Press-in reinforced steel plate underwater bulging prevention structure and steel plate press-in construction method

Abstract

To provide a press-in reinforcing steel plate underwater bulging prevention structure and a steel plate press-in construction method, which reduces the risk of the reinforcing steel plate bulging out or shifting due to the internal pressure of a filler even when a columnar structure to be reinforced is high and its lower part is underwater. [Solution] This is an underwater bulge prevention structure for pressed-in reinforcing steel plate that prevents the reinforcing steel plate, which is pressed into the area around an existing columnar structure, part of which is constructed underwater, from becoming bulged when filling material is filled in. A pair of bulge prevention materials with a Z-shaped cross-section are attached above the water level during construction of the existing columnar structure, and a slit is formed between these bulge prevention materials. A number of stiffening materials with a T-shaped cross-section are attached to the inner surface of the reinforcing steel plate, and at least a portion of the multiple stiffening materials is inserted into the slit.

Description

[Technical field]

[0001] The present invention relates to a press-in reinforcing steel plate underwater bulging prevention structure and a steel plate press-in construction method. [Background technology]

[0002] Conventionally, a steel plate press-in method is known in which a columnar structure is reinforced by pressing in a reinforcing steel plate while the columnar structure itself bears a reaction force. For example, Patent Document 1 discloses that a press-in device is fixed to the columnar structure, and a cylindrical steel plate is pressed in with a telescopic jack to reinforce the columnar structure (see paragraphs

[0026] to

[0030] of the specification of Patent Document 1, and Figures 8 to 14 of the drawings, etc.).

[0003] However, when the height of the columnar structure from the foundation is high and the height of the part reinforced with the reinforcing steel plate is large, a problem occurs in which the internal pressure of the filler material, such as mortar, filled in the gap between the steel plate and the columnar structure causes the reinforcing steel plate to bulge or shift.

[0004] On the other hand, Patent Document 2 discloses a steel plate pressing method in which spacers and rollers are attached to a rectangular reinforcing steel plate to be pressed in when uneven pressure such as soil pressure or water pressure acts on a columnar structure (see paragraphs

[0033] to

[0057] of the specification of Patent Document 2, Figures 7 to 10 of the drawings, etc.).

[0005] However, the steel plate pressing method described in Patent Document 2 assumes that the external force is an unbalanced pressure acting from the outside as a compressive force, and therefore has the problem that although this can be countered with spacers and rollers, it is not possible to prevent the pressed-in steel plate from bulging out from the inside to the outside.

[0006] Furthermore, Patent Document 3 discloses a reinforcement structure for an existing columnar structure in which a flat plate portion with a Z-shaped cross section is attached near the lower end of the inner surface of a reinforcing steel plate to be pressed in to form a slit, and a restraining steel material made of H-shaped steel is inserted to fill the gap between the existing columnar structure and the reinforcing steel plate, thereby preventing the lower end of the reinforcing steel plate from separating from the existing columnar structure and protruding (see claims 1 and 2 of Patent Document 2, paragraphs

[0032] to

[0047] of the specification, Figures 1 to 8 of the drawings, etc.).

[0007] Furthermore, contrary to the reinforcement structure for columnar structures described in Patent Document 3, it is also possible to form a slit in the existing columnar structure and insert a buckling prevention material that stiffens the reinforcing steel plate so that it does not buckle when pressed in, thereby combining the function of a bulge prevention material with that of a guide material that guides the reinforcing steel plate vertically when it is pressed in.

[0008] However, when the bulge prevention material is also used as a guide material, high precision is required for marking and installation. In particular, when the bulge prevention material is located underwater, even a diver will have difficulty in ensuring the precision of the bulge prevention material during underwater construction. Furthermore, chemical anchors (registered trademark) are generally used to fasten steel materials to existing columnar structures, but it is difficult to use chemical anchors underwater, which also makes it difficult to attach the bulge prevention material to existing columnar structures underwater. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2012-167474 A [Patent Document 2] Patent No. 6855151 [Patent Document 3] Patent No. 6189597 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention has been devised in consideration of the above-mentioned problems, and its purpose is to provide a pressed-in reinforcing steel plate underwater bulging prevention structure and steel plate pressing method that reduces the risk of the reinforcing steel plate bulging out or shifting due to the internal pressure of the filler, even when the existing columnar structure to be reinforced is tall and its lower part is underwater. [Means for solving the problem]

[0011] The press-in reinforced steel plate underwater bulging prevention structure according to claim 1 is a steel plate that is press-in reinforced around an existing columnar structure that is partially constructed underwater. Press Fit A press-in reinforcing steel plate underwater bulging prevention structure that prevents the reinforcing steel plate from bulging when filling with filler, in which a pair of Z-shaped bulging prevention materials are attached above the water level during construction of the existing columnar structure, and a slit is formed between these bulging prevention materials, Press Fit The inner surface of the reinforcing steel plate is fitted with multiple stiffeners with a T-shaped cross section. 、 At least a portion of the stiffeners is inserted through the slits. A single or multiple supports made of steel materials are installed around the underwater portion of the press-in reinforcing steel plate to prevent the press-in reinforcing steel plate from being engulfed when filling the filler. It is characterized by:

[0013] Claim 2 The steel plate pressing method according to the present invention is a steel plate pressing method for pressing a reinforcing steel plate around an existing columnar structure constructed underwater to reinforce the existing columnar structure, and includes a bulge prevention material installation process for installing a pair of Z-shaped cross-section bulge prevention materials above the construction water level of the existing columnar structure and forming a slit between the bulge prevention materials, a press-in process for pressing a press-in reinforcing steel plate around the existing columnar structure, and a filler filling process for filling a filler material in the gap between the press-in reinforcing steel plate and the existing columnar structure, and in the press-in process, a stiffener protruding from the inner surface of the press-in reinforcing steel plate is inserted into the slit between the bulge prevention materials installed in the bulge prevention material installation process, and the press-in direction is guided by the bulge prevention materials. and a support installation step of installing a support around the underwater portion of the press-fitted reinforcing steel plate before the filler filling step, the support preventing the press-fitted reinforcing steel plate from being sunk during the filler filling step. It is characterized by: Effect of the Invention

[0015] First Invention and No. 2According to the invention, the bulge prevention material is provided above the water level during construction of the existing columnar structure, so that the bulge prevention material can be attached with precision even if the existing columnar structure to be reinforced is tall and its lower part is underwater.The bulge prevention material also serves the function of a guide material that guides the reinforcing steel plate vertically when it is pressed in, and prevents the reinforcing steel plate from bulging or shifting due to the internal pressure of the filling material. In addition, according to the first and second inventions, in addition to the bulge prevention material, supports are installed around the underwater portion of the pressed-in reinforcing steel plate, so that it is possible to reliably prevent the reinforcing steel plate from bulging out or shifting due to the internal pressure of the filling material. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a front view of a bridge pier to which a press-fitted reinforcing steel plate underwater intrusion prevention structure according to an embodiment of the present invention is applied, viewed in a direction perpendicular to the bridge axis. [Diagram 2] FIG. 2(a) is a plan view showing a bridge pier to which the above-mentioned press-fitted reinforced steel plate underwater bulging prevention structure is applied, and FIG. 2(b) is an enlarged view of part A in FIG. 2(a). [Diagram 3] FIG. 3(a) is a partially enlarged plan view showing the bulge prevention material of the above-mentioned press-fitted reinforcing steel plate underwater bulge prevention structure, and FIG. 3(b) is a detailed elevation view showing the above-mentioned bulge prevention material. [Figure 4] FIG. 4 is a flowchart showing each step of the steel plate press-in method according to the embodiment of the present invention. [Diagram 5] FIG. 5 is a process explanatory diagram showing advance preparations for the above-mentioned steel plate press-in method. [Figure 6] FIG. 6 is a process explanatory diagram showing a reaction steel plate installation process of the above-mentioned steel plate press-in construction method. [Figure 7] FIG. 7 is a process explanatory diagram showing a press-in device installation process of the steel plate press-in method. [Figure 8] FIG. 8 is a process explanatory diagram showing the process of attaching the bulge prevention material in the above-mentioned steel plate press-in method. [Figure 9] FIG. 9 is a process explanatory diagram showing the reinforcing steel plate assembling process of the above-mentioned steel plate press-in method. [Figure 10] FIG. 10 is a process explanatory diagram showing the reinforcing steel plate assembly and sinking process of the above-mentioned steel plate press-in method. [Figure 11]FIG. 11 is a process explanatory diagram showing the press-in process of the above-mentioned steel plate press-in method. [Figure 12] FIG. 12 is a process explanatory diagram showing a state in which the press-in process of the steel plate press-in method is completed. [Figure 13] FIG. 13 is a process explanatory diagram showing a process of removing the press-in device in the above steel plate press-in method. [Figure 14] FIG. 14 is a process explanatory diagram showing a first stage support assembly process in the support installation process of the steel plate pressing method. [Figure 15] FIG. 15 is a process explanatory diagram showing a second stage support assembly process in the support installation process of the steel plate pressing method. [Figure 16] FIG. 16 is a process explanatory diagram showing the first and second stage lifting point replacement process in the shoring installation process of the above-mentioned steel plate pressing method. [Figure 17] FIG. 17 is a process explanatory diagram showing the third stage support assembly process in the support installation process of the steel plate press-in method. [Figure 18] FIG. 18 is a process explanatory diagram showing the second stage hanging point replacement process in the shoring installation process of the steel plate pressing method. [Figure 19] FIG. 19 is a process explanatory diagram showing a support lowering and installation step in the support installation step of the steel plate pressing-in method. [Figure 20] FIG. 20 is a process explanatory diagram showing a post-installation reinforcing steel plate installation process of the above-mentioned steel plate press-in construction method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, one embodiment of the post-construction method for preventing slippage and growth according to the present invention will be described in detail with reference to the drawings.

[0019] <Press-fitted reinforced steel plate structure to prevent underwater bulging> First, the press-fitted reinforced steel plate underwater bulging prevention structure 1 according to the embodiment of the present invention will be described with reference to Figs. 1 to 3. An existing bridge pier P1 constructed in a river and having an oval horizontal cross section will be described as an example of an existing columnar structure to which the press-fitted reinforced steel plate underwater bulging prevention structure 1 according to the present embodiment is applied. Fig. 1 is a front view of the pier P1 to which the press-fitted reinforced steel plate underwater bulging prevention structure 1 is applied, as viewed in the bridge axis direction X, Fig. 2(a) is a plan view showing the pier P1 to which the press-fitted reinforced steel plate underwater bulging prevention structure 1 is applied, and Fig. 2(b) is an enlarged view of part A in Fig. 2(a).

[0020] 3(a) is a partially enlarged plan view showing the bulge prevention material 6 of the press-in reinforcing steel plate underwater bulge prevention structure, and FIG. 3(b) is a detailed elevation view showing the same bulge prevention material. In the figure, the symbol X indicates the bridge axis direction X of the pier P1, the symbol Y indicates the direction perpendicular to the bridge axis Y, and the symbol Z indicates the up-down direction Z. In FIG. 1, H indicates the height H of the reinforcement range of the columnar structure to be reinforced, and H1 indicates the height H1 of the reinforcing steel plate obtained by excluding the clearance from the height H of the reinforcement range. H2 indicates the height H2 of the press-in reinforcing steel plate 2, and H3 indicates the height H3 of the post-construction portion.

[0021] The pressed-in reinforcing steel plate underwater bulging prevention structure 1 (hereinafter simply referred to as bulging prevention structure 1) in this embodiment is an underwater reinforcing steel plate bulging prevention structure that prevents a pressed-in reinforcing steel plate 2, which is pressed into the periphery of a bridge pier P1, an existing columnar structure partially constructed underwater (in a river), for reinforcement purposes, from becoming bulged when filling material 3 is filled.

[0022] This bulge prevention structure 1 comprises a press-fit reinforcing steel plate 2 that is pressed into the periphery of the pier P1 to reinforce the pier P1, a filling material 3 that is filled into the gap G between the press-fit reinforcing steel plate 2 and the pier P1, and a support 5 that prevents the press-fit reinforcing steel plate 2 from bulging when the filling material 3 is filled. The pier P1 also comprises a bulge prevention material 6 that prevents the press-fit reinforcing steel plate 2 from bulging by moving away from the pier P1 when the filling material 3 is filled into the gap G between the press-fit reinforcing steel plate 2 and the pier P1.

[0023] (Press-fitted reinforcement steel plate) The press-fit reinforcing steel plate 2 is made of a steel plate of a predetermined thickness (9 mm in the illustrated embodiment) according to the structural design, which is welded and assembled on-site to form a reinforcing steel plate assembly 20 with an oval horizontal cross section that corresponds to the cross-sectional shape of the pier P1, as shown in Figures 2 and 3(a). Of course, it goes without saying that the shape and thickness of the press-fit reinforcing steel plate 2 may be appropriately set according to the cross-sectional shape and structural design of the existing columnar structure to be reinforced.

[0024] Furthermore, stiffeners 21 with a T-shaped cross section are provided on the inner surface of the reinforcing steel plate assembly 20 in the axial direction to stiffen the steel plate against stresses such as buckling stresses that act on the steel plate when it is pressed in. As shown in Fig. 2(a), the stiffeners 21 are densely arranged at 400 mm pitches on the flat portion 2a of the oval reinforcing steel plate assembly 20, which is at high risk of buckling, and at 800 mm pitches on the arc portion 2b. As shown in Fig. 2(a), the gap G between the pressed-in reinforcing steel plate 2 and the pier P1 is set to 150 mm in this actual embodiment.

[0025] The post-installed reinforcing steel plate 2' shown with diagonal lines in FIG. 1 is a post-installed portion that is installed after the press-in device (PD) and the reaction steel plate (7) described below are removed.

[0026] (filling material) The filler 3 is a general filling concrete, and the design standard strength is appropriately determined depending on the structural design. Of course, this filler 3 may be any hardening material that has a predetermined compressive strength to hold the pressed-in reinforcing steel plate 2 after a certain period of time has passed, and may not be concrete, such as non-shrink mortar.

[0027] (Shoring) As shown in Fig. 2(a), the support 5 is a structure in which H-shaped steel materials (general structural rolled steel: SS400) used as earth retaining materials are assembled into a rectangular shape (rectangular shape), and has the function of preventing the pressed-in reinforcing steel plate 2 from becoming entrapped when the filler 3 is filled. H-350x350x12x19 H-shaped steel materials are used for the long sides 5a, and H-300x300x10x15 H-shaped steel materials are used for the short sides 5b. Corner pieces 5c are attached to these corners to prevent angular deformation between the perpendicular long sides 5a and short sides 5b.

[0028] As shown in Fig. 1, in this embodiment, the shoring 5 is installed at three locations at approximately equal intervals of the difference in height between the height L2 of the riverbed surface, which is the ground surface, and the water level L1 during construction, at each height of the first to third shoring stages. The pressed-in reinforcing steel plate 2 pressed into the ground is not likely to be bulged out by the internal pressure of the filling material 3 when it is filled, and the bulge prevention material 6 described below prevents the pressed-in reinforcing steel plate 2 from bulging outward above the water level L1 during construction. Of course, the installation position of the shoring 5 and the dimensions of the steel material may be appropriately set by structural calculations depending on the distance from the height L2 of the ground surface to the water level L1 during construction, and it is also possible to install only one location.

[0029] The gap between the outer periphery of the press-fitted reinforcing steel plate 2 and the support 5 is adjusted by inserting a Uniblock (registered trademark) or a wedge made of steel material (not shown) as a back-filling material. Of course, it is also possible to assemble the structure so that there is no gap.

[0030] (Anti-burst material) As shown in Figures 3(a) and 3(b), the bulge prevention material 6 consists of a pair of hanging plates 61, 62 made of steel material with a Z-shaped cross section, and has the function of hanging the aforementioned stiffener 21, which has a T-shaped horizontal cross section, between the hanging plates 61, 62, thereby preventing the pressed-in reinforcing steel plate 2 to which the stiffener 21 is joined from bulging out and moving away from the pier P1.

[0031] As shown in Figures 3(a) and 3(b), the hanging plates 61, 62 are fixed to the pier P1 with M16 chemical anchors, spaced apart in the horizontal direction (direction Y perpendicular to the bridge axis). A slit 63 is formed between the hanging plates 61 and 62, and as shown in Figure 3(a), the stiffener 21 is inserted into the slit 63 of the bulge prevention material 6, and the flange of the stiffener 21 is hooked onto the hanging plates 61, 62, thereby preventing the pressed-in reinforcing steel plate 2 from moving away from the pier P1 and bulging.

[0032] As shown in Fig. 1, the bulge prevention material 6 is installed above the construction water level L1 in the river where the pier P1 was constructed. As described in the background art, if the bulge prevention material 6 is installed at an angle, it will become an obstacle when the press-in reinforcing steel plate 2 is pressed in, and high accuracy is required for the marking and installation position, so that underwater construction is avoided. Here, "above the construction water level L1" refers to the case where most of the bulge prevention material 6 (at least half or more in the height direction) is higher than the construction water level L1 and the construction position of the chemical anchor is higher than the construction water level L1. If the construction position of the chemical anchor is higher than the construction water level L1, the bulge prevention material 6 can be easily installed by ground work from a float or scaffolding, as described later.

[0033] However, in the installation portion (post-installed portion) of the post-installed reinforcing steel plate 2' shown with diagonal lines in Figure 1, the installation of the steel plate and the filling of the filler are carried out separately after the pressing device and the reaction steel plate are removed, so there is no need for the function as a guide material or the function of preventing bulging, and therefore no bulging prevention material 6 is installed.

[0034] 2, the illustrated embodiment shows a case where all the stiffening materials 21 are hung and secured by the bulge prevention material 6, but it is also possible to hang some of the stiffening materials 21 by the bulge prevention material 6. This is because when the pressure during filling of the filler material 3 is small, it is not necessary to provide all of the stiffening materials as guide materials.

[0035] <Steel plate press-in method> Next, a steel plate press-in construction method according to an embodiment of the present invention will be described with reference to Figures 1 to 20. Taking as an example a pier P1 constructed in a river as the above-mentioned existing columnar structure and having an oval horizontal cross section, the above-mentioned press-in reinforcing steel plate 2 is pressed into the periphery of the oval pier P1 to reinforce it.

[0036] (Advance preparation) First, in the steel plate pressing method according to this embodiment, floats are lined up and connected around a bridge pier P1 constructed in the river as advance preparation to install a prefabricated float F2, and a wedge-type scaffolding, frame scaffolding, etc. are assembled on top of the float to install scaffolding Sf to be used during pressing and lifting described later. Fig. 4 is a flow chart showing each step of the steel plate pressing method according to this embodiment, and Fig. 5 is a process explanatory diagram showing the advance preparation of the steel plate pressing method according to this embodiment.

[0037] (Reaction steel plate installation process) Next, as shown in Fig. 4 and Fig. 6, in the steel plate press-in method according to this embodiment, a reaction steel plate installation process is carried out to install a reaction steel plate 7 of the press-in device (PD) and a reaction steel plate 7' of a manual lifting device (LD) such as a chain block or a lever block (registered trademark) on the pier P1. Fig. 6 is a process explanatory diagram showing the reaction steel plate installation process of the steel plate press-in method according to this embodiment.

[0038] Specifically, in this process, post-installed anchors are installed on the top of the pier P1, and the reaction steel plates 7, 7' are fixed and installed by bolting to the post-installed anchors. Of course, the method of fixing the reaction steel plates 7, 7' to the pier P1 is not limited to post-installed anchors, and may be determined appropriately depending on the columnar structure.

[0039] (Press-in device installation process) As shown in Figures 4 and 7, in the steel plate press-in method according to this embodiment, a press-in device installation step is then performed in which a press-in device PD is attached to the reaction steel plate 7 (7') installed in the previous step. Figure 7 is a process explanatory diagram showing the press-in device installation step in the steel plate press-in method according to this embodiment.

[0040] Specifically, in this process, the press-in device PD is supported and fixed to the top of the pier P1 by bolting to the reaction steel plate 7, and the manual lifting device LD is attached to the reaction steel plate 7'. Of course, the method of supporting and fixing the press-in device PD to the pier P1 is not limited to bolting, and it goes without saying that any method of fixing may be used.

[0041] This pressing device PD is a hydraulically driven linear motion mechanism, and is composed of an expansion jack J that presses in the aforementioned reinforcing steel plate assembly 20, and a pressing jig D1 made of steel that transmits the pressure of the expansion jack evenly to the reinforcing steel plate assembly 20.

[0042] (Installation process of anti-burst material) As shown in Fig. 4 and Fig. 8, in the steel plate press-in method according to this embodiment, a bulge prevention material attachment step is then performed to attach the above-mentioned bulge prevention material 6. Fig. 8 is a process explanatory diagram showing the bulge prevention material attachment step in the steel plate press-in method according to this embodiment.

[0043] Specifically, in this process, multiple hanging plates 61, 62 are attached to the outer peripheral surface of pier P1 above the construction water level L1 at a distance from each other in the horizontal direction (direction Y perpendicular to the bridge axis), and are fixed to pier P1 with M16 chemical anchors, and slits 63 are formed between the hanging plates 61 and 62 (see Figure 3). This process may be performed simultaneously with the reinforcing steel plate assembly process described below.

[0044] (Reinforcing steel plate assembly process) As shown in Fig. 4 and Fig. 9, the next step in the steel plate press-in method according to this embodiment is a reinforcing steel plate assembling step for assembling one stage of reinforcing steel plate assemblies 20. Fig. 9 is a process explanatory diagram showing the reinforcing steel plate assembling step in the steel plate press-in method according to this embodiment.

[0045] Specifically, in this process, the left and right end faces of the reinforcing steel plate are welded together by full penetration welding, and one stage of the reinforcing steel plate assembly 20 is assembled in an oval shape at a certain distance from the outer periphery of the pier P1. In this embodiment, since the cross-sectional shape of the pier P1 is oval, the assembly is made to form a frame along the oval outer periphery, which has a similar cross-sectional shape. Of course, if the cross-sectional shape of the pier P1 is circular, elliptical, or rectangular, the assembly is made to form a cross-sectional shape similar to that of the pier P1. In addition, when assembling the reinforcing steel plate assembly 20, as described above, the stiffener 21 with a T-shaped cross section protruding from the inner surface of the reinforcing steel plate assembly 20 is inserted into the slit 63 of the bulge prevention material 6 (see FIG. 3(a)).

[0046] The joining of the end faces of the press-fitted reinforcing steel plate 2 is not limited to welding, and other joining methods such as mechanical joining such as riveting or bolting, or FSW (FSW Friction Stir Welding) may also be used.

[0047] (Reinforcing steel plate assembly and settling process) As shown in Figures 4 and 10, in the steel plate press-in method according to this embodiment, the reinforcing steel plate assembly 20 is then joined at the top and bottom by welding or the like and lowered, and a reinforcing steel plate assembling and submerging process is performed in which the reinforcing steel plate assembly 20 connected at the top and bottom is repeatedly assembled and lowered until it reaches the riverbed surface L2, which is the ground surface. Figure 10 is a process explanatory diagram showing the reinforcing steel plate assembling and submerging process of the steel plate press-in method according to this embodiment.

[0048] Specifically, in this process, using a manual lifting device LD or the like, the reinforcing steel plate assembly 20 assembled in the previous reinforcing steel plate assembly process is joined at the top and bottom by welding or the like and then lowered, and the assembly and lowering are repeated until the reinforcing steel plate assembly 20 connected at the top and bottom reaches the riverbed surface L2, which is the ground surface.

[0049] (Press-fitting process) As shown in Figures 4 and 11, in the steel plate pressing method according to this embodiment, a pressing process is then carried out in which the reinforcing steel plate assembly 20 that reaches the riverbed surface L2, assembled in the reinforcing steel plate assembling and settling process, is pressed into the ground around the pier P1 using the pressing device PD attached to the top of the pier P1 in the previous pressing device installation process. At this time, soil that has invaded the gap G (see Figure 2(a)) between the reinforcing steel plate assembly 20 and the pier P1 is removed by spraying high-pressure water using a water jet or the like. Figure 11 is a process explanatory diagram showing the pressing process of the steel plate pressing method according to this embodiment.

[0050] As described above, the bulge prevention material 6 is attached to the outer peripheral surface of the pier P1 in the bulge prevention material attachment process, and the stiffener 21 is inserted through the slit 63 of the bulge prevention material 6 in the reinforcing steel plate assembly process, so in this process, the reinforcing steel plate assembly 20 is pressed in using the bulge prevention material 6 as a guide material that guides it in the vertical direction. Therefore, the reinforcing steel plate assembly 20 (press-in reinforcing steel plate 2) can be pressed in vertically with high accuracy.

[0051] (Repeat assembling reinforcing steel plates and pressing) As shown in Figures 4 and 12, in the steel plate press-in method according to this embodiment, the above-mentioned reinforcing steel plate assembly process and press-in process are then repeated multiple times until the lower end of the reinforcing steel plate assembly 20 reaches a predetermined depth according to the structural design. Figure 12 is a process explanatory diagram showing a state where the press-in process of the steel plate press-in method according to this embodiment is completed.

[0052] (Press-in device removal process) As shown in Fig. 4 and Fig. 13, in the steel plate press-in method according to this embodiment, a press-in device removal process is then performed to remove the press-in device PD installed in the press-in device installation process. Fig. 13 is a process explanatory diagram showing the press-in device removal process of the steel plate press-in method according to this embodiment.

[0053] (Shoring installation process) As shown in Figures 4 and 14 to 20, in the steel plate pressing method according to this embodiment, a support installation process is then carried out in which supports 5 are installed around the reinforcing steel plate assembly 20 (press-in reinforcing steel plate 2) to prevent the reinforcing steel plate assembly 20 (press-in reinforcing steel plate 2) from collapsing during the filler filling process described below.

[0054] Specifically, in this process, as shown in Figure 1, three sets of supports 5 are installed from the bottom, 1st to 3rd tiers, at approximately equal intervals around the underwater portion of the pressed-in reinforcing steel plate 2 between the construction water level L1 and the riverbed surface L2.

[0055] First, in this process, as shown in Fig. 14, a first-stage shoring assembly process is performed in which a manual lifting device LD such as a chain block is used to lift and support the first stage shoring 5 from the bottom on the float F2, by assembling the long side portion 5a, short side portion 5b, corner piece 5c, etc. (see also Fig. 2(a)). Fig. 14 is a process explanatory diagram showing the first stage shoring assembly process in the shoring installation process of the steel plate press-in method according to this embodiment.

[0056] Next, in this process, as shown in Fig. 15, the lifting support of the first stage shoring 5 is transferred from the manual lifting device LD to the reaction steel plate 7 using a wire or the like, and then the free manual lifting device LD is used to lift and support the H-shaped steel, which is an earth retaining material, and a second stage shoring assembly process is performed in which the second stage shoring 5 is assembled from the bottom on the float F2. Fig. 15 is a process explanatory diagram showing the second stage shoring assembly process in the shoring installation process of the steel plate pressing method according to this embodiment.

[0057] Furthermore, in this process, as shown in Fig. 16, after assembling the second stage shoring 5, a first-stage / second-stage hanging point changing process is performed in which the hanging point of the second stage shoring 5 is changed from the manual lifting device LD to the reaction steel plate 7, and the hanging point of the first stage shoring 5 is changed from the reaction steel plate 7 to the assembled second stage shoring 5 by tying the wire with a wire or the like. Fig. 16 is a process explanatory diagram showing the first-stage / second-stage hanging point changing process in the shoring installation process of the steel plate pressing method according to this embodiment.

[0058] Next, in this process, as shown in Fig. 17, a third-stage shoring assembly process is performed in which the H-shaped steel is hoisted and supported by using the free manual lifting device LD, and the third stage of shoring 5 from the bottom is assembled on the float F2 (see also Fig. 2(a)). Fig. 17 is a process explanatory diagram showing the third stage shoring assembly process in the shoring installation process of the steel plate pressing method according to this embodiment.

[0059] Next, in this process, as shown in Fig. 18, after assembling the third stage shoring 5, a second stage hanging base replacement process is performed in which the hanging base of the second stage shoring 5 is replaced from the reaction steel plate 7 to the assembled third stage shoring 5. Fig. 18 is a process explanatory diagram showing the second stage hanging base replacement process in the shoring installation process of the steel plate press-in construction method according to this embodiment.

[0060] Finally, in this process, as shown in Fig. 19, a manual lifting device LD is used to lower the first to third stages of shoring 5 all together to a predetermined position, and a shoring lowering and installation process is performed in which Uniblock (registered trademark) or wedges made of steel or the like are inserted as back-filling materials into the gap G between the outer circumferential surface of the reinforcing steel plate assembly 20 (press-in reinforcing steel plate 2) and the shoring 5 to fix them in place. Fig. 19 is a process explanatory diagram showing the shoring lowering and installation process in the shoring installation process of the steel plate press-in construction method according to this embodiment.

[0061] (Cleaning process) As shown in FIG. 4, in the steel plate press-in method according to this embodiment, a cleaning step is then carried out to clean the gap G, which is a clearance at the time of press-in.

[0062] Specifically, in this process, soil and floating matter adhering to the inner surface of the reinforcing steel plate assembly 20, the surface of the pier P1, and in the gap G are washed away and cleaned by spraying high-pressure water using a water jet or the like.

[0063] (Filling material filling process) As shown in Figure 4, in the steel plate pressing method according to this embodiment, a filler filling process is then carried out in which the above-mentioned filler 3 is filled into the gap G between the reinforcing steel plate assembly 20 and the pier P1 (see Figures 2(a) and 2(b)).

[0064] In this process, the gap G that has been cleaned in the pre-cleaning process is filled with a filler 3 made of a cement-based time-hardening material such as mortar or concrete. Note that the filler 3 to be filled is not limited to a cement-based time-hardening material, and may be a filler made by mixing a resin-based adhesive such as an epoxy resin into a filler.

[0065] (Shoring dismantling and removal process) As shown in Fig. 4, in the steel plate pressing method according to this embodiment, a shoring dismantling and removal process is then carried out in which the first to third tiers of shoring installed in the shoring installation process are dismantled and removed. In this process, which is the reverse process of the shoring lowering and installation process described above and shown in Fig. 19, the first to third tiers of shoring 5 are hoisted together to above the float F2 using the manual lifting device LD, and while rearranging the hoisting points, they are dismantled and removed in order starting from the lowest tier of shoring 5.

[0066] In addition, after all of the shoring 5 has been dismantled and removed, the reaction steel plates 7 that are no longer needed are also removed.

[0067] (Post-installation reinforcing steel plate installation process) As shown in Figures 4 and 20, in the steel plate press-in method according to this embodiment, a post-installed reinforcing steel plate assembly installation process is then carried out in which the reinforcing steel plate assembly 20' of the post-installed reinforcing steel plate 2', which is the above-mentioned post-installed portion shown by the diagonal line, is assembled and installed on scaffolding. This process is carried out in the same way as in the conventional steel plate winding method. Figure 20 is a process explanatory diagram showing the post-installed reinforcing steel plate installation process of the steel plate press-in method according to this embodiment.

