Bridge construction methods
The described bridge construction method addresses safety concerns by rotating the column head and mobile work vehicle to align with the span direction, ensuring the bridge is constructed without risking objects falling onto intersecting facilities, thereby ensuring safe and efficient bridge construction.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- PS CONSTRUCTION CO LTD
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-22
AI Technical Summary
Existing bridge construction methods, such as the cantilever erection method, pose a safety risk as the cantilever erection machine may be constructed above a road or railway, leading to the potential of objects falling onto the intersecting facility.
A bridge construction method involving pier construction, column head construction, mobile work vehicle installation, and rotation of the column head with the mobile work vehicle until the bridge axis aligns with the span direction, ensuring the column head is not positioned above the intersecting facility during installation, followed by integration and extension of the bridge girder.
Ensures the safety of intersecting facilities by preventing objects from falling onto them during bridge construction, allowing for efficient and safe construction of bridges over intersecting facilities.
Smart Images
Figure 2026100981000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a bridge construction method.
Background Art
[0002] In the construction of a bridge straddling a facility (intersection facility) that intersects a bridge such as a road or railway in use, when the road intersects the bridge axis in plan view, a construction method that ensures safety is required so that no objects fall onto the road during construction.
[0003] Conventionally, in the case of constructing a bridge by the cantilever erection method, there has been a cantilever erection machine equipped with a formwork support structure and a working scaffold for the construction of the bridge girder (for example, Patent Document 1).
[0004] However, in the conventional cantilever erection method, the cantilever erection machine may be constructed above the road. Therefore, there is a risk of objects falling from the cantilever erection machine.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0006] An object of the present invention is to provide a bridge construction method capable of constructing a bridge while ensuring the safety of the intersection facility.
Means for Solving the Problems
[0007] (1) A bridge construction method according to one aspect of the present invention includes a pier construction step of constructing a pier; a column head construction step of constructing a column head that is rotatable horizontally above the pier, with the bridge axis direction not intersecting with the intersecting facility; a mobile work vehicle installation step of installing a mobile work vehicle on the column head; and a rotation step of rotating the column head together with the mobile work vehicle after the mobile work vehicle installation step until the bridge axis direction is aligned with the span direction. (2) In (1) above, an integration step may be included after the rotation step in which the bridge pier and the column head are integrated. (3) The above (1) or (2) includes an extension step in which the bridge girder is extended from the column head using the mobile work vehicle during construction, and the rotation step may be performed after the extension step. (4) In (3) above, the bridge girder may be extended in the extension process until the mobile work vehicle moves to a position corresponding to a position that is not above the crossing facility after the turning process. (5) In the above (1) or (2), in the column head construction process, the pivot erected on the pier is passed through a through hole formed in the column head, one end of the tension member is attached to the pier at a position eccentric to the rotation center of the column head, the other end of the tension member is attached to the column head, and in the rotation process, the tension member is tensioned to rotate the column head relative to the pier. (6) In (5) above, the tensioning member used in the rotation process or the tensioning member used in the temporary fixing process to temporarily fix the pier and the column head before the mobile work vehicle installation process may be repurposed as a connecting member to integrate the pier and the column head in the integration process. [Effects of the Invention]
[0008] According to the present invention, a bridge construction method is available that allows for the construction of bridges while ensuring the safety of intersection facilities. [Brief explanation of the drawing]
[0009] [Figure 1]This diagram shows the construction process from the bridge pier to the column head. The upper diagram is a front view, and the lower diagram is a plan view. [Figure 2] This diagram shows the process from the installation of the mobile work vehicle to before the rotation process. The upper diagram is a front view, and the lower diagram is a top view. [Figure 3] This diagram shows the process from the rotation process to the extension process; the upper diagram is a front view, and the lower diagram is a top view. [Modes for carrying out the invention]
[0010] (Embodiment) Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 shows the process from pier construction to column head construction; the upper figure is a front view and the lower figure is a plan view. Figure 2 shows the process from mobile work vehicle installation to before the rotation process; the upper figure is a front view and the lower figure is a plan view. Figure 3 shows the process from after the rotation process to the cantilever process; the upper figure is a front view and the lower figure is a plan view. In the following, parts with common functions may be given the same reference numeral or symbol. Hereinafter, span direction B refers to the bridge axis direction X of the bridge girder G in the completed bridge. Intersecting facility R is a facility whose safety must be maintained, and in a plan view, the extension direction of the intersecting facility R intersects with the span direction B of the completed bridge, such as a road or railway (or the space enclosed by the building clearance of that facility).
