JP2005113673A - Construction method for building highway bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct an elevated section, a ramp section and an approaching section, utilizing a narrow working space effectively without generating a traffic jam, during a process of building a new highway bridge having a plurality of traffic lanes over an existing road. <P>SOLUTION: The ramp section 2 is composed in such a way that a pair of left and right main girders 4 from both ends of the elevated section down to the ground are arranged closely to each other to have a width not too narrow to regulate the traffic on the ground, so that the passage of vehicles even during the construction period is not impeded. Later, the distance between the main girders 4 is opened and a slab 8b is fit into the space 13 to form the final girder width. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a method of newly installing a multi-lane elevated road bridge above an existing ground multi-lane road, and in particular, when providing ramps located at both ends of a central elevated portion, The present invention relates to a construction method in which the construction limit of a multi-lane passage cannot be ensured, so that the traffic of the vehicle is not blocked and the occurrence time of secondary congestion due to construction can be reduced as much as possible.

  Conventionally, as a method of erection of an elevated road bridge above a multi-lane road above ground, among existing multi-lane roads on the ground, a width that can secure a girder width at the time of completion and a work band necessary for the construction work. In general, there is a known method of erection of a road bridge with elevated lanes while closing the traffic lane, such as closing the lane and reducing the number of existing lanes to only one lane. Yes.

  However, in this construction method, the lane portion of the existing multi-lane road on the ground is closed with a wide width from the initial stage of construction, so the existing lane on the ground is from the beginning of construction until the completion of construction. There is a problem that over the long period of time, only the reduced lane width is obtained, and the state of traffic congestion continues for a long time.

  As a method for solving the above problems, conventionally, as a method of constructing a new bridge without closing the existing traffic road, a floor slab as a ceiling is supported by bridge piers on both sides above the existing road. After the bridge was built and the entire length of the bridge was erected, the slope part was formed by gradually lowering one end of the floor slab of the road bridge in an inclined manner, and finally the inclined part that was inclined and lowered Patent Document 1 and Patent Document 2 disclose a construction method in which one end of the bridge is connected to an existing road to open an elevated road bridge.

JP 2003-27424 A JP 2003-27425 A

  In the elevated road bridge shown in Patent Document 1 and Patent Document 2, an elevated road bridge in which a floor slab as a ceiling is supported by bridge piers on both sides is installed directly above the existing road. Until the construction of the bridge is completed, all the floor slabs constituting the road bridge are supported on the piers. Therefore, theoretically, the installation of the floor slab is a vehicle that passes on the ground road. The vehicle can be made to travel without stopping.

  However, in this method, because the floor slab is supported by the piers on both sides so that the floor slab becomes the ceiling, the construction can proceed without stopping the vehicle. When a floor slab is installed on the ceiling, it is often necessary to temporarily stop the passage of the vehicle so as not to cause a danger to the vehicle passing underneath.

  In addition, in this method, after the installation of the central elevated part of the road bridge with the floor slab as the ceiling over the entire length, the floor slabs located at the front and rear ends of the central elevated part are gradually lowered toward the ground. Since the slope part is formed in such a manner that the slope part is lowered, the floor slab forming the slope part is lowered to the construction limit height position where it hits the roof of the car passing on the existing road on the ground. Until the descent to the lowest existing road surface, the existing road under the elevated road bridge will be greatly restricted in traffic, and the existing road on the ground will be congested for a long time. Forced and has the problem of having to provide a detour.

  As a means for solving the problems of the above-described road bridge erection method as described above, the present invention includes an elevated part of a plurality of lanes that do not three-dimensionally interfere with existing ground lanes, and the elevated part. It is a construction method for erected in a short time with a ramp section having a continuous cross section at both ends of the road, and the ramp section regulates multiple lane roads on the ground before it reaches the ground from both ends of the elevated section The main girder can be erected with a width and height that do not occur, and this makes it possible to make use of a lane passage that does not hinder the passage of vehicles even during the construction period, while the elevated part is a ramp part The main girder having the same structure as that of the main girder is continuously integrated, so that it is possible to construct a road bridge that is advantageous in terms of vehicle running performance and earthquake resistance.

