JP4162291B2 - Railway work girder cradle and rail work girder cradle construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a railroad girder cradle that supports a railroad girder that supports sleepers when performing construction such as excavation under a railroad track, and a method of constructing the railroad girder cradle. is there.
[0002]
[Prior art]
In a railway, a structure that crosses a track in the direction perpendicular to the track (track) may be constructed. For example, water pipes and sewers, gas pipes, pipes that accommodate electric power / telephone lines, etc., or box-shaped structures that are used for traffic such as waterways, pedestrians, automobiles, etc. It is. Such under-track crossing structures are often excavated below the tracks and constructed in a space formed by excavation. In such a case, if the train operation on the track to be constructed can be stopped, the sleepers and rails can be temporarily removed and excavation can be carried out. There are many cases where it is necessary to construct a crossing structure under the track by excavating underneath the train while running the business train (hereinafter referred to as “hot line construction”).
[0003]
In the case of such live-line construction, even if the bottom of the track becomes hollow due to excavation, it is necessary to take measures to firmly support the track above the track so that the train can travel safely in the section. As one of the countermeasures for this, the “construction girder method” is known. The construction girder method uses steel girders (hereinafter referred to as “railway girder”) to support the sleeper of the track at the site to be excavated, on a solid support roadbed that is not affected by excavation. This is a method of excavation under the railway track after the railway construction girder is supported by the installed cradle (hereinafter referred to as the “railway girder cradle”).
[0004]
Conventionally, a construction called a “wooden sanddle” has been used as the rail work girder. This uses a large number of wooden squares (for example, length: 3.6 meters, cross-section: square with a side of 20 centimeters), and these are combined vertically and horizontally to form a rectangular parallelepiped structure (not shown). A railway construction girder (not shown) is placed on the upper part of the structure.
[0005]
The reason why such a wooden sandle was used as a cradle for railway works was as follows.
[0006]
(1) The rail work girder cradle is formed in the recess for receiving installation by forming a small excavation just below the track to form the receiving installation recess. Since it is set as small as possible in consideration, the inside is narrow, and it is most appropriate in terms of construction to configure the cradle by combining relatively small parts.
[0007]
(2) In hot-line construction, it is necessary to start and end work within a time interval between a certain train and its succeeding train (hereinafter referred to as “train interval”). In addition, in order to ensure safety when passing through trains, construction materials or construction equipment, etc. are strictly regulated so that they do not protrude inside specified areas including railway vehicles (hereinafter referred to as “building limits”). Yes. For this reason, wooden squares that can be transported by hand during trains are suitable as parts for the cradle.
[0008]
(3) The rail girder cradle is a temporary construction material and is removed after the construction under the track is completed. Wooden timber was easy to obtain and inexpensive, had a certain level of durability, could be diverted several times to other constructions, and met the conditions as temporary construction materials.
[0009]
[Problems to be solved by the invention]
However, the conventional wooden sandal rail girder described above has the following problems.
[0010]
i) Timber is low in strength and may be broken due to repeated train loads.
[0011]
ii) Although it is configured by combining a number of wooden squares, rattling is likely to occur between the squares due to manufacturing dimensional errors of each square.
[0012]
iii) It is composed of a combination of a number of wooden timbers, and the pressing load from vertically above corresponds to an almost integral structure, but the lateral resistance force against the lateral force from the horizontal direction is small, and due to the lateral force Deviation may occur, and in the case of a large lateral force such as a seismic force, a significant deformation may occur, or in an extreme case, there is a risk of disassembly.
[0013]
For the reasons described above, conventionally, from the viewpoint of preventing an unexpected train accident, the traveling speed of the train at the place where the railroad work girder is installed is regulated, for example, at 45 km / hour, and forced to drive slowly. However, in recent years, from the viewpoint of improving passenger services on railways, there has been a demand for higher train speeds, and an increase in train slowing speed in sections where railway works are installed has been demanded.
[0014]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the problem to be solved by the present invention is a railway work girder cradle and a railway work girder that is strong and stable and can improve the train speed. The purpose is to provide a construction method for the cradle.
