JP2006161488A - Injection pressure measuring device in grouting, and method of connecting/disconnecting signal lead wire of pressure sensor and signal cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of directly measuring injection pressure to be controlled within an injection section even for a small-diameter injection hole. <P>SOLUTION: A pressure sensor 57 is disposed at the lower end of an air packer provided at the tip of an injection rod so that pressure in the injection section can be directly measured. The device is provided with a lower housing 45 screw-connected to the lower end of a packer hose 40; a flange mounted with the pressure sensor; and a housing having a pocket part for enclosing the head of the pressure sensor. The lower housing and the housing have through holes for the lead wire of the pressure sensor to pass through. The flange is disposed at the lower part of the housing, and the flange and the housing are jointly fastened to the lower face of the lower housing by a bolt. When assembling the lower housing, flange and housing, the through holes of both housings are put in communication with each other, and the signal lead wire is allowed to pass through in a longitudinal direction through the through holes. When disassembling the lower housing, flange and housing, the signal lead wire is pulled out in the longitudinal direction through the through hole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a device for measuring an injection pressure in an injection section during grouting of an injection solution such as cement milk in a dam foundation work, and a method for connecting / disconnecting a signal lead wire of a pressure sensor and a signal cable.

A grout injection system for injecting an injection solution such as cement milk is known for strengthening the dam foundation rock and ground or for stopping water.
FIG. 7 shows an example.
The injection liquid such as cement milk well mixed in the grout mixer 100 is injected into the rock to be injected through the return valve 102, the electromagnetic flow meter 103, and the pressure gauge 104, which returns part of the injection liquid to the grout mixer 100 by the grout pump 101. It is pumped into an injection section 109 partitioned by an air packer 108 below the injection hole 106 drilled in the ground, and injected into a crack 110 protruding from the injection rod 107 to the hole wall.

The pressure of the injection liquid and the injection flow rate in the injection section 109 are determined by the properties of the rock and the ground investigated in advance. The pressure and amount of the injected liquid are measured by the electromagnetic flow meter 103 and the pressure gauge 104 placed on the ground, and are managed by the management device 105.
The problem with this injection system is the injection pressure. Originally, the pressure in the injection section 109 should be directly measured and managed, but since a measuring device that can withstand practical use has not been developed, the depth from the ground surface of the injection section 109 position, the groundwater level surface The pressure is controlled by taking into account the correction pressure calculated from the depth of the pipe and the pipe resistance on the way. In particular, since the pipe resistance varies greatly depending on the thickness and length of the pipe and the surface properties, the error of the correction pressure cannot be avoided.

In particular, as shown in Patent Document 1, a pulsation pressure generating device is additionally installed on the downstream side of the electromagnetic flow meter in the grout injection system shown in FIG. A system that significantly increases injection efficiency by applying a pulsating pressure with an amplitude of about 0.5 to 2 MPa is being put into practical use. In this infusion system, it is very important to accurately manage the amplitude of the pulsating pressure within the infusion section.
Japanese Patent Laid-Open No. 2004-197305

However, the correction value of the amplitude of the pulsation pressure must be calculated in consideration of the rigidity of the pipeline in the middle, the body elastic modulus of the injected liquid, the volume of the injected liquid in the injection section, etc. in addition to the above-described factors. The correction error becomes extremely large, and there is no way other than directly measuring the injection pressure in the injection section to accurately measure the injection pressure in the injection section.
In this sense as well, it is possible to measure not only the 66mm diameter injection hole used in dam foundation work, but also a small 46mm diameter injection hole, and it is compact, inexpensive, reliable and easy to handle. Development of internal pressure devices is awaited.

  The present invention has been made in order to meet such a conventional demand, and its purpose is to measure the injection pressure in the injection section directly on the ground instead of directly measuring the injection pressure at the time of grouting to the injection hole as in the prior art. The device that can directly measure the injection pressure to be controlled in the injection section, even for a small-diameter injection hole, and the signal lead of the pressure sensor It is to provide a method for connecting / disconnecting a wire and a signal cable.