[0011] (Bridge construction method) The bridge construction method according to this embodiment will be explained below using as an example the case where there is an intersecting facility R that intersects the span direction B of the PC bridge in a plan view, that is, when the bridge girder is constructed so as to straddle the intersecting facility R from above, and the bridge girder G is erected by cantilevering.
[0012] (1) As shown in Figure 1, bridge piers P are constructed at appropriate locations adjacent to the crossing facility R (building clearance) (bridge pier construction process).
[0013] (1-1) Appropriately install a pivot A erected upward from the upper surface of the pier P. The pivot A is passed through a through-hole Q formed in the column head H during the column head construction process. The pivot A is, for example, a cylindrical steel pipe having sufficient strength. It is preferable to wrap an insulating material such as a Teflon (registered trademark) sheet around the surface of the pivot A to prevent adhesion to the concrete column head H. And, in order to reduce the friction between the column head H (and its through-hole Q) during the rotation of the column head H, it is more preferable to wrap a thin iron plate or the like around the outside of the insulating material. The lower end of the pivot A may be fixed in a state embedded in the pier P, and may be mechanically connected to a pivot mounting plate (not shown) anchor-fixed inside the pier P.
[0014] (1-2) Install a support bracket K for constructing the column head H on the upper side surface of the pier P.
[0015] (1-3) Install an insulating material such as a vinyl chloride sheet on the upper surface of the pier P to prevent adhesion between the pier P and the concrete column head H. Place concrete on the insulating material and construct the column head H as described later.
[0016] (2) Next, as shown in FIG. 1, above the pier P, construct a horizontally rotatable column head H in a direction that does not intersect the bridge axis direction X with the intersection facility R (for example, a direction parallel to the bay direction B straddling the intersection facility R) (column head construction process).
[0017] (2-1) Specifically, using the support bracket K as a foothold, install a formwork for placing the concrete for forming the column head H.
[0018] (2-2) Place the concrete for the column head H. Appropriately perform curing until the placed concrete hardens.
[0019] (2-3) After constructing the column head H (after the concrete strength of the column head H is developed), before the mobile work vehicle installation process, the pier P and the column head H are appropriately tightened and integrated with a tensioning material such as PC steel bars and temporarily fixed (temporary fixing process). This temporary fixing may be for resisting the unbalanced moment acting around the pier P and the lateral load during an earthquake when assembling the mobile work vehicle C on the column head H.
[0020] (3) Next, as shown in Fig. 2, install the mobile work vehicle C on the column head H (mobile work vehicle installation process). The mobile work vehicle C mainly includes a beam C1 that is detachably fixed to the existing column head H (bridge girder G) and projects above the bridge girder G that is added to the existing column head H (bridge girder G), a suspension member C2 from the beam C1, and a scaffold C3 supported by the suspension member C2. The mobile work vehicle C can support a formwork (not shown) for placing concrete to form the bridge girder G.
[0021] (3-1) After the mobile work vehicle installation process, after appropriately releasing the temporary fixing, jack up the column head H on which the mobile work vehicle C is installed from the pier P to create a gap between the pier P and the column head H. Specifically, hydraulic jack seats are provided at the four corners of the pier P. Install hydraulic jacks on the hydraulic jack seats.
[0022] (3-2) Then, install a sliding contact support F (friction reducing material) that rotatably supports the column head H while reducing the friction with the column head H on the upper surface of the pier P or the lower surface of the column head H in the gap between the pier P and the column head H. The sliding contact support F is preferably arranged at a plurality of locations on the circumference having a diameter larger than the outer diameter of the pivot A centered on the pivot A. The sliding contact support F may be a combination of a stainless steel plate and a PTFE sheet. Since the friction coefficient between the stainless steel plate and the PTFE sheet is very small, even when the load of the mobile work vehicle C and the column head H is loaded on the pier P, when a couple is applied to the column head H by a rotating device (not shown), relative rotation can occur between the stainless steel plate and the PTFE sheet.
[0023] (3-3) After installing the sliding support F, the jack is lowered to lower the column head H and place the column head H on top of the sliding support F. This results in the sliding support F being sandwiched between the bridge pier P and the column head H.
[0024] (4) After the mobile work platform installation process, the column head H is rotated together with the mobile work platform C until the bridge axis direction X is aligned with the span direction B (rotation process). In this way, since the rotation process is after the mobile work platform installation process, when the mobile work platform C is installed on the column head H, the mobile work platform C is not positioned above the intersection facility R. Also, even if something falls when the mobile work platform C is installed, it will not fall onto the intersection facility R, thus ensuring the safety of the intersection facility. Therefore, the risk of something falling onto the intersection facility R is eliminated, and the bridge can be constructed while ensuring the safety of the intersection facility R.
