JP5069611B2 - Groundwater level measuring device and inspection cable insertion method - Google Patents

Description

  The present invention relates to a groundwater level measuring device that can be inserted while protecting an inspection cable with respect to an inspection hole excavated in the ground, and an inspection cable insertion method.

  Conventionally, as a method for detecting the tendency of ground liquefaction, there is a detection method disclosed in Patent Document 1. In this detection method, an inspection hole is excavated in the ground to be inspected, and an inspection cable having a detection probe at the tip is inserted into the inspection hole to detect the degree of liquefaction inside the ground. The periphery of the inspection cable is protected by a cylindrical inner tube so as to prevent buckling of the inspection cable. A cylindrical outer tube is inserted into the inspection hole to prevent the inspection hole from collapsing. That is, the detection probe and the inspection cable are protected by a double structure of the inner tube and the outer tube.

JP 58-68656 A

  However, in the detection method, when the detection probe reaches a desired depth, an inner tube having the same length as the depth is required, which is not only costly in manufacturing the inner tube but also has poor transportability. Had.

  The groundwater level measuring device of the present invention includes an outer tube inserted into an inspection hole excavated in the ground, an inner tube that can be inserted through the outer tube, and an inner tube that is inserted into the inner tube and inserted into the inspection hole. An inspection cable having a detection probe for detecting the condition of the ground at the tip, a chuck unit for holding or releasing the outer tube, the inner tube, and the inspection cable as necessary, and the chuck unit are attached to the lifting motor. A lifting platform that can be moved up and down along the column by driving, a cable holder that holds or releases the inspection cable as necessary, calculates the lifting amount of the lifting table, and analyzes the data detected by the detection probe And a control unit for determining a situation inside the ground.

  In addition, the inspection cable insertion method of the present invention lowers the lifting / lowering table while the chuck unit attached to the lifting / lowering table that can be moved up and down along the column holds the outer tube, the inner tube, and the inspection cable. When the outer tube, the inner tube, and the inspection cable are inserted into the holes and the lifting platform is lowered to a predetermined position, the outer tube is separated from the chuck unit and the inspection cable is released, and the chuck unit is released. The inspection cable can be held or released by the inspection cable and is held by a cable holder attached to the support column. The inspection platform is raised with the inspection cable staying in the inspection hole. When raised to a predetermined position, the inspection cable is released from the cable holder, and the released inspection cable is released from the chuck unit. In a state of holding by preparative lowers the elevation frame, and wherein inserting the test cable to the inspection hole.

  According to the present invention, it is possible not only to automatically insert the inspection cable to a desired depth, but also the inner pipe moves up and down with the vertical movement of the lifting platform, and the inspection cable is inserted into the inner pipe. In this state, the inspection cable is inserted to a desired depth. Therefore, the length of the inner tube necessary to protect the inspection cable from the insertion resistance generated during the insertion process of the inspection cable is not required by the desired depth, and the transportability and storage property can be improved. In addition, it is possible to provide an inexpensive groundwater level measuring device.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. In FIG. 1, 1 is a groundwater level measuring device of the present invention. This groundwater level measuring device 1 employs an electric exploration method which is an example of a physical exploration method, and estimates the structure of underground geology and the like from an electric resistance value. Specifically, an inspection probe 2a is attached to the tip of the inspection cable 2 shown in FIG. 1, and a plurality of electrodes (not shown) are attached to the inspection probe 2a. The inspection cable 2 with the inspection probe 2a attached to the tip is inserted into a pre-drilled inspection hole H as shown in FIGS. 3 to 8, and the current is passed between the electrodes of the inspection probe 2a when attached to the tip. Thus, a potential difference is generated, and these detection data are transmitted to a control unit (not shown) through an inspection cable, and an electric resistance value can be calculated from the current and the potential difference. Since this electrical resistance value varies greatly depending on the type of formation and the presence or absence of groundwater, the underground situation is determined by performing analysis based on these values.

  The inspection cable 2 is inserted into a long tube having a double structure composed of an outer tube 3 and an inner tube 4 shown in FIGS. The outer tube 3 is inserted into the inspection hole H and is configured to prevent the inspection hole H formed by excavating the ground from collapsing. Further, an inner tube 4 formed sufficiently longer than the outer tube 3 is inserted into the outer tube 3, and the inspection cable 2 is inserted into the inner tube 4. Since the inspection cable 2 is inserted into the inner tube 4 in this way, the inspection cable 2 is not easily buckled and damaged by the insertion resistance, and a sufficient insertion thrust can be transmitted to the inspection cable 2 so that the insertion depth can be increased. It becomes possible to set deeply.

  The groundwater level measuring device 1 includes a column 6 attached to a stand 5 so as to stand on the ground surface, an elevator 7 that can be moved up and down along the column 6, and a chuck unit 10 that is attached to the elevator 7. And a lifting unit 30 that lifts and lowers the lifting platform 7. The chuck unit 10 includes a tube chuck 11 that holds the outer tube 3 and the inner tube 4, and a cable chuck 20 that can be manually operated to hold and release the inspection cable 2.

  As shown in FIG. 1, the elevating unit 30 includes an elevating motor 31 as an elevating drive source installed at the rear part of the elevating platform 7, and the elevating motor 31 extends along the support column 6. A sprocket (not shown) is rotated along an endless chain 8 arranged vertically, and the elevator 7 is configured to move up and down as the sprocket rotates. In addition, an encoder (not shown) is attached to the rotating shaft of the sprocket to detect the amount of rotation of the sprocket, and is configured to detect a pulse signal generated along with the rotation of the sprocket. . By analyzing the pulse signal output from the encoder by a control unit (not shown), the moving distance of the lifting platform 7 is obtained, and accordingly, it is held by the cable chuck 20 of the chuck unit 10 attached to the lifting platform 7. The amount of inspection cable 2 that is inserted into the ground is required.

  As shown in FIG. 2, the tube chuck 11 has a cylindrical shape, and includes a guide sleeve 12 attached to the upper surface of the lifting platform 7 so that the rear end is suspended below the lifting platform 7. A spring 13 is fitted on the outer periphery of the guide sleeve 12, and a cylindrical slide sleeve 14 that is constantly urged upward by the spring 13 is inserted therethrough.

  Near the distal end of the guide sleeve 12, through holes 15 penetrating from the outer periphery to the inner periphery are formed at three locations so as to divide the circumference into three, and steel balls 16 operate in the through holes 15 respectively. It is stored as possible. Further, a disc-shaped stopper 17 having a hole having the same diameter as the inner diameter of the guide sleeve 12 is provided at the tip of the guide sleeve 12 so as to protrude in the outer peripheral direction. Further, the inner peripheral surface of the slide sleeve 14 has an inner hole having a slightly larger diameter than the outer peripheral surface of the guide sleeve 12 formed from the lower surface, and an inner hole having a larger diameter formed continuously at the upper portion of the inner hole. The steel ball 16 located in the through hole 15 of the guide sleeve 12 is moved from the through hole 15 by sliding the slide sleeve 14 downward along the outer periphery of the guide sleeve 12. It is configured so that it can operate to the extent that it does not fall out.

  As shown in FIG. 2, the guide sleeve 12 is configured to insert the distal end of the outer tube 3 at the rear end thereof and hold the outer tube 3 in the vicinity of the rear end. As a specific method for holding the outer tube 3, a through hole 18 is formed in the rear end of the guide sleeve 12 from the outer periphery to the inner periphery, and a locking pin 19 is inserted therein. With the front end of the outer tube 3 inserted in the vicinity of the rear end of the guide sleeve 12, a locking hole 3a is formed from the outer periphery to the inner periphery at the upper end of the outer tube so as to be continuous with the through hole 15 of the guide sleeve 12. The outer tube is held by connecting the through hole 18 and the locking hole 3a and inserting the locking pin 19.

