Ultrasonic groove wall measuring device and method for constructing an ultrasonic groove wall measuring device

Abstract

To provide a junction structure securing accuracy of an assembly after joining as simplifying junction work upon joining long members to each other through a bolt joint using a splice plate.SOLUTION: A junction structure for long members joining long members to each other through a bolt joint using a splice plate comprises steps of arranging a junction plate over the long members adjacent to each other and arranging a rotating prevention member abutting an outer peripheral edge of a joint plate and preventing rotation of the joint plate on at least one of the adjacent long members.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a joint structure for long members in which long members are joined together by bolt joints using splice plates. Ultrasonic groove wall measuring device using the same, and method for constructing an ultrasonic groove wall measuring device Regarding. [Background technology]

[0002] For example, when constructing a diaphragm wall using an excavation trench constructed in the ground, the shape of the excavation trench has a significant impact on the finished shape of the diaphragm wall. For this reason, once the excavation trench is constructed, an ultrasonic sensor suspended from the ground into the excavation trench is used to check the trench wall condition. Specifically, the ultrasonic sensor emits ultrasonic waves toward the trench wall and receives the reflected waves, measuring the horizontal distance between the ultrasonic sensor and the trench wall. This work is carried out while moving the ultrasonic sensor in the depth direction within the excavation trench.

[0003] However, if there is an underground obstacle in the construction area of ​​the diaphragm wall, the underground obstacle must be removed and relocated, and a trench area must be dug below the obstacle to create a trench. When inspecting the trench wall condition in the trench area, the underground obstacle interferes, making it impossible to place an ultrasonic sensor suspended from the ground. Under these circumstances, for example, Patent Document 1 discloses an ultrasonic trench wall measurement device that can place an ultrasonic sensor in the trench area while avoiding the underground obstacle.

[0004] The ultrasonic trench wall measurement device of Patent Document 1 has a mobile device that moves on the ground surface along the extension direction of the excavation trench, a vertical frame that is inserted vertically into the excavation trench, and a sensor positioning member that extends from the tip of the vertical frame toward the open trench area and from whose tip an ultrasonic sensor is suspended.As a result, by moving the mobile device on the ground surface and inserting the tip of the sensor positioning member into the open trench part, the ultrasonic sensor can be suspended within the open trench part. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-125744 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the underground obstacle is located deep underground, the length of the vertical frame must be extended so that the tip end equipped with the sensor positioning member can reach the excavated section located below the underground obstacle.

[0007] One possible solution to this problem is to construct the vertical frame by connecting multiple long members in the longitudinal direction and then connecting these long members with bolts using splice plates. However, bolt connections using splice plates are prone to relative rotation between the members due to the play in the bolt holes, which could cause the tip of the vertical frame to shift from its intended position. This could also cause the ultrasonic sensor to shift from its hanging position, which could affect the accuracy of measuring the horizontal distance between the ultrasonic sensor and the groove wall.

[0008] For this reason, when joining long members using bolt joints with splice plates, it is necessary to place the long members in a lying position in a large space and join them while controlling assembly accuracy using a transit or level. Not only is this work complicated, but it cannot be used on narrow construction sites.

[0009] Even if a large space can be secured, if a vertical frame is constructed by joining long members in a laid-down position, it will need to be erected before being inserted into the excavated trench, which may result in bending or twisting during the erection work.Furthermore, this method cannot be used at construction sites with low overhead.

[0010] The present invention has been made in consideration of such problems, and its main object is to simplify the joining work when joining long members together by bolt joining using splice plates, while ensuring assembly accuracy after joining. [Means for solving the problem]

[0011] In order to achieve this object, the present invention The ultrasonic trench wall measuring device is an ultrasonic trench wall measuring device for measuring the distance to the trench wall of an excavation trench including a perforated excavation portion, and comprises an ultrasonic measuring device stand suspended down into the excavation trench, and an ultrasonic sensor suspended down into the excavation trench via a wire wound around the ultrasonic measuring device stand, and the ultrasonic measuring device stand comprises a vertical frame including a plurality of longitudinally adjacent elongated members joined together using a joint structure including a splice plate and a pair of rotation restraining members, and a cantilevered member supported by the vertical frame. and a sensor base having a sheave at its tip that guides the wire vertically downward, wherein the adjacent elongated members are arranged with a gap between their opposing end faces, the splice plate is arranged on the adjacent elongated members across the gap, and the pair of rotation inhibiting members are integrally provided near the ends of the adjacent elongated members, facing each other across the splice plate and in contact with the outer periphery of the splice plate, at positions that inhibit relative rotation between the adjacent elongated members. It is characterized by:

