Mat member, method for manufacturing mat member, and strain measurement system of mat member

Abstract

To provide a mat member, a method for manufacturing a mat member, and a strain management system of a mat member which can measure a strain of a mat member with a simple configuration.SOLUTION: A mat member is, for example, a scouring prevention mat 1 installed in a water bottom. The mat member (scouring prevention mat 1) includes block bodies 3 to which strain sensors 5 are stuck, a body part 9 in which a plurality of block bodies 3 is embedded with asphalt with the strain sensors 5 as a lower surface side, and other strain sensors 19 stuck to the upper surface of the body part 9.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mat member, a method for manufacturing the mat member, and a strain measurement system for the mat member. [Background technology]

[0002] Conventionally, underwater foundations such as piles for offshore wind power generation facilities have been subject to the problem of scouring, where sand and mud from the surrounding ground are sucked out or dug in by the flow of water. To prevent scouring, asphalt mat members are sometimes installed on the ground surrounding the underwater foundation. Asphalt has viscoelasticity, and can conform to uneven ground conditions to some extent, bending appropriately, effectively preventing scouring. Such mat members are called scour prevention mats.

[0003] The method for installing a scour prevention mat on the bottom of the water involves first hanging the mat on a hook or similar device attached to the hanging part on the edge above the water (on land), and lifting it up.The mat is then moved in the lifted state to above the installation position.The mat is then lowered, landed in the water, submerged, and then lowered to the bottom of the water and installed.

[0004] During this process, the scour prevention mat is deformed by various external forces, causing strain in the mat. If the strain is too great (the deformation is too great), cracks may occur and, in the worst case scenario, the mat may lose its scour prevention function. Therefore, in order to ensure that the scour prevention mat functions properly, it is desirable to be able to quantitatively measure the strain that occurs in the scour prevention mat during the process from when it is lifted above the water to when it is lowered to the bottom.

[0005] As a method for measuring strain in such structures, for example, a method has been proposed in which, when pouring asphalt for the structure, a heat-resistant pipe made of a thin, spirally wound steel strip is buried in the asphalt and an optical fiber sensor for measuring strain is inserted into the pipe (Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2001-116654 Summary of the Invention [Problem to be solved by the invention]

[0007] However, if a pipe made of steel strip or heat-resistant resin is buried in the asphalt of a scouring prevention mat, as in Patent Document 1, the elastic modulus of the pipe part is much greater than that of the asphalt, which hinders the flexibility of the asphalt in that area and makes it impossible to accurately measure the strain occurring in the scouring prevention mat.

[0008] Furthermore, if the deformation of the scour prevention mat is partially suppressed, it will be difficult for the mat to freely conform to uneven ground when installed on the ground. Furthermore, when the scour prevention mat is lifted up using a lifting part, the entire mat bends and deforms, dispersing stress. In contrast, if a rigid pipe is partially buried, the deformation of the asphalt is partially suppressed, causing stress to be concentrated in one area, which could damage the scour prevention mat when it is lifted up.

[0009] Therefore, it is desirable to install the scour prevention mat in a state that allows free deformation, so that deformation during lifting, etc. is not hindered, and it is also desirable that the strain can be measured directly.

[0010] On the other hand, when using strain sensors to measure the strain of a scour prevention mat, it is desirable to place strain sensors on both the bottom and top surfaces of the scour prevention mat. However, asphalt mats of the size required for scour prevention mats are generally formed near the installation site by placing forms on the ground and pouring asphalt into them. Therefore, in order to install strain sensors on the bottom surface of the scour prevention mat, for example, it is necessary to lift the asphalt mat after it has been formed and have workers enter and work underneath the lifted mat, which is undesirable from a safety management perspective.

[0011] Alternatively, for example, it is possible to place strain sensors on the ground before pouring asphalt into the formwork and bury the strain sensors under the scouring prevention mat, but because the asphalt is very hot when poured, there is a risk that the heat will cause the strain sensors to malfunction.

[0012] The above problem is not limited to scouring prevention mats, but is common to all mat components that are lifted and installed in a designated location, and is particularly important for mat components that are large enough that they cannot be easily turned upside down, so a solution is desirable.

[0013] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a mat member, a method for manufacturing a mat member, and a strain measurement system for a mat member that can measure the strain of the mat member with a simple configuration. [Means for solving the problem]

[0014] In order to achieve the above-mentioned object, the first invention is a mat member that can be lifted and installed, characterized in that it comprises a block body to which a strain sensor is attached, a main body in which a plurality of the block bodies are buried in asphalt with the strain sensor on the underside, and another strain sensor attached to the upper surface of the main body.

[0015] It is desirable that the block body be made of the same material as the main body.

[0016] It is desirable that the strain sensor be attached to the block body, and that a waterproof member be attached so as to cover the strain sensor.