[0015]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, a railroad girder cradle according to the present invention is a cradle that supports a railroad girder that supports sleepers of the railroad when excavating below a railroad track, Produced in advance at a location other than the location where the railroad girder cradle is installed, and approximately below the sleeper and at the construction girder support point of the railroad girderOpposite with a predetermined intervalInstalledA pair ofA prefabricated member;A pair ofPrefabricated partsBetweenOn-site connection means for connectingEach of the pair of pre-fabricated members is made of a rectangular parallelepiped precast concrete member, and a bolt hole member for screwing a main girder fixing bolt is provided on an upper portion thereof, and the construction girder support point is provided. When installed, connecting reinforcing bars protrude from opposing surfaces, and the on-site connecting means is ultra-high strength concrete or cast-in-place concrete using early strength concrete, and the pair of concrete members Between the opposed surfaces and integrated with the protruding connecting reinforcing barsIt is characterized by that.
[0017]
  Further, the method for constructing a railroad girder cradle according to the present invention is a railroad girder beam cradle construction method that supports sleepers of the railroad track when excavating below the railroad railroad track. At a place other than where the work girder cradle is installed, Made of concrete, in the shape of a rectangular parallelepiped, with bolt hole members for screwing the main girder fixing bolts at the top, and a pair of reinforcing bars protruding from one sideA pre-manufactured member manufacturing step for pre-manufacturing the pre-manufactured member in advance,A pair ofA recessed portion excavation process for cradle installation for excavating a recessed portion for cradle installation for installing a cradle for railroad work girders, and a position of a work girder support point for supporting the railroad work girder in the recessed portion for cradle installation To the aboveA pair ofPrefabricated partsA predetermined interval is provided, and the side surfaces from which the connecting reinforcing bars protrude are opposed to each other.A prefabricated member installation process to be installed;Super early-strength concrete or cast-in-place concrete using early-strength concrete is placed between the opposing surfaces of the pair of prefabricated members, and the protruding connecting reinforcing bars and the cast-in-place concrete are integrated to form a pair of precast concrete. Integrated by connecting production membersPrefabricated material on-site connection process to form a rail girder cradleAnd haveIt is characterized by doing.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
(1) First embodiment
FIG. 1 is a cross-sectional view showing the configuration of a railroad girder cradle according to the first embodiment of the present invention and the relationship between the railroad girder and tracks. FIG. 2 is a top view showing the configuration of the rail work girder cradle according to the first embodiment of the present invention.
[0021]
As shown in FIGS. 1 and 2, the rail girder pedestal 10 includes a chestnut stone layer 13, precast concrete members 11 </ b> A and 11 </ b> B installed on the top, and a cast-in-place concrete 12. . The precast concrete member 11A is disposed substantially below the rail R1 (described later), the precast concrete member 11A is disposed substantially below the rail R2 (described later), and the cast-in-place concrete 12 is composed of these precast concrete members 11A and 11B. Between. Here, the precast concrete members 11A and 11B correspond to prefabricated members. The on-site concrete 12 corresponds to on-site connection means.
[0022]
The chestnut layer 13 is a layer of cracked stone (coarse crushed stone) laid on the excavated roadbed surface G ′.
[0023]
The precast concrete member 11A is a reinforced concrete member having a rectangular parallelepiped shape and having a lower main reinforcing bar 111A, an upper main reinforcing bar 112A, and a power distribution reinforcing bar 113A inside the production yard (for example, a construction pier) other than the installation location. It is a member that is manufactured in advance and then transported to the installation location. The same applies to the precast concrete member 11B, which is a reinforced concrete member having a rectangular parallelepiped shape having a lower main reinforcing bar 111B, an upper main reinforcing bar 112B, and a distribution reinforcing bar 113B. It is the member conveyed to. Bolt hole members for screwing main girder fixing bolts to be described later are provided on the upper portions of the respective precast concrete members 11A and 11B.
[0024]
Further, the cast-in-place concrete 12 is a reinforced concrete having a rectangular parallelepiped shape having a lower main reinforcing bar 121, an upper main reinforcing bar 122, and a distribution reinforcing bar 123, and is not solidified in a viscous or fluid state at an installation location. (Ready concrete) was cast on-site.
[0025]
In this case, as the ready-mixed concrete to be cast on site, “early high-strength concrete” or “super-early high-strength concrete” is used. Early-strength concrete is concrete that uses early-strength Portland cement as cement. Compared to ordinary concrete using ordinary Portland cement, the daily strength is about 3 times that of 3 days, and the early strength is about twice. large. Super early-strength concrete is concrete using ultra-early strong Portland cement that develops strength even earlier than early-strength Portland cement, and can exhibit the 3-day strength of early-strength concrete in almost one day. Is possible. From the viewpoint of speeding up the construction in consideration of train spacing, it is more desirable to use super early-strength concrete as the cast-in-place concrete 12.
[0026]
Further, the connecting rebar 114A is disposed between the precast concrete member 11A and the cast-in-place concrete 12 (hereinafter referred to as “interposition”), and between the precast concrete member 11B and the cast-in-place concrete 12 is disposed. A connecting rebar 114B is interposed. By these connecting reinforcing bars 114A and 114B, the precast concrete member 11A, the cast-in-place concrete 12 and the precast concrete member 11B are integrated. Here, the connecting reinforcing bars 114A and 114B correspond to on-site connecting means.
[0027]
Next, the construction of the railway construction girder 20 supported by the above-described railway construction girder 10 and the track supported by the railway construction girder 20 will be described.
[0028]
The railway girder 20 includes two main girders 21A and 21B, a cross girder 22, cross girder support portions 23A and 23B, cross girder fixing bolts 24A and 24B, main girder fixing plates 25A and 25B, Girder fixing bolts 26A and 26B are provided.
[0029]
The main girders 21A and 21B are made of steel and are beam-like members having a substantially “I” or “H” cross-sectional shape, and are arranged so that the longitudinal direction of the main gird coincides with the longitudinal direction of the track. Is done. The cross-sectional shape of the main girder may be substantially “Π” shape, substantially “B” shape, or the like. Main girder fixing plates 25A and 25B are attached to the main girders 21A and 21B in advance by welding or the like at the lower part of the position where they are supported by the rail work girder cradle 10. The main girder fixing plates 25A and 25B are plate members made of steel, and bolt insertion holes are formed in a part of them, and the main girder fixing bolts 26A and 26B are inserted into the bolt insertion holes, so that a precast concrete member The main girders 21A and 21B can be fixed to the precast concrete members 11A and 11B by being screwed into bolt hole members provided in 11A and 11B.
[0030]
The cross beam 22 is a beam-like member made of steel, having a cross-section with a shape of “U” and having a groove-like recess inside, and the longitudinal direction of the cross beam is perpendicular to the longitudinal direction of the track. It is arranged to become. Further, the sleeper S of the track is accommodated in the groove-like recess of the cross beam 22. In addition, bolt insertion holes are formed at both ends of the cross beam 22. The cross beam may have a substantially “H” cross-sectional shape or the like, and may be connected to a lower portion of the bottom plate such as a substantially “I” shape or a substantially “B” shape. Further, a misalignment prevention projection (not shown) for preventing the sleeper S from shifting in the horizontal direction (perpendicular to the trajectory) in the groove-shaped recess of the cross beam 22, for example, the upper surface of the bottom plate or the inner surface of the side wall. Etc. may be provided. Further, the cross beam 22 may be provided with a bolt hole (not shown) for fixing the sleeper S to the cross beam 22.
[0031]
In the main girders 21A and 21B, cross beam support portions 23A and 23B are attached in advance by welding or the like at the side portions where the cross beam 22 is to be supported. The cross beam support portions 23A and 23B are members having a cross-sectional shape of approximately “T” shape or approximately “Π” shape, and are configured to place the end portion of the cross beam on the upper surface of the upper plate-like portion. ing. Bolt insertion holes are formed in the upper plate-like portions of the cross beam support portions 23A and 23B, and the horizontal beam fixing bolts 24A and 24B are inserted through the bolt insertion holes of the cross beam support portions 23A and 23B. The both ends of the horizontal beam 22 can be fixed to the main beams 21A and 21B by being inserted into bolt insertion holes at both ends of the wire 22 and fastened with nuts.