[0012] Furthermore, the method for constructing an ultrasonic trench wall measurement device of the present invention includes suspending the long member equipped with the sensor mount into the excavation trench, then suspending a new long member to be added above the long member so that their end faces face each other with a gap between them, and using the rotation suppressing member provided on the long member as a positioning member; The splice plate The vertical frame is constructed by placing the splice plate on the adjacent elongated members across the gap so that the outer peripheral edge of the splice plate contacts the rotation inhibiting member, and joining the adjacent elongated members using the splice plate.

[0013] The ultrasonic groove wall measuring device of the present invention According to the method for constructing an ultrasonic groove wall measurement device, the rotation-preventing member not only prevents rotation between adjacent longitudinal members but also functions as a positioning member for the splice plate. This allows the rotation-preventing member to be fixed in an appropriate position on the longitudinal members in advance, such as at a factory. On-site, workers can use the rotation-preventing member to position the splice plate relative to the longitudinal members and then bolt them together, ensuring assembly accuracy while joining the longitudinal members. This eliminates the need for measurement work during joining, simplifying the joining process while ensuring assembly accuracy after joining.

[0014] Also, By fixing anti-rotation members in advance at a factory or other location to appropriate positions on the long members that make up the vertical frame, the vertical frame can be transported to the site in a disassembled state, and the long members can be joined in an upright position using an excavation trench on site to construct the vertical frame.

[0015] This not only prevents relative rotation between the long materials, but also prevents bending and twisting, which are likely to occur when the materials are erected in a tilted position. Therefore, it is possible to prevent positional deviations caused by inaccuracies in the assembly of the vertical frame when hanging the ultrasonic sensor from the ultrasonic measuring device stand, which has a vertical frame, and it is possible to carry out highly reliable work of checking the condition of the trench wall.

[0016] In addition, by using the excavation trench to join long members in an upright position and construct a vertical frame, even if the construction site is in a narrow or low-headroom environment, the excavation trench can be used to construct a vertical frame and place a stand for an ultrasonic measuring device.Therefore, it is possible to use an ultrasonic sensor positioned by the stand for an ultrasonic measuring device to carry out work to check the condition of the trench walls of the excavation trench, including the openwork section.

[0017] Furthermore, because the rotation-preventing member can be used to position the splice plate, measurement work can be omitted and long members can be joined in a short time. Therefore, even when the excavation trench is deep and a large number of long members must be joined to build a vertical frame, it is possible to significantly reduce work time. [Effects of the Invention]

[0018] According to the present invention, when adjacent long members are joined by bolt joining using a splice plate, by providing a rotation prevention member that abuts the outer peripheral edge of the splice plate on at least one of the adjacent long members, it is possible to simplify the joining work while ensuring assembly accuracy after joining. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing an outline of an ultrasonic groove wall measuring device according to an embodiment of the present invention; [Figure 2] 1A to 1C are diagrams illustrating a method of using an ultrasonic sensor according to an embodiment of the present invention. [Figure 3] 10A to 10C are diagrams illustrating a groove wall state confirmation operation using an ultrasonic groove wall measuring device according to the embodiment of the present invention. [Figure 4] 1 is a diagram showing a mount for an ultrasonic measuring device as seen from a perforated portion in an embodiment of the present invention. FIG. [Figure 5] 1A and 1B are diagrams showing a joining structure of long members in an embodiment of the present invention. [Figure 6] 10A and 10B are diagrams illustrating bending that occurs at the lower end of a vertical frame in an embodiment of the present invention. [Figure 7]10A and 10B are diagrams illustrating another example of a rotation inhibiting member according to the embodiment of the present invention. [Figure 8] 10A and 10B are diagrams showing a measurement operation (leveling operation) carried out when joining elongated members and fixing a rotation restricting member in the embodiment of the present invention. [Figure 9] 10A and 10B are diagrams showing a measurement operation (centering operation) carried out when joining elongated members and fixing a rotation restricting member in an embodiment of the present invention. [Figure 10] 10A to 10C are diagrams showing a procedure for constructing a vertical frame in an upright position according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention uses a rotation-preventing member to prevent rotation between adjacent long members caused by play in the bolt holes when joining adjacent long members using a bolt joint with a splice plate. The rotation-preventing member also functions as a positioning member for the splice plate, simplifying the joining work while ensuring assembly accuracy after joining. Below, we will explain the joining structure of long members and the ultrasonic groove wall measurement device that uses the joining structure of long members, taking the example of using H-shaped steel as the long members, with reference to Figures 1 to 10.