[0017] It is desirable that a plurality of hanging portions be provided at predetermined positions on the edge of the main body, and that the block body be disposed between the hanging portions.

[0018] It is desirable that the main body portion has a hole in the center, and that multiple suspension wires with suspension devices at both ends are embedded radially inside the main body portion, with the suspension devices exposed at the outer and inner edges of the main body portion, and that the suspension devices be the suspension devices arranged at each of the outer and inner edges of the main body portion.

[0019] The mat member is preferably a scour prevention mat to be installed on the bottom of the water.

[0020] According to the first aspect of the present invention, the block body to which the strain sensor is attached is embedded in the asphalt of the main body so that the strain sensor faces the underside of the mat member, making it possible to easily install the strain sensor on the underside of the mat member, where installation is normally difficult. In addition, because multiple block bodies are embedded in various parts of the main body, it is possible to measure the in-plane distribution of strain and grasp the deformation state of the entire mat member.

[0021] Furthermore, if the block body and the main body are made of the same material, their elastic moduli will be approximately the same, allowing the block body to integrally follow the deformation of the main body of the mat member, making it possible to accurately measure the strain of the mat member.

[0022] Furthermore, if the strain sensor is attached to the block body and a waterproof member is attached so as to cover the strain sensor, the strain sensor can be protected from the outside with a simple configuration.

[0023] Furthermore, if multiple hanging parts are provided at predetermined positions on the edge of the main body and the block body is placed between the hanging parts, a strain sensor can be placed in a location where the mat member bends particularly greatly, thereby managing the risk of defects such as cracks occurring.

[0024] In this case, if the suspension wires are embedded radially inside the main body and the suspension fixtures at both ends of the suspension wires are exposed to the outside at the outer and inner edges to form the above-mentioned suspension parts, strain sensors can be placed in areas near the outer and inner edges of the mat member that are subject to particularly large deflections, making it possible to more effectively manage risks such as cracking.

[0025] Furthermore, if the mat member is a scour prevention mat, defects such as cracks can be fatal to the scour prevention mat, and distortions during the installation process can be grasped to prevent malfunctions, and it is also possible to grasp the state of deformation after installation on the water bottom, which is normally difficult to check.

[0026] The second invention is a method for manufacturing a mat member according to the first invention, comprising the steps of: molding a block body; attaching a strain sensor to the top surface of the block body; placing a plurality of the block bodies in a formwork with the strain sensor facing downward; pouring asphalt into the formwork to form a main body with the block bodies embedded in it; and attaching another strain sensor to a predetermined position on the top surface of the main body.

[0027] It is desirable to place a release sheet inside the formwork, place the block body on top of the release sheet, and pull the lead wires of the strain sensor below the release sheet and out of the formwork before pouring the asphalt.

[0028] In the process of pouring asphalt into the formwork, it is desirable to first pour asphalt up to the upper surface of the block body to form the lower layer of the main body, place reinforcing material on top of the lower layer, and then pour asphalt to a predetermined thickness to form the upper layer of the main body.

[0029] It is desirable that the size of the block body be set so that the temperature of the strain sensor is below the heat-resistant temperature when the asphalt is filled into the formwork.

[0030] According to the second invention, first, only a block body, which is very small compared to the mat member, is molded, and a strain sensor is attached to the block body, which is easy to handle, with its top surface facing the worker. These steps are easy to perform and do not require much work space. The surface to which the strain sensor is attached becomes the underside when the block body is embedded in the main body of the mat member. Then, this block body is placed in a formwork with the strain sensor facing downward, and asphalt is poured into the formwork to form the main body by embedding the block body. This makes it possible to manufacture a mat member with a strain sensor on its underside using only a simple and safe process.

[0031] Furthermore, before pouring the asphalt that will form the main body into the formwork, a release sheet can be placed inside the formwork, a block body can be placed on top of that, and the lead wires connected to the strain sensor can be pulled out below the release sheet, thereby preventing the lead wires from being unintentionally buried in the asphalt and damaged.

[0032] Furthermore, if the asphalt for the lower layer of the main body is poured into the formwork up to the top surface of the blocks, the pouring work can be carried out using the top surface of the blocks as a guide, making it easier for workers to grasp the required amount of asphalt and improving work efficiency.Furthermore, since reinforcing material is placed on the lower layer of the main body after it has been formed, and then the upper layer of the main body is formed with asphalt, the reinforcing material can be embedded in the mat member in a simple process.

[0033] Furthermore, if the size of the block is set to a size that prevents excessive heat from being transmitted to the surrounding area of ​​the strain sensor when filling the formwork with hot asphalt to form the main body, the strain sensor will be kept below its heat resistance temperature and will not break down.

