.

However, if the processes carried out within one lane restriction period are up to the first process or up to the second process, the main girder 2 will be exposed after the existing deck pieces 11 are removed. In this case, the work of installing the temporary covering plate 7 and the work of applying the temporary gap filling 9 and temporary paving 8 will be carried out on the main girder 2 just before the traffic release period arrives. As a result, when the traffic release period arrives, traffic can be released even if construction work has been suspended.

On the other hand, if the third step is completed within one lane restriction period, the existing deck pieces 11 are removed and the new deck 3 is installed on the main girders 2 after filling with filler concrete 51 and applying the permanent pavement 6. Therefore, in this case, traffic can be opened as soon as the traffic release period arrives, even without setting up the temporary deck 7.

<Temporary covering deck>
As shown in Fig. 6(a), the temporary covering deck 7 that allows vehicles to pass is a member that can temporarily cover the half cross section on the driving lane side of the cross section of the bridge B1 divided into the driving lane side and the passing lane side, and is integrally formed with the deck body 71, the ground cover 72, and the balustrade 73. In this way, the time required for the installation work of the temporary covering deck 7 can be significantly reduced, but the deck body 71, the ground cover 72, and the balustrade 73 may also be manufactured separately and configured to be assembled on-site.

As shown in Fig. 6(b), the deck body 71 of the temporary covering deck 7 has a temporary pavement 8 applied in advance on its upper surface except for the area near the outer edge, and the bridge axis direction length L2 is formed to be approximately the same as the bridge axis direction length L1 of the existing deck piece 11 shown in Fig. 1(b). However, this is not limited to this, and two types of deck pieces smaller than the bridge axis direction length L1 of the existing deck piece 11, for example 1/2 and 1/4, may be prepared.

By preparing two types of bridge axis direction length L2, 1/2 and 1/4, even if it becomes necessary to change the bridge axis direction length L1 of the existing deck slab piece 11 during construction, it is easy to install the temporary covering deck 7 on the main girder 2 that is exposed after removing the existing deck slab piece 11. In other words, if the removed existing deck slab piece 11 has the predefined bridge axis direction length L1, the temporary covering deck slabs 7 with the bridge axis direction length L2 of 1/2 are arranged in parallel in the required number.

On the other hand, when cutting the work section D1 to create the existing deck piece 11, if the planned cutting position overlaps with the longitudinal connection between the main girders 2 where a splice plate is installed on the top surface of the upper flange, the cutting position must be shifted to avoid the splice plate. In that case, the bridge axis direction length L1 of the existing deck piece 11 will not be the predetermined length, and the bridge axis direction length of the exposed main girder 2 after removing the existing deck piece 11 will also change. However, by appropriately combining and using temporary covering decks 7 with bridge axis direction lengths L2 of 1/2 and 1/4, it is possible to address these problems.

Furthermore, the temporary covering deck 7 may be installed directly on the upper surface of the upper flange of the main girder 2 depending on the material thickness, or it may be installed via a height adjustment material 74 made of processed steel material or the like, as shown in Figure 6 (a). When installing via a height adjustment material 74, the height adjustment material 74 is installed in advance on the underside of the deck body 71, and the temporary covering deck 7 can be easily and detachably fixed to the main girder 2 by clamping the height adjustment material 74 and the upper flange of the main girder 2 with a clamp or the like.

In addition, when installing directly, it is advisable to prepare two types of deck body 71 with a flat underside shape and one that is processed so that it can be placed on the splice plate installed on the upper surface of the main girder 2.

<Newly constructed floor slab>
7(a) and 7(b), the newly constructed deck 3 made of precast concrete includes a deck body 31, a pedestal 32, joint reinforcing bars 33, and stud dowel insertion holes 34. The pedestal 32 may be manufactured as an integral part, or may be manufactured separately and installed on the deck body 31 together with a parapet (not shown) on-site.

The connecting rebars 33 are installed so that they protrude parallel to each other from the three sides of the deck body 31: both sides facing the bridge axis direction, and the side facing the existing deck 1 on the passing lane side. They are arranged in two rows in the height direction, and are staggered in plan view in the horizontal joints J1 extending perpendicular to the bridge axis and the vertical joints J2 extending in the bridge axis direction. When construction is complete, they are embedded in the filling concrete 51 poured into the horizontal joints J1 and vertical joints J2.