[0025] (4-1) In detail, during the construction process of the column head, the pivot A erected on the pier P is passed through the through hole Q formed in the column head H. One end of the tension member is attached to a position eccentric to the rotation center of the column head H on the pier P (such as the side of the pivot A), and the other end of the tension member is attached to the column head H. Then, during the rotation process, the column head H is rotated relative to the pier P by tensioning the tension member.
[0026] (4-2) Specifically, the turning of the column head H is carried out using a rotating device. The rotating device includes a hydraulic jack, PC steel bars (tension bars), and a bracket for attaching PC steel bars. Two hydraulic jacks are installed on a hydraulic jack anchor base fixed to the upper surface of the column head H. The bracket for attaching PC steel bars is fixed and installed on a pivot A protruding from the upper surface of the column head H. Then, the hydraulic jack and the bracket for attaching PC steel bars are connected by PC steel bars. Since the hydraulic jack is fixed to the column head H and the bracket for attaching PC steel bars is fixed to the pivot A, an operation of the hydraulic jack causes the column head H to turn (rotate). The hydraulic jack is arranged at a predetermined distance from the axial line of the column head H passing through the center of the pivot A and the width direction line of the column head H. The two hydraulic jacks are arranged at positions that are point-symmetric with respect to the center of the pivot A. The hydraulic jack is arranged such that the axis of the hydraulic jack is parallel to the axial direction of the column head H. Here, if the distance between the axes of the two hydraulic jacks is a and the tension of the PC steel bar is T, the rotational torque Mp is given by Mp = T·a. Also, if the weight of the rotating column head H and the mobile working vehicle C assembled on the column head H is W, the friction coefficient of the sliding contact support F is f, and the distance from the center of the pivot A to the sliding contact support F is r, the frictional resistance Mw is given by Mw = W·f·r. When Mw < Mp, the column head H turns (rotates). The turning is terminated when the direction of the axis of the column head H becomes the normal direction (when, as shown in FIG. 3, the bridge axis direction X is parallel to the span direction B).
[0027] (4-3) After the turning is completed, the rotating device is removed, and again, the column head H is lifted by a hydraulic jack or the like, the sliding contact support F is removed, and the column head H is lowered. If necessary, for unevenness adjustment between the upper surface of the pier P and the lower surface of the column head H, the gap between the upper surface of the pier P and the lower surface of the column head H is filled with resin mortar or non-shrink mortar.
[0028] (5) After the rotation process, the pier P and the column head H are integrated (integration process). This makes it possible to create a structure that can withstand the unbalanced moment acting on the column head H during cantilever erection, the lateral load due to earthquakes, and the various loads during service. Furthermore, it is preferable that the integration process takes place after the rotation process and before the cantilever process. By performing the integration process before the cantilever process, it is possible to withstand the unbalanced moment acting on the column head H that is likely to occur during the cantilever process.
[0029] (5-1) In detail, the pier P and the column head H are connected and integrated using connecting members such as reinforcing bars or PC steel. With the column head H rotated to its proper position, a sheath capable of housing the connecting member, such as reinforcing bars or PC steel, is pre-positioned (embedded) inside the pier P and column head H at the location of the connecting member that connects the pier P and the column head H. After the column head H rotates to its proper position, the connecting member is inserted into the sheath, and tension is applied to the connecting member. The sum of this tension is to be large enough to resist the unbalance moment centered on the pier P and the lateral load during an earthquake that will occur in the process of constructing the bridge for each girder block separated by the cantilever construction method in the cantilever construction process.
[0030] (5-2) Then, the sheath is filled with a fixing material such as grout to integrate the pier P and the column head H.
[0031] (6) Next, as shown in Figure 3, the bridge girder G is extended outwards from the column head H using a mobile work vehicle C (extension process). The extension process may include a so-called cantilever construction method, in which the bridge girder G is constructed in blocks while maintaining balance from both ends of the column head H in the bridge axis direction X. That is, blocks of bridge girder G that are connected to the end face of the column head H are constructed so as to extend from the tip of the column head H in the bridge axis direction X. Then, the mobile work vehicle C is moved to the block of bridge girder G that has just been constructed, fixed to the top surface of the block of bridge girder G, and the beam C1 of the mobile work vehicle C is extended outwards from the block of bridge girder G to construct the next block following the block of bridge girder G that has just been constructed. These processes are repeated to extend the bridge girder G until it reaches the center of the span. Finally, the ends of the bridge girder G are connected at the center of the span.