[0034] The third invention is a strain measurement system for a mat member using the mat member of the first invention, characterized in that it has a measuring unit that acquires information from each strain sensor of the mat member, and is capable of measuring the measurement values ​​from each strain sensor when the mat member is lifted up and lowered to an installation position, thereby determining the amount of deformation of each part of the mat member.

[0035] According to the third invention, when the mat member is hoisted up and lowered to the installation position, measurements are obtained from each strain sensor, and the amount of deformation at each part can be grasped, so the deformation state of the mat member can be checked in real time during work. It is also possible to feed back this information to the work conditions, preventing defects such as cracks. Furthermore, even after it is lowered to the bottom of the water, the deformation state can be easily checked, making it possible to know whether it has been installed in the desired shape. [Effects of the Invention]

[0036] According to the present invention, it is possible to provide a mat member capable of measuring strain of a mat member with a simple configuration, a method for manufacturing a mat member, and a system for measuring strain of a mat member. [Brief explanation of the drawings]

[0037] [Figure 1] 1(a) is a plan view of a scour prevention mat 1, and FIG. 1(b) is a plan view of a block body 3. FIG. [Figure 2] (a) is a schematic cross-sectional view of line AA in Figure 1(a), (b) is an enlarged view of C in Figure 2(a), and (c) is an enlarged view of D in Figure 2(a). [Figure 3] Schematic cross section of line BB in Figure 1(a). [Figure 4] FIG. 2 is a diagram showing the scour prevention mat 1 in a lifted state. [Figure 5] 1(a) is a diagram showing a state in which the scour prevention mat 1 is hung down, and FIG. 1(b) is a diagram showing a state in which the outer edge portion 11 of the scour prevention mat 1 is buried in the ground 90. FIG. [Figure 6] FIG. 1( a ) is a diagram showing the process of forming a block body 3, FIG. 1( b ) is a diagram showing the process of attaching a strain sensor 5 to the block body 3, and FIG. 1( c ) is a diagram showing the process of attaching a waterproofing member 7 to the block body 3. [Figure 7] 1(a) is a diagram showing a step of placing the block body 3 in a mold 89, and FIG. 1(b) is a diagram showing a step of forming a lower layer 9a of the main body portion. [Figure 8] 1(a) is a diagram showing a step of placing a reinforcing material 31 on a main body lower layer 9a, and FIG. 1(b) is a diagram showing a step of forming a main body upper layer 9b. [Figure 9] 10A and 10B are diagrams showing a process of attaching a strain sensor 19 and a waterproof member 21 to the upper layer 9b of the main body portion. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiment, as an example, a case where a mat member of the present invention is a scour prevention mat 1 will be described.

[0039] (Scour prevention mat 1) 1(a) is a plan view of the scour prevention mat 1, seen from the underside of the scour prevention mat 1. The underside is the surface that faces the ground underwater when the scour prevention mat 1 is installed on the bottom of the water. The scour prevention mat 1 has a main body 9, a hanging wire 15, a hanging tool 17, edge reinforcements 27, outer edge holes 29, a block body 3, etc.

[0040] The main body 9 is formed of, for example, asphalt. The main body 9 has a substantially circular outer shape and is provided with a substantially circular hole 93 in the center. The outer peripheral edge of the main body 9 is the outer edge 11, and the inner peripheral edge (i.e., the outer peripheral edge of the hole 93) is the inner edge 13. The main body 9 may be made of other materials than asphalt, but is preferably made of a material with high elongation capacity that is less likely to crack, such as a viscoelastic body. As will be described later, the scour prevention mat 1 can be appropriately bent when lifted, and can freely follow uneven ground when installed on the ground. The shapes of the main body 9 and the hole 93 are not particularly limited to being substantially circular, and may be any shape, such as a polygon.

[0041] A plurality of suspension wires 15 are embedded radially inside the main body 9. Each of the suspension wires 15 has a suspension tool 17 at each end. That is, a plurality of suspension tools 17 are arranged exposed at predetermined positions (positions corresponding to the ends of the suspension wires 15) on each of the outer edge 11 and the inner edge 13. The suspension tool 17 is, for example, a ring-shaped end of the suspension wire 15, or a metal fitting or rope attached to the end of the suspension wire 15.

[0042] The edge reinforcements 27 are embedded inside the main body 9 near the outer edge 11 and the inner edge 13 so as to be perpendicular to the suspension wires 15, and are made of, for example, a steel strip or reinforcing bars. The outer edge holes 29 are multiple through-holes formed in the main body 9 near the outer edge 11 and between the suspension wires 15. The multiple outer edge holes 29 are located, for example, on double circles concentric with hole 93.

[0043] The block bodies 3 are made of, for example, asphalt, just like the main body 9. A plurality of block bodies 3 are embedded and integrated in the asphalt of the main body 9 at predetermined positions on the underside of the scour prevention mat 1. The arrangement positions of the block bodies 3 will be described later.