  As shown in FIG. 2, the tube chuck 11 holds the inner tube in a state where the inner tube is inserted from above and the tip of the inner tube 4 protrudes a predetermined amount above the tube chuck 11. It is configured as follows. A locking groove 4a is cut into the upper portion of the inner tube 4 by dividing the outer periphery into three equal parts, and a steel ball 16 in the guide sleeve 12 can be fitted. When holding the inner tube 4, first, the slide sleeve 14 of the tube chuck 11 is pulled down along the guide sleeve 12, and the steel ball 16 is moved in the through hole with the stepped shape of the inner peripheral surface of the slide sleeve 14. Next, the inner tube 4 is inserted into the guide sleeve 12, the inner tube 4 is positioned in the guide sleeve 12 near the end where the locking groove 4 a of the inner tube 4 is cut, and the slide sleeve 14 is opened while the inner tube 4 is opened. 4 is rotated, the steel ball 16 and the locking groove 4a of the inner tube 4 are engaged with each other, and the slide sleeve 14 is moved upward by the force of the spring 13, and the inner periphery of the guide sleeve 12 is moved. The through-hole 15 is covered, the steel ball 16 is made inoperable, and the inner tube 4 is held.

  As shown in FIG. 2, the cable chuck 20 is attached to the upper end of the tube chuck 11 so as to hold the upper end of the inner tube 4 held in a state of protruding a predetermined amount from above the tube chuck 11. It is attached and configured to hold the inspection cable 2 protruding from the upper opening of the inner tube 4. As a method of holding the inspection cable 2 by the cable chuck 20, the cable chuck 20 is configured such that two stays 21 having a structure in which the tips are engaged with each other are coupled by a shaft 22, and the stays 21 are opened and closed as the lever 23 is operated. The inspection cable 2 is inserted between the stays 21 and the lever 23 is operated to hold the inspection cable 2.

  A cable holder 40 shown in FIGS. 3 (a) and 3 (b) is attached to the upper end of the column 6, and this cable holder 40 is located above the cable chuck 20 and above the inner tube 4. The inspection cable 2 protruding from the opening is constrained or released. The cable holder 40 includes a cable holding groove 41 extending in the same line as the extending direction of the inner tube 4, and the inspection cable 2 is fitted in the cable holding groove 41 so that the shaft 42 can be opened and closed as a fulcrum. The clamp lever 43 is operated to restrain or release the inspection cable 2. In addition, the cable holder 40 includes a holding member 45 that is always urged by the spring 44 to the clamp lever 43. As shown in FIG. 3B, the cable holder 40 holds the clamp lever 43 in a closed state. The inspection cable in which the member 45 is fitted in the holding groove 41 is pressed from the outer peripheral side, and in this state, the locking pin 47 is inserted into the engagement hole 46 formed in the clamp lever, and the inspection cable 2 It is comprised so that it may restrain.

  Hereinafter, a method for inserting the inspection cable 2 in the groundwater level measurement device 1 of the present invention will be described. FIG. 4 is a diagram showing a state immediately before operating the lifting platform 7 of the groundwater level measuring device 1. At this time, the inspection cable 2 is detached from the cable holder 40, while the inspection cable 2 is attached to the cable chuck 20. Is retained. From this state, when the elevating motor 31 is operated to lower the elevating table 7, the outer tube 3 and the inner tube 4 held by the tube chuck 11 of the chuck unit 10 and the cable chuck 20 of the chuck unit 10 are connected. The held inspection cable 2 is inserted into the inspection hole H. When the outer tube 3, the inner tube 4, and the inspection cable 2 continue to be inserted into the inspection hole H as the elevating table 7 is lowered, they reach the position shown in FIG. The lowest point.

  When the lifting platform 7 reaches the position shown in FIG. 5, the operator engages the outer tube 3 and the guide sleeve 12 of the tube chuck 11 as shown in FIG. 6. 19 is removed. On the other hand, on the descending track of the outer tube 3, there is located a regulating tube 5 a that is attached to the stand 5 and can be inserted through the outer tube 3. 3b is attached. Therefore, in the outer tube 3 removed from the tube chuck 11, the regulating member 3b of the outer tube 3 comes into contact with the regulating tube 5a as shown in FIG. 6, and the outer tube 3 does not descend below this position. ing. In addition, at the position shown in FIG. 6, the operator fixes the inspection cable 2 to the cable holder 40 and operates the cable chuck 20 of the chuck unit 10 to release the holding of the inspection cable 2 by the cable chuck 20. .

  FIG. 7 shows a state in which the elevator 7 is raised after this operation is completed. In the state shown in FIG. 7, the outer tube 3 remains in the position shown in FIG. 6, and the inner tube 4 is fixed to the tube chuck 11. It rises from the position to the position shown in FIG. Further, the inspection cable 2 is removed from the cable chuck 20 and is held by the cable holder 40, so that it does not move up and down and remains at the position shown in FIG.