  The road bridge erection method according to the present invention, as a specific means for that purpose, is for constructing a ramp portion that cannot secure a building limit among the construction of installing a multi-lane road bridge above a multi-lane road above the ground. In this construction method, parallel main girders are arranged and supported close to each other at the same gradient as the gradient of the finally installed ramp, and after the installation of the ramp main girder, The main girders that were arranged close to each other were laterally moved to both ends so that the side edges of the main girders expanded, and a space between parallel main girders was provided, and a floor slab was placed in the space between the main girders. And having a predetermined digit width.

  There are two methods for laying the ramps: a method in which the end of the main girder is rigidly connected to the pier, and a method in which the end of the main girder is rigidly connected to the pier via a support rod. Now, until the main beam is installed on the both sides of the pedestal, the crossing of the cross beam placed at a position perpendicular to the bridge axis supporting the end of the main girder After the main girder is installed, it is supported by pushing the lifting device to lower the cross beam to the same height as the main girder and supporting it on the pedestal. Preferably, the method is

  The main girder forming this ramp portion is arranged and supported in parallel with each other in close proximity to and in parallel with the gradient portion of the ramp portion to be finally installed on the preemption device. It is preferable that the space between the sides is expanded and supported so as to move sideways.

  After the main girder of the ramp is moved laterally on both sides so that the side edges of the ramp are widened and a space is provided between the main girders, the space between the main girders on both sides via the lifting device It is preferable to use a method in which a floor slab is fitted into the part.

  At the upper end of the ramp, there is an elevated part such as an existing road on the ground that intersects three-dimensionally. It is preferable that the ramp portion is integrally and continuously formed at one end of the main part girder.

  When the approach portion is provided at the lower end of the ramp portion, the parallel main girders of the ramp portion are arranged close to each other, and then the ramps are arranged close to each other at the approach portion at the tip of the ramp portion. A plurality of U-shaped blocks that are less than the width between the main girder and the height of the side wall decreases sequentially are arranged, and the parallel main girder of the ramp portion is laterally extended to both sides so that the side sides are expanded. When moving, on the U-shaped block, a concrete floor slab having the same width as the width between both main girders after finally expanding between the side walls may be arranged along the slope of the ramp portion. preferable.

  When constructing the approach part, as a means to properly introduce the approach part into the ground, between the plurality of L-shaped retaining walls where the height of the side wall sequentially decreases at the tip of the U-shaped block forming the approach part. It is preferable to provide an approach tip portion arranged so that the embankment is filled between the retaining walls.

  Of the above construction method inventions, in the first invention, parallel main girders are brought close to each other, and are arranged and supported on the upper surface of the pier with the same slope as the predetermined slope of the slope part to be finally constructed. From the top to the bottom, the girder width can be installed in a narrow state that is not affected by the construction limit. As a result, the ground on both sides of the ramp section until the main girder has been installed. Construction can proceed without causing traffic congestion by maintaining other lanes on multiple lanes on one side.

Also, in this construction method, a pair of symmetrical main girders are arranged close to each other in parallel with the inner surfaces facing each other, and arranged on the pier with the same slope as the slope of the slope part to be finally built. After the construction of the main girder, the main girder, which has been arranged so far, is laterally moved to both sides and expanded, but the upper part from the middle part of the ramp portion is expanded. However, there is no effect on the construction limit, and the impact of the construction limit on vehicles traveling in the existing lane is due to the expansion of the main girder of the section from the middle part of the ramp to the lower part. If the main girder of this section is expanded at night, the construction can proceed without significant vehicle traffic restrictions.