The invention according to claim 1 is characterized in that a pressure sensor capable of directly measuring the pressure in the injection section of the injection hole is arranged at the lower end portion of the air packer provided at the tip of the injection rod.
According to a second aspect of the present invention, there is provided a lower housing screwed to the lower end of the packer hose, a flange having a pressure sensor capable of directly measuring the pressure in the injection section of the injection hole, and a pocket for accommodating the head of the pressure sensor. A housing having a portion, the lower housing and the housing have a through hole through which a signal lead wire of the pressure sensor passes, and the flange and the housing are arranged with the flange at a lower portion of the housing. Bolts are fastened to the lower surface of the lower housing with bolts, and when the lower housing, the flange, and the housing are assembled, the through holes of both housings communicate with each other, and the signal leads are passed through the through holes. When the lower housing, the flange, and the housing are disassembled, the wire passes through the longitudinal direction. Then, the signal lead wire is pulled out in the longitudinal direction.

  The invention according to claim 3 is an upper housing screwed to the lower end of the injection rod, a packer hose screwed to the lower end of the upper housing, a lower housing screwed to the lower end of the packer hose, and the upper housing A center tube disposed at one end of the inner passage of the packer hose and the lower housing, a flange attached with a pressure sensor capable of directly measuring the pressure in the injection section of the injection hole, A housing having a pocket for accommodating the head of the pressure sensor, wherein the upper housing has a signal cable lead-out port connected to the signal lead wire of the pressure sensor, an air packer air supply / discharge port, and a signal cable through-hole. And an air passage, and the signal cable through hole has the signal cable and the signal A connection portion with a lead wire is formed, and the packer hose has a gap in the longitudinal direction between the center tube and the internal passage for passing the signal lead wire communicating with the signal cable through hole, The lower housing and the housing have a through hole through which the signal lead wire passes, and the flange and the housing are arranged on the lower surface of the lower housing with bolts by placing the flange at the lower portion of the housing. When assembling the lower housing, the flange, and the housing, the through holes of both housings are communicated, the signal lead wires are passed through the through holes in the longitudinal direction, and the lower housing and the housing are When disassembling the flange and the housing, the signal lead wire is pulled out in the longitudinal direction through the through hole.

  According to a fourth aspect of the present invention, in the grouting injection pressure measuring device according to any one of the first to third aspects, the tip portion comprising the flange and the housing is disposed inside the packer hose. The injection solution passage inside the center tube is branched into a plurality of passages, and the passages of the plurality of passages have the same passage cross-sectional area, and the sum of their cross-sectional areas is smaller than the passage cross-sectional area of the passage of the injection solution Without disposing and at an equal pitch on the same circumference, a discharge port for discharging the injection liquid is formed at the upper part of the injection section of the injection hole, and the pressure sensor is formed at the center of the injection pressure measuring device, It is arranged so as to be surrounded by the plurality of branched passages.

  According to a fifth aspect of the present invention, in the grout injection pressure measuring device according to any one of the second to fourth aspects, a groove for mounting an O-ring and a dust seal is provided on the inner peripheral surface of the internal passage of the lower housing. The center hole of the packer hose is extended through the guide hole, and the center tube through which the injected liquid passes is attached so as to be rotatable and slidable in the longitudinal direction. Between the lower end surface of the center tube and the lower end portion of the center tube, when the packer hose is expanded in the injection hole and when the injection solution is pumped into the injection section, the lower end portion of the center tube is in the guide hole. An interval is provided so as not to reach the lower end surface.

  The invention according to claim 6 is a method for connecting and disconnecting a signal lead wire of a pressure sensor and a signal cable in the grout injection pressure measurement device according to claim 3, wherein when the injection pressure measurement device is assembled, The signal lead wire of the pressure sensor that has passed through the through hole in the injection pressure measuring device and the internal gap of the air packer is pulled out from the signal cable through hole of the upper housing, and connected to a signal cable connected to a measuring instrument on the ground, Next, the connecting portion is pushed into the signal cable through hole, fixed and sealed with a connector, and held in the signal cable through hole. When the injection pressure measuring device is disassembled, the connecting portion is held. The signal cable is pulled out from the signal cable through hole, the signal cable and the signal lead wire are separated, and the signal And the lead wires in a state pushed inside from the signal cable through holes, characterized in that separating the said upper housing being screwed Pakkahosu.

(Function)
In the present invention, a pressure sensor is arranged at the tip of an air packer attached to the lower end of an injection rod inserted into an injection hole so that the pressure-sensitive part directly contacts the injection liquid in the injection section. Several signal lead wires covered with vinyl or Teflon (registered trademark) with a metal wire that transmits the signal coming out of the part pass through the signal lead wire through-hole of the component, the packer hose, and its central part Pass the gap on the outside of the center tube through which the injected liquid is passed, connect the signal lead wire to the signal cable that twists several signal lead wires with the through hole of the air packer upper member, and molds the outside with rubber, From there, the signal cable is pulled out of the air packer and connected to a measuring instrument such as a bridge box or dynamic strain meter on the ground to directly measure the pressure in the injection section without correction. It is Noh.