  Thereafter, as shown in FIG. 8, the inspection cable 2 is removed from the cable holder 40, and the elevator 7 is lowered again while being held by the cable chuck 20. Then, the lifting platform 7 reaches the position shown in FIG. 5 again. The inspection cable 2 is inserted to a desired depth by repeating the lifting and lowering operations of the lifting platform shown in FIGS. 5, 6, 7, and 8. According to such a method of inserting the inspection cable 2, the inspection cable 2 is inserted between the lifting platform 7 and the opening surface of the inspection hole H with the inner tube 4 always protecting the inspection cable 2. Therefore, even if the inner tube 4 is not as long as the insertion depth of the inspection cable 2, the inspection cable 2 can always be protected from buckling when the inspection cable 2 is inserted, and damage can be avoided.

It is a front view of the groundwater level measuring device of the present invention. It is a principal part expanded sectional view of the groundwater level measuring apparatus of this invention. It is a plane view expanded sectional view of the groundwater level measuring device of the present invention, (a) shows the state where the inspection cable by the cable holder was restrained, and (b) shows the state where the inspection cable was released. It is operation | movement explanatory drawing of the groundwater level measuring apparatus of this invention, and is a figure which shows the state just before operating a lifting platform. It is operation | movement explanatory drawing of the groundwater level measuring apparatus of this invention, and is a figure which shows the state which the lifting platform reached the lowest point. It is operation | movement explanatory drawing of the groundwater level measurement measure of this invention, and is a figure which shows the state just before raising the lifting platform which reached the lowest point. It is operation | movement explanatory drawing of the groundwater level measurement measure of this invention, and is a figure which shows the state which the lifting platform reached | attained the highest point. It is operation | movement explanatory drawing of the groundwater level measuring apparatus of this invention, and is a figure which shows the state which descends again the raising / lowering stand which reached the highest point.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Groundwater level measuring device 2 Inspection cable 2a Inspection probe 3 Outer tube 3a Locking hole 3b Restriction member 4 Inner tube 4a Locking groove 5 Stand 5a Restriction tube 6 Post 7 Lifting stand 8 Endless chain 10 Chuck unit 11 Tube chuck
12 Guide sleeve 13 Spring 14 Slide sleeve 15 Through hole 16 Hard ball 17 Stopper 18 Through hole 19 Locking pin 20 Cable chuck 21 Stay 22 Shaft 23 Lever 30 Lifting unit 31 Lifting motor 40 Cable holder 41 Cable holding groove 42 Shaft 43 Clamp lever 44 Spring 45 Holding member 46 Engagement hole 47 Locking pin


H Inspection hole G Ground

Claims (2)

An outer tube inserted into an inspection hole excavated in the ground;
An inner tube that can be inserted into the outer tube;
An inspection cable having a detection probe inserted into the inner tube and detecting the state of the ground by being inserted into the inspection hole;
A chuck unit for holding or releasing the outer tube, the inner tube, and the inspection cable as necessary;
This chuck unit is attached, and a lifting platform that can be moved up and down along the column by driving a lifting motor;
A cable holder for holding or releasing the inspection cable as necessary;
A groundwater level measuring device, comprising: a control unit that calculates the amount of lifting of the lifting platform and analyzes data detected by the detection probe to determine a situation inside the ground. With the chuck unit attached to the lifting platform that can be moved up and down along the column holding the outer tube, the inner tube, and the inspection cable, the lifting table is lowered, and the outer tube, the inner tube, and the inspection cable are inserted into the inspection hole. Insert
When the lift is lowered to a predetermined position, the outer tube is separated from the chuck unit and the inspection cable is released. The inspection cable released from the chuck unit can hold or release the inspection cable, and The elevator is raised with the inspection cable staying in the inspection hole while being held by the cable holder attached to the column, and when the elevator is raised to a predetermined position, the inspection cable is removed from the cable holder. An inspection cable insertion method, wherein the inspection cable is inserted into the inspection hole by lowering the lifting platform in a state where the inspection cable is released and held by the chuck unit.

Images