  Further, in this construction method, after the main girder is expanded and the horizontal girder and the floor slab are attached between the main girder, each main girder is supported on the bridge pier. Then, in the first stage, the horizontal beam is raised to an upper position where the building limit can be cleared, and then the horizontal beam is lowered and the main girder is supported by this horizontal beam. It can be a rigid structure and has the advantage that a reliable construction can be performed in a short time.

  When the ramp section is continuously connected to the elevated section, the main girder constituting the ramp section is arranged between the upper part of the left and right ramp sections in accordance with the parallel arrangement of a pair of symmetrical main girders. By using a main girder having the same cross-sectional structure as that of the main girder constituting the ramp part, the main girder of the elevated part and the main girder of the ramp part can be continued in a short time. It is possible to make an earthquake resistant structure suitable for the above.

  In the method of providing the approach part at the tip of the ramp part, when parallel main girders of the ramp part are arranged close to each other, between the main part of the ramp part before the lateral width is widened at the tip part of the ramp part Since a plurality of U-shaped blocks with the same sidewall width and decreasing side wall height are arranged in sequence, the construction of the approach section can be started immediately after the construction of the main section of the ramp section is completed. A concrete floor slab having the same width as the width between the ramp main beams after the horizontal width has been expanded may be disposed on the U-shaped block when laterally moving so as to expand the main main beam. Therefore, most of the construction of the approach section can be completed before the construction of the main ramp of the ramp is completed, and the construction period can be shortened and the work can be efficiently performed.

  When comparing the present invention with the conventional viaduct erection method, as in the case of the conventional method, when the girder width of the ramp is widened from the beginning to the same width as when completed, the ramp will collide with the vehicle. The existing ground multiple lane road must be largely regulated for a long period from when it is lowered to the height position (building limit) until the construction is completed. In the method of the present invention, the ramp portion is configured. By arranging the main girders close to each other and narrowing the width, it is possible to effectively utilize the existing multi-lane roads over a long period of time with the wide width as it is, and to prevent adverse effects due to traffic congestion.

  In this invention, when laying the ramp portion, a pair of symmetrical main girders are made to approach in parallel so that the inner surfaces face each other, and as this main girder, a floor slab is provided in advance on the upper surface of the box girder, In addition, a handrail is provided above one side along the length direction of the box girder, and further, a side girder connecting side is provided on the other side surface along the length direction of the box girder. It is preferable that a horizontal girder having a floor slab provided on the upper surface is attached between the left and right main girders when the main girder is installed and expanded.

  Next, the construction method of the present invention will be described with respect to an embodiment of a road bridge constructed on a four-lane road shown in the drawings. FIG. 1 is a side view of the main part of the road bridge after construction, and 1 is an elevated structure. Reference numeral 2 denotes a ramp part, and 3 denotes an approach part. 2 is a partial side view showing a process in the middle of constructing the elevated portion 1, FIG. 3 is a plan view of this portion, and FIG. 4 is a sectional view taken along the line AA of FIG.

  As shown in FIGS. 2 and 3, the elevated portion 1 uses a central separation band portion having a width of about two lanes of the existing lane as a work band 21, with a predetermined interval in the work band 21. The bridge pier 5 and the ground vent 6 are erected, and the elevated main girder 4 is lifted by the crane 7, and sequentially bridged on the bridge pier 5 and the ground vent 6.

  As the erection process, whether the elevated part 1 is erected first or the ramp part 2 is erected first is not particularly limited because it differs depending on the situation at the site, but in this embodiment, for example, The main girder 4 of the elevated part 1 is erected while the crane 7 is moved backward from the substantially central part of the entire length of the elevated part 1 in the direction of the left and right ramp parts 2.

  As shown in FIG. 4, the elevated main girder 4 basically includes a main girder 4 composed of a pair of symmetrical box girder corresponding to both side portions in the main girder cross section after the completion of the construction. Are arranged in parallel so that the inner surfaces face each other. These main girders 4 are pre-installed at the factory in advance, and a floor slab 8a is provided on the upper surface, along the length direction of the main girders 4. A rail 9 is provided on the upper side of the other side, and a cross beam connecting side 10 is provided between the left and right main beams 4.