[0044] It is desirable that the block body 3 is made of the same material as the main body 9. Since the elastic modulus of both is approximately the same, even when the scour prevention mat 1 is significantly deformed, the block body 3 can integrally follow the deformation.

[0045] Fig. 1(b) is a plan view of the block body 3 and an enlarged view of the block body 3 in Fig. 1(a). A strain sensor 5 is attached to the underside of the block body 3, and a waterproof member 7 is attached to cover the strain sensor 5.

[0046] The strain sensor 5 is a general strain sensor that measures strain on one axis or on other axes. From the standpoint of cost and thinness, it is preferable to use an electrical resistance detection type strain sensor, but other types are also acceptable. The waterproofing member 7 is, for example, vinyl mastic tape. Any material can be used as long as it is waterproof, moisture-proof, chemical-resistant, and corrosion-resistant, and can protect the strain sensor 5 from the external environment.

[0047] Here, the arrangement positions of the block bodies 3 (i.e., strain sensors 5) in a plan view will be explained with reference to Fig. 1(a). First, multiple block bodies 3 are arranged on the scour prevention mat 1. This allows the in-plane distribution of strain to be measured, making it possible to understand how each part of the scour prevention mat 1 is deforming.

[0048] Furthermore, it is preferable that the block bodies 3 are arranged in a location where the amount of deformation is particularly large when the scour prevention mat 1 is deformed, so that the risk of defects such as cracks occurring can be managed.

[0049] An example of a portion where the amount of deformation becomes very large is the area between adjacent hanging devices 17. In particular, cracks are likely to occur approximately in the center between the hanging devices 17, at a position relatively close to the outer edge 11 or the inner edge 13 (the position of the block body 3 located closest to the outer edge 11 or the inner edge 13 in FIG. 1(a)). The reason for this is thought to be that when the scour prevention mat 1 is lifted by the hanging devices 17, a strong tensile force is applied around the hanging devices 17, causing the mat to be in a tensile state, whereas the tensile force between the hanging devices 17 is relatively small, causing localized large deflection as a reaction.

[0050] In view of this, it is desirable that the block body 3 be positioned between a plurality of hanging parts (hanging devices 17) provided at predetermined positions (positions corresponding to the ends of the hanging wires 15) on the edge (outer edge 11 or inner edge 13) of the main body 9.

[0051] Another example of a portion where the amount of deformation is large is the vicinity of the radial center of the scour prevention mat 1. Therefore, for example, as shown in Figure 1(a), another block body 3 may be placed between a block body 3 near the outer edge 11 and a block body 3 near the inner edge 13 in the radial direction of the scour prevention mat 1. This is not limiting, and block bodies 3 may be placed appropriately in positions where strain is expected to be large.

[0052] FIG. 2(a) is a schematic cross-sectional view taken along line AA in FIG. 1(a). The main body 9 comprises a main body lower layer 9a and a main body upper layer 9b. The main body lower layer 9a and the main body upper layer 9b are both formed of, for example, asphalt. It is preferable that the thicknesses of the main body lower layer 9a and the main body upper layer 9b are approximately the same. If the thicknesses differ significantly, excessive force may be concentrated on one of the layers when the scour prevention mat 1 deforms, which is undesirable. A reinforcing material 31 is embedded between the main body lower layer 9a and the main body upper layer 9b. The reinforcing material 31 is a reinforcing core material for the scour prevention mat 1 and is made of, for example, glass cloth. An outer edge hole 29 is formed near the outer edge 11 so as to penetrate the main body lower layer 9a, the main body upper layer 9b, and the reinforcing material 31.

[0053] The block bodies 3 are embedded in the asphalt of the main body lower layer 9a on the underside of the scour prevention mat 1 and are integrated with it. The undersides of the block bodies 3 are exposed, and the undersides of the block bodies 3 and the main body lower layer 9a are located at approximately the same position. The upper surfaces are also located at approximately the same position. In other words, the thickness of the block bodies 3 is approximately the same as that of the main body lower layer 9a. Furthermore, since it is preferable that the thicknesses of the main body lower layer 9a and the main body upper layer 9b are approximately the same as described above, it is preferable that the thickness of the block bodies 3 is approximately half that of the main body 9.

[0054] Figure 2(b) is an enlarged view of C in Figure 2(a). The block body 3 is positioned so that the strain sensor 5 is on the underside. The block body 3 has a cutout 33 on its underside, and the strain sensor 5 is attached to the cutout 33. This prevents the weight of the scour prevention mat 1 from being applied to the strain sensor 5 when the scour prevention mat 1 is installed on the water bottom and its underside comes into contact with the underwater ground, as described below. Note that the cutout 33 is not essential, and if the strain sensor 5 has a large load-bearing capacity, the strain sensor 5 may be attached directly to the block body 3. Below the strain sensor 5, a waterproof member 7 is attached to the block body 3 so as to cover the strain sensor 5.