[0032]
The track supported by the railroad girder 20 and the railroad girder cradle 20 has a sleeper S, tie plates T1, T2, rail fastening devices F1, F2, and rails R1, R2. Orbit.
[0033]
With the configuration as described above, the railroad girder cradle 10 of the present embodiment has the following advantages.
[0034]
1) Since the material of the cradle is concrete, the strength is high and there is no risk of damage even if the train load is repeatedly received.
[0035]
2) Looking at each main girder, the support structure of the main girder 21A is a single precast concrete member 11A, and the support structure of the main girder 21B is a single precast concrete member 11B. For this reason, rattling or the like does not occur. In addition, the two precast concrete members 11A and 11B have the cast-in-place concrete 12 placed in an intermediate space portion and are connected by connecting reinforcing bars 114A and 114B. Therefore, no rattling occurs in this portion.
[0036]
3) As described above, the rail work girder pedestal 10 according to the present embodiment is a concrete integrated member when viewed as a whole, and the main girder fixing plates 25A and 25B coupled to the lower part of the main girder are provided. Since it is fixed to the precast concrete members 11A and 11B by the main girder fixing bolts 26A and 26B, in addition to responding to a pressing load from vertically above as a solid solid structure, the horizontal force from the horizontal direction In contrast, the lateral resistance force is large, and deformation or the like is not caused by the lateral force.
[0037]
4) From the above advantages, in the case of a railroad girder supported by the railroad girder cradle of this embodiment, it has become possible to further improve the speed of slow running that has been conventionally performed. For example, in the test construction, during the construction of the railway construction girder (before the main girder fixing bolts 26A and 26B are fastened), the train travels at 60 km / hour and after the construction of the railway construction girder is completed (the main girder fixing bolt 26A, After the conclusion of 26B), the train could run at 80 km / hour. After that, when various data such as subsidence, deformation, train shaking, etc. of the rail girder 10 were continuously measured, the amount of subsidence was about 2 mm or less, and no particular deformation was observed. The train shaking also remained below about 0.2 g (g: gravitational acceleration). Based on these facts, the train was finally able to run at 100 km / hour. Since the maximum train speed in the normal section is 120 kilometers / hour, the speed reduction in the railway girder section is only 20 kilometers / hour. For this reason, the point which contributes to the passenger service improvement in a railroad is big.
[0038]
5) Since the strength of the concrete used for the cradle is much higher than that of wood, the overall size of the cradle can be made smaller than that of a wooden sanddle, and the soil at the recessed portion for the cradle installation can be reduced. The amount of excavation is reduced. Moreover, since only the two precast concrete members 11A and 11B are mainly transported on site to construct the cradle, the transport work amount is reduced. For these reasons, it is possible to significantly reduce the construction cost compared to the case of a wooden sanddle.
[0039]
6) Furthermore, since the precast concrete members 11A and 11B are pre-manufactured at a place other than the place where the cradle is installed, the cradle construction process is simplified compared to the wooden sandle method that combines a large number of wooden slabs, and construction is easy. It becomes. Furthermore, since super early-strength concrete or early-strength concrete is used as the cast-in-place concrete 12 for connection, it can be easily constructed even in a track section such as a metropolitan area where the train interval is short.
[0040]
(2) Second embodiment
Next, a method for constructing a railroad girder cradle according to a second embodiment of the present invention will be described in detail with reference to FIGS.
[0041]
FIG. 3: is sectional drawing which shows the state before construction among the figures explaining the construction method of the cradle for railway construction girders which is 2nd Embodiment of this invention. As shown in FIG. 3, before construction, a ballast roadbed B made of crushed stone or the like is formed on the roadbed G. On the ballast roadbed B, sleepers S, tie plates T1, T2, and rail fastening devices A track composed of F1, F2 and rails R1, R2 is installed.