  The left and right main girders 4 and 4 are bridged by the crane 7 on the pier 5 and the ground vent 6 in parallel at a predetermined interval, and the horizontal girders provided between the main girders 4 are arranged. Between the connecting sides 10 and 10, the horizontal girder 11 with the floor slab 8 b attached to the upper surface is arranged and joined, so that the left and right main girders 4 and 4 are set to a predetermined width interval, and finally, These main girders 4 and 4 are supported on the pier 5 via the bearing rods 12 respectively.

  On the other hand, when laying the ramp portion 2 connected to the elevated portion 1, as shown in FIG. 5 a, the ramp pier 5 and the upper surface are laterally installed on the ramp ridge portion from one end of the elevated portion 1 toward the front approach portion 3. The ground vent 6 equipped with the device 23 is installed, and the slope part main girder 4 having a predetermined length is lowered from above with the same slope as the slope part 2 of the slope part 2 finally built by the construction crane 7. It is built and supported sequentially.

  The above-mentioned ramp main girder 4 is symmetrical as shown in FIG. 7 and corresponding to both side portions in the cross section of the main girder after the completion of erection in the same manner as that shown for the elevated main girder 4. The main girders 4 and 4 made up of a pair of box girders are arranged in parallel so that their inner surfaces face each other. These main girders 4 and 4 are preliminarily provided on the upper surface of the floor slab 8a at the factory. , 8a, a high column 9 is provided on one side of the main girder 4 along the length direction, and a horizontal girder connecting side 10, 10 is provided between the left and right main girds 4, 4. ing. In addition, it is not necessary in the process of laying the main girders 4 and 4 on the bridge pier 5 and the groundwork vent 6 on the work band 21 in the lower part where the main girders 4 and 4 are to be constructed, but the later process. When the left and right main girders 4 and 4 are expanded in both directions in FIG. 9, the central floor slab 8 b is fitted on the upper surface to be fitted between the floor slabs 8 a and 8 a on the upper surface of the main girders 4 and 4. The provided cross beam 11 is arranged in advance.

  When the ramp main girder 4 is installed, as shown in FIG. 6a and FIG. 7, two parallel main girder 4 installed at the respective height positions are connected to the ground provided with the pier 5 and the sidewalk device 23. A width W1 in which the main girders 4 and 4 are arranged close to each other so as to be parallel to each other on the set vent 6 is shorter than the main girder width of the elevated portion 1 in FIG. It is constructed like this.

  At that time, the main girder 4 is provided in each main girder 4 until it is erected sequentially from the upper side to the lower side with the same gradient as that of the ramp portion 2 from one end of the elevated portion 1 toward the front approach portion 3. Further, the cross beam 11 shown in FIG. 4 is joined between the cross beam connecting sides 10 and 10, or the center floor slab 8b is interposed between the floor slabs 8a and 8a on the upper surfaces of the left and right main girders 4 and 4. The bridge pier 5 and the ground structure are arranged so that the main girders 4 and 4 which are to face each other with a space therebetween can be separated from each other by laterally moving in the left-right direction by the preemption device 23. It is installed on the vent 6.

  As shown in FIGS. 5 and 6, the main girder 4 of the ramp portion 2 is a vehicle that passes on the ground lane road 22 from the elevated portion 1 that does not affect the vehicle height H of the vehicle. The vehicle descends in the direction of the ground approach section 3 that affects the vehicle height H. The two main girders 4 and 4 are arranged close to each other in parallel to be installed in a narrow state. Therefore, the ground lane road 22 can be used in the upper and lower lanes (2 lanes on one side) until all the main girders 4 have been installed on the bridge piers 5 and the groundwork vents 6 Does not cause.

