PCTlJP2009/52911 SPECIFICATION [Title of the Invention] DEVICE FOR DETECTING STATE-CHANGE OF WIRE ROD [Technical Field] [0001] The present invention detects an extension change of a wire r od embedded in a matrix, which is bedrock, ground, and concrete, et c., and outputs the information about a magnitude of the extension, such as the rockbolt, the earth anchors, and reinforced concretes. [Background Art] [0002] The rockholt, the earth anchor, and the reinforced concrete, et c. are the reinforcement frequently used in ground engineering, rock engineering, and the concrete technology. The rockbolt is input to th e tunnel wall etc. , and the anchor bolt drives to the slope etc. whe re the soil was cut out, and is reinforced of the prevention of the di sasters such as sudden falls and landslides. These play an important role to keep strength for a long term after it is constructed, and to keep the stability of the structure. However, the disasters such as sudden falls and landslides mi ght be caused for deterioration time of passing even of the use of re inforcement of the rockbolt and the earth anchor, etc. and the groun d change not anticipated. The sudden fall or the landslide with a us ually small omened scale often precedes before such a disaster is ca used. Therefore, the distortion gauge and the load cell are installed on the tunnel wall and the slope etc. where the soil was cut out tha t used reinforcement of the rockbolt and the earth anchor, etc. and abnormality is monitored. (For instance, see document 1.) [0003] However, the monitor that uses the distortion gauge and the load cell is expensive. Moreover, time and the cost are necessary for judging risk by using measurements. Therefore, problem that promp t treatment is difficult is specified. Then, in place of an expensive distortion gauge and the load cell the device that could detect the abnormal earth's crust at a low price and easily is known. (See document 2.) With this device, the 6 /32 PCT/JP2009/52911 abnormal earth's crust can be perceived visually and intuitively, with out requiring the data processing to judge risk by using measuremen ts, by exposing the coloring head and using lighting LED for inform ation etc. Therefore, time and the cost needed by the counter measu re are few in the case with this device. Moreover, a suitable monitor is enforceable for reinforced tunnel wall and slope where soil was c ut out, for which prompt correspondence is necessary. [0004] The society's infrastructure is made a passing age. It is urged by the necessity the verification that is whether the function of rei enforcement of the rockbolt and the earth anchor, etc. is kept. It is d emanded that the rockbolt and the earth anchor, etc., which will be constructed in the future, be able to achieve the functions of grasp o f current state and detection of strangeness, etc. with low-cost. [Prior art documents] [Patent documents] [0005] [Document 1] JP2002-54922A [Document 2] JP2004-163118A [Disclosure of the Invention] [Problems to be Solved by the Invention] [0006] The device disclosed by the above-mentioned document 2 is as sumed to be the following compositions. It is composed of the project ion part for piercing and the pierced displacement part which follows to the edge of the exposure such as the rockbolt. Moreover, it accu mulates in order of the tunnel wall etc., the projection part for pierc ing and the pierced displacement part. And, the projection part for p iercing penetrates through the displacement part by displacing or tra nsforming the rockbolt and the anchor bolt. As a result, the abnorm al earth's crust is perceived. Therefore, the problem includes only th e observation of one behavior of a part near the outcrop in the tunn el wall etc. The rockbolt etc. reach about ten meters by the total len gth in the long one. Therefore, it is hoped to be able to detect plura I displacements over the total length such as the rockbolt, and to di splay information on each displacement around the outcrop. 7 / 32 PCT/JP2009/52911 [0007] Moreover, there are many discontinuities in the bedrock. The one of either specific discontinuity might shift. This is a phenomenon to threaten the stability of the bedrock. Therefore, it is very import ant to know by which depth the shift has happened. Plural displace ments are observed over the total length such as the rockbolt to ach ieve this. And, those data is compared, and where a local transforma tion has concentrated is ascertained. [0008] Moreover, the device disclosed by the above-mentioned docume nt 2 doesn't have the data processing circuit to judge risk from mea surements. The abnormal earth's crust can be perceived visually and intuitively of the exposure of the coloring head and lighting LED fo r information, etc. However, the backup detection function when trou ble is caused in the outcrop and the LED lighting circuit, etc. has n ot been installed. Trouble is caused in the electrical system when monitoring it for several years. It is important in the emergency on the business with a realistic backup detection function for that time. [0009] In addition, it is assumption in the device disclosed by the above-mentioned document 2 to have exposed one side. Therefore, correspondence to embedded underground both ends etc. is difficult. In the case where both ends are embedded underground like the reinforced concrete etc. , the device that can be flexibly designed is needed to comprise an enough detection function. [0010] In order to resolve the above issues, the present invention provides a device capable of detecting an extension change of a total length or an interval between two arbitrary points of a wire rod embedded in a matrix and performing in-situ information output of information on a magnitude of the extension. In particular, the present invention provides a device that displays the information on the magnitude of the extension by a color of light. Also, in assumption of occurrence of a problem in the electrical system, the present invention provides a device that includes a backup 8 / 32 PCT/JP2009/52911 detection function that does not use the electrical system at all. [Means to Solve the Objects] [0011] The inventors researched earnestly for achieving the objects, and as a result of repeating the improvement, completed the device for detecting state-change of a wire rod of the present invention. According to a first aspect of the present invention, a device for detecting state-change of a wire rod that detects an extension change of a wire rod embedded in a matrix and has the following characteristics la) to le). la) a casing member is disposed in a longitudinal direction of the wire rod. 1b) a first rigid cable and an elastic member are connected in series between fixing members disposed at both ends of the wire rod inside the casing member. IC) a switch unit is formed and fixed on the fixing member connected to the elastic member. 