The stud dowel insertion hole 34 formed in the deck body 31 is located in a position where the stud dowel 21 can be inserted when the new deck 3 is placed on the top surface of the upper flange of the main girder 2, and when the new deck 3 is joined to the main girder 2, the non-shrink mortar 4 is filled through this stud dowel insertion hole 34.

<< Bridge deck replacement method >>
Next, the procedure for the deck replacement method, in which the existing deck 1 in the work area D1 is replaced with a new deck 3 made of precast concrete while alternating between lane restriction periods and traffic-free periods, will be described below.

In this embodiment, the first step is carried out during the first lane restriction period, and then the second and third steps are carried out consecutively during the second lane restriction period after the end of the traffic release period, and this is repeated to complete one cycle (replace the work area D1 with the new deck 3). In addition, the temporary covering deck 7 and the new deck 3 used have lengths L2 and L3 in the bridge axis direction that are approximately the same as or approximately smaller than those of the existing deck piece 11.

<Preparation work to be carried out each time a lane restriction period begins>
Each time a lane restriction period arrives, as shown in Figure 1 (b), lane restrictions are implemented to reduce the two uphill lanes of bridge B1 to one lane, and the deck erection device 10 is brought in and installed near the work area D1 that was previously set up as one cycle of the deck replacement method during the construction planning.

<Deck erection device>
The deck erection device 10 may be any device that has conventionally been used for replacing an existing deck 1, but in consideration of the need to repeatedly load and unload the deck during each lane restriction period, this embodiment employs a gate-type deck erection device 10 that is manufactured so that it can be loaded onto the bed of a vehicle such as a trailer.

As shown in Fig. 1(b) and Fig. 8(a), the deck erection device 10 comprises a pair of portal frames 101 arranged with a gap between them, a pair of crane garters 102 spanned across the portal frames 101, and an overhead crane 103 suspended from each of the crane garters 102. The overhead crane 103 has a structure that allows it to move along the crane garters 102, and all work related to removing the existing deck 1, installing or removing the temporary covering deck 7, and installing the new deck 3 is performed using this overhead crane 103.

<Preceding work to be carried out before the first process>
As described above, the existing deck 1 of the work section D1 set as one cycle is cut with seven cutting lines along the direction perpendicular to the bridge axis as shown in Fig. 1 (b) to create six existing deck pieces 11 (Step 1). Note that it is preferable to cut at equal intervals, but if the position of the cutting line coincides with the position of the splice plate installed on the upper surface of the upper flange of the main girder 2, the cutting position is appropriately changed to avoid the splice plate.

<First lane restriction period: First step>
As shown in Fig. 8(a), the deck erection device 10 is installed at a predetermined position near the work area D1. Next, in order to separate the first of the six existing deck pieces 11 (the rightmost one in Fig. 1(b)) located on the upstream side of the two up-bound lanes from the existing deck 1, a cutting line is drawn on the boundary line along the bridge axis direction of the work area D1, and then the existing deck piece 11 is lifted and removed by the deck erection device 10.

This work is carried out twice in succession to remove the two existing deck pieces 11 as shown in Figure 5 (a). Next, the space created by removing the two existing deck pieces 11 is used to install a work platform 22 as shown in Figure 8 (b) in the required location between the main girders 2 (Step 2).

After this, the work scaffolding 22 is used to perform preparatory work on the upper surface of the upper flange of the main girder 2. Preparatory work includes, for example, removing concrete debris and anchor rebars that remain on the upper surface of the upper flange of the main girder 2 from the existing deck pieces 11 that have been removed, and preparing the base for later installation of the stud dowels 21, which is known as scraping work (Step 3).

After these operations are completed, as shown in FIG. 8(b), the temporary lining deck 7 is installed on the upper surface of the upper flange of the main girder 2 via the height adjustment material 74. As shown in FIG. 9(a), temporary gap filling 9 is performed on the horizontal joints J1 formed between the adjacent temporary lining decks 7, and between the existing deck 1 or existing deck piece 11 and the temporary lining deck 7.

The temporary gap filling 9 is made by placing an opening closing plate 91 such as a steel plate to close the underside of the horizontal joint J1, and then filling it with a filler 92 such as sponge or sand. If the opening of the horizontal joint J1 is large, it is a good idea to also place an opening closing plate 91 on the top surface. Note that if an opening closing plate 91 is placed to close the top surface of the horizontal joint J1, it is not necessary to fill the horizontal joint J1 with filler 92.

Specifically, as shown in FIG. 9(b), a pair of opening closing plates 91 close the upper and lower sides of the horizontal joint portion J1, and the pair of opening closing plates 91 are fastened with fasteners 93 such as bolts so as to sandwich the temporary lining deck 7. At this time, if the opening closing plate 91 on the upper side is fixed to the temporary lining deck 7 in a state in which it closes the entire surface of the horizontal joint portion J1, the opening closing plate 91 on the lower side may close the entire surface of the lower side of the horizontal joint portion J1, as shown in FIG. 9(c), or may be positioned so as to close a portion of the lower side, as shown in FIG. 9(d).

This significantly improves workability and shortens the construction period compared to filling the horizontal joints J1 with filler 92. This process is carried out not only for the horizontal joints J1, but also for the vertical joints J2 formed between the temporary covering deck 7 and the existing deck 1 on the passing lane side.

Next, temporary pavement 8 is applied to the entire upper surface of the temporary lining deck 7. As described above, the preliminary temporary pavement 81 has already been applied to the upper surface of the temporary lining deck 7, so the following temporary pavement 82 can be applied to the edges of the temporary lining deck 7 where the preliminary temporary pavement 81 has not been applied, so as to cover the horizontal joint portion J1 and the vertical joint portion J2. In this way, by applying the preliminary temporary pavement 81 to the upper surface of the temporary lining deck 7 in advance, the overall work time for the temporary pavement 8 can be significantly reduced. After this, the gate-type deck erection device 10 is removed, completing the first step and making the two upbound lanes available for vehicles.

<The second lane restriction period: second and third steps>
As in the start of the first process, the deck erection device 10 is installed at a predetermined position near the work area D1. Next, the temporary covering deck 7 installed on the upper surface of the upper flange of the main girder 2 is temporarily removed by the deck erection device 10, and the scraping condition of the upper surface of the upper flange of the main girder 2 is checked, and scraping work is performed again as necessary to adjust the base surface.

After this, the second step is carried out. That is, as shown in Figure 10, multiple stud dowels 21 are installed at a specified interval on the upper surface of the upper flange of the main girder 2, and anti-rust paint is applied (Step 4). The stud dowels 21 are arranged in a group of multiple dowels aligned in the direction perpendicular to the bridge axis, and multiple dowels are installed in the bridge axis direction with intervals between them. Figure 10 shows an example in which three stud dowels 21 are installed in the direction perpendicular to the bridge axis, but the number can be changed as appropriate depending on the width of the main girder 2, the position of the span, etc.

After these tasks are completed, the third step is carried out. First, the new deck 3 is installed on the upper surface of the upper flange of the main girder 2 using the deck erection device 10 (Step 5). As shown in FIG. 11(a), the new deck 3 is positioned so that the stud dowel insertion holes 34 house the stud dowels 21 installed on the upper surface of the upper flange of the main girder 2, and the stud dowel insertion holes 34 are filled with non-shrink mortar 4 to firmly join the main girder 2 and the new deck 3 (Step 6). Before installing the new deck 3, mortar stoppers 41 are installed on both sides of the upper flange of the main girder 2.

Before, after or at the same time as the filling work with non-shrink mortar 4, the work of joining adjacent new deck slabs 3 using permanent plates 52 (Step 7) is carried out as shown in Figure 11 (b).

The permanent plate 52 is installed so as to straddle the upper part of the horizontal joint J1 formed between the adjacent new deck slabs 3. The permanent plate 52 is made of precast concrete plate material manufactured in a factory from the same material as the filling concrete 51, and has a width sufficient to cover the horizontal joint J1 and a length approximately equal to the length L3 of the deck body 31 in the direction perpendicular to the bridge axis.

The permanent plate 52 may be installed by any method, such as by fixing with anchors or adhesives, and may be installed by placing the permanent plate 52 on the top surface of the deck body 31. In this embodiment, however, the permanent plate 52 is placed on a notch provided on the edge of the deck body 31. In this case, the notch should be formed to a depth such that the top surface of the permanent plate 52 and the top surface of the deck body 31 are flush with each other.