  By adopting such a structure, the maximum outer diameter of this measuring device is generally used even if a commercially available pressure sensor (strain gauge type 4-bridge type, maximum measuring pressure 10 MPa, mounting screw diameter M8) is used. It is possible to make the maximum outer diameter of the air packer 38 mm. Therefore, the pressure in the injection section of the 46 mm diameter injection hole as well as the 66 mm diameter injection hole generally adopted in dam grouting can be directly measured.

  According to the present invention, it is made compact so that even a small injection hole can be measured, a pressure sensor is attached to the tip of the air packer, and the pressure in the injection section can be directly measured without the need for correction. In addition, by connecting and protecting the connection portion between the signal lead wire of the pressure sensor and the signal cable in the apparatus, a highly reliable measurement system was obtained.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
1 to 5 show an injection pressure measuring device 1 during grouting according to an embodiment of the present invention.
The injection pressure measuring device 1 according to the present embodiment is basically capable of directly measuring the pressure of the injection liquid in the injection section at the tip of a currently marketed grouting air packer (not shown). The pressure sensor 57 is attached, the signal lead wire 57a is passed through the inside of the packer hose 40, is connected to the signal cable 30 in the upper constituent member, and the signal cable 30 is pulled out to the outside. Note that commercially available products are employed for the pressure sensor 57 and the packer hose 40 of the injection pressure measuring apparatus 1 according to the present embodiment, thereby greatly reducing the cost.

  The injection pressure measuring device 1 according to this embodiment includes an upper housing 20 attached to the tip of the injection rod 10, a packer hose 40 attached to the lower end of the upper housing 20, a lower housing 45 attached to the lower end of the packer hose 40, and a lower part. The pressure sensor housing 54 is attached to the lower end of the housing 45, the flange 61 is attached to the pressure sensor housing 54, and the pressure sensor 57 is attached to the flange 61.

The upper housing 20 is screwed to the tip of the injection rod 10 that is suspended from the ground surface in the injection hole.
In the central portion of the upper housing 20, a passage 21 that communicates with the injection liquid passage 11 of the injection rod 10 is formed by being bent into a V shape in the middle. A notch 22 is formed on the outer side of the central portion of the upper housing 20. As shown in FIG. 2, the notch 22 is provided with a signal cable outlet 23 and a packer air supply / exhaust port 24. The signal cable outlet port 23 and the packer air supply / exhaust port 24 communicate with each other via a signal cable through hole 26 and an air passage (not shown) in a pocket portion 25 provided below the signal cable outlet port 23 and the packer air supply / exhaust port 24.

  As shown in FIG. 4, a signal cable connector 27 is screwed to the signal cable outlet 23, and a signal cable 30 that is electrically connected to a measuring instrument on the ground is passed through the center thereof. The inside of the signal cable outlet 23 is sealed with an O-ring 28, and a cap nut 29 is screwed to a signal cable connector 27 on the upper portion of the O-ring 28. A connecting portion 31 between the signal cable 30 and the signal lead wire 57 a of the pressure sensor 57 is held in the signal cable through hole 26.

  A connector 32 is screwed to the packer air supply / exhaust port 24 as shown in FIG. The connector 32 is fitted with an end portion of an air packer vinyl tube 33 connected to a high-pressure air compressor (not shown) placed on the ground, and a narrow tube 34 provided with an air throttle hole 35 at the end portion. The end portion of the air packer vinyl tube 33 is caulked to the connector 32 by a cap nut 37 via a caulking piece 36. The air throttle hole 35 is provided in order to prevent the rubber tube 43 from being damaged by restricting the flow rate of the air supplied to or discharged from the packer hose 40 so that the rubber tube 43 is slowly expanded and contracted.

  A female screw 38 is provided at the lower end of the upper housing 20. An upper base 41 of the packer hose 40 is screwed to the female screw 38. A female screw 39 is provided on the outer peripheral portion of the injection liquid passage 21 at the center of the pocket portion 25 of the upper housing 20. One end 44a of a center tube 44, the inside of which is a passage for the injection liquid, is screwed to the female screw 39, and the center tube 44 penetrates the interior of the packer hose 40 with a slight gap therebetween. The guide hole 46 formed in the center is slidable in the longitudinal direction and the rotational direction.