  After the main girders 4 and 4 are installed close to the ramp portion 2 from the elevated portion 1 to the ground approach portion 3, as shown in FIGS. 6c and 8, up to four lanes (two lanes on one side) until now. The lane road 22 on the ground that has been used as a vehicle is restricted to two upper and lower lanes on the outside (one lane on one side). The device 23 is laterally moved in both directions so that the sides are spread from each other when viewed from the plane, so that the width W2 is such that the space 13 is provided between the main girders 4 and 4, and then, The main girder 4 of the ramp portion 2 and the main girder 4 of the elevated portion 1 are connected.

  If the space 13 is provided between the left and right main girders 4 and 4 as described above, as shown in FIG. 9, the portal steel floor board lifting device 14 is placed on the main girders 4 and 4 on both sides. The floor slab is arranged between the main beam 4 and 4 between the side beam connecting sides 10 and 10 by placing the cross beam 11 having the central floor slab 8b on the upper surface through the space 13 and lifting it from below. By joining the horizontal beam 11 provided with 8b, the left and right main beams 4, 4 are set to a predetermined width interval W2, and finally the end of the main beam 4 is placed on the bridge pier 5 via the support rod 12. By connecting and supporting, paving is performed on the floor slabs 8a, 8a and 8b to complete the construction of the ramp portion 2.

  In the above embodiment, as the floor portion structure provided in the space 13 between the parallel main girders 4 and 4, the horizontal girder 11 having the floor slab 8b on the upper surface is lifted from below by the lifting device 14, and this horizontal The floor slab 8b on the girder 11 is fitted between the floor slabs 8a and 8a on the main girders 4 and 4, but the apparatus for attaching the cross girder 11 and the floor slab 8b is not limited to the lifting device 14. The horizontal girder 11 and the floor slab 8b may be attached using a laying apparatus that moves along the length direction on the main girder 4, and is provided in the space 13 between the main girder 4. The floor portion structure may also be a normal floor set other than a floor slab such as a steel slab.

  FIG. 10 shows another construction method of the ramp portion 2. In this construction method, a grounding device 23 shown in FIG. 7 and FIG. 8 is provided on the ground vent 6 of the ramp construction part, and the main girder 4 having a predetermined length is constructed by the construction crane 7. A pair of main girders 4 and 4 constructed at respective height positions are connected to each other at the same point as shown in FIG. Points arranged in parallel and close to each other, and as the next step, move laterally in both directions so that the side of each main girder 4 is widened, The space 13 is provided in the same manner as in the previous embodiment.

  As shown in FIG. 12, since the pre-emption device 23 on the ground vent 6 that supports the main girders 4 and 4 temporarily supports the main girders 4 and 4 at the construction stage, finally, Will be removed. Therefore, a cross beam portion 24 for finally supporting the main girders 4 and 4 is provided between the upper portion of the ramp portion 2 near the elevated portion 1 and the lower portion near the ground approach portion 3.

  As shown in FIG. 13, the cross beam 24 is arranged in a direction perpendicular to the bridge axis and supports the end of the main girder 4, and the cross beam 25 is initially supported at a predetermined height position from the ground. It is comprised from the raising device 26, such as a jack arrange | positioned above the grounding vent 6, and the pedestal 27 for lowering the cross beam 25 to a low position after that.

  As shown in FIGS. 12 and 13, the length W3 of the cross beam 25 in the cross beam portion 24 is larger than the width W1 in which the pair of main girders 4 and 4 are arranged close to each other in parallel. Later, when the elevating device 26 is operated to lower the cross beam 25 to a low position, the cross beam 25 can be supported at a target height position.

  When installing the horizontal beam portion 24, as shown in FIG. 10b, after the upper ramp portion 2a having a predetermined height near the elevated portion 1 is installed, the horizontal crane 25 is used to connect the horizontal beam 25 to the upper ramp portion. As shown in FIG. 13, the horizontal beam 25 is arranged at a predetermined height position where the hoisting device 26 is hoisted.