[0021] <<Ultrasonic groove wall measuring device>> As shown in Fig. 1, the ultrasonic trench wall measurement device 1 is a device used to check the trench wall shape of an excavation trench 10 created underground, and comprises an ultrasonic measurement device stand 6 inserted into the excavation trench 10, and an ultrasonic measurement device main body 5 installed on the ground via an installation stand 8. It also comprises a wire 4 that is unwound from a wire drum 51 of the ultrasonic measurement device main body 5 and wound around the ultrasonic measurement device stand 6, and an ultrasonic sensor 2 that is joined to the tip of the wire 4 via a suspender 3.

[0022] The ultrasonic sensor 2 is widely used for distance measurement, and is suspended in the excavation trench 10 via a wire 4. As shown in the plan view of Fig. 2(a), it incorporates a transmitter (not shown) that emits ultrasonic waves toward the trench wall 101 and a receiver (not shown) that receives the reflected waves. As a result, the horizontal distance from the ultrasonic sensor 2 to the trench wall 101 can be measured by receiving the reflected waves of the ultrasonic waves emitted from the transmitter perpendicular to the trench wall 101.

[0023] In the ultrasonic trench wall measurement device 1 equipped with such an ultrasonic sensor 2, the ultrasonic measurement device stand 6 is formed in an L-shape when viewed from the trench wall 101 side, making it possible to place the ultrasonic sensor 2 in a hollow excavated portion 102 of the excavation trench 10, as shown in Fig. 3. The hollow excavated portion 102 is a portion formed by hollow excavating the area below an underground obstacle F when it exists near the ground surface, without removing or relocating the underground obstacle F.

[0024] 3, the ultrasonic measuring device stand 6 is a jig for adjusting the hanging position of the wire 4 suspended in the excavation trench 10, and comprises a vertical frame 61, a sensor stand 62, and a traveling device 63. The traveling device 63 is configured to be able to support the vertical frame 61 in an upright position while being able to travel on the ground surface along the longitudinal direction of the excavation trench 10.

[0025] As shown in Fig. 4, the vertical frame 61 includes H-shaped steels 611 arranged in parallel with a gap between them and connecting members 612 that connect their lower ends together. As shown in Fig. 3, each of the H-shaped steels 611 arranged in parallel is placed in the excavation trench 10 in an upright position with its flange 611a facing the openwork portion 102. A sensor stand 62 is provided in a cantilevered manner at the lower end of the vertical frame 61.

[0026] The sensor mount 62 is provided so as to protrude from the vertical frame 61 in a direction opposite to the openwork section 102, and is equipped with a first sheave 621 and a second sheave 622. The first sheave 621 is arranged on the base end side of the sensor mount 62, and guides the wire 4 reeled out from the wire drum 51 toward the tip of the sensor mount 62. The second sheave 622 is arranged on the tip side of the sensor mount 62, and guides the tip of the wire 4 guided by the first sheave 621 vertically downward.

[0027] As a result, the ultrasonic sensor 2 suspended into the excavation trench 10 via the wire 4 is suspended at a position spaced apart from the vertical frame 61 by the overhanging length of the sensor mount 62. Therefore, as shown in Figure 3, when the ultrasonic measuring device mount 6 is caused to travel in the longitudinal direction of the excavation trench 10 via the traveling device 63 and the vertical frame 61 is brought close to the underground obstacle F, the sensor mount 62 is inserted into the openwork section 102, and the ultrasonic sensor 2 suspended via the wire 4 can be positioned in the openwork section 102.