Next, as shown in FIG. 11(c), the permanent pavement 6 is applied to the top surface of the new deck 3 (Step 8). In addition, simultaneously with or before or after the work related to the permanent pavement 6, a formwork 53 is installed below the horizontal joint J1 so as to straddle it. Filling holes, air holes, or filling confirmation holes (none of which are shown) for filling the interfacial concrete 51 are formed in the formwork 53.

Then, as shown in FIG. 11(d), filler concrete 51 is filled from the underside of the horizontal joint J1, and the joint reinforcing bars 33 are embedded (Step 9). Any high-strength, high-durability concrete may be used as the filler concrete 51.

In this way, if the permanent plate 52 is manufactured from the same material as the interfacial concrete 51, it can be handled as a permanent member that can function as part of the new deck slab . Therefore, if the upper side of the horizontal joint J1 is covered with the permanent plate 52, the work of laying the permanent pavement 6 can be carried out immediately thereafter with priority, and therefore the work of filling the interfacial concrete 51 can be carried out from the lower side of the new deck slab 3 while opening the road to traffic. In this way, the work carried out during lane restriction hours can be reduced, making it possible to significantly improve work efficiency.

Before applying the permanent pavement 6, the vertical joints J2 and the horizontal joints J1 formed between the existing deck 1 or existing deck piece 11 and the new deck 3 are temporarily filled with an opening blocking plate 91 and a filler 92 as shown in the first step. After this, the deck erection device 10 is removed, the third step is completed, and the two upbound lanes are made available for vehicles to use.

As described above, when the second lane restriction period ends, the work of replacing the first and second existing deck pieces 11 on the upstream side of the two upbound lanes in the work section D1 with the new deck 3 will be completed through the first to third steps. At some stage in the third step, a gusset will be installed on the ground guard 32 of the new deck 3.

As shown in FIG. 11(d), in the third step, the permanent pavement 6 is laid over the entire surface of the two new decks 3. Therefore, when the third and fourth existing deck pieces 11 located in the middle of the work area D1 are next replaced with the new decks 3, the following additional process is performed.

As shown in Figure 12(a), for the second new deck 3 on which the permanent pavement 6 has already been applied, a specified width of the permanent pavement 6 is removed near the edge adjacent to the third new deck 3 on which the permanent pavement 6 has not been applied. Then, as shown in Figure 12(b), a permanent plate 52 is installed across the horizontal joint J1 formed between the second and third new deck slabs 3, after which the permanent pavement 6 is applied, and as shown in Figure 12(c), filling concrete 51 is filled in.

In this way, if the process carried out immediately before the traffic release period is the first process, at the end of the process, the temporary lining deck 7 is laid and the joints are filled with temporary gap filling 9. Also, in the case of the third process, at the end of the process, the lining deck 3 is laid, the joints are filled with gap filling 51, and the permanent pavement 6 is laid. As a result, no matter which process is completed during the lane restriction period, vehicles will be able to pass during the traffic release period, so it is possible to efficiently replace the existing deck 11 with the new deck 3 while repeatedly releasing traffic.

By repeating the preceding lane restriction period during which the first step is carried out and the following lane restriction period during which the second and third steps are carried out three times using the above procedure, i.e., after six lane restriction periods, the work section D1 can be replaced with the new deck slab 3, thus completing one cycle of work.

<7th and subsequent lane restriction periods: 2nd cycle>
Next, as shown in FIG. 3(c), the deck replacement method is carried out in accordance with the above-described procedure for the first passing lane work section O1 parallel to the work section D1.

That is, after the process (Step 1) of creating the existing deck piece 11 in the passing lane work section O1 is completed as a preceding task, the first to third steps are repeated three times. In this way, as shown in Fig. 3(d), the existing deck 1 in the work section D1 and work section B1 in the first section of the multiple sections set on the bridge B1 is replaced with the new deck 3, and the deck replacement method is completed.

<Lane restriction period after the deck replacement work in work area O1 is completed>
Returning to the flow chart of Figure 2 (fourth step), as shown in Figure 3(d), the new deck 3 of the work section D1 on the driving lane side and the new deck 3 of the work section O1 on the passing lane side are joined.

As shown in FIG. 13(a), the joining work involves removing a specified width of the permanent pavement 6 from the edge adjacent to the vertical joint J2 formed between the new deck 3 of the work section D1 and the new deck 3 of the work section O1 on the passing lane side, and then installing the permanent plate 52 in the cutout formed on the edge of the new deck 3 so as to straddle the vertical joint J2 above. The permanent plate 52 has a width sufficient to cover the vertical joint J2, and its length is formed to be approximately equal to the length of the work sections D1 and O1 in the bridge axis direction.

The material used for the permanent plate 52 is the same as that used to cover the horizontal joint section J1, and the installation direction on the new deck slab 3 is the same as that used when installing it on the horizontal joint section J1.

Finally, as shown in Figures 13(b) and (c), the permanent pavement 6 is laid and the interfacial concrete 51 is filled in. This completes the deck replacement work for the first section of the bridge B1 divided in the bridge axis direction.

After this, return to the second step of the flow diagram in Figure 2 and repeat the same construction work for all sections set on bridge B1 from the second section onwards, following the above procedure (fifth step).

This completes the replacement of all existing deck slabs 1 in the planned construction areas of bridge B1 (1st section, 2nd section, 3rd section, etc.) with new deck slabs 3. Note that the order in which the half-section deck replacement method is carried out on the driving lane side and the passing lane side is not limited to the above procedure.

In other words, in this embodiment, as shown in FIG. 14(a), the first work section D1 is replaced with the new deck 3, and then the parallel work section O1 is replaced with the new deck 3. After this, the second work section D2 is replaced with the new deck 3, and then the parallel work section O2 is replaced with the new deck 3. This process is repeated.

However, this procedure is not limited to this. For example, as shown in FIG. 14(b), the first work area D1 is replaced with the new deck slab 3, and then the parallel work area O1 is replaced with the new deck slab 3. After this, the second work area O2 is replaced with the new deck slab 3, and then the parallel work area D2 is replaced with the new deck slab 3. A procedure in which this work is repeated may be adopted.

In this way, the existing deck replacement method can appropriately select the stage at which to suspend work during the series of work steps from the first to third steps shown in Figure 4, depending on the site conditions and construction status (for example, the progress of scraping work and installation of stud dowels 21, etc.). This makes it possible to adjust the progress of work processes carried out during one construction traffic control period while preparing for the arrival of traffic release periods, making it possible to efficiently carry out the replacement work of the new deck slab 3.

Therefore, by setting lane restriction times at night, it is possible to replace the existing deck 1 with the new deck 3 while opening up traffic during the day. This makes it possible to carry out the work while minimizing the impact on the traffic environment in the surrounding area, even if the road bridge B on which the existing deck replacement work is to be carried out is located on a heavy traffic road in an urban area, or in a mountainous area sandwiched between long tunnels.

In addition, by forming the cross section of the existing deck piece 11 seen from the bridge axis direction into a half cross section that divides the cross section of the existing deck 1 in half, both bridge B1 for the two upbound lanes and bridge B2 for the two downbound lanes are opened to traffic during the day, and at night, lane restrictions are imposed only on bridge B1 for the two upbound lanes. This allows replacement work of the existing deck 1 on bridge B1 to be carried out using a half-section deck replacement method.

As a result, there is no need to completely close one of the bridges B1 and B2 for the inbound and outbound lanes that make up road bridge B to traffic while carrying out construction work and restricting two-way traffic on the other, which ensures safety for passing vehicles and also makes it possible to reliably carry out replacement work for the existing deck 1 even in road environments with various challenges, such as when two-way traffic restrictions cannot be implemented due to circumstances such as the road structure, or when long-term traffic restrictions are difficult even if they can be implemented due to traffic conditions in the surrounding area.

The bridge deck replacement method of the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

For example, in this embodiment, by using the permanent plate 52, the permanent pavement 6 can be carried out before pouring the fill concrete 51 into the horizontal joints J1 and vertical joints J2 formed between adjacent new deck slabs 3. For this reason, steps 5 to 9 are carried out in the third step, but if the permanent plate 52 is not used, the third step can be divided into two steps.

In this case, the first half of the third process involves installing the new slab 3 and filling it with non-shrink mortar 4 (Steps 5 and 6). The second half of the third process involves filling the horizontal joints J1 of the adjacent new slabs 3 with filler concrete 51 (Step 9) and then laying the main pavement 6 (Step 8). The first half of the third process is carried out when the third lane restriction period arrives, and the second half of the third process is carried out when the fourth lane restriction period arrives.

In the third first half process, after filling with non-shrink mortar 4 in step 6, temporary gap filling 9 is performed on the horizontal joints J1 formed between the adjacent new decks 3, as shown in Figure 15 (a), and temporary paving 8 is applied to the entire top surface of the new deck 3.