  Even if the length W3 of the cross beam 25 is larger than the width W1 in which the two main girders 4 and 4 are arranged close to each other in parallel, in the first step, the cross beam 25 is moved by the lifting device 26 to the ground lane road. The vehicle passing on the ground lane road 22, as shown in FIG. 11b, is supported at a height that can be pushed up to an upper position that does not affect the vehicle height H of the vehicle passing on It is possible to pass under the cross beam 25 and does not cause a stagnation of traffic even during construction.

  After the horizontal beam 25 is provided, as shown in FIG. 10 c, the inclined portion 2 b of the lower portion closer to the approach portion 3 than the horizontal beam 25 is constructed. It is the same as the construction method of the upper ramp portion 2a that the ramp portion 2b is also constructed so that the two main girders 4 and 4 are arranged close to each other in parallel.

  As shown in FIGS. 10c and 11c, the main girder 4 and 4 are lowered to a height that affects the vehicle height H of the vehicle traveling on the ground lane road 22 while the ramp portion 2b of the lower portion is installed. However, because the width W1 of the two main girders 4 and 4 arranged close to each other in parallel is narrow, the ground lane road 22 can be used as it is with four round-trip traffic lanes, resulting in stagnation in traffic. I won't let you.

  In addition, according to FIG. 11c, both ends 25a and 25b of the horizontal beam 25 seem to block a part of the ground lane road 22. However, the horizontal beam 25 is crossed by the lifting device 26 as shown in FIG. 10c. Is pushed up to an upper position that does not affect the vehicle height H of the vehicle passing over the ground lane road 22, so that a vehicle passing through the ground lane road 22 can pass under the cross beam 25. , Do not disturb the traffic.

  After the downward ramp portion 2b from the cross beam 25 to the approach portion 3 is installed, as shown in FIGS. 11d and 14, the ground lane road 22 that has been used as a round-trip four lane until now is turned into a round-trip two lane. Then, the hoisting device 26 of the cross beam portion 24 is operated until the surface of the cross beam 25 becomes the same height as the surface of the floor slabs 8a and 8a provided above the main girders 4 and 4. I'm going to be a majesty.

  After the cross beam 25 is lowered to a predetermined height as described above, the main girders 4 and 4 arranged so far as shown in FIG. 11e and FIG. 23, each side girder is moved laterally in such a way that the side edges are expanded from each other when viewed from the plane, and the ends of the respective main girders 4 and 4 are connected to the cross beam 25, whereby each main girder 4 The space 13 is formed between the four, and the cross beam 11 and the floor slab 8b are fitted into the space 13 by the lifting device 14 as described in the embodiment shown in FIGS.

  As shown in FIGS. 15 to 17, the approach portion 3 provided at the tip of the ramp portion 2 includes a main body portion 3a including a plurality of U-shaped blocks 15 and a precast floor slab or a concrete composite floor slab 17, and the concrete. A plurality of L-shaped retaining walls 18 arranged so that the height of the side wall 19 is reduced on the ground on the near side where the composite floor slab 17 is to be landed, and the space between the retaining walls 18 is filled. It is comprised by the front-end | tip part 3b which consists of the lightweight mixed embankment 20. FIG.

  The U-shaped block 15 of the main body 3a has a width W4 equal to or less than the width W1 of the two main girders 4 and 4 before spreading, which are arranged close to each other in the process of laying the ramp portion 2, and And a side wall 16 formed so as to decrease in height along the slope of the ramp portion 2, and the concrete composite floor slab 17 is disposed on the U-shaped block 15. The width W5 is the same as the width W2 of the two main girders 4 and 4 on the ramp portion after being expanded.

  Furthermore, the tip 3b has a plurality of L-shaped retaining walls 18 arranged so that the height of the side wall 19 gradually decreases on the ground on the near side where the concrete composite floor slab 17 will land. The lightweight mixed embankment 20 is filled between the retaining walls 18.