[0028] Incidentally, in order to insert the sensor mount 62 into the openwork section 102, as shown in Figure 3, it is necessary to ensure that the vertical frame 61 has a member length that allows the lower end (the position where the sensor mount 62 is installed) to reach the depth of the openwork section 102. Therefore, the vertical frame 61 is provided with an H-shaped steel 611 in an upright position, which is extended in the longitudinal direction (vertical direction) to ensure the necessary member length.

[0029] When connecting the H-shaped steel 611 in an upright position in the longitudinal direction (vertical direction), a bolt-jointed connection structure 7 employing splice plates 71 as shown in Fig. 4 is used between these H-shaped steels 611. The connection structure 7 for long members will be described below.

[0030] <<<Joint structure for long members>>> The H-shaped steel beams 611 joined in the longitudinal direction are arranged coaxially so that their flanges 611a are flush with each other, as shown in Fig. 5(a), and are arranged with a gap between the opposing end faces 611c, as shown in Fig. 5(b). A splice plate 71 is arranged on the flanges 611a so as to straddle this gap.

[0031] 5(a), the flanges 611a of adjacent H-shaped steels 611 on which splice plates 71 are arranged are joined together with splice plates 74 arranged on their backsides via bolts 72. Similarly, the webs 611b of opposing H-shaped steels 611 are joined together with splice plates 71 arranged so as to straddle them via bolts 72.

[0032] When bolted together in this manner, the bolt holes in the H-shaped steel 611 and the splice plate 71 are generally formed larger than the outer diameter of the bolt 72, which allows for play, and this can result in relative rotation between the components, as shown in Fig. 6(a) . When this rotation occurs, a positional deviation ΔL1 occurs between the actual placement position P1 on the sensor mount 62 and the planned placement position P2.

[0033] For example, if the lower H-shaped steel 611 rotates by about 0.5 degrees relative to the upper H-shaped steel 611, a positional deviation ΔL1 of 61 mm will occur if the member length of the H-shaped steel 611 is 7 m. This will then cause a similar positional deviation ΔL1 in the ultrasonic sensor 2 suspended via the sensor mount 62, creating an issue with the reliability of the horizontal distance to the groove wall 101 measured by the ultrasonic sensor 2.

[0034] Therefore, in the joining structure 7 for long members, as shown in Fig. 5(b), a rotation suppressing member 73 that abuts against the outer periphery of the splice plate 71 is provided on each of the adjacent H-shaped steels 611. The rotation suppressing member 73 is made of a member that abuts linearly against the outer periphery of the splice plate 71, and is fixed to the flange 611a of the H-shaped steel 611 by a fixing means such as welding.

[0035] However, the shape and fixing means are not limited in any way, and for example, as shown in Fig. 7(a), they may be provided on either the upper or lower H-shaped steel 611. Also, as shown in Fig. 7(b), the rotation preventing member 73 may be provided in the shape of a dotted line. Furthermore, as shown in Fig. 7(c), they may be formed into a hook shape, and are not limited in any way as long as they are in an appropriate position and shape that can prevent relative rotation between adjacent H-shaped steels 611 that are bolted together using splice plates 71.

[0036] <<Positioning and Fixing Method of Rotation Suppression Member 73>> The procedure for fixing the rotation inhibiting member 73 to an appropriate position on the H-shaped steel 611 will be described below with reference to FIGS. 8 and 9, taking the vertical frame 61 as an example.

[0037] First, the vertical frame 61 in a laid-down position and the sensor stand 62 are joined by bolting using the joining plate 71 while ensuring assembly precision. Specifically, the H-shaped steel 611 equipped with the sensor stand 62 and another H-shaped steel 611 to be added thereto are coaxially arranged on the leveled mounting surface of the assembly stand 21.

[0038] Next, as shown in Fig. 8, multiple staffs 23 are set up vertically at intervals on the flanges 611a of the H-shaped steel 61 placed in a lying position. Then, while reading the scales on these staffs 23 with a level 22, the height positions of adjacent flanges 611a are adjusted as appropriate to place them on the same horizontal plane (leveling work). Furthermore, as shown in Fig. 9, a transit 24 placed in the longitudinal direction of the H-shaped steel 611 is used to adjust the positions of adjacent H-shaped steels 611 as appropriate so that they are positioned on the same axis (centering work).

[0039] As described above, with the flanges 611a of adjacent H-shaped steel 611 forming the same horizontal plane and positioned on the same axis, the flanges 611a and the webs 611b are bolted together using the splice plates 71. In this way, the adjacent H-shaped steel 61 is joined while ensuring assembly precision, and in this state, the rotation suppressing members 73 as described in Fig. 5(b) are fixed to the flanges 611a of the adjacent H-shaped steel 611 so as to abut against the outer periphery of the splice plates 71.

[0040] As a result, even if the bolts 72 are removed and the vertical frame 61 is disassembled, when reassembling, the splice plate 71 is positioned so that its outer periphery abuts the rotation suppression member 73, and then bolted together. This makes it possible to construct the vertical frame 61 while ensuring assembly precision without performing the measurement work described above.

[0041] The rotation prevention member 73 fixed to the H-shaped steel 611 in this way not only prevents rotation between adjacent H-shaped steels 611, but can also function as a positioning member for the splice plate 71 when the bolts 72 are removed, disassembled, and reassembled.

[0042] Therefore, for example, in a factory, the rotation suppression members 73 are fixed in advance in appropriate positions of the H-shaped steel 611 (i.e., positions that will not cause relative rotation between the members when adjacent H-shaped steels 611 are joined) using the above procedure. After that, the vertical frame 61 is carried in a disassembled state to the construction site, and workers can assemble the vertical frame 61 using a simple procedure similar to that of normal bolt joining, omitting the measurement work, and still ensure assembly precision.

[0043] The work of joining the H-shaped steel 611 provided with the rotation inhibiting members 73 to construct the vertical frame 61 may be carried out with the H-shaped steel 611 in a laid-down position, but it is also possible to construct it in an upright position by utilizing the excavation trench 10. If it is constructed in an upright position, the erection work required when constructing it in a laid-down position can be omitted.

[0044] This makes it possible to avoid bending and twisting that are likely to occur during erection, and to maintain the assembly precision. Below, we will explain the procedure for assembling the vertical frame 61 in an upright position using the excavation trench 10 to construct the ultrasonic measurement device stand 6 and installing the ultrasonic trench wall measurement device 1 in the excavation trench 10, with reference to Figure 10.

[0045] <<Procedure for constructing the vertical frame 61 in an upright position, and procedure for installing the ultrasonic trench wall measuring device 1 in the excavation trench 10>> First, the vertical frame 61 is assembled in a factory or the like using the procedure explained with reference to Figures 8 and 9, and the rotation suppression members 73 are fixed to appropriate positions on the H-shaped steel 611. After that, these are disassembled and transported to the construction site. At this time, the H-shaped steel 611 equipped with the sensor mount 62 and the H-shaped steel 611 to be connected thereto are formed to a size and shape that allows transportation by vehicle.

[0046] Next, as shown in Figure 10(a), an H-shaped steel 611 equipped with a sensor mount 62 is hung into the excavation trench 10 and supported on the ground surface, for example, by providing a support jig on the ground surface. At this time, the tip of the sensor mount 62 is directed toward the open-cut excavation section 102. It is also advisable to wrap the wire 4 equipped with the ultrasonic sensor 2 around the first sheave 621 and second sheave 622 of the sensor mount 62.

[0047] After the H-shaped steel 611 equipped with the sensor mount 62 is supported on the ground surface, for example, the H-shaped steel 611 to be added is hung above it and positioned with the end faces 611c of each steel facing each other with a gap between them, as shown in Figure 10(b). Near these facing end faces 611c, rotation suppression members 73, which have been fixed in advance, are secured to the flanges 611a.

[0048] Therefore, the rotation suppressing member 73 is used as a positioning member, and the splice plate 71 is placed on the flange 611a so that the outer circumferential edge abuts against it. After this, as shown in Fig. 5(b), the adjacent flanges 611a are bolted together using the splice plate 71. Furthermore, as shown in Fig. 5(a), the splice plate 71 is also placed on the web 611b, and the adjacent webs 611b are bolted together.

[0049] 10(c), a joint structure 7 is provided between the H-shaped steel 611 equipped with the sensor mount 62 and the H-shaped steel 611 added thereto, thereby constructing the vertical frame 61. As described above, the vertical frame 61 is in a state where assembly accuracy is ensured even without carrying out measurement work, so the measurement work is omitted and a traveling device 63 is provided at the upper end of the H-shaped steel 611.

[0050] In this way, since measurement work can be omitted, even when the upper end of the openwork section 102 in the excavation trench 10 is deep and a large number of H-shaped steel beams 611 need to be added to construct the vertical frame 61, it is possible to efficiently construct the vertical frame 61 while maintaining assembly accuracy and significantly reducing work time.

[0051] <<Procedure for installing the ultrasonic trench wall measuring device 1 in the excavation trench 10 and performing trench wall condition confirmation work>> The vertical frame 61 and ultrasonic measurement device stand 6 are constructed using the above procedure, and by landing them, the ultrasonic trench wall measurement device 1 can be installed in the excavation trench 10 as shown in Figure 1. As explained with reference to Figure 3, the ultrasonic trench wall measurement device 1 installed in the excavation trench 10 can insert the sensor stand 62 into the openwork section 102 by running the ultrasonic measurement device stand 6 via the running device 63, and the ultrasonic sensor 2 can be easily positioned at the desired position within the openwork section 102.

[0052] Then, after placing the ultrasonic sensor 2 at a desired position in the openwork portion 102, the wire 4 is let out at a constant speed to lower the ultrasonic sensor 2 toward the bottom of the groove, while repeating the process of measuring the horizontal distance to the groove wall 101 with the ultrasonic sensor 2, as described with reference to Figure 2. At the same time, the horizontal distance between the end face perpendicular to the groove wall 101 and the ultrasonic sensor 2 is also measured.

[0053] According to this procedure, by adjusting the member length of the H-shaped steel 611 to correspond to the height limit of the construction site, the vertical frame 61 can be constructed using the excavation trench 10 when the construction site is in a low-headroom environment. Therefore, even when the underground obstacle F is located deep and the member length of the vertical frame 61 is long, it is possible to use the ultrasonic trench wall measuring device 1 to carry out work to check the trench wall condition of the excavation trench 10, including the openwork portion 102.

[0054] <Accuracy verification experiment> The following accuracy verification experiment was carried out to verify the assembly accuracy of the above-mentioned vertical frame 61. The procedure of the experiment is as follows.

[0055] First, the H-shaped steel 11 equipped with the sensor mount 62 and the H-shaped steel 611 to be added thereto are joined by bolts using splice plates 71, following the procedure described with reference to Figures 8 and 9, to construct the vertical frame 61. After this, as shown in Figure 6(b), rotation suppression members 73 that abut against the outer peripheral edges located above and below the splice plates 71 are fixed to each H-shaped steel 611, and the vertical frame 61 is then dismantled.

[0056] Next, as explained with reference to Fig. 10, the H-shaped steel 11 with the disassembled sensor mount 62 and the H-shaped steel 611 to be added were joined in the excavation trench 10 to construct the vertical frame 61 having the joint structure 7. After this, they were raised to the ground, and the assembly accuracy of the vertical frame 61 was confirmed using a transit. As shown in Figs. 6(b) and (c), the amount of bending ΔL2 in the direction parallel to the flange 611a of the H-shaped steel 611 and the amount of bending ΔL3 in the direction parallel to the web 611b were calculated. The member length of the vertical frame 61 was 14 m.

[0057] This process of disassembling and reassembling the components and then measuring the bending amounts ΔL2 and ΔL3 in two directions was repeated twice, and it was confirmed that the average bending amount ΔL2 in the direction parallel to the flange 611a shown in Fig. 6(b) was less than 1.0 mm, indicating that almost no bending had occurred. Furthermore, the average bending amount ΔL3 in the direction parallel to the web 611b shown in Fig. 6(c) was also sufficiently small at around 3 to 4 mm, confirming that high assembly precision was ensured.

[0058] As described above, by adopting a long-member joining structure 7 and joining H-shaped steel 611 to assemble a vertical frame 61 and constructing a stand 6 for an ultrasonic measuring device, it is possible to prevent positional deviations at the suspension position of the ultrasonic sensor 2 suspended by the wire 4 due to the assembly accuracy of the vertical frame 61, making it possible to carry out highly reliable work of checking the condition of the groove wall.

[0059] It goes without saying that the joining structure 7 of long members and the ultrasonic groove wall measuring device 1 of the present invention are not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention.

[0060] For example, in this embodiment, the rotation inhibiting member 73 is provided only on the flange 611a of the H-shaped steel 611, but it may also be provided on the web 611b of the H-shaped steel 611. Also, although the H-shaped steel 611 is used as a long member, it may be used for any member that can be joined by bolt joining using the splice plate 71.

[0061] Furthermore, the joining structure 7 for long members has been explained using the example of joining adjacent H-shaped steel 611 in the longitudinal direction, but it can also be applied when joining long members arranged so that their axes intersect on the same plane, such as the corners of a frame.

[0062] Furthermore, the bolt holes provided in splice plate 71 are configured to have a play that is approximately 2 mm larger than the outer diameter of commonly used bolts 72. However, this is not limitative, and the play of the bolt holes near the outer periphery that abuts against rotation inhibiting member 73 may be reduced to approximately 0.5 mm.

[0063] In addition, the vertical frame 61 provided on the ultrasonic measuring instrument stand 6 does not have to be made up of H-shaped steel 611 arranged in parallel with gaps between them, and any structure that allows the length of the member to be adjusted by adding H-shaped steel 611 may be used.

[0064] In addition, Figures 8 and 9 show an example in which leveling work is performed using a level 22 and a staff 23, and centering work is performed using a transit 24, but these measurement work may be performed using either means. [Explanation of symbols]

[0065] 1. Ultrasonic groove wall measuring device 2 Ultrasonic sensors 3 Lifting equipment 4 wire 5 Ultrasonic measuring device 51 Wire Drum 6 Ultrasonic measuring device stand 61 Vertical Frame 611 H-beam (long member) 612 Connecting member 62 Sensor stand 621 1st Sheave 622 Second Sheave 7 Joint structure 71 Connection plate 72 volts 73 Rotation prevention member 74 Plate 8 Installation stand 10 Excavation trench 101 Groove Wall 102 Openwork Excavation Section 21 Mounting stand 22 levels 23 Leveling rod 24 Transit F. Underground obstacles

Claims

1. An ultrasonic trench wall measurement device for measuring a distance to a trench wall of an excavation trench including a perforated portion, an ultrasonic measuring device stand suspended in the excavation trench; and an ultrasonic sensor suspended in the excavation trench via a wire wound around the ultrasonic measuring device stand; The ultrasonic measuring device stand comprises: A vertical frame including a plurality of longitudinally adjacent elongated members joined using a joining structure including a splice plate and a pair of rotation suppressing members; a sensor stand that is cantilevered relative to the vertical frame and has a sheave at its tip that guides the wire vertically downward; Adjacent elongated members are arranged with a gap between opposing end faces, the splice plates are disposed on the adjacent elongated members across the gap, An ultrasonic groove wall measurement device characterized in that a pair of the rotation suppression members are integrally provided near the ends of each of the adjacent elongated members, facing each other across the splice plate and in contact with the outer peripheral edge of the splice plate, in a position that suppresses relative rotation between the adjacent elongated members.

2. 2. A method for constructing the ultrasonic groove wall measurement device according to claim 1, comprising: After the elongated member equipped with the sensor mount is lowered into the excavation trench, The elongated member to be newly added is hung down above the elongated member so that the end faces of the elongated member face each other with a gap therebetween, the rotation inhibiting members provided on the elongated members are used as positioning members, and the splice plates are disposed on the adjacent elongated members across the gap so that the outer peripheral edges of the splice plates contact the rotation inhibiting members; A method for constructing an ultrasonic groove wall measuring device, characterized in that the vertical frame is constructed by joining adjacent elongated members using the splice plate.

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