1d) the switch unit detects a relative displacement with respect to a contact point on the first rigid cable. le) an information output circuit, outputting information in accordance with the displacement, is provided. [0012] Due to having the above characteristics a) to e), when the wire rod undergoes the extension change in the longitudinal direction, the elastic member undergoes an extension change and information is output from the information output circuit in accordance with the relative displacement of the contact point with respect to the switch unit. [0013] Moreover, according to a second aspect of the present invention, a device for detecting state-change of a wire rod that detects an extension change of a wire rod embedded in a matrix and has the following characteristics 2a) to 2e). 2a) a casing member is disposed in a longitudinal direction of the wire rod. 2b) a first rigid cable and an elastic member are connected in series between fixing members disposed at two arbitrary points in the 9 / 32 PCT/JP2009/52911 longitudinal direction of the wire rod inside the casing member. 2c) a switch unit is formed and fixed on the fixing member connected to the elastic member. 2d) the switch unit detects a relative displacement with respect to a contact point on the first rigid cable. 2e) an information output circuit, outputting information in accordance with the displacement, is provided. [0014] Due to having the above characteristics 2a) to 2e), when the wire rod undergoes an extension change in the longitudinal direction, information is output from the information output circuit. [0015] Moreover, according to a third aspect of the present invention a device for detecting state-change of a wire rod that detects an ex tension change of a wire rod embedded in a matrix and has the fol owing characteristics 3a) to 3g). 3a) a casing member is disposed in a longitudinal direction of the wire rod. 3b) a first rigid cable and an elastic member are connected in series between fixing members disposed at both ends of the wire rod or between fixing members disposed at two arbitrary points in the longitudinal direction of the wire rod inside the casing member. 3c) a first switch unit is formed and fixed on the fixing member connected to the elastic member. 3d) the first switch unit detects a relative displacement with respect to a contact point on the first rigid cable. 3e) a second rigid cable with a diameter expanding in a tapering manner is connected to an end of the first rigid cable connected to the elastic member. 3f) a second switch unit, which, at an exposed portion of the first rigid cable, detects a relative displacement with respect to a contact point on a side surface of the first rigid cable or the second rigid cable, is provided. 3g) an information output circuit, outputting information in accordance with a state of both or either of the first switch unit and the second switch unit, is provided. [0016] 10 / 32 PCT/JP2009/52911 Due to having the above characteristics 3a) to 3g), when the wire rod undergoes an extension change in the longitudinal direction, information is output from the information output circuit via both or either of the first switch unit and the second switch unit. [0017] In a mine, etc., since a digging site becomes deeper (to several hundred meters underground or deeper), a high strain energy becomes accumulated inside a rock bed and may cause so-called rock burst to occur in a surrounding region after insertion of a rockbolt or other wire rod. This is an instability phenomenon in which the strain energy that is accumulated in a specific location in the ground is released all at once, and it is known that in this process, in addition to destruction of the rock bed, a discontinuity plane that is already present may deform and an extremely large extension may occur in the rockbolt or other wire rod. [0018] In this process, an instantaneous extension of approximately 100 to 300mm may occur in the rockbolt. Presently, technical developments, such as development of a rockbolt or other wire rod that does not break even in such a case, are being made to maintain safety of mine digging sites at deep underground locations. In a case of occurrence of such an extreme phenomenon, the rockbolt is positioned as a valuable reinforcing member that marginally stabilizes the rock bed that is destroyed to some degree, and it is extremely important to accurately ascertain the conditions of the extension in this state. By further providing the second switch unit arranged in accordance with the constituent features 3e) and 3f), displacements of no more than 1mm to large deformations corresponding to displacements of approximately 300mm can be accommodated. [0019] Moreover, according to a fourth aspect of the present inventio n, a device for detecting state-change of a wire rod that detects an extension change of a wire rod embedded in a matrix and has the fo allowing characteristics 4a) to 40. 4a) at least two opposing casing members are disposed in a longitudinal direction of the wire rod. 4b) at least one set of a first rigid cable and an elastic m ember are connected in series between fixing members disposed at b 11/ 32 PCT/JP2009/52911 oth ends of the wire rod inside the casing member or between fixing members disposed at two arbitrary points in the longitudinal directi on of the wire rod in the same manner inside each of the casing me mbers. 4c) a switch unit is formed and fixed on a fixing member connected to the elastic member. 4d) the switch unit detects a relative displacement with respect to a contact point on the first rigid cable. 4e) the switch unit detects a bending displacement from a difference in the relative displacements from the respective casing members. 