[0055] 2(c) is an enlarged view of D in FIG. 2(a). A strain sensor 19 is attached to the top surface of the upper layer 9b of the main body at a position corresponding to the strain sensor 5 in a plan view. Note that the strain sensor 19 may be attached to another position where a large strain is expected, rather than being limited to the position corresponding to the strain sensor 5, as necessary. Furthermore, a waterproof member 21 is attached to the upper layer 9b of the main body so as to cover the strain sensor 19. The strain sensor 19 and the waterproof member 21 may be the same as the strain sensor 5 and the waterproof member 7, respectively. Alternatively, a notch may be provided in the top surface of the upper layer 9b of the main body, and the strain sensor 19 may be attached to the notch.

[0056] Fig. 3 is a schematic cross-sectional view taken along line BB in Fig. 1(a). A suspension wire 15 is disposed on the upper surface of the lower layer 9a of the main body. An edge reinforcement member 27 and a reinforcement member 31 are placed on the suspension wire 15 and embedded in the upper layer 9b of the main body.

[0057] As described above, according to the scour prevention mat 1 of the present invention, the block bodies 3 to which the strain sensors 5 are attached are embedded and integrated into the asphalt of the lower layer 9a of the main body, with the strain sensors 5 facing the underside of the scour prevention mat 1. This makes it possible to install the strain sensors 5 with a simple configuration on the underside of the scour prevention mat 1, where it is normally difficult to install a strain sensor. Furthermore, because multiple block bodies 3 are embedded in various parts of the lower layer 9a of the main body, it is possible to measure the in-plane distribution of strain and to grasp the deformation state of the entire scour prevention mat 1.

[0058] Furthermore, because the block bodies 3 are made of the same material as the main body 9 (main body lower layer 9a, main body upper layer 9b), their elastic moduli are approximately the same, and when the scour prevention mat 1 is deformed by an external force, the block bodies 3 can integrally follow the deformation of the main body 9. This makes it possible to accurately measure the strain of the scour prevention mat 1. It also prevents damage to the scour prevention mat 1.

[0059] Furthermore, by attaching a waterproof member 7 so as to cover the strain sensor 5 attached to the block body 3, the strain sensor 5 can be protected from the outside with a simple configuration.

[0060] In addition, multiple hanging parts are provided at predetermined positions on the edge of the main body part 9, and the block body 3 is placed between the hanging parts, so that the strain sensor 5 can be placed in an area where the scouring prevention mat 1 bends particularly greatly, and the risk of defects such as cracks occurring can be managed.

[0061] In this case, if the main body 9 has suspension wires 15 embedded radially inside it, and the suspension devices 17 at both ends of the suspension wires 15 are exposed to the outside at the outer edge 11 and inner edge 13 to form the above-mentioned suspension parts, the strain sensors 5 can be placed in areas near the outer edge 11 and inner edge 13 that are subject to particularly large deflections, thereby effectively managing the risk of cracks, etc.

[0062] (Strain measurement system for scour prevention mat 1) Next, a strain measurement system for a scour prevention mat 1 (hereinafter referred to as the "strain measurement system") using the scour prevention mat 1 will be described. The strain measurement system has a measurement unit along with the scour prevention mat 1. The measurement unit, not shown, is connected to the lead wires of each strain sensor 5, 19 of the scour prevention mat 1 and acquires information such as the measured values ​​and measurement times of the strain sensors 5, 19. Note that communication between the measurement unit and the strain sensors 5, 19 may be wireless rather than wired. The measurement unit can continuously acquire information from each strain sensor 5, 19 at predetermined intervals from the time the scour prevention mat 1 begins to be lifted until it is lowered into its installation position on the water bottom, and even after it has been lowered, making it possible to monitor changes in strain in each unit over time in real time.

[0063] FIG. 4 shows the scour prevention mat 1 in a lifted state. After being manufactured, the scour prevention mat 1 is lifted by a lifting jig 70 and carried to an installation position above water. The lifting jig 70 is, for example, a steel section or steel pipes arranged in a lattice pattern. One end of a sling wire 75 is attached to the underside of the lifting jig 70. An auto-release hook 77 is attached to the other end of the sling wire 75, which can remotely release a suspended load from a distance. The lifting tool 17 for the scour prevention mat 1 is hung on this auto-release hook 77. In addition, a lifting wire 73 is attached to the top surface of the lifting jig 70. The lifting jig 70 is lifted upward via the lifting wire 73, and the scour prevention mat 1 is lifted.