[0042]
Next, although not shown in the drawings, the precast concrete members 11A and 11B described above are manufactured in advance at a place other than the place where the railway work girder is installed, for example, at a construction pier near the railroad. In this case, although not shown, the lower main reinforcing bar 111A, the upper main reinforcing bar 112A, the distribution reinforcing bar 113A, and the connecting reinforcing bar 114A are set in a predetermined shape by a spacing member (spacer: not shown). After placing and holding in position, ready-mixed concrete (not shown) is cast, cured and hardened, and then removed from the mold to form the precast concrete member 11A. Similarly, the lower main reinforcing bar 111A, the upper main reinforcing bar 112A, the distribution reinforcing bar 113A, and the connecting reinforcing bar 114A are set in a predetermined form by a spacing member (not shown) in a mold (not shown). After placing and holding in position, ready-mixed concrete (not shown) is cast, cured and hardened, and then removed from the mold to form the precast concrete member 11B. Accordingly, the connecting reinforcing bars 114A and 114B are projected from one surface of the completed precast concrete members 11A and 11B. This is the “prefabricated member production process”.
[0043]
In the pre-manufactured member manufacturing process, as for the surface of the precast concrete members 11A and 11B from which the connecting reinforcing bars 114A and 114B protrude, an uneven protrusion or a rough surface is formed on the inner surface of the mold in advance. It is more preferable to roughen the surface by using a jig such as a wire brush after preparing the precast concrete members 11A and 11B. If it does in this way, in the pre-fabrication member site | part connection process mentioned later, the adhesiveness of each precast concrete member 11A, 11B and the spot cast concrete 12 will improve, and the effect that both integration is further accelerated | stimulated is exhibited. The
[0044]
Next, a recessed portion 15 for installing the cradle for installing the pedestal 10 for railroad work girders is excavated substantially below the sleeper S (see FIG. 4). FIG. 4A is a cross-sectional view taken along the line AA in FIG. FIG. 4B is a side view of the portion shown in FIG. As shown in FIG. 4, the recess 15 for installing the cradle is formed by performing a small-scale excavation on the roadbed G after taking measures against earth retaining such as a sheet pile P, and digging down to a new roadbed surface G ′. In this case, there are several sleepers S (about 2 to 4) that are completely exposed by excavation and suspended on the rail (the lower part is hollow), and the other sleepers S are formed by the ballast road bed B. It is supported. This is a recess excavation process for cradle installation. In addition, you may perform the said prefabricated member manufacturing process simultaneously with the recessed part excavation process for cradle installation, or after completion | finish of the recessed part excavation process for cradle installation.
[0045]
Next, the crushed stone layer 13 is formed by placing the crushed stone on the new roadbed surface G ′ in the recess 15 for installing the cradle and sufficiently solidifying it (see FIG. 5). Thereafter, a precast concrete member that has already been manufactured on the chestnut layer 13 that is the position for supporting the railway construction girder 20 (hereinafter referred to as “construction girder support point”) in the recess 15 for installing the cradle. 11A and 11B are installed (see FIG. 6). In this case, the connecting rebars 114A and 114B projecting from one surface of the precast concrete members 11A and 11B face the vicinity of the center of the cradle installation recess 15 and are arranged so as to face each other. This is a prefabricated member installation process. In FIG. 5, the sleeper S and the rails R <b> 1 and R <b> 2 are illustrated so as to float in the air. Several (up to 2 to 4) are provided above, and the other sleepers S are supported by the ballast road bed B. The same applies to FIGS.
[0046]
Next, in the above state, a mold (not shown) is installed so as to close the open side of the portion sandwiched between the placed precast concrete members 11A and 11B, and the inside of the mold Further, after the lower main reinforcing bar 121, the upper main reinforcing bar 122, and the distribution reinforcing bar 123 are arranged and held at predetermined positions by a spacing member (spacer: not shown) or the like, the viscous or fluid state is solidified. The cast-in-place concrete 12 is formed by placing ultra-high-strength concrete or early-strength concrete (fresh concrete), curing and hardening, and then removing the formwork (see FIG. 7). As a result, the connecting reinforcing bars 114A and 114B are embedded in the cast-in-place concrete 12, and the precast concrete members 11A and 11B are connected on-site to form the railroad work girder cradle 10. This is the prefabricated member site connection process.