  The plurality of U-shaped blocks 15 constituting the approach main body 3a have the same width W4 as the width W1 before expanding the ramp main girders 4 and 4, and even if this block is arranged in the work band 21. Since the traffic lane will not be restricted, the construction of placing the U-shaped block 15 on the approach section 3 should be started when the construction for arranging and arranging the ramp main girders 4 and 4 close to each other is completed. In addition, at the time when the lateral movement construction for expanding the ramp portion main girders 4 and 4 is started, the width between the ramp portion main girders 4 and 4 after being spread on the U-shaped block 15. Since the concrete composite floor slab 17 having the same width W5 as W2 (FIG. 8) can be arranged, most of the construction of the approach portion 3 can be completed before the construction of the ramp main girder 4 is completed. Work can be expedited.

  Further, the approach tip portion 3b sequentially decreases the height of the side wall 19 on the extension line along the rail 29 of the concrete composite floor slab 17 from the position before the concrete composite floor slab 17 of the main body 3a contacts the ground. A plurality of L-shaped retaining walls 18 are arranged, and a light mixed embankment 20 is filled between these L-shaped retaining walls 18, 18, and the surface of the concrete composite floor slab 17 is grounded by the surface of the embankment 20. invite.

  As shown in FIG. 17, since the width W5 between the L-shaped retaining walls 18 and 18 forming the approach tip 3b is the same as the width W5 of the precast composite floor slab 17 of the main body 3a, the L-shaped retaining walls 18 and 18 The arrangement work of (1) must be carried out within the time when lane regulation such as nighttime has already started after the installation of the precast composite slab 17 is finished. Therefore, by shortening the length of the approach tip 3b where the L-shaped retaining walls 18 are arranged in the bridge axis direction, the work time for filling the lightweight mixed embankment 20 between the L-shaped retaining walls 18 and 18 is shortened. Thus, the construction of the approach unit 3 can be completed in a short time.

  In this construction method, when the ramp portion 2 is constructed, if the width of the left and right main girders 4 is opened from the beginning with the same size as that at the time of completion, the ramp portion 2 may collide with a vehicle passing on the ground. The existing traffic lane will be regulated when it is lowered to the (building limit) position, and the regulation will continue until the construction is finally completed. In this construction method, the left and right main girders 4 Therefore, it is not necessary to start the regulation until all the main girders are installed, and traffic congestion can be avoided, which is preferable as a construction method.

  In addition, the main girder 4 of the ramp portion 2 is installed and supported from the upper side to the lower side with the same gradient as that of the finally installed ramp portion 2, and then the left and right main girders 4 are arranged close to each other on the inner surface. The girder 4 is laterally moved so as to widen between the side sides to provide a space portion 13, and then the cross beam 11 and the floor slab 8 b are fitted in the space portion 13 to complete the installation. Therefore, there is an advantage that the construction period can be shortened.

  Further, since the approach portion 3 is composed of the U-shaped block and the concrete composite floor slab 17 in which the main body portion 3a and the tip portion 3b are successively reduced in height, the construction of the upper ramp portion 2 is finished and the attachment is completed. The U-shaped block can be laid during the work such as the above, and during that time, the construction can be proceeded without the need for traffic restrictions, so that the construction period can be accelerated.

The principal part side view of the road bridge constructed by the construction method of this invention. The side view which shows a part of construction process in an elevated part. The top view which looked at the process of FIG. 2 from the top. Sectional drawing in the AA of FIG. The side view which shows the construction process order of a ramp part. The top view which looked at the process of FIG. 5 from the top. Sectional drawing in the BB line of FIG. Sectional drawing in the CC line | wire of FIG. Sectional drawing in the DD line | wire of FIG. The side view explaining another construction process of a ramp part. The top view which looked at the process of FIG. 10 from the top. Sectional drawing in the EE line | wire of FIG. Sectional drawing in the FF line | wire of FIG. Sectional drawing in the GG line of FIG. The side view of an approach part. Sectional drawing in the HH line | wire of FIG. Sectional drawing in the II line | wire of FIG.