  Here, the minimum radial gap between the packer hose 40 and the center tube 44 is generated in the upper base 41 and the lower base 42. In the present embodiment, the inner diameter of the packer hose base is 18.5 mm and the outer diameter of the center tube is 16 mm, so the minimum radial gap between the packer hose 40 and the center tube 44 is 1.25 mm. For this reason, twisting a signal lead wire having a wire diameter of 0.7 mm results in 1.4 mm for two wires and 1.8 mm for four wires. . Further, the signal cable 30 has four cores and a wire diameter of 3 mm, and it is impossible to pass it as it is. The only way to pass this is to reduce the outer diameter of the center tube 44 and increase the inner diameters of the upper base 41 and the lower base 42 of the packer hose 40. However, in the former case, it is difficult to further reduce the outer diameter in consideration of an increase in the flow rate of the injected solution and a decrease in the strength of the tube. In the latter case, in order to increase the inner diameter, the outer diameter must be increased. Therefore, measurement with an injection hole having an inner diameter of 46 mm is impossible.

  A lower housing 45 is screwed to the lower base 42 of the packer hose 40. Three grooves 47, 48 and 49 are provided on the inner peripheral surface of the guide hole 46 of the lower housing 45. O-rings 51 and 52 are attached to the two grooves 47 and 48, and a dust seal 53 is attached to the one groove 49. The seals of the injection solution and the high-pressure air and the injection solution to the inside of the packer hose 40 are provided. To prevent foreign material intrusion.

A clearance (gap) is provided between the end surface 44 b of the center tube 44 inserted into the guide hole 46 and the upper end surface 54 a of the pressure sensor housing 54. This is because the packer hose 40 contracts when the packer hose 40 expands and when the hydraulic pressure in the injection section increases as compared to the contraction of the packer hose 40 shown in FIG.
On the outside of the O-ring grooves 47 and 48 and the dust seal groove 49, signal lead wire through holes 50 of the pressure sensor 57 are formed.

A tap hole 66 is formed in the lower surface of the lower housing 45. A flange 61 and a pressure sensor housing 54 are attached to the lower surface of the lower housing 45 by being fastened together with bolts 63 screwed into the tap holes 66. Bolt holes 64 and 65 for screwing the bolt 63 are formed in the pressure sensor housing 54 and the flange 61.
The pressure sensor housing 54 is formed so that the cross-sectional areas of the individual passages are equal downward from the center of the upper surface, and the sum of the total areas thereof is the same as or slightly larger than the inner cross-sectional area of the center tube 44. Several injection liquid branch passages 55 are formed penetratingly formed in a letter shape and arranged at equal pitches on the same circumference. In the present embodiment, since the passage diameter of the center tube 44 is 12 mm, three branch passages having an inner diameter of 7 mm are arranged at a pitch of 120 degrees on the same circumference.

  A pocket portion 56 is provided at the center of the lower surface of the housing surrounded by the plurality of branch passages 55. When the flange 61 and the pressure sensor housing 54 are fastened to the lower housing 45 with bolts 63, the pocket portion 56 can accommodate the head 58 of the pressure sensor 57 attached to the center of the upper surface of the flange 61 by screw connection. It is. As a result, the pressure-sensitive portion 59 faces the bottom surface of the flange 61, and the pressure of the injected liquid in the injection section can be directly measured.

A signal lead wire through hole 60 communicating with the signal lead wire through hole 50 of the lower housing 45 is formed in the upper portion of the pocket portion 56 obliquely upward.
The flange 61 is provided with discharge ports 62 communicating with the respective branch passages 55 of the pressure sensor housing 54. The injection liquid pumped from the ground grout pump is supplied to the passage 11 in the injection rod 10 and the center tube. 44, and is supplied into the injection section from these discharge ports 62.

  In the injection pressure measuring apparatus 1 according to the present embodiment, a structure in which one injection liquid passage is branched into several passages arranged at equal pitches on the same circumference and arranged at the inner central portion of these passages. In order to make the outer diameter of the measuring device as small as possible, the pressure distribution applied to the lower surface of the flange 61 having the injection liquid discharge port 62 is axisymmetric, and the injection pressure measuring device 1 is tilted in the hole. This is to prevent moments from occurring.

  On the other hand, for example, as shown in FIG. 6, if a pressure sensor 57 is attached eