Pressure control system

Abstract

To provide a system, method, and method for fracture concrete members that enable the control of pressure within multiple expansion members in a labor-saving and efficient manner. [Solution] The pressure control system is a system that controls the pressure in a plurality of expansion members that expand by the supply of fluid, and includes a supply means that supplies the fluid to a plurality of expansion members inserted into each of a plurality of gaps formed in a concrete member, a plurality of opening and closing means provided in each pipe after branching when supplying fluid to each expansion member by branching from the supply means, which open and close to supply or stop the supply of the fluid, a plurality of backflow prevention means provided in each pipe between each expansion member and each opening and closing means to prevent backflow of the fluid, a plurality of pressure detection means connected to each pipe between each expansion member and each backflow prevention means to detect the pressure of the fluid, and a control means that controls the opening and closing operation of the plurality of opening and closing means based on the change in each pressure detected by each pressure detection means over time.

Description

Technical Field

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[0001] The present invention relates to a system, a method for controlling the pressure in a plurality of expansion members that expand by the supply of a fluid, and a method for breaking a concrete member.

Background Art

[0002] The floor slab of a structure such as a road bridge is one of the concrete members, and due to deterioration and damage over time, it is necessary to carry out renewal work to replace the existing floor slab. In the renewal work of the existing floor slab, it is necessary to minimize the impact of traffic restrictions and perform the cutting and removal work efficiently and in a short time.

[0003] As a method for disassembling a concrete member, a slit for inserting a pressurizing mechanism such as a plate jack is formed in the concrete member, the pressurizing mechanism is inserted into the slit, and pressure is applied by the pressurizing mechanism to crush the concrete or generate a crack penetrating in the thickness direction of the concrete member, and a technique for separating a block surrounded by a free surface and the crack from the remaining concrete is known (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0006] Therefore, there was a need for systems and methods that enable labor-saving and efficiency improvements, as well as methods for fracture concrete members using such systems. [Means for solving the problem]

[0007] The present invention has been made in view of the above problems, and is a system for controlling the pressure in a plurality of expandable members that expand by the supply of fluid, A supply means for supplying the fluid to multiple expansion members inserted into each of the multiple gaps formed in a concrete member, Multiple opening and closing mechanisms are provided in each pipe after the branching when supplying fluid to each expansion member by branching from the supply means, and which perform opening and closing operations to supply or stop the supply of said fluid. Multiple backflow prevention means are provided in each pipe between each expansion member and each opening / closing means to prevent backflow of fluid, Multiple pressure sensing means are connected to the piping between each expansion member and each backflow prevention means to detect the fluid pressure, A control means controls the opening and closing operations of multiple opening and closing means based on the time-dependent changes in each pressure detected by each pressure detection means. A pressure control system is provided, which includes the following: [Effects of the Invention]

[0008] According to the present invention, it is possible to control the pressure within multiple expansion members in a labor-saving manner. [Brief explanation of the drawing]

[0009] [Figure 1] A diagram showing an example of the structure of a road bridge. [Figure 2] This diagram shows a simulated test specimen that mimics an example of a joint between the main girder and the deck slab in a road bridge. [Figure 3] Figure 2 shows an example of a girder material equipped with a shear-preventing member used in the test specimen. [Figure 4] A diagram showing an example of an expansion member. [Figure 5] A flowchart showing an example of a conventional operation of breaking and removing a floor slab. [Figure 6] A diagram showing an example of the personnel arrangement during the conventional operation. [Figure 7] A diagram showing a first configuration example of the pressure control system according to the present embodiment. [Figure 8] A diagram showing an installation example of the expansion member and the pressure control system. [Figure 9] A flowchart showing a first example of an operation of breaking and removing a floor slab while automatically controlling the pressure inside the expansion member. [Figure 10] A flowchart showing a second example of an operation of breaking and removing a floor slab while automatically controlling the pressure inside the expansion member. [Figure 11] A diagram showing an example of the change over time of the pressure of the fluid. [Figure 12] A diagram showing the cracking and breaking status of the floor slab corresponding to the change over time of the pressure inside the expansion member. [Figure 13] A diagram showing an example of the personnel arrangement when using the pressure control system. [Figure 14] A diagram showing a second configuration example of the pressure control system according to the present embodiment.

Embodiments for Carrying Out the Invention

[0010] The pressure control system according to the present embodiment is a system that controls the pressure inside a plurality of expansion members inserted into each of a plurality of gaps formed in a concrete member and expanded by the supply of fluid. The concrete member may be any member as long as it is a member made of concrete, and may be a member containing reinforcing bars or the like. Examples of the concrete member include walls, floors, columns, beams of buildings, etc., segments of shield tunnels, floor slabs of road bridges, etc.

[0011] The expansion member that expands by the supply of fluid is a member that is expanded by the supply of high-pressure fluid and has an expanded volume. As an example, a plate jack or the like can be mentioned. Hereinafter, a concrete member will be described as a floor slab and an expansion member as a plate jack, but the concrete member and the expansion member to which the pressure control system is applied are not limited thereto.

[0012] FIG. 1 is a diagram showing an example of the structure of a road bridge having a floor slab as a concrete member. A road bridge is one of the bridges, and other bridges include railway bridges, pedestrian bridges, etc. A bridge is a road structure erected with a space left under the girder to cross a river or the like, and has a bridge length of 2 m or more.

[0013] The road bridge 10 is composed of a substructure (substructure work) such as a pier and a superstructure (superstructure work) constructed on the substructure and directly supporting pedestrians, vehicles, etc. The superstructure work includes a bearing 11 that transmits the load to the substructure, a main girder 12 that is a girder member extending vertically from the bearing 11 that supports the entire superstructure work and transmits the load to the substructure via the bearing 11, and a floor slab 13 that is a plate that transmits the weight of pedestrians, vehicles, etc. as a load to the main girder 12.

[0014] The bearing 11 may be a movable bearing that absorbs the rotation and expansion / contraction of the superstructure work, a fixed bearing that absorbs only the rotation of the superstructure work, or a seismic isolation bearing using laminated rubber or the like that is elastically fixed.

[0015] The main girder 12 includes an I-girder, a box girder, etc. according to the shape of the cross-section cut in the vertical direction, and includes a steel girder, a reinforced concrete girder, a PC (prestressed concrete) girder, etc. depending on the material difference. The floor slab 13 is also constructed from materials such as steel, reinforced concrete, and PC similar to the main girder 12. A floor slab waterproof layer 14 such as a waterproof sheet is provided on the floor slab 13 to prevent deterioration due to water intrusion into the floor slab 13, and asphalt or the like is laid on the floor slab waterproof layer 14 to perform paving 15.

[0016] At both ends of the bridge in the width direction, a curb 16 is provided, which is a raised section above the pavement 15. A protective fence 17 is provided on the curb 16 to prevent people, vehicles, etc. from falling from the bridge.

[0017] The main girders 12 are, for example, plate girders such as I-beams, and are installed at regular intervals in the width direction of the bridge. To resist lateral loads caused by wind, the main girders 12 are connected to each other by horizontal braces 18 and diagonal braces 19. The horizontal braces 18 are members that connect the main girders 12 in the horizontal direction, and the diagonal braces 19 are members that diagonally connect the upper part of one main girder 12 to the lower part of the other main girder 12. In addition, plate-shaped connecting members called gussets 20 are used to join the main girders 12 to the horizontal braces 18 and diagonal braces 19.

[0018] The deck slab 13 may be constructed by installing formwork, laying reinforcing bars, and pouring concrete after the main girder 12 has been installed, or it may be constructed using precast reinforced concrete deck slab members. In this case, in order to strengthen the connection between the main girder 12 and the deck slab 13, horseshoe-shaped (U-shaped) dowel bars 21 are provided on the girder flange of the main girder 12 as shear prevention members. A girder having a structure in which the main girder 12 and the deck slab 13 are integrated by the dowel bars 21 is called a composite girder.

[0019] When replacing the deck slab 13 in a composite girder, the main girder 12 and the deck slab 13 are firmly joined by dowel reinforcement bars 21. Therefore, the deck slab 13 can be cut and removed using a road cutter or wire saw, and the concrete remaining on the girder flange around the dowel reinforcement bars 21 can be removed by hand chipping or the like.

[0020] However, when using the above-mentioned methods of cutting the deck slab 13 with road cutters or wire saws, a large amount of concrete remains on the girder flange around the dowel reinforcement 21, increasing the amount of work that needs to be done by hand, and thus making the cutting and removal process time-consuming. In addition, using road cutters or wire saws can cause problems with vibration and noise, and may also damage the main girder 12.

[0021] Therefore, a method is adopted in which a plate jack is used as an expansion member to break and remove the structure. By adopting this method, the amount of concrete remaining on the girder flange of the main girder 12 can be reduced, shortening the time required for breaking and removal, and reducing vibration and noise.

[0022] Referring to Figure 2, a method for breaking and removing the deck slab using plate jacks will be explained. Figure 2 shows a simulated test specimen of the deck slab. The superstructure includes an H-shaped steel beam 30, which corresponds to the main girder 12, an I-beam, shown in Figure 1, with an H-shaped cross-section when cut vertically; multiple horseshoe-shaped dowel reinforcements 31 welded at regular intervals to one flange of the H-shaped steel beam 30; and a reinforced concrete deck slab 33, which corresponds to the deck slab 13 shown in Figure 1, which is joined to the flange of the H-shaped steel beam 30 by arranging reinforcing bars 32 and pouring concrete.

[0023] The H-shaped steel beam 30 is a long steel material formed into a specific cross-sectional shape, with two substantially parallel sections of the H-shaped cross-section forming flanges, and the section connecting these two sections forming the web. The dowel reinforcement 31 is provided on one of the two flanges of the H-shaped steel beam 30 as a shear-preventing member to maintain the integrity between the H-shaped steel beam 30 and the floor slab 33. In addition to horseshoe-shaped dowel reinforcement, the dowel reinforcement 31 may also be a headed stud with a rod-shaped, expanded head, or a perforated steel plate dowel with multiple holes in a flat plate.

[0024] The reinforcing bars 32 extend in two layers, upper and lower, in the direction in which the H-shaped steel 30 extends, and multiple bars are arranged at predetermined intervals in the width direction of the bridge. Additionally, multiple bars extend in two layers, upper and lower, in the width direction of the bridge, and multiple bars are arranged at predetermined intervals in the direction in which the H-shaped steel 30 extends, surrounding the outside of these multiple reinforcing bars 32. Therefore, in the cross-section shown in Figure 2, the reinforcing bars 32 are arranged in two layers, upper and lower, extending in the width direction of the bridge. Furthermore, in order to increase the strength of the joint between the H-shaped steel 30 and the deck slab 33, the thickness of the concrete on the flange of the H-shaped steel 30 is made thicker, and reinforcing bars are also arranged in this thickened portion. For this reason, the deck slab 33 is provided with haunch portions 34 such that the thickness increases toward the flange of the H-shaped steel 30. The haunch portions 34 are the portions on both sides of the portion having a horizontally extending joint surface 35 between the flange of the H-shaped steel 30 and the deck slab 33, as indicated by the dashed line, and have an inclined lower surface relative to the joint surface 35.

[0025] First, dowel reinforcement bars 31 are provided by welding them onto the flange of the H-shaped steel beam 30, and a gap (slit) 36 is formed from two surfaces on either side of the joint surface 35 between the flange of the H-shaped steel beam 30 and the floor slab 33, i.e., the two inclined lower surfaces of the haunch portion 34, extending upward toward the top of the joint surface 35 and inclined toward the joint surface 35. The angle θ between the joint surface 35 and the cutting depth direction in which the slit 36 ​​extends is not limited to this, but is preferably about 30° to 45° with respect to the joint surface 35.

[0026] An H-shaped steel beam 30 with dowel bars 31 is, for example, as shown in Figure 3. The dowel bars 31 are welded to one flange of the H-shaped steel beam 30 at regular intervals. The spacing (pitch) of the dowel bars 31 is not limited to this, but can be, for example, 150 mm or 300 mm.

[0027] Referring again to Figure 2, the cutting depth when forming the slit 36 ​​can be any depth, such as a depth exceeding the lower reinforcing bar 32 provided in the upper and lower stages, but it is preferable that the depth does not exceed the lower reinforcing bar 32 provided in the upper and lower stages. The cutting depth of the slit 36 ​​is most desirable to be just before reaching the lower reinforcing bar 32. The width of the slit 36 ​​can be any width as long as the plate jack, which acts as an expansion member, can be inserted, but if the width is too large, even if the plate jack expands, it will not be able to push open the slit 36 ​​and cause cracks, so a width of approximately 5 to 10 mm is desirable.

[0028] The slit 36 ​​can be formed using a cutting means capable of cutting to a predetermined width and depth. As a cutting means, for example, a wall saw can be used, which rotates a disc-shaped member with multiple blades around its circumference using an electric motor while it runs on a rail to form the slit 36 ​​in the direction in which the flange of the H-shaped steel 30 extends (the depth direction in Figure 2). Note that the wall saw is just one example of a cutting means, and the cutting means is not limited to a wall saw. The length of the slit 36 ​​(the length in the depth direction in Figure 2) is in the direction in which the flange of the H-shaped steel 30 extends, and can be formed to any length using a wall saw, but can be, for example, 1 m or more in length to allow the insertion of a plate jack.

[0029] Next, plate jacks are inserted into each of the two formed slits 36 as expansion members. As shown in Figure 4, the plate jacks 37 are made by welding special steel plates into a bag shape, and can be expanded by supplying pressurized fluid such as water to the inside. Generally, the plate jacks 37 are about 1 m long, about 10 cm high, and about 2-3 mm thick, and when a fluid such as water pressurized to about 5-6 MPa is supplied to the inside, they expand to a thickness of about 20-30 mm. Any fluid such as water or air can be used as long as it can expand the plate jacks 37. The following explanation will use water as the fluid.

[0030] The plate jack 37 has a connection port (nozzle) 38 that connects to a hydraulic unit (e.g., a pump) as a supply means for pressurizing and supplying water, and water pressurized to a predetermined pressure is supplied to the inside by the hydraulic unit. This applies water pressure to the inside of the plate jack 37 inserted into each of the two slits 36, causing the plate jack 37 to expand. The expansion of the plate jack 37 pushes the slits 36 open, causing cracks to form, which then propagate, causing the concrete of the floor slab 33 to rupture.

[0031] In the case of unreinforced concrete, cracks generally propagate almost straight in the direction of the cutting depth through which the slit 36 ​​extends. However, in the case of reinforced concrete, the adhesive force between the concrete and the reinforcing steel at the location of the reinforcing steel resists the tensile force caused by the expansion of the plate jack 37. Therefore, after the cracks propagate straight in the direction of the cutting depth through which the slit 36 ​​extends, the cracks will then propagate along the direction in which the reinforcing steel 32 extends.

[0032] If the slit 36 ​​is formed to a cutting depth that exceeds the lower reinforcing bar 32, the crack will propagate straight down to the upper reinforcing bar 32, and then propagate along the direction in which the upper reinforcing bar 32 extends. On the other hand, if the slit 36 ​​is formed to a cutting depth that does not exceed the lower reinforcing bar 32 (including cutting depths that reach the lower reinforcing bar 32), the crack will propagate straight down to the lower reinforcing bar 32, and then propagate along the direction in which the lower reinforcing bar 32 extends.

[0033] The cracks propagate from each of the two slits 36 along the upper or lower reinforcing bars, eventually connecting the two slits 36. As a result, the deck slab 33 is severely fractured, leaving a roughly trapezoidal shape of concrete on the flange of the H-shaped steel 30. Although a roughly trapezoidal shape of concrete remains around the dowel reinforcement bars 31, the amount of remaining concrete is significantly reduced compared to when cutting with conventional road cutters or wire saws, minimizing the time-consuming chipping work and thus shortening the time required for cutting. The fractured deck slab 33 is lifted and removed using a crane or other lifting equipment.

[0034] Figure 5 is a flowchart illustrating an example of a conventional procedure for breaking and removing a floor slab. The floor slab has multiple slits 36 formed in it, and each of the multiple plate jacks 37 is inserted into each of the multiple slits 36. The multiple plate jacks 37 are connected to a hydraulic unit (pump), and water is supplied as a fluid from the pump. The pump is equipped with a hydraulic pressure regulating valve for adjusting the water pressure of the supplied water, a main valve for supplying water with adjusted pressure, and a pressure gauge for detecting the water pressure. The water supplied from the pump passes through a single pipe, branches off along the way, and is supplied to each plate jack 37 through each branch pipe to which each branch valve is connected.

[0035] The process of breaking and removing the floor slab using plate jacks begins in step 100, with the pump being activated in step 101. In step 102, the water pressure regulating valve is opened while referring to the pressure gauge, and this operation is continued until the standard pressure (approximately 4-5 MPa) is reached. After adjusting the water pressure to the standard pressure, the process proceeds to step 103, where the main valve is fully opened and the water supply is started.

[0036] In step 104, each branch valve is fully opened to begin supplying water to each plate jack 37. The plate jacks 37 begin to expand once the water supply begins. When the plate jacks 37 have expanded to a certain extent, cracks will appear in the floor slab in step 105.

[0037] Cracks rarely occur simultaneously in multiple plate jacks 37. This is because it is difficult to make the direction and length of the slits 36 exactly the same and to fully open multiple branch valves at the same time, and the composition of the concrete in the floor slab is not uniform. Therefore, it is possible that cracks may occur in one plate jack 37, but not yet in another plate jack 37.

[0038] In this situation, if water is continued to be supplied without closing the branch valves, the expansion of the plate jacks 37 that have not yet developed cracks will be restricted, but the plate jacks 37 that have developed cracks will be able to expand and will continue to expand, overloading the plate jacks 37 and potentially causing them to burst. Therefore, in step 106, in order to prevent the plate jacks 37 from continuing to expand, the branch valves at the locations where cracks have occurred, which are connected to the plate jacks 37 that have developed cracks, are closed. At this time, the branch valves at the locations where cracks have not occurred, which are connected to the plate jacks 37 that have not developed cracks, are left open, and the supply of water to the plate jacks 37 continues. In step 107, once it is confirmed that cracks have occurred in all the plate jacks 37, all the branch valves are closed.

[0039] After all the branch valves are closed, in step 108, all the branch valves are fully opened and water is supplied to each plate jack 37 for a certain period of time. This widens the cracks. In step 109, widening the cracks causes the concrete that makes up the floor slab to break. This separates the concrete from the main girder to which the dowel reinforcement is installed. Then, in step 110, the broken concrete is lifted and removed using a crane or the like, and if necessary, chipping work is performed to complete the work.

[0040] Figure 6 shows an example of personnel arrangement during conventional work. In conventional work, an operator is required to start the pump 40, adjust the water pressure, and operate the pump 40 to stop it. Furthermore, since the pressure gauge equipped on the pump 40 cannot measure the pressure applied to each of the plate jacks 37 individually, it is necessary to visually check for cracks and fractures in the concrete 41 at the location of each plate jack 37 from the front or side, and an inspector is also required to check for cracks and fractures. In addition, an opener is required to open and close the branch valve 42 based on signals.

[0041] The floor slab has slits 36 formed on each of the inclined undersides on either side of the joint, into which the plate jacks 37 are inserted. Therefore, one person is required on each side to open and close the slits and another to check them, requiring at least five workers.

[0042] Since the opening and closing of the branch valve 42 is performed manually by the operator, it requires effort and may lead to insufficient signal transmission or operational errors. Furthermore, when the branch valve 42 is operated manually, the pressure state of the plate jack 37 tends to become unbalanced, making uniform rupture difficult and prolonging the rupture process. In addition, checking for cracks and ruptures is performed while closing the branch valve 42 each time, resulting in a loss of time.

[0043] Thus, conventional methods require a large number of workers, are labor-intensive, prone to operational errors, and place a heavy load on the plate jacks 37. These problems arise because the branch valve 42 is operated manually, making it impossible to measure the pressure applied to each plate jack 37. To solve these problems, the pressure control system according to this embodiment is provided.

[0044] Figure 7 shows a first configuration example of the pressure control system according to this embodiment. The pressure control system includes a pressure control unit and an operating unit. The pressure control unit includes a supply means, a plurality of opening / closing means, a plurality of backflow prevention means, and a plurality of pressure detection means. The operating unit includes an input means, a control means, and a display means.

[0045] The supply means is, for example, a pump 50, which supplies water at a predetermined pressure as a fluid at a predetermined pressure to the plate jacks 37. The multiple opening and closing means are, for example, multiple solenoid valves 51, which are installed in each pipe after branching when water is supplied to each plate jack 37 from the pump 40, and perform opening and closing operations to supply or stop the water supply. The multiple solenoid valves 51 are connected to an operating unit via wired or wireless communication, and perform opening and closing operations according to instructions from the operating unit.

[0046] Multiple backflow prevention means include, for example, multiple check valves 52, each check valve 52 installed in the piping between each plate jack 37 and each solenoid valve 51 to prevent backflow of water. This is because if water flows back from the plate jack 37 that first developed a crack to the plate jack 37 that did not develop a crack, the pressure will fluctuate, making it impossible to accurately measure the pressure of the plate jack 37 that did not develop a crack.

[0047] The multiple pressure sensing means are, for example, multiple pressure sensors 53, each pressure sensor 53 connected to the piping between each plate jack 37 and each check valve 52, and detecting the pressure inside each plate jack 37. The multiple pressure sensors 53 are connected to the control unit via wired or wireless communication and transmit the detected pressure information to the control unit. The multiple pressure sensors 53 individually measure the water pressure acting on each plate jack 37 in real time and transmit the measurement results to the control unit.

[0048] Each plate jack 37 is connected to a piping system, in the following order from the plate jack 37 side: a pressure sensor 53, a check valve 52, and a solenoid valve 51. Each solenoid valve 51 is connected to a manifold 54 via its respective piping, and then to a pump 50 via a control valve 55 that adjusts the total water flow. The piping may be made of steel pipe, or it may be made of pressure-resistant hose or the like.

[0049] In the example shown in Figure 7, slits 36 are formed on each of the inclined lower surfaces on either side of the joint surface of the floor slab, and plate jacks 37 are inserted into them. Therefore, each side is equipped with measurement units 56 and 57, each containing multiple pressure sensors 53, multiple check valves 52, multiple solenoid valves 51, a manifold pipe 54, and a control valve 55. For this reason, a branch pipe is provided on the discharge side of the pump 50 to distribute water to the measurement units 56 and 57 on each side.

[0050] The input and display means provided by the control unit are, for example, an operation panel (touch panel) 60 that allows input by the operator and displays information to the operator. The operation panel 60 accepts inputs such as instructions to start operation, instructions to end operation, a set value for the reference pressure, a set value for the time to resupply water, and settings for automatic opening and closing of the solenoid valve 51, and displays the pressure of each plate jack 37, the occurrence of cracks, etc. Note that the input means and the display means may be separate means, and the input means may be, for example, an operation button, and the display means may be, for example, a liquid crystal display or an organic EL (Electro Luminescence) display.

[0051] The control means is, for example, a sequencer 61, which is connected to the operation panel 60 via a relay device (for example, a hub) 62. The sequencer 61 includes a processor and memory, and executes a program stored in the memory to achieve predetermined control. The sequencer 61 includes a communication interface and communicates with each solenoid valve 51 and each pressure sensor 53. The communication between the communication interface and each solenoid valve 51 and each pressure sensor 53 may be wired communication or wireless communication such as Wi-Fi (registered trademark).

[0052] The control panel 60 and the sequencer 61 may be configured as a single unit or as separate units. In the example shown in Figure 7, the control panel 60 and the sequencer 61 are configured as separate units, and a sequencer 61 is provided for each measurement unit. That is, a sequencer 61 is provided for each of the two measurement units. Incidentally, one measurement unit is connected to four plate jacks 37, and is therefore configured to include four pressure sensors 53, four check valves 52, four solenoid valves 51, one manifold 54, and one control valve 55.

[0053] The control panel 60 can, through prior settings, instruct the sequencer 61 to automatically perform a series of operations, such as pressurizing all plate jacks 37 and opening and closing the solenoid valves 51, when, for example, the "Pressure Start" button is pressed. Therefore, the control panel 60 can display the "Pressure Start" button and accept its press. In addition to the above series of operations being performed automatically, the prior settings may also allow for settings to be configured to perform all operations manually or to perform only some operations automatically.

[0054] The control panel 60 can receive pressure information from each pressure sensor 53 regarding the pressure inside each plate jack 37, and information on the opening and closing status of each solenoid valve 51 from each solenoid valve 51, and display this information. This allows the pressure inside each plate jack 37 and the status of each solenoid valve 51 to be remotely checked and understood on the control panel 60.

[0055] The sequencer 61 determines the first pressure peak (pressure drop) inside the plate jack 37 from a threshold value. If a pressure drop is detected, it determines that a crack has occurred and implements an algorithm to automatically close the solenoid valve 51. The algorithm can be created based on data of the pressure change inside the plate jack 37 over time, and a model trained using machine learning may also be used.

[0056] Therefore, the solenoid valve 51 connected to the plate jack 37 that has caused the crack is automatically closed, and once all the solenoid valves 51 are closed, all of them are opened simultaneously, as in the conventional method, and repressurization is performed for a certain period of time, which widens the crack and causes it to break.

[0057] Figure 8 shows an example of the installation of the expansion members and pressure control system. The plate jacks 37, which serve as expansion members, are inserted into slits 36 formed in the floor slab 33, which is constructed on the flange of an H-shaped steel beam 30 having dowel reinforcement bars 31. Each plate jack 37 is connected by piping to measurement units 56 and 57, which are connected to a pump 50 that supplies pressurized water. The measurement units 56 and 57 are installed near the construction site where the floor slab 33 is located, within a few meters of the construction site. The pump 50 is connected to a generator and is powered by the generator to start it.

[0058] Measurement units 56 and 57 are adjacent to an IF (Interface) panel containing a sequencer 61, and the sequencer 61 communicates with an operation panel 60 installed indoors, such as in a temporary house. In the example shown in Figure 8, four plate jacks 37 are connected to each measurement unit 56 and 57 via piping.

[0059] Figure 9 is a flowchart showing a first example of the process of rupturing and removing a floor slab while automatically controlling the pressure inside the expansion member. Multiple slits 36 are formed in the floor slab 33, and multiple plate jacks 37 are inserted into each of the multiple slits 36. Multiple plate jacks 37 are connected to a pump 50.

[0060] The process of breaking and removing the floor slab using plate jacks 37 begins in step 200. As with conventional methods, the water pressure is adjusted using the water pressure regulating valve and the main valve is opened. When performed automatically, in step 201, the "Start Pressurization" button displayed on the control panel 60 is pressed. In step 202, upon receiving the instruction to start pressurization from the control panel 60, the sequencer 61 instructs the multiple solenoid valves 51 to open. The multiple solenoid valves 51, upon receiving this instruction, open their valves simultaneously, begin supplying water to the multiple plate jacks 37, and start pressurizing the multiple plate jacks 37.

[0061] Each plate jack 37 begins to expand when pressurization starts. When the plate jacks 37 have expanded to a certain extent, in step 203, the sequencer 61 determines the first peak of pressure received from the pressure sensor 53 from a threshold value and, upon seeing that the pressure has begun to decrease, determines that a crack has occurred. If no crack occurs even after a considerable amount of time has passed, the insertion position of the plate jacks 37 is reconsidered.

[0062] In step 204, if the sequencer 61 determines that a crack has occurred, it closes the solenoid valve 51 connected to the plate jack 37 that caused the crack. More specifically, the sequencer 61 instructs the solenoid valve 51 connected to the plate jack 37 that caused the crack to close the valve, and the solenoid valve 51 closes the valve in response to that instruction.

[0063] In step 205, the sequencer 61 closes the solenoid valve 51 connected to the plate jack 37 that has cracked each time it determines that a crack has occurred in the plate jack 37, until all solenoid valves 51 are closed. After all solenoid valves 51 are closed, in step 206, the operator operates the control panel 60 and presses the "Start Repressurization" button displayed on the control panel 60. The sequencer 61 receives the instruction to start repressurization from the control panel 60 and instructs the multiple solenoid valves 51 to open. In step 207, the multiple solenoid valves 51 open simultaneously and repressurization begins. The duration is not limited to this, but is approximately 30 seconds. No operation on the control panel 60 is required at this time. During this duration, the pressure in the plate jack 37 rises due to repressurization, reaches a second peak, and when the concrete ruptures, the pressure begins to decrease again.

[0064] Therefore, after a certain period of time has elapsed, in step 208, the sequencer 61 determines that the concrete has fractured, and in step 209, it closes all the solenoid valves 51 simultaneously. At this time, the solenoid valves 51 close automatically, so no operation is required. Then, proceed to step 210, where the fractured concrete is lifted and removed using a crane or the like, and if necessary, chipping work is performed to complete the work. If the concrete has not fractured after the solenoid valves 51 have closed, the insertion position of the plate jacks 37 should be reconsidered.

[0065] Figure 10 is a flowchart showing a second example of the process of rupturing and removing the floor slab while automatically controlling the pressure within the expansion member. Steps 300 to 305 and 307 to 310 are the same processes as steps 200 to 205 and 207 to 210 shown in Figure 9, so their explanation is omitted here.

[0066] In step 306, after all solenoid valves 51 have closed, the system waits for a set time to elapse, and after the set time has elapsed, it proceeds to step 307. The set time can be any time, but for example it can be 10 seconds. Note that this is just an example and is not limited to this.

[0067] Incidentally, as shown in Figure 9, when repressurization is performed manually by an operator, the operation is carried out in two stages: the initial pressurization and the subsequent repressurization. By performing the operation in two stages, it becomes possible to visually check whether cracks have occurred when the pressure drops, and repressurization can be performed after visually confirming the presence of cracks. As shown in Figure 10, when repressurization is performed automatically by a timer, it is not possible to visually confirm the presence of cracks, but by automating the process until rupture, the work time can be shortened and operational errors or forgetting to perform the operation can be prevented.

[0068] Figure 11 shows an example of the change in pressure over time within the plate jack 37. Figure 11(a) shows the change in pressure over time when the maximum pressurizing force is 4.5 MPa. When pressurization is started and water is supplied into the plate jack 37, the pressure inside the plate jack 37 rises rapidly, peaks at the maximum pressurizing force of 4.5 MPa, and then decreases thereafter.

[0069] In Figure 11(a), period (1) is the period from the start of pressurization until cracks appear and the pressure inside the plate jack 37 decreases, and period (2) is the period from the start of repressurization until the concrete fractures.

[0070] Until cracks occur, the plate jack 37 expands freely until it contacts the concrete on both sides of the slit into which it is inserted. After contact with the concrete, the volume of the plate jack 37 remains almost unchanged due to the resistance of the concrete on both sides, but the pressure inside the plate jack 37 increases as water pressure continues to be applied. The pressure inside the plate jack 37 rises to a maximum applied pressure of 4.5 MPa.

[0071] When cracks occur, the concrete's resistance decreases rapidly, allowing the plate jack 37 to expand. The plate jack 37 expands due to the internal pressure that has risen up to that point. Once the plate jack 37 expands, it does not contract, so the internal pressure drops at the moment of expansion. However, because water pressure is continuously applied, the pressure drop inside the plate jack 37 becomes small, and the pressure then begins to rise.

[0072] Once the concrete is completely fractured, its resistance is lost, allowing the plate jack 37 to expand freely. It then reaches a peak pressure again, the pressure inside the plate jack 37 decreases again, and then remains at a constant pressure.

[0073] Figure 11(b) shows the signals for opening and closing the solenoid valve 51. Signal "0" indicates closed, and signal "1" indicates open. After pressurization is started, a signal is given to open the solenoid valve 51. If a pressure drop occurs and it is determined that a crack has occurred, a signal is given to close the solenoid valve 51. Then, when the repressurization operation is started, a signal is given to open the solenoid valve 51, and after a certain period of time has elapsed, a signal is given to close the solenoid valve 51.

[0074] Figure 12 shows the cracking and fracture conditions of the floor slab in response to changes in pressure within the expansion member over time. Two slits 36 are formed diagonally upwards in the inclined portion of the lower surface of the floor slab 33, and multiple plate jacks 37 are inserted into each slit 36. The plate jacks 37 are connected to a pump 50 via piping, and a pressure sensor 53, a check valve 52, and a solenoid valve 51 are provided along the way.

[0075] Figure 12(a) shows the cracking of the deck slab, where cracks 70 have formed connecting from the respective ends of the two slits 36 in the cutting direction, along the shortest distance. Figure 12(b) shows the fracture of the deck slab, where the width of each of the two slits 36 has widened, and the width of the crack 70 formed between them has widened, causing the upper part of the deck slab and the lower part that is in close contact with the main girder to completely separate and fracture. As a result, the upper part of the deck slab can be removed by lifting it with a crane or the like. The upper part of the deck slab occupies most of the deck slab, while the lower part of the deck slab that remains on the main girder is a significantly smaller amount compared to the upper part of the deck slab.

[0076] Figure 13 shows an example of personnel arrangement when using the pressure control system according to this embodiment. When using the pressure control system, multiple solenoid valves 51 open and close automatically, so there is no need for an operator to open and close the valves. In addition, since the occurrence of cracks or fractures is determined by the pressure from the pressure sensor 53, there is no need for an inspector to check for the occurrence of cracks or fractures. As with conventional methods, an operator to operate the pump 50 is required.

[0077] On the other hand, unlike conventional methods, a separate operator is required to operate the control panel 60. Therefore, at least two workers are required, but this is fewer than the five required in conventional methods, making it possible to reduce manpower by using the pressure control system.

[0078] Figure 14 shows a second configuration example of the pressure control system according to this embodiment. The second configuration example shown in Figure 14 is substantially the same as the first configuration example shown in Figure 7, but a flow meter 58 is provided in the piping between each plate jack 37 and each check valve 52 as a means of detecting flow rate. The other configurations are the same as the first configuration example shown in Figure 7, so their explanation will be omitted.

[0079] The flow meter 58 can be used to measure the flow rate (water delivery rate) of water supplied to the plate jack 37 and to determine the degree of expansion of the plate jack 37. By determining the degree of expansion of the plate jack 37, the condition of concrete fracture can be determined. Therefore, the sequencer 61 can determine the crack occurrence and concrete fracture status based on the pressure detected by the pressure sensor 53 and the flow rate detected by the flow meter 58, and control the opening and closing operation of the solenoid valve 51 according to the determination result. If it is determined that the concrete has not yet fractured, all of the solenoid valves 51 will remain open, and only when it is determined that the concrete has fractured can all of the solenoid valves 51 be closed. In addition, by determining the degree of expansion of the plate jack 37, it is possible to prevent damage such as the plate jack 37 bursting due to excessive expansion.

[0080] This invention provides a pressure control system and method that allows the solenoid valve 51 to be opened and closed automatically, thereby reducing the need for manual valve opening and closing operations and eliminating the need for signals between workers, thus enabling labor savings. Furthermore, since pressure can be managed remotely using the control panel 60, close visual inspection of the plate jack 37 is unnecessary, improving safety.

[0081] Furthermore, because the water pressure can be controlled, overloading of the plate jack 37 can be reduced, enabling reuse and extending the lifespan of the plate jack 37. Additionally, a method for rupturing concrete members using a pressure control system or method can be provided.

[0082] The method for rupturing a concrete member can be carried out using a plurality of expansion members that expand upon the supply of fluid, and a pressure control system that controls the pressure within the plurality of expansion members. The method may include the steps of inserting and installing each of the plurality of expansion members into each of the plurality of gaps formed in the concrete member, supplying fluid to the plurality of expansion members using a supply means, and controlling the opening and closing operation of a plurality of opening and closing means based on the time-dependent change in each pressure detected by each pressure detection means.

[0083] In this case, the control means may include the steps of determining that a crack has occurred in the concrete member when it is determined from the change in pressure over time detected by the pressure detection means that the pressure has reached its (first) peak and a pressure drop has occurred, and when it is determined that a crack has occurred, it may close the opening / closing means connected to the expansion member that caused the crack.

[0084] The control means may include the step of closing all of the multiple opening / closing means, then opening all of the multiple opening / closing means, and supplying the fluid to each of the multiple expansion means for a certain period of time.

[0085] The pressure control system may include a plurality of flow detection means for detecting the flow rate of fluid supplied to each of a plurality of expansion members, and the above control step can control the opening and closing operation of the plurality of opening and closing means based on the change in each pressure over time and the flow rate of the fluid detected by each flow detection means.

[0086] The pressure control system, pressure control method, and concrete member fracture method of the present invention have been described in detail with reference to the embodiments shown in the drawings. However, the present invention is not limited to the embodiments described above, and can be modified to include other embodiments, additions, changes, or deletions within the scope that a person skilled in the art can conceive. Any embodiment that achieves the function and effect of the present invention is included within the scope of the present invention.

[0087] Therefore, methods for removing concrete members, methods for breaking deck slabs, methods for removing deck slabs, etc., can also be provided. [Explanation of Symbols]

[0088] 10… Road bridges 11...Support 12…Main digit 13…Floor slab 14…Floor slab waterproof layer 15…Pavement 16...Earth cover 17...protective fence 18…Horizontal composition 19…Opposing structure 20... Gusset 21...Gibber's muscle 30...H-shaped steel 31…Gibber's muscle 32…reinforcement bars 33…Floor slab 34... Hunchback 35…Joint surface 36... Slit 37... Plate jack 38…Connection port 40... Pump 41…Concrete 42... Branch valve 50... Pump 51... Solenoid valve 52... Check valve 53... Pressure sensor 54…Collecting pipe 55... Adjustment valve 56, 57... Measurement Unit 58…Flow meter 60... Control Panel 61... Sequencer 62…Relay device 70...Cracks

Claims

1. A system for controlling the pressure within multiple expandable members that expand due to the supply of fluid, A supply means for supplying the fluid to multiple expansion members inserted into each of the multiple gaps formed in the concrete member, Multiple opening and closing means are provided in each pipe after the branching, when the fluid is supplied to each of the expansion members by branching from the supply means, and which perform opening and closing operations to supply or stop the supply of the fluid, A plurality of backflow prevention means for preventing backflow of the fluid are provided in each pipe between each expansion member and each opening / closing means, Multiple pressure sensing means are connected to the piping between each of the expansion members and each of the backflow prevention means, and detect the pressure of the fluid. Based on the time-dependent changes in each pressure detected by each of the aforementioned pressure detection means, a control means controls the opening and closing operations of the plurality of opening and closing means. A pressure control system, including a pressure control system.

2. The pressure control system according to claim 1, wherein the control means determines, based on the change in pressure over time detected by the pressure detection means, that the pressure has reached a peak and a pressure drop has occurred, and determines that a crack has occurred in the concrete member, and causes the opening / closing means connected to the expansion member that caused the crack to close.

3. The pressure control system according to claim 2, wherein the control means closes all of the plurality of opening and closing means, then opens all of the plurality of opening and closing means, and supplies the fluid to each of the plurality of expansion means for a certain period of time.

4. It includes a plurality of flow rate detection means for detecting the flow rate of the fluid supplied to each of the plurality of expansion members, The pressure control system according to claim 1, wherein the control means controls the opening and closing operation of the plurality of opening and closing means based on the change in each pressure over time and the flow rate of the fluid detected by each flow rate detection means.

5. A method for controlling the pressure in a plurality of expansion members that expand by the supply of fluid, using a pressure control system, wherein the pressure control system includes: a supply means for supplying the fluid to a plurality of expansion members inserted into each of a plurality of gaps formed in a concrete member; a plurality of opening and closing means provided in each pipe after branching when the fluid is supplied to each of the expansion members by branching from the supply means, which open and close to supply or stop the supply of the fluid; a plurality of backflow prevention means provided in each pipe between each of the expansion members and each of the opening and closing means for preventing backflow of the fluid; a plurality of pressure detection means connected to each pipe between each of the expansion members and each of the backflow prevention means for detecting the pressure of the fluid; and a control means. The aforementioned method, The control means controls the opening and closing operation of the plurality of opening and closing means based on the change in pressure over time detected by each of the pressure detection means. A pressure control method, including a pressure control method.

6. The control means determines, based on the change in pressure over time detected by the pressure detection means, that the pressure has reached a peak and a pressure drop has occurred, and determines that a crack has occurred in the concrete member. When the control means determines that the crack has occurred, it takes the step of closing the opening / closing means connected to the expansion member that caused the crack. The pressure control method according to claim 5, including the method described in claim 5.

7. The pressure control method according to claim 6, wherein the control means includes the step of closing all of the plurality of opening and closing means, then opening all of the plurality of opening and closing means, and supplying the fluid to each of the plurality of expansion means for a certain period of time.

8. A method for rupturing a concrete member using a plurality of expansion members that expand upon the supply of fluid, and a pressure control system that controls the pressure within the plurality of expansion members, The pressure control system includes a supply means, a plurality of opening / closing means provided in each pipe after branching when supplying the fluid from the supply means to each expansion member, which open and close to supply or stop the supply of the fluid, a plurality of backflow prevention means provided in each pipe between each expansion member and each opening / closing means to prevent backflow of the fluid, a plurality of pressure detection means connected to each pipe between each expansion member and each backflow prevention means to detect the pressure of the fluid, and a control means. The aforementioned method, The steps include inserting and installing each of the multiple expansion members into each of the multiple gaps formed in the concrete member, The supply means includes the step of supplying the fluid to the plurality of expansion members, The control means controls the opening and closing operation of the plurality of opening and closing means based on the time-dependent change in each pressure detected by each of the pressure detection means. A method for fracturing concrete members, including [the specified method].

9. The control means determines, based on the change in pressure over time detected by the pressure detection means, that the pressure has reached a peak and a pressure drop has occurred, and determines that a crack has occurred in the concrete member. When the control means determines that the crack has occurred, it makes the opening / closing means connected to the expansion member that caused the crack close, The control means, after closing all of the plurality of opening / closing means, opens all of the plurality of opening / closing means and supplies the fluid to each of the plurality of expansion means for a certain period of time. A method for breaking a concrete member according to claim 8, including the following:

10. The pressure control system includes a plurality of flow rate detection means for detecting the flow rate of the fluid supplied to each of the plurality of expansion members, The method for rupturing a concrete member according to claim 8, wherein the control step controls the opening and closing operation of the plurality of opening and closing means based on the change in each pressure over time and the flow rate of the fluid detected by each flow rate detection means.

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