Then, in the third latter half of the process, the temporary pavement 8 applied to the top surface of the new deck 3 is peeled off, the temporary filler 9 in the horizontal joint J1 formed between the adjacent new deck slabs 3 is removed, formwork 53 is placed on the bottom of the horizontal joint J1, filler concrete 51 is filled from above the horizontal joint J1, and cured, and the permanent filler 5 is performed.

After the prescribed curing period has been completed, as shown in FIG. 13(b), the permanent pavement 6 is applied to the entire top surface of the new deck 3. Note that for the vertical joints J2 and the horizontal joints J1 formed between the existing deck 1 or existing deck piece 11 and the new deck 3, the temporary gap filling 9 applied in the first half of the third process is left in place, and the permanent pavement 6 is applied from above.

1 Existing deck 11 Existing deck piece 2 Main girder 21 Stud dowel 22 Work scaffold 3 New deck 31 Deck body 32 Ground covering 33 Joint reinforcing bar 34 Stud dowel insertion hole 4 Non-shrink mortar 41 Mortar stopper 5 Permanent interfacial filling 51 Interfacial filling concrete 52 Permanent plate 53 Formwork 6 Permanent pavement 7 Temporary covering deck 71 Deck body 72 Ground covering 73 Parapet 74 Height adjustment material 8 Temporary pavement 81 Preceding temporary pavement 82 Following temporary pavement 9 Temporary interfacial filling 91 Opening closing plate 92 Filling material 93 Fastener 10 Deck erection device

J1 Horizontal joint J2 Vertical joint B Road bridge B1 Bridge (uphill 2 lanes)
B2 Bridge (2 lanes downhill)

Claims (5)

This is a bridge deck replacement method in which an existing deck installed on a steel girder is replaced with a new deck made of precast concrete while alternating between construction traffic restriction time periods and traffic release time periods.
A first step of removing at least a portion of a plurality of existing deck pieces formed by dividing an existing deck of a bridge in the bridge axis direction to expose the main girder;
A second step of installing stud dowels on the upper surface of the main girder before installing the new deck exposed by removing the existing deck piece in the first step;
A third step of installing a plurality of the new deck slabs on the main girder on which the stud dowels were installed in the second step, joining the new deck slabs to the main girder, and then joining adjacent new deck slabs;
The first step to the third step are carried out during the construction traffic control time period, and include a case where two or more steps are carried out consecutively within one construction traffic control time period,
A bridge deck replacement method characterized in that, when the first step or the second step is carried out immediately before the traffic release period arrives, a temporary covering deck is installed on the main girder, which is exposed at the end of the work, in place of the removed existing deck piece. In the bridge deck replacement method according to claim 1,
A bridge deck replacement method, characterized in that the first to third steps are repeated in the bridge axis direction every time the construction traffic control period arrives. In the bridge deck replacement method according to claim 1 or 2,
A bridge deck replacement method, characterized in that the cross section of the existing deck piece as viewed from the bridge axis direction is formed into a half cross section obtained by dividing the cross section of the existing deck in half. In the bridge deck replacement method according to any one of claims 1 to 3,
In the third step,
A bridge deck replacement method characterized by joining adjacent new decks with a permanent plate that functions as part of the new deck . This is a bridge deck replacement method in which an existing deck installed on a steel girder is replaced with a new deck made of precast concrete while alternating between construction traffic restriction time periods and traffic release time periods.
A first step of removing at least a portion of a plurality of existing deck pieces formed by dividing an existing deck of a bridge in the bridge axis direction to expose the main girder;
a second step of installing a stud dowel on the upper surface of the main girder exposed in the first step;
A third step of installing a plurality of the new deck slabs on the main girder on which the stud dowels were installed in the second step, joining the new deck slabs to the main girder, and then joining adjacent new deck slabs;
The first step to the third step are carried out during the construction traffic control time period, and include a case where two or more steps are carried out consecutively within one construction traffic control time period,
When the first step or the second step is carried out immediately before the traffic release time period, a temporary covering deck is installed on the main girder that is exposed at the end of the work,
After the temporary covering deck is installed on the main girder,
A bridge deck replacement method characterized in that the upper and lower surfaces of the joints adjacent to the temporary covering deck are covered with opening closing plates, and the opening closing plates are fastened together using fasteners.

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