[0064] At this time, the strain measurement system measures the measurement values ​​from each strain sensor 5, 19 in real time and grasps the amount of deformation of each part of the scour prevention mat 1. Therefore, during the lifting work, it is possible to refer to the measured strain values ​​and immediately reflect them in the work conditions (lifting speed, etc.).

[0065] Furthermore, the strain measurement of each part continues in real time when the scouring prevention mat 1 is hung above the water at the installation position, lowered to the water, and submerged in the water, when it is hung underwater to the installation position, and even after the scouring prevention mat 1 is hung down to the bottom of the water.

[0066] Figure 5(a) shows the state in which the scour prevention mat 1 has been hung down to the installation position. Immediately after being hung down, the scour prevention mat 1 is simply placed on the ground 90, and if left in this state, it may be subjected to tidal currents and the outer edge 11 may be turned up. In contrast, if there are outer edge holes 29 near the outer edge 11, the tidal currents will promote the suction of soil from the ground through the outer edge holes 29 and upwards on the scour prevention mat 1 (dotted arrow), gradually eroding the ground 90 near the outer edge 11 (white arrow). As this is repeated, the outer edge 11 will gradually sink into the ground.

[0067] FIG. 5(b) shows the state after time has passed since FIG. 5(a), when the outer edge 11 of the scour prevention mat 1 has been buried in the ground 90. This is preferable because the outer edge 11 is protected by the soil and sand of the ground 90 and there is no risk of it being turned up. At this time, it is possible to easily confirm whether this state has occurred by acquiring the measured values ​​of each strain sensor 5, 19 using the strain measurement system. Note that, although the above description describes acquiring the measured values ​​of the strain sensors 5, 19 in real time at predetermined time intervals, they may also be acquired at any timing selected by the administrator.

[0068] As described above, according to the strain measurement system for the scour prevention mat 1 of the present invention, measurements are taken by the strain sensors 5, 19 when the scour prevention mat 1 is hoisted up and lowered to the installation position, and the degree of deformation of each part can be roughly grasped. This makes it possible to immediately check the deformation state of the scour prevention mat 1 during installation work and provide feedback to the work. This makes it possible to prevent defects such as cracks. It is also possible to check whether the scour prevention mat 1 has the desired shape after being lowered to the bottom of the water.

[0069] (Method of manufacturing the scour prevention mat 1) Next, a method for manufacturing the scouring prevention mat 1 of the present invention will be described. In the present invention, first, the block body 3 is formed (FIG. 6), and then the main body 9 of the scouring prevention mat 1 is manufactured (FIGS. 7 to 9).

[0070] FIG. 6(a) shows the process for forming the block body 3. Forming the block body 3 can be achieved by a well-known method. First, a block body formwork 83 is placed on the ground 95, and a release sheet 85 is placed inside the block body formwork 83. A standard release sheet 85 may be used, but it is preferable that it be heat-resistant. Next, asphalt is poured to a predetermined height, and then a notch formwork 87 is placed. For example, the notch formwork 87 should be placed approximately in the center of the block body formwork 83 in a plan view. If the block body 3 is made of a material other than asphalt, an appropriate material is poured in. After the asphalt has cooled, the block body formwork 83, the notch formwork 87, and the release sheet 85 are removed to obtain the block body 3.

[0071] The size of the block bodies 3 is very small compared to the scour prevention mat 1, and the work of forming the block bodies 3 can be easily carried out in a relatively small work space. Therefore, before manufacturing the scour prevention mat 1, a large number of block bodies 3 alone can be formed in advance at a location different from the site where the scour prevention mat 1 will be cast in place. The detailed size of the block bodies 3 (size and height in a plan view) is set to a predetermined value, but how to determine the detailed size will be described later.

[0072] Next, as shown in Figure 6(b), strain sensor 5 is attached to the notch 33 on the top surface of the obtained block body 3, and then, as shown in Figure 6(c), waterproof member 7 is attached to the block body 3 so as to cover the strain sensor 5. As mentioned above, since the block body 3 is relatively small, it is very easy to face the top surface with the notch 33 toward the worker and attach the strain sensor 5 and waterproof member 7.

[0073] Next, the block body 3 to which the strain sensors 5 and the like are attached is used to manufacture the main body 9 of the scour prevention mat 1. FIGS. 7 to 9 are diagrams showing each step in a cross section taken along line AA in FIG.

[0074] First, as shown in Figure 7(a), a formwork 89 is placed on the ground 95, and a release sheet 23 is placed inside the formwork 89. The release sheet 23 is the same as the release sheet 85. Next, the block body 3 is placed inside the formwork 89 with the strain sensor 5 facing downward.