Explanation of symbols

1: Elevated part,
2: Ramp part,
3: Approach section,
3a: Approach body part,
3b: Approach tip,
4: Main digit,
5: Pier
6: Ground assembly vent,
7: Crane,
8a, 8b: floor slab,
9: handrail,
10: Side girder connection side,
11: Horizontal beam,
12: bearing rod,
13: Space part,
14: Lifting device,
15: U-shaped block,
16: sidewall,
17: Concrete composite floor slab,
18: L-shaped retaining wall,
19: side wall,
20: Lightweight mixed embankment,
21: Working zone,
22: Lane road,
23: preparatory device,
24: Cross beam part,
25: Cross beam,
26: Hoisting device,
27: Pillar,
29: handrail

Claims (8)

Among the construction work to install a multi-lane road bridge above the ground multi-lane road, it is a construction method for constructing a ramp section that cannot secure the building limit,
The parallel main girders are arranged and supported in close proximity to each other at the same gradient as the ramp portion gradient finally installed on the ramp portion,
After the installation of the main ramps of the ramp section, the main beams that have been arranged close to each other are laterally moved to both ends so that the sides of the main beams are widened to provide a space between the parallel main beams. ,
A road bridge erection method in which a floor slab is provided in a space between the main girders to obtain a predetermined girder width. At a position perpendicular to the bridge axis that supports the end of the ramp main girder, a horizontal beam having a width larger than the width in which the main girder is arranged close to each other in parallel is a height position at which vehicles on the ground can pass. Push up to support,
2. The road bridge erection method according to claim 1, wherein after the construction of the main part of the ramp portion, the horizontal beam is lowered to the height position of the main girder and the ends of the main girder are connected to the horizontal beam.   The horizontal beams for supporting the ends of the main ramps of the ramps will not interfere with the passage of vehicles on the ground road by the lifting devices placed on both sides of the pedestal until all the main beams have been installed. 2. After the main girder has been installed, the horizontal beam is lowered to the same height position as the main girder and supported on the pedestal after the main girder is installed. Road bridge erection method.   The means for forming the ramp portion are arranged and supported close to each other at the same gradient as the ramp portion gradient to be finally installed by the pre-emption device. The construction method of the bridge according to claim 1, wherein the bridge is moved laterally so as to be expanded.   After the main girder of the ramp is moved laterally to the both sides so that the side side is widened above the preemption device and a space is provided between the main girders, the main girder on both sides is connected via the lifting device. The construction method of the road bridge according to claim 1, wherein a floor slab is fitted in the space portion between.   After installing an elevated part consisting of a main girder of the same structure as the main girder of the ramp part to be finally built above other ground lanes, the main part of the ramp part is integrated with one end of the elevated main girder. The construction method of the road bridge according to claim 1, wherein the construction is continuous.   After the parallel main girders of the ramp portion are arranged close to each other, the height of the side wall is sequentially increased to the approach portion at the tip of the ramp portion with a width equal to or less than the width between the oblique portion main girders arranged close to each other When a plurality of U-shaped blocks with a reduced width are arranged and the parallel main girders of the ramp portion are laterally moved to both ends so that the sides are spread apart, the U-shaped block is finally placed on the U-shaped block. The road bridge erection method according to claim 1, wherein a floor slab having the same width as that between both main girders after expanding the side edges is arranged along the slope of the ramp.   8. The road according to claim 7, wherein an approach tip portion is provided at the tip of the U-shaped block in the approach portion, wherein a plurality of L-shaped retaining walls whose side walls are successively reduced in height are arranged so that embankments are filled between the retaining walls. Bridge construction method.

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