4f) an information output circuit outputs information in accordance with the displacement. when the wire rod undergoes an extension change or a bending change in the longitudinal direction, information is output from the information output circuit. [0020] Due to having the above characteristics 4a) to 4), when the wire rod undergoes the extension change in the longitudinal direction, the elastic member undergoes extension change and information is output from the information output circuit in accordance with the contact point undergoing relative displacement with respect to the switch unit or the detection of a bending displacement from the difference in the relative displacements from the respective casing members. In a case of an earth material, a fracture plane that is generated due to stress concentration, etc., becomes a discontinuity plane, and since a shear deformation occurs along this plane, a wire-like rockbolt, ground anchor, or other wire rod that intersects the discontinuity plane undergoes not only extension/contraction but also bending displacement. Thus, not only the extension change of the wire rod in the longitudinal direction but the bending displacement is also detected. [0021] Here, the wire rod that is embedded in the matrix may be of a hollow type or a solid type. In the case of the hollow type wire rod, the rigid cable is installed inside the hollow space. In the case of the solid type, a pipe of small diameter is mounted so as to fix the cable between the side surface of the wire rod and the matrix and the rigid cable for displacement 12 / 32 PCT/JP2009/52911 measurement is installed inside the pipe. [0022] Moreover, it is a preferable embodiment that the switch unit has a conductor formed at a moving portion of the contact point and the conductor is a power supply point of the information output cir cuit. [00231 Moreover, it is a preferable embodiment that the switch unit is that the first rigid cable is wound around a pulley wheel shaft an d the conductor that is the power supply point of the information ou tput circuit is disposed at a side circumferential portion of the wheel shaft. [0024] Moreover, it is a preferable embodiment that the switch unit has a variable resistance portion formed at a moving portion of the contact point and a resistance value of the variable resistance portio n changes in accordance with a relative displacement of the contact point. [0025] Moreover, it is a preferable embodiment that a position of an exposed portion of the first rigid cable or an exposed portion of an elongate rod disposed on the first rigid cable is measured to detect t he extension change of the wire rod embedded in the matrix. A backup detection function that does not use the electrical s ystem at all is realized using the first rigid cable. [0026] Moreover, it is a preferable embodiment that a second rigid c able, with only an end at an insertion direction side being fixed, is f urther disposed inside the casing member, and a position of a free e nd of the second rigid cable is measured to detect the extension cha nge of the wire rod embedded in the matrix. A backup detection function that does not use the electrical system is realized independent of the first rigid cable. This is an embodiment that is applied in a case where there is an allowance in the hollow space inside the wire rod. [0027] 13 / 32 PCT/JP2009/52911 Moreover, it is a preferable embodiment that a colored reflecti on sticker, disposed on an exposed portion of the first rigid cable, is observed to detect the extension change of the wire rod embedded i n the matrix. By the present embodiment, the colored reflection sticker is di sposed on the exposed portion as the backup detection function and the deformation amount can thus be checked visually by color even when a fault occurs in the electrical system. [0028] Here, it is a preferable that the first rigid cable or a third ri gid cable comprises a temperature measuring unit. By providing the temperature measuring unit, the extension c hange of the wire rod can be detected in consideration of expansion and contraction according to temperature change. [0029] Moreover, the above-mentioned wire rod is specifically a rockb olt, an earth anchor, or a reinforcing bar embedded inside concrete. [0030] Moreover, it is a preferable embodiment that the information output circuit is a light emitting circuit of a light emitting diode. The extension amount of the wire rod can be checked in-situ at any time by the color of light. [0031] Moreover, it is a preferable embodiment that the information output circuit is a light emitting circuit of a light emitting diode, co mputes a time variation rate of an extension displacement or a bend ing displacement and, when the variation rate is greater than a pre determined threshold value, temporarily changes a light emitting pat tern of the light emitting diode. By the present embodiment, in a normal state, data are stored at fixed time intervals to store the displacement (or bend) and the time variation rate of the displacement (or bend) is calculated, and in a case where these are found by collation to control standard values to be of levels requiring the issuing of an alarm, the light emitting display pattern of the light emitting diode is changed temporarily, and blinking or issuing of an alarm sound, etc., is performed to enable danger to be made known to the 14 / 32 PCT/JP2009/52911 surroundings. [0032] Moreover, it is a preferable embodiment that the information output circuit computes a time variation rate of an extension displac ement or a bending displacement and, when the variation rate is gre ater than a predetermined threshold value, stores displacement data of the extension displacement or the bending displacement at time in tervals shorter than a time of an interval set in advance. By the present embodiment, from the instant a sudden vibrati on is applied due to an earthquake, etc., all data (displacement, acce leration, etc.) are automatically subject to data storage in a memory at short time intervals for a fixed period time, such as approximatel y 60 seconds, and the normal monitoring state can be returned to af ter the end of the data storage task. [Effects of the Invention] [0033] The device for detecting state-change of a wire rod of the present invention provides the effect of enabling detection of the extension change of the entire length or an interval between two arbitrary points of the wire rod embedded in the matrix and in-situ information output of the information on the magnitude of the extension. [0034] Also, the information on the magnitude of the extension can be displayed in-situ by the color of light. Furthermore, in a case where a problem occurs in the electrical system, the magnitude of the extension can be checked visually because the backup detection function that does not use the electrical system is actuated. [Brief Description of the Drawings] [0035] FIG. I shows a structural schematic drawing of the device for detecting state-change of a wire rod of embodiment 1. FIG. 2 shows an explanation chart when installing in wire rod (rockbolt) that has exposed one side. FIG. 3 shows an explanation chart of position of casing of rockbolt. FIG. 4 shows a side view cross section where the device for detecting state-change of a wire rod of embodiment 1 was installed in rockbolt. 15 / 32 PCT/JP2009/52911 FIG. 5 shows a schematic drawing that shows appearance in which the device for detecting state-change of a wire rod of embodiment 1 is installed in rockbolt. FIG. 6 shows a structural explanation chart of switch unit. FIG. 7 shows an operation explanation chart of switch unit. FIG. 8 shows a detailed explanation chart of switch unit. FIG. 9 shows an electric wiring diagram of the device for detecting state-change of a wire rod of embodiment 1. FIG. 10 shows a whole composition chart of the device for detect ing state-change of a wire rod of embodiment 1. FIG. 11 shows an appearance chart of installation with rockbolt in midair. FIG. 12 shows a side view cross section where the device for detecting state-change of a wire rod of embodiment 1 was installed in rockbolt. FIG. 13 shows a schematic drawing that shows appearance in w hich the device for detecting state-change of a wire rod of embodime nt 2 is installed in rockbolt. FIG. 14 shows an explanation chart of the device for detecting s tate-change of a wire rod of embodiment 3. FIG. 15 shows an explanation chart of the device for detecting s tate-change of a wire rod of embodiment 4. FIG. 16 shows an application example of ferroconcrete. FIG. 17 shows an application example in bedrock discontinuity. FIG. 18 shows an explanation chart of rigidity cable with part t hat has taper of embodiment 5. FIG. 19 shows an explanation chart of the first switch unit and the second switch unit composed of elastic member of embodiment 5, and the rigidity cable with part that has taper. FIG. 20 shows an operation explanation chart of the second switch of embodiment 5.(1)A small transformation was caused.(2)A big transformation was caused. FIG. 21 shows a schematic drawing of device of embodiment 5. FIG. 22 shows an image chart where the colored reflection sticke r of embodiment 6 was installed in the first rigidity cable. FIG. 23 shows an example of window used together with the col ored reflection sticker of embodiment 6. 16 / 32 PCT/JP2009/52911 FIG. 24 shows an example of visually checking amount of transf ormation by using the colored reflection sticker of embodiment 6. FIG. 25 shows the structure of the switch, Only the backup func tion part, that installs the colored reflection sticker of embodiment 6 in the first rigidity cable. FIG. 26 shows an explanation chart of composition in which axis power monitor unit is set up on surface of concrete of embodiment 7. FIG. 27 shows a flow chart of data processing program of embod iment 8. FIG. 28 shows a schematic drawing of wire rod such as rockbolt transformed including bend of embodiment 9. FIG. 29 shows an explanation chart when gap is caused along di scontinuity in the vicinity of wall of embodiment 9. FIG. 30 shows an explanation chart when gap is caused along di scontinuity on interior side of embodiment 9. FIG. 31 shows an arrangement chart of rigidity cable of plural p airs of embodiment 9. FIG. 32 shows an arrangement chart (1) of rigidity cable for dis placement measurement of embodiment 9. FIG. 33 shows an arrangement chart (2) of rigidity cable for dis placement measurement of embodiment 9. [Best Mode for Carrying Out the Invention] [0036] Embodiments of the present invention will be described in det ail below with reference to the drawings. [Example 1] [0037] The device for detecting state-change of a wire rod of embodi ment 1 converts relative displacement into the color of light. FIG. 1 shows a structural schematic drawing of the device for detecting state-change of a wire rod of embodiment 1. The device for detecting state-change of a wire rod of embodiment 1 is the following as shown in Fig. 1. In a casing member, a first rigid cable (21) used as a displacement measurement line and an elastic member (41) are connected in series between fixing members disposed at two ends of the wire rod (10). A switch 17/ 32 PCT/JP2009/52911 unit (16) is formed and fixed on the base plate (100) of fixing member connected to the elastic member (41), and detects a relative displacement from a contact point (shown by arrow to touch switch 16) on the first rigid cable (21). And, it is composed by LED luminescence part (13) where full-color can be displayed with the light emitting diode in accordance with the displacement. Since the device for detecting state-change of a wire rod of e mbodiment 1 comprises the above-mentioned composition, when the wire rod (10) undergoes an extension change in the longitudinal dire action, the elastic member (41) extends and changes in state, and the contact point is displaced relative to the switch unit (16), so that t he information is output from the information output circuit (13). That is, it is composed of the first rigidity cable (21), switch (16), and LED luminescence part (13). Here, switch (16) converts rel ative displacement into the color of light, and LED luminescence par t (13) originates the color of light by relative displacement. These ha ve been installed between two points of both ends A and B of wire rod (10). And, the extension amount between two points of both ends A and B of wire rod (10) is detected with switch (16). And, LED lu minescence part (13) displays in-situ by the color of light. [0038] The structure is described specifically about the device for det ecting state-change of a wire rod of embodiment 1. The example of i nstalling the rockbolt of the wire rod that exposes one side and is e mbedded underground is described referring to Fig. 2. Rockbolt (1) is usually inserted in the hole, where the diameter dug up in the bed rock is several cm, dug up in the bedrock as shown in Fig. 2. And, cement grout (2) is injected into this remaining space. When the tra nsformation is caused in the bedrock after cement grout (2) solidifies , the effect that rockbolt (1) suppresses the transformation is produce ed. Face plate (4) and nut (5) are installed in the edge that has bee n exposed, and it ensures the displacement controlling effect on the surface. [0039] Fig. 3 shows figure where the installation situation of the roc kbolt was seen axially. Fig. 3(a) shows casing (6) to insert hole dug 18 / 32 PCT/JP2009/52911 up in the bedrock, rockbolt (1), and the device for detecting state-ch ange of a wire rod of the present invention. Face plate (4) and nut ( 5) are installed in the surface under such a condition as shown in F ig. 3(2) and rockbolt (1) is completed. Fig. 4 shows the side view cross section that the rockbolt sets up. Casing (6) is fixed by using fixed member (7) for the edge of t he rockbolt in the depth part. [0040] Fig. 5 shows the composition schematic drawing that installs the device for detecting state-change of a wire rod is installed in roc kbolt (1) as a side view cross section. The first rigidity cable (21) fo r displacement measurement is fixed to the depth part of rockbolt (1 ) by using the space secured with casing (6). It is desirable in this f irst rigidity cable (21) to put the temperature measurement function. Even if the temperature measurement device is not installed i n the first rigidity cable (21), it is also possible to dispose the temp erature measurement device for instance separately in casing (6). Th e edge on the surface side of this first rigidity cable (21) is connecte d with switch (16) where relative displacement is converted into the color of light. Moreover, LED luminescence part (13) where the displ acement measurement result is displayed is installed. [0041] Next, one example of the switch that converts the result of m easuring relative displacement into the color of light is described ref erring to Fig. 6. Rotation member (42) is installed in base plate (51) on A side of Fig. 6. And, the rigidity cable for the displacement me asurement is installed from B side of Fig. 6. The terminal is connect ed to the elastic member such as the springs of the tension power i ntroduction. Four contact points (44R, 44G, 44B, 44R') are installed i n rotation member (42). These four contact points are the contact po ints in full-color LED (50) (Red, Green, Blue) for the power supply r espectively. The fourth Red indicates the same place as the first Red . The power supply point from the power supply (Not shown) is inst alled at the position that can come in contact with these contact poi nts. This power supply point is installed in elasticity member (52) s uch as the springs fixed to base plate (51). This point is a structure 19 / 32 PCT/JP2009/52911 that comes in contact with four contact points with constant pressu re. [0042] Next, the operation of one example of the above-mentioned switch is described. Fig. 7(1) shows the initial state of one example of the above mentioned switch. Under such a condition, the power supply point to uches contact point (44R), and LED lights in red. Fig. 7(2) shows the state that it is extended between A and B a little. The rotation member rotates, the power supply point touch hes contact point (44R) and contact point (44G), and the electric pow er is supplied to a red, green LED circuit. Under such a condition, LED lights in yellow. The power supply point is installed in the elas tic member. Therefore, the state to touch two contact points continue s for a certain period not momentary. Next, Fig. 7(3) shows the state that the transformation increa ses in addition. The power supply point enters the state to touch onl y contact point (44G) when the rotation advances. Thereafter, whene ver the rotation advances, the electric power is supplied to one point or two points. As a result, LED lights to a single color or the mixe d color. [0043] Fig. 8 shows the enlarged drawing of rotation member (42) a nd contact points (44R, 44G, 44B, 44R'). Six colors are roughly displ ayed at each displacement of P/2 when four contact points are instal led by the change in the state of the power supply as shown in Fig. 8. Here, P is an installation pitch of the contact point. This pitch d ecides diameter D of the rotation member and diameter D of the con tact point etc. considerately. The accuracy of the displacement measu rement will improve by becoming small of the pitch. [0044] Fig. 9 shows an electric wiring diagram for the device for detecting state-change of a wire rod of embodiment 1 to function. The example that shows here is one example of the switch that converts relative displacement into the color of light. Besides this, various methods are considered about the setting of the displacement measurement accuracy, the measurement 20 / 32 PCT/JP2009152911 stroke, displacement, and the color etc. according to the situation. [0045] Fig. 10 shows the whole image of the device for detecting sta te-change of a wire rod of embodiment 1. Moreover, Fig. 11 shows t he image that uses the bolt in the midair. In this case, it only has to pass rigidity cable (40) through the midair space of rockbolt (1). There is basically no difference besides in the case to use casing (6). [Example 2] [0046] Next, the device for detecting state-change of a wire rod of e mbodiment 2 is described. The device for detecting state-change of a wire rod of embodiment 2 has installed the electric circuit where th e power supply and the light emitting diode were used. Moreover, th e device for detecting state-change of a wire rod of embodiment 2 as sumes the case where the phenomenon such as the corrosion of the switch contact part is caused and has installed the backup function. The displacement measurement function that is the simplest, and ca n be trusted is a structure to install measure (61) in rigidity cable ( 60) as shown in Fig. 12 and Fig. 13. (It is actually desirable to inst all calipers.) The expansion of rockbolt (1) can be read with the fixed point (point (63) triangular in figure) that marks nut (5) or face plate (4) and the scale of measure (61) that crosses the fixed point. [Example 3] [0047] The displacement between both ends such as the rockbolts is measured. As a result, the whole image turns out what power it rec eives and it expands. However, expansion and contraction is different for the wire rod that has clung the cement grout such as the rockb olt according to the difference of the part of the wire rod. Moreover, the rockbolt might expand and contract locally only in the part whe n big displacement is caused in the vicinity of the crack of a specifi c location in the bedrock. It is also very important to understand su ch a situation accurately. The example of setting up plural cable cas ings is shown as one sample that enables this. Fig. 14(1) is an exa mple of installing three casings (6a, 6b, 6c) in face plate (4), and m 21 / 32 PCT/JP2009/52911 easuring three relative displacements. Fig. 14(2) shows the side view. A similar device for detecting state-change of a wire rod is prepared by three sets by using three casings. These relative displacements are measured between A and B, between A and C, between A and D. And, everything is displayed by the light emitting diode as a color of light. [Example 4] [0048] Next, the device for detecting state-change of a wire rod of e mbodiment 4 is described. Fig. 15 shows the schematic drawing of t he device for detecting state-change of a wire rod of embodiment 4. In the device for detecting state-change of a wire rod of embodiment 4, slide resistance (80) that is the changeable resistance part has b een installed in the movement part of contact point (81). And, the r esistance of slide resistance (80) has been changed by moving the sli de in the switch by which contact point (81) changes the resistance of slide resistance (80) according to relative displacement of contact point (81). Moreover, resistance is digitalized. Microcomputer (82) that de cides the blinking pattern of LED is installed. The signal is sent fro m microcomputer (82) to LED luminescence part (13). [0049] Moreover, the reinforced concrete material cannot usually be seen from the outside in ferroconcrete. However, in constructional, as shown in Fig. 16(1), the edge of the reinforced concrete material can be exposed for instance in the beam structure. Fig. 16(2) shows the example that uses the device for detecting state-change of a wire rod for the midair reinforced concrete. Moreover, a similar measurement system can be constructed by setting up a thin casing that builds the device for detecting state-change of a wire rod into as shown in Fig. 16(3) even if both ends are embedded. [0050] Moreover, there are many discontinuities in the bedrock as sh owing in Fig. 17, and the shift of either of the specific thing might be caused. This is a phenomenon to threaten the stability of the bed rock. Therefore, it is very important to know whether the shift has happened by how much depth from the surface. By using the compos 22 / 32 PCT/JP2009/52911 ition of the device for detecting state-change of a wire rod of embodi ment 4, plural displacements can be observed over the total length o f the rockbolt. And, where a local transformation has concentrated c an be ascertained by comparing the data. [Example 5] [0051] In embodiment 5, the device for detecting state-change of a w ire rod of the third viewpoint of the above-mentioned present inventi on is described. In particular, the composition of the second switch a dded to the above-mentioned embodiment is described to correspond to a large-scale transformation. First of all, a specific embodiment, e mbodiment that the second rigidity cable that extends the diameter 1 ike the taper is connected with the edge connected with the elastic member in the first rigidity cable, is described. Next, a specific embo diment, the second switch where relative displacement with the cont act point of the side view of the first rigidity cable or the second rig idity cable is detected in the outcrop of the first rigidity cable, is de scribed. [0052] First of all, a specific embodiment, the second switch where r elative displacement with the contact point of the side view of the fi rst rigidity cable or the second rigidity cable is detected, is described referring to Fig. 18. Fig. 18 shows the rigidity cable with the part that has a taper (shape that the size of the section is different acco rding to the position) necessary to correspond for the large-scale tran sformation. In this, a part of the first rigidity cable (21) of Li in le ngth (diameter D1) is a composition connected directly with the seco nd rigidity cable 22 of L2 in length that has the taper. The diamete r of the other end is D2 though the diameter of uniting part (23) wi th the first rigidity cable 21 is D1 in the second rigidity cable (22) t hat has the taper. The second rigidity cable (22) may be formed wit h a material (for instance, plastic and flexible wire, etc.) different fr om the composition material of the first rigidity cable (21). Moreover , an expansion and contraction rigidity of the second rigidity cable ( 22) axially may be strong as well as the first rigidity cable. [0053] 23 / 32 PCT/JP2009/52911 Next, a specific embodiment, embodiment that the second rigi dity cable that extends the diameter like the taper is connected with the edge connected with the elastic member in the first rigidity cab le, is described referring to Fig. 19. Fig. 19 shows the rigidity cable with the first switch composed of the elastic member such as the sp rings, the second switch, and the part that has the taper. The direct ion where the expansion of the wire rod such as the rockbolt is mea sured is x-axially in Fig. 19. Moreover, elasticity member (41) is fixed by bases of wire rod s such as and the rockbolt in 1F (41a) in Fig. 19. Moreover, IM (41 b) in Fig. 19 is an operation point that exists in x-axial direction. A nd, the amount of the expansion of the wire rod such as the rockbol t is measured. (For instance, the transformation is in the range of a bout 30mm or less.) Moreover, elasticity member (71) newly set up as the second switch is fixed to the base of the wire rod such as the rockbolt with the point of 2F (71a). The point of 2M (71b) is an operation point of y axial direction. Operation point 2M (71b) is opposed to fixed pa rt (72) through the space. The function to measure a large-scale tran sformation (from 30 to 300mm) is achieved with the second switch c omposed of elasticity member (71). [0054] The installation image, in the first switch composed of elasticity member (41) and in the second switch composed of elasticity member (71), of the cable that unites the first rigidity cable (21) and the second rigidity cable (22) that has taper, is shown in Fig. 19. The right side is from a right edge of Fig. 19 to the area in the bedrock here. This is omitted in figure. Uniting parts (23) of the first rigidity cable (21) and the second rigidity cable (22) are connected with IM point to measure displacement. At this time, the one to which the rigidity to the pull is strong and the rigidity to the bend is weak is assumed to the part that has the taper. Therefore, power is not received from the free space in the device. The first rigidity cable (21) (diameter D1) is arranged for the space between 2M and fixed part (72) to pass. [0055] Next, the movement of the second switch corresponding to a large-scale transformation is described referring to Fig. 20. Fig. 20(1) shows 24 / 32 PCTJP2009/52911 the state that a small-scale transformation is caused. Fig. 20(2) shows the state that a large-scale transformation is caused. First of all, the state that expansion transformation ul (sm all-scale transformation) is caused in the wire rod such as the rockb olt is shown in Fig. 20(1). Expansion ul is caused in elasticity mem ber (41) that composes the first switch as shown in Fig. 20(1). And, a usual position (Original position of 1M in figure) of the first rigid ty cable (21) changes into the state that only ul is drawn in intern ally as shown in Fig. 19. At that time, the transformation is not ca used in elasticity member (71) that composes the second switch. Mor eover, power is not applied to the taper part of the second rigidity c able (22). This state continues until the size of amount ul of the tr ansformation reaches the limit value (For instance, about 30mm). [0056] On the other hand, Fig. 20(2) shows the state that a large-sc ale transformation that exceeds the measurement range of the first s witch is caused. The edge (41b) of elasticity member (41) of the first switch automatically parts from uniting part (23) of the first rigidit y cables (21), and changes into the state that doesn't function any lo nger. The first rigidity cable (21) enters the state greatly drawn in. And, the part of the taper enters between 2M(71b) of elasticity mem ber (71) that composes the second switch and fixed part (72), and ch anges into the state to expand the distance. At this time, when a large-scale transformation of u2 is cause d from the first installation position as a whole, elasticity member ( 71) that composes the second switch causes the shrinking transforma tion of u3 as an amount decided by the degree of the taper. That is, large-scale transformation u2 of x-axial direction corresponds to the treatment as small-scale transformation u3 of y-axial direction. [0057] Next, Fig. 21 shows the schematic drawing of the device of embodiment 5 that has two switches. Basically, elasticity member (41) of which the first switch is composed and elasticity member (71) of which the second switch is composed measure the amount of the transformation of different range respectively. For instance, it is range up to the first about 30mm, and, for instance, range by 30mm or more up to about 300mm. The 25 / 32 PCT/JP2009/52911 displacement measurement operation point of each spring is connected with potentiometer (75,80). And, the displacement data is processed by microprocessor (CPU) (91). And, the measurement result of a small-scale transformation and the measurement result of a large-scale transformation are displayed by using the color variation respectively for display (92) of LED1 and display (93) of LED2 respectively. [Example 6] [0058] (Confirmation of strangeness with a colored reflection sticker) A specific embodiment that installs the colored reflection stick er in the outcrop of the cable for the displacement measurement is described in the above-mentioned embodiment in embodiment 6. It d etects an extension change of a wire rod embedded in a matrix by o bserving the color. The colored reflection sticker is installed in the o utcrop of the first rigidity cable. As a result, even if the breakdown is caused in the electrical system, the amount of the transformation can visually be confirmed from the distance by the color. Moreover, i t is used as a backup function when the function that oneself shines is lost. When light is applied with the colored reflection sticker, dis placement can be recognized. Though the size of this colored reflection sticker is not especially limited, each colored reflection sticker width is several millimeter or several centimeters. These can confirm watching in daytime. Moreover, these can be checked visually by applying the light at nighttime. The one with such a characteristic is used. Fig. 22 shows the image chart where the colored reflection sticker (110) was installed in cable (120) for the displacement measurement. This colored reflection sticker (110) is used together with parts 111 (Fix to the base of the device for detecting state-change of a wire rod) that have window (112) shown in Fig. 23. As a result, the colored reflection sticker (110) of the opponent in wi ndow (112) can be checked visually according to the movement of ca ble (120) for the displacement measurement. When the breakdown is caused in the electrical system, the amount of the transformation c an visually be confirmed by the color. Fig. 24 shows the example of checking the amount of the tra 26 / 32 PCT/JP2009/52911 nsformation visually with the colored reflection sticker. The cable (12 0) for the displacement measurement expands and contracts. Green p art (G) at the center of the colored reflection sticker moves left and right. The color that can be checked visually, through window (112), changes from light blue (S) to yellow (Y). As a result, the amount of the transformation can be confirmed. Fig. 25 shows the structure of the switch that installs colored reflection sticker (111) in the cable (120) for the displacement meas urement (Only the backup function part). [Example 71 [00591 The rockbolt used by the tunnel construction etc. is usually p1 aced with concrete after it is covered finally with the trail tarp. The refore, the surface cannot be seen. Therefore, it is considered to leav e the device that makes the axis power visible embedded undergroun d or to be detached. Therefore, the first rigidity cable in the bedrock is left just as it is, and axis power monitor unit (90) shown in Fig. 26(1) in other parts is made detachable. As a result, after concrete is placed, relat ive displacement in the part (About 300mm usually) where a bedroc k and concrete thickness were added can be monitored. After concrete is placed, axis power monitor unit (90) (Not shown) is not detached as shown in Fig. 26(2). Sheath tube (121) is installed internally concrete (9) as shown in Fig. 26(3). And, the first rigidity cable (21) and edge (122) are united, and cable (120) for the displacement measurement is constructed at the edge in the outcrop of the first rigidity cable (21) newly. And, axis power monitor unit (90) is set up again on a surface concrete (9). By assuming this state, after concrete is placed, the state of the entire structure tunnel including information in the bedrock can be observed by the color of light on the final surface. [Example 81 [0060] Fig. 27 shows the flow chart of the data processing program. Data is memorized usually by an interval of a fixed time. And, displacement or bending change is memorized as data. And, the change rate is calculated during that time (step S1-S3). Those data is compared with the management 27 / 32 PCTIJP2009/52911 standard value (step S4 and S6). The display pattern of LED is changed and blinked temporarily when judged that it is a warned level. Or, danger is notified to the surrounding by originating the warning sound (step S5 and S7). Moreover, when there is excitation rapidly due to the earthquake etc. (step S8), All data (displacement and acceleration, etc.) is memorized since the moment by an interval of a fixed time (for instance, short time of about 60 seconds) (step S9). It changes into a usual monitor mode after this data storage processing ends (step S10). The object of the above-mentioned data storage is a lock burst (small-scale earthquake that happens because of local destruction of the bedrock) caused in the earthquake or the mine, etc. It is very useful for the safety confirmation to record and to analyze the behavior of the rockbolt structure at the earthquake. [Example 9] [0061] (Structure to detect state of bending change of wire rod) As for the discontinuity in the ground, there are a lot of crac ks of the existing bedrock at first in the bedrock. On the other hand, the destruction side generated by the stre ss concentration etc. becomes a discontinuity for the nature of soil m aterial. And, the gap transformation is caused along the respect. In that case, not only expansion and contraction but also the bend tran sformation occurs in the wire rod, of rockbolt and grand anchor, etc., that intersects with the discontinuity. [0062] Fig. 28 shows the schematic drawing of the wire rod such as the rockbolt that receive the transformation including the bend. Exp ansion and the bend transformation operate to rockbolt 1(Original fo rm) of L in length that has not received the transformation at the s ame time, and it changes in the state of Deformed. In this case, roc kbolt (1) expands and contracts about AL according to the centerline as a whole (Whether it is an expansion or it is shrinking is done b y an individual case). Only if one displacement measurement cable is used, only the amount of expansion and contraction in the location where it was arranged can be detected. 28 / 32 PCT/JP2009/52911 [0063] On the other hand, when two rigidity cables (tl-t2,bl-b2) for the displacement measurement are arranged in the top and bottom o f rockbolt 1 as shown in Fig. 29, an upper and lower rigidity cable receives the influence by the bend and measures a different amount of expansion and contraction. The difference of the displacement dete cted at this time is an index that shows the size of the bend transf ormation. It can be confirmed to cause the discontinuity in the group nd, and to cause the gap transformation along the discontinuity. Thi s is extremely important information for evaluating the state of the transformation and the stability of the ground. [0064] Moreover, it can know whereabouts in the ground to cause th e gap transformation when plural rigidity cables for the displacemen t measurement are installed. When the discontinuity is caused in th e vicinity of the wall (left side of figure) as shown in Fig. 30 and th e shift transformation occurs, it can be confirmed according to the di fference between Uti-t2 (displacement between t1-t2) and Ubl-b2 (displa cement between bl-b2). It is obviously understood that there is little difference between Uti-t 2 and Ul-b2 at this time referring to figure. [0065] There is little difference between Uti-t2 and Ubl-b2 when the di scontinuity is generated on the interior side and on the other hand, there is a shift as showing in Fig. 31. However, the difference betwe en Uti-t2 and Ubl-b2 can be detected. As a result, it can be confirmed the discontinuity was generated on the interior side. Thus, it is un derstood to be able to specify the size and the location of occurrence of the bend transformation by arranging the displacement cable tha t becomes a pair on both sides of rockbolt (1). [0066] Moreover, the shift transformation of the ground that parallel s the discontinuity is not necessarily caused in the vertical direction. For that case, plural pair cables (130,131) are installed as shown in Fig. 32(1) (2). As a result, the level of the bend in each direction c an be confirmed. Therefore, the direction of the shift transformation can be specified from those results overall. In this case, the case wh 29 1 32 PCT/JP2009/52911 ere cable is set up outside of bolt in usual rockbolt (1) in Fig. 32(1) and the case where cable is set up in inner wall in rockbolt (IA) o f midair in Fig. 32(2) exist. Reference letters 2 show the cement gro ut in figure. Two kinds of cables of short cable (1325-125S) and long cable (132L-125L) are set up in the direction of depth of the ground on the basis of the above-mentioned background. And, it only has to set up the rigidity cable for the displacement measurement of eight totals as shown in Fig. 33(1) and Fig. 33(2) to achieve the purpose to detect the bend transformation of length and side. Fig. 33(1) is a case where the cable is set up outside of the bolt in usual rockbolt (1). Moreover, Fig. 33(2) is a case where the cable is set up in the inner wall in the rockbolt (1A) of the midair. Reference letters 2 show the cement grout in figure. [Industrial Applicability] [0067] The device for detecting a state-change of a wire rod accordin g to the present invention is utilized as a system that is monitoring amount of the extension change of the wire rod embedded in the m atrix. [Description of Symbols] [0068] 1 Rockbolt 2 Cement grout 3 Matrix 4 Face plate 5 Nut 6 Casing 10 Wire rod 13 Information output circuit (LED luminescence part) 16 Switch unit 21 First rigid cable 41,52 Elastic member 80 Slide resistance 81 Contact point 82 Microcomputer 100 Base plate 30 / 32 PCT/JP2009/52911 31 / 32