[0075] In this case, the block body 3 is placed on the release sheet 23. In addition, the heat-resistant lead wires 25 connected to the strain sensors 5 for transmitting and receiving signals are drawn below the release sheet 23 near the strain sensors 5, passed under the release sheet 23, and led out to the outside of the formwork 89. To achieve this, a slit or the like for passing the lead wires 25 may be provided in the release sheet 23, or if multiple release sheets 23 are placed inside the formwork 89, the lead wires 25 may be passed through the gaps between the release sheets 23. This prevents the lead wires 25 from being accidentally buried in the asphalt when asphalt is poured into the formwork 89 in a later process, and protects the lead wires 25 from being cut or damaged by heat.

[0076] 7(b), asphalt is poured into the formwork 89, and the blocks 3 are embedded therein to form the lower layer 9a of the main body portion integrated with the blocks 3. If the material of the main body portion 9 (lower layer 9a of the main body portion) is not asphalt, an appropriate material is poured in.

[0077] In this case, it is preferable to pour the asphalt up to the top surface of the block body 3. Since the top surface of the block body 3 can be used as a guide, workers can easily grasp the required amount of asphalt during the pouring process, improving work efficiency. Furthermore, since the top surfaces of the block body 3 and the lower layer 9a of the main body are roughly flush with each other and the boundary between the block body 3 and the lower layer 9a of the main body can be visually confirmed from above, the boundary can be heated with a burner to blend the interface and more firmly integrate the block body 3 and the lower layer 9a of the main body. After this, although not shown, a suspension wire 15 is placed at a predetermined position on the top surface of the lower layer 9a of the main body, and an edge reinforcement 27 is placed on top of it (see Figure 3).

[0078] 8(a), the reinforcing material 31 is placed on the main body lower layer 9a and the block body 3. The upper surfaces of the block body 3 and the main body lower layer 9a are at approximately the same level, so the reinforcing material 31 can be placed easily.

[0079] Next, as shown in Figure 8(b), a predetermined thickness of asphalt is poured into the formwork 89 to form the upper main body layer 9b. As mentioned above, it is preferable that the thickness of the upper main body layer 9b is approximately the same as that of the lower main body layer 9a. This prevents excessive force from concentrating on one side when the scour prevention mat 1 is deformed. Therefore, it is preferable to set the thickness of the block body 3 in advance to approximately half that of the main body 9 (lower main body layer 9a and upper main body layer 9b).

[0080] In the manufacturing method of the scour prevention mat 1 described above, asphalt is poured when forming the lower and upper main body layers 9a and 9b (FIGS. 7(b) and 8(b)). At this time, the poured asphalt is at a high temperature (generally 180°C to 220°C). Therefore, if the size of the block body 3 is too small, heat will be transferred to the area around the strain sensor 5 on the underside, causing it to become too hot and potentially causing the strain sensor 5 to malfunction. For this reason, it is desirable to set the size of the block body 3 so that the strain sensor 5 can be kept at or below its heat-resistant temperature when asphalt is filled in when forming the lower and upper main body layers 9a and 9b.

[0081] Next, as shown in FIG. 9 , strain sensor 19 is attached to the top surface of main body upper layer 9b at a position corresponding to strain sensor 5 in a plan view, and waterproof member 21 is then attached to cover strain sensor 19. Attaching strain sensor 19 and waterproof member 21 is a simple process that is performed after main body upper layer 9b is formed. Therefore, the attachment position of strain sensor 19 may be adjusted as needed. For example, strain sensor 19 may be attached to a position where strain sensor 5 is located in a plan view and another position where large strains are expected, or strain sensor 19 may be attached only to an arbitrary position, not to a position corresponding to strain sensor 5 in a plan view. In this manner, the scour prevention mat 1 of the present invention can be manufactured.

[0082] As described above, according to the manufacturing method of the scour prevention mat 1 of the present invention, first only the block bodies 3, which are very small compared to the scour prevention mat 1, are formed, and the strain sensors 5 are attached to the upper surfaces of the block bodies 3, which are easy to handle, so there are no constraints on the work space and the work is easy.The block bodies 3 are then placed in formwork 89 with the strain sensors 5 on the underside, and asphalt is poured into formwork 89 to form the main body lower layer 9a by burying the block bodies 3, so that the scour prevention mat 1 having the strain sensors 5 on its underside can be manufactured using only simple and safe processes.

[0083] Furthermore, before the asphalt that will become the lower layer 9a of the main body is poured into the formwork 89, a release sheet 23 is placed inside the formwork 89, the block body 3 is placed on top of it, and the lead wires connected to the strain sensors 5 are pulled out below the release sheet 23, so that the lead wires 25 can be prevented from being unintentionally buried in the asphalt and being damaged by breakage or heat.