[0047]
In this way, the railway construction girder base 10 is formed. After that, after forming the groove-like recesses for accommodating the main girders 21A and 21B of the above-mentioned railroad girder 20 to the side of the track, the main girders 21A and 21B are constructed to the work girder 10 for the railroad girder 10. After being installed so as to be supported at the support point position, it is fixed on the precast concrete members 11A and 11B by the main girder fixing bolts 26A and 26B. Next, after removing the ballast crushed stone on the lower side and the side of the sleeper S, the horizontal beam 22 is inserted below the sleeper S, and the horizontal beam 22 is placed on the horizontal beam support portions 23A and 23B of the main beams 21A and 21B. The rails are supported by the railroad work girder 20 by fixing the sleeper S with the bottom plates of the groove-like recesses of the cross beam 22. After that, the space around the rail girder cradle 10 is backfilled with earth and sand, and the sheet pile P is pulled out, so that the state shown in FIG. After this, excavation under the railway line at the place where the railway work girder is installed becomes possible.
[0048]
The present invention is not limited to the above embodiments. Each of the embodiments described above is an exemplification, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and has the same operational effects can be used. It is included in the technical scope of the present invention.
[0049]
  For example, in each of the above-described embodiments, the reinforced concrete (RC) member (for example, 11A, 11B) manufactured in advance at a place other than the place where the rail work girder cradle is installed has been described as an example of the prefabricated member. However, the present invention is not limited to this, and may be a prefabricated member having another configuration, for example, a prestressed concrete (PC) member manufactured in advance in a place other than a place where a rail work girder cradle is installed. Good.
[0050]
  Further, in each of the above embodiments, the on-site cast concrete 12 that is reinforced concrete and the connecting reinforcing bars 114A and 114B have been described as examples of the on-site connecting means, but the present invention is not limited to this, and other configurations are possible. On-site connection means, for example, cast-in-place concrete that is unreinforced concrete. MaIn addition, when producing a precast concrete member, a bolt hole member is embedded in one surface of the precast concrete member, and a bolt screw is formed at one end of a connecting rebar or a connecting jig, thereby precast concrete. After the member is manufactured, the connecting reinforcing bar and the connecting jig may be attached to the precast concrete member at the manufacturing site or at the site. Alternatively, it is not necessary to use a connecting jig or the like only by giving sufficient roughening to the facing surfaces of the precast concrete members 11A and 11B or by providing uneven portions..
[0051]
【The invention's effect】
As described above, according to the present invention, it is pre-manufactured in a place other than the place where the railroad girder cradle is installed, and is preliminarily installed below the sleeper and at the construction girder support point of the railroad girder. Since the construction member and the prefabricated member are connected at the site, the rail girder cradle is constructed, so that the train load is formed by forming the prefabricated member with a high-strength material such as concrete. It can be assumed that there is no risk of damage even if it is repeatedly subjected. In addition, since the pre-fabricated member itself is integrated, there is no backlash and the base can be made strong. Moreover, in addition to responding to the vertical load from the top as a solid structure, the lateral resistance force is large against the lateral force from the horizontal direction, and deformation or the like occurs due to the lateral force. There is no. In addition, slow train travel can be minimized, which can greatly contribute to the improvement of passenger services on railways. In addition, the construction cost can be significantly reduced by reducing the amount of excavation of the recess for installing the cradle and reducing the small transport members on site. In addition, pre-manufactured parts can be pre-manufactured at locations other than the construction site, and if construction site using ultra-early high-strength concrete or early-strength concrete is used as the on-site connection means, the construction period can be greatly shortened. However, it can be easily constructed even in railway sections such as short metropolitan areas.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a railroad girder cradle according to a first embodiment of the present invention and a relationship between the railroad girder and a track.