[0032] (6-1) Here, the rotation process may be performed after the cantilever process. In other words, the cantilever process may be performed before the rotation process described above. This allows the rotation process to be performed at any time while extending the bridge girder G by cantilever erection, without stopping the construction of the bridge girder G and waiting for the rotation process, while the bridge girder G is oriented with the bridge axis direction X of the column head H facing in a direction that does not intersect with the span direction B (see Figures 1 and 2). Thus, the overall bridge construction process can be made more efficient.
[0033] (6-2) In particular, during the cantilevering process, the bridge girder G may be cantilevered until it reaches a position where the mobile work vehicle C is not above the intersecting facility R after the rotation process (in a plan view, the mobile work vehicle C and the intersecting facility R do not overlap, and in the span direction B, it is ahead of the intersecting facility R when viewed from the column head H). That is, with the bridge axis direction X of the column head H facing in a direction that does not intersect the span direction B (see Figures 1 and 2), the bridge girder G is extended to a length longer than the horizontal distance from the column head H to the intersecting facility R at completion, and then the column head H is rotated together with the mobile work vehicle C and the completed bridge girder G. This ensures that the mobile work vehicle C is not positioned above the intersecting facility R even after the column head H has been rotated. Thus, the bridge can be constructed more safely. In addition, since the mobile work vehicle C can be moved away from the center of the column head H before the rotation process, it is easier to install the rotation device required in the rotation process at the center of the column head H.
[0034] Furthermore, the tension members used in the rotation process may be repurposed as connecting members to integrate the pier P and the column head H in the integration process. Also, the tension members used in the temporary fixing process, which temporarily fixes the pier P and the column head H before the mobile work vehicle installation process, may be repurposed as connecting members to integrate the pier P and the column head H in the integration process. This allows for the saving of materials necessary for bridge construction work.
[0035] In this way, the bridge can be constructed while ensuring the safety of the crossing facility R.
[0036] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.
[0037] Furthermore, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, without departing from the spirit of the present invention. Also, the above-described modifications may be combined as appropriate, without departing from the spirit of the present invention.
[0038] The bridge construction method according to this embodiment includes a pier construction step of constructing a pier P, a column head construction step of constructing a column head H above the pier P with the bridge axis direction X not intersecting with the intersecting facility R, a mobile work vehicle installation step of installing a mobile work vehicle C on the column head H, a rotation step of rotating the column head H together with the mobile work vehicle C after the mobile work vehicle installation step until the bridge axis direction X is aligned with the span direction B, and an integration step of integrating the pier P and the column head H after the rotation step. In this way, since the rotation step is after the mobile work vehicle installation step, when the mobile work vehicle C is installed on the column head H, the mobile work vehicle C can be made not to be positioned above the intersecting facility R. Therefore, the risk of objects falling onto the intersecting facility R can be eliminated, and the bridge can be constructed while ensuring the safety of the intersecting facility R. [Explanation of Symbols]
[0039] Axis B span direction C Mobile work vehicle C1 beam C2 Hanging material C3 Scaffolding F Sliding support G Bridge girder H Column head K support bracket P Bridge Pier Q through hole R Crossing Facility X Bridge axis direction
Claims
1. The bridge pier construction process involves constructing bridge piers, A column head construction process is performed above the aforementioned bridge pier, in which a column head that can rotate horizontally is constructed with the bridge axis direction not intersecting with the intersecting facility, A mobile work vehicle installation step involves installing a mobile work vehicle on the column head, The process includes, after the mobile work vehicle installation step, a rotation step in which the column head is rotated together with the mobile work vehicle until the bridge axis direction is aligned with the span direction. Bridge construction method.
2. The rotation process includes an integration process in which the bridge pier and the column head are integrated together. The bridge construction method according to claim 1.
3. This includes an extension process in which the bridge girder is extended from the column head using the mobile work vehicle during construction, The rotation process is performed after the extension process. The bridge construction method according to claim 1 or claim 2.
4. In the extension process, the bridge girder is extended until the mobile work vehicle moves to a position corresponding to a position that is not above the crossing facility after the turning process. The bridge construction method according to claim 3.
5. In the column head construction process, the pivot erected on the pier is passed through the through hole formed in the column head. One end of the tension member is attached to the pier at a position eccentric to the rotation center of the column head, and the other end of the tension member is attached to the column head. In the aforementioned rotation process, the column head is rotated relative to the pier by tensioning the tension member. The bridge construction method according to claim 1 or claim 2.
6. The tensioning member used in the rotation process or the tensioning member used in the temporary fixing process to temporarily fix the pier and the column head before the mobile work vehicle installation process is repurposed as a connecting member to integrate the pier and the column head in the integration process. The bridge construction method according to claim 5.