[0068] (Post-construction filler filling process) Then, as shown in Figure 4, in the steel plate pressing method according to this embodiment, a post-installation filler filling process is carried out to fill the gap G (see Figure 2(a)) between the reinforcing steel plate assembly 20' of the post-installation reinforcing steel plate 2' installed in the pre- and post-installation reinforcing steel plate installation process and the pier P1 with the aforementioned filler 3.

[0069] After the post-construction filler filling process is completed, the filler 3 hardens and the reinforcing steel plate assembly 20', 20 and the pier P1 are integrated, completing the steel plate press-in construction method according to this embodiment. Of course, anticorrosive coating may be applied to the press-in reinforcing steel plate 2 and the post-construction reinforcing steel plate 2' as necessary.

[0070] According to the bulge prevention structure 1 and steel plate pressing method of this embodiment described above, the bulge prevention material 6 is provided above the water level during construction, so the bulge prevention material 6 can be attached with high precision even if the existing columnar structure (pier P1) to be reinforced is high and its lower part is underwater. Therefore, according to the bulge prevention structure 1 and steel plate pressing method, the bulge prevention material 6 can be pressed in accurately by also functioning as a guide material that guides the pressed-in reinforcing steel plate 2 in the vertical direction when it is pressed in, and the internal pressure of the filling material 3 can be prevented from causing the pressed-in reinforcing steel plate 2 to bulge out or become displaced.

[0071] Furthermore, according to the bulge prevention structure 1 and steel plate pressing method, in addition to the bulge prevention material 6, supports 5 are installed around the underwater portion of the pressed-in reinforcing steel plate 2, so that it is possible to reliably prevent the pressed-in reinforcing steel plate 2 from bulging out or shifting due to the internal pressure of the filling material 3.

[0072] The above describes in detail the underwater bulging prevention structure 1 of the press-in reinforced steel plate according to the embodiment of the present invention and the steel plate press-in construction method using the same. However, the above-mentioned and illustrated embodiments are merely specific embodiments for carrying out the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these. [Explanation of symbols]

[0073] 1: Press-fit reinforced steel plate structure to prevent underwater bulging 2: Press-fit reinforcement steel plate 2': Post-installed reinforced steel plate 2a: Flat part 2b: Arc section 20,20': Reinforced steel plate assembly 21: Stiffener 3: Filling material 5: Shoring 5a: Long side 5b: Short side 5c: Corner piece 6: Anti-pimples material 61, 62: Hanging plate 63: Slit D1: Pressing tool F2: Float G: Gap J: Telescopic jack L1: Water level during construction L2: River bed surface LD: Manual lifting device P1: Pier PD: Press-in device Sf: Scaffolding

Claims

1. A press-in reinforcing steel plate underwater bulging prevention structure that prevents a press-in reinforcing steel plate, which is pressed into the periphery of an existing columnar structure partially constructed underwater for reinforcement, from being bulged in when filling with a filler material, A pair of Z-shaped bulge prevention materials are attached to the existing columnar structure above the construction water level, and a slit is formed between these bulge prevention materials. A plurality of stiffeners having a T-shaped cross section are attached to the inner surface of the press-fitted reinforcing steel plate, At least a portion of the stiffeners are inserted into the slits, A single or multiple supports made of steel materials are installed around the underwater portion of the press-in reinforcing steel plate to prevent the press-in reinforcing steel plate from being engulfed when filling with filler. A press-fit reinforced steel plate structure that prevents underwater bulging.

2. A steel plate press-in method for reinforcing an existing columnar structure constructed underwater by pressing a reinforcing steel plate around the columnar structure, a step of attaching a pair of Z-shaped bulge prevention materials to the existing columnar structure above the construction water level and forming a slit between the bulge prevention materials; a press-in process of pressing a press-in reinforcing steel plate around the existing columnar structure; A filler filling step is provided for filling a gap between the press-fitted reinforcing steel plate and the existing columnar structure with a filler, In the press-fitting step, a stiffener protruding from an inner surface of the press-fitted reinforcing steel plate is inserted into the slit between the bulge prevention materials attached in the bulge prevention material attachment step, and the press-fitting is performed while the bulge prevention material is used to guide the press-fitting direction; A support installation process is provided for installing a support around the underwater portion of the press-in reinforcing steel plate prior to the filler filling process to prevent the press-in reinforcing steel plate from being filled in during the filler filling process. This is a steel plate pressing method characterized by the above.

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