FIG. 2 is a top view showing a configuration of a railroad girder cradle according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a state before construction in a diagram for explaining a construction method of a rail work girder cradle according to a second embodiment of the present invention.
FIG. 4 is a diagram showing a roadbed excavation state at a place where a cradle is constructed in a diagram for explaining a method for constructing a cradle for railroad work girders according to a second embodiment of the present invention, and FIG. FIG. 4B shows a side view.
FIG. 5 is a cross-sectional view illustrating a construction state of a chestnut layer in a diagram for explaining a construction method for a rail girder cradle according to a second embodiment of the present invention.
FIG. 6 is a cross-sectional view showing a state in which a precast concrete member is installed in a diagram for explaining a method of constructing a rail girder cradle according to a second embodiment of the present invention.
FIG. 7 is a cross-sectional view showing a state in which cast-in-place concrete is constructed among the diagrams for explaining the construction method of the rail work girder cradle according to the second embodiment of the present invention.
FIG. 8 is a cross-sectional view showing a state in which a railroad work girder is installed on a railroad work girder cradle among the diagrams for explaining a method for constructing a railroad girder cradle according to a second embodiment of the present invention. is there.
[Explanation of symbols]
10 Railing girder cradle
11A, 11B Precast concrete members
12 On-site concrete
13 Kuriishi Formation
15 Recess for cradle installation
20 Railway construction girder
21A, 21B Main girder
22 Horizontal girder
23A, 23B Cross beam support
24A, 24B Cross girder fixing bolt
25A, 25B Main girder fixing plate
26A, 26B Main girder fixing bolt
111A, 111B Lower main reinforcement
112A, 112B Upper main reinforcement
113A, 113B Power distribution reinforcing bars
114A, 114B Rebar for connection
121 Lower main reinforcement
122 Upper rebar
123 Rebar
B Ballast roadbed
F1, F2 rail fastening device
G, G 'roadbed
P sheet pile
R1, R2 rail
S sleeper
T1, T2 tie rate

Claims (2)

A cradle that supports a railroad girder that supports sleepers of the railroad track when excavating below the railroad track,
A pair of pre-fabricated parts that are pre-manufactured at a place other than the place where the railroad girder cradle is installed, and that are installed substantially below the sleepers and facing the construction girder support points of the railroad girder at a predetermined interval. Production members;
A site connecting means for connecting in situ between the pair of preformed operating member,
Each of the pair of pre-fabricated members is made of a rectangular parallelepiped precast concrete member, and a bolt hole member for screwing a main girder fixing bolt is provided on an upper portion of the pair of pre-manufactured members. In addition, the connecting rebar protrudes from the opposite surface,
The on-site connection means is ultra-early high-strength concrete or cast-in-place concrete using early-strength concrete, and is placed between opposing surfaces of the pair of concrete members, and is integrated with the protruding connection reinforcing bars. railway construction digits for the pedestal, characterized in that there. When excavating below the railroad track, it is a method for constructing a railroad girder cradle that supports the sleeper of the railroad track,
It is made of concrete and has a rectangular parallelepiped shape at a place other than the place where the rail girder cradle is installed, and a bolt hole member for screwing the main girder fixing bolt is provided on the upper part, and the connecting rebar is provided from one side. A prefabricated member production process for producing a pair of protruding prefabricated members in advance;
A recessed portion excavation step for cradle installation for excavating a recessed portion for cradle installation for installing the cradle for a pair of railroad construction girders substantially below the sleepers;
The pair of pre-fabricated members are spaced apart from each other in the recess for mounting the cradle and at the position of the construction beam support point that supports the railroad work beam , and the side surfaces on which the connecting reinforcing bars protrude are opposed to each other A prefabricated member installation process to install
Super early-strength concrete or cast-in-place concrete using early-strength concrete is placed between the opposing surfaces of the pair of prefabricated members, and the protruding connecting reinforcing bars and the cast-in-place concrete are integrated to form a pair of precast concrete. Pre-manufactured member on-site connection process for forming an integrated rail girder pedestal by connecting the manufactured members ;
A method for constructing a railroad girder cradle characterized by comprising:

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