[0084] Furthermore, in the process of pouring the asphalt that will become the lower layer 9a of the main body into the formwork 89, the asphalt is poured up to the top surface of the block bodies 3. This allows the pouring work to be performed using the top surface of the block bodies 3 as a guide, making it easier for workers to grasp the required amount of asphalt and improving work efficiency. Furthermore, the boundary between the block bodies 3 and the lower layer 9a of the main body can be heated from above with a burner to blend the interface and further solidify the two layers. Furthermore, the reinforcing material 31 is placed on the formed lower layer 9a of the main body before the upper layer 9b of the main body is formed, making it easy to embed the reinforcing material 31.

[0085] Furthermore, the size of the block body 3 is set so that when hot asphalt is filled into the formwork 89 during the formation of the lower layer 9a and upper layer 9b of the main body, the heat is not transmitted too far to the periphery of the strain sensor 5. This keeps the strain sensor 5 below its heat resistance temperature and prevents it from breaking down.

[0086] While preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples and may be embodied in other ways, such as a configuration in which suspension wires are installed radially, or a configuration in which heat-resistant strain gauges are used instead of blocks, etc. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas disclosed herein, and it is understood that these modifications and alterations naturally fall within the technical scope of the present invention.

[0087] For example, in the above embodiment, an example was described in which the mat member of the present invention is a scour prevention mat that is installed on the bottom of a body of water and used as a scour prevention work, but this is not limited to this, and the present invention can be applied to other mat members that are installed by lifting. For example, it may be applied to a test mat member and subjected to a durability test, and the measurement values ​​measured by the strain sensors 5, 19 may be used to correlate with defects such as cracks that actually occurred in the test mat member. This allows for a quantitative evaluation of the risk of defects, and feedback can be provided to the working conditions when installing other mat members. [Explanation of symbols]

[0088] 1...Scour prevention mat 3...Block letters 5, 19...Strain sensor 7, 21...Waterproof materials 9...Main body 9a……Lower layer of main body 9b: Upper layer of main body 11...Outer edge 13...Inner edge 15.... Lifting wire 17.... Lifting device 23, 85...Release sheet 25...Lead wire 27...Edge reinforcement 29...Outer edge hole 31...Reinforcement material 33...Notch 70...Lifting jig 73... Lifting wire 75...Sling wire 77………Auto-release hook 79... Underwater foundations 83...Block formwork 87...Notched formwork 89...Formwork 90, 95……ground 93……hole

Claims

1. A mat member that can be lifted and installed, A block body with a strain sensor attached, a main body portion in which the plurality of block bodies are buried in asphalt with the strain sensors on the underside; Another strain sensor attached to the upper surface of the main body; A mat member comprising:

2. 2. The mat member according to claim 1, wherein the block body is made of the same material as the main body.

3. 2. The mat member according to claim 1, wherein the strain sensor is attached to the block body, and a waterproof member is attached so as to cover the strain sensor.

4. 2. The mat member according to claim 1, wherein a plurality of hanging portions are provided at predetermined positions on the edge of the main body, and the block body is disposed between the hanging portions.

5. The main body has a hole in the center, A plurality of suspension wires each having a suspension tool at each end are embedded radially inside the main body, and the suspension tools are exposed at the outer and inner edges of the main body.

5. The mat member according to claim 4, wherein the hanging portion is a hanging tool disposed on each of the outer edge and the inner edge of the main body.

6. 2. The mat member according to claim 1, wherein the mat member is a scour prevention mat to be installed on the bottom of the water.

7. A method for manufacturing a mat member according to any one of claims 1 to 6, forming a block body; a step of attaching a strain sensor to an upper surface of the block body; a step of placing the plurality of block bodies in a formwork so that the strain sensors are on the lower surface side; pouring asphalt into the formwork to form a main body portion in which the block bodies are embedded; attaching another strain sensor to a predetermined position on the top surface of the main body; A method for manufacturing a mat member, comprising:

8. A method for manufacturing a mat member according to claim 7, characterized in that a release sheet is placed inside a formwork, the block body is placed on the release sheet, and the lead wires of the strain sensor are pulled below the release sheet and out of the formwork before pouring asphalt.

9. In the step of pouring asphalt into the formwork, First, asphalt is poured up to the upper surface of the block body to form the lower layer of the main body portion, 8. The method for manufacturing a mat member according to claim 7, wherein a reinforcing material is placed on the lower layer, and then asphalt is poured in to a predetermined thickness to form the upper layer of the main body portion.

10. 8. The method for manufacturing a mat member according to claim 7, wherein the size of the block body is set so that the temperature of the strain sensor is below the heat resistance temperature when the asphalt is filled into the formwork.

11. A mat member strain measurement system using the mat member according to any one of claims 1 to 6, a measuring unit that acquires information from each strain sensor of the mat member; A strain measurement system for a mat member, characterized in that it is possible to measure the measurement values ​​from each strain sensor when the mat member is lifted and lowered to an installation position, and to grasp the amount of deformation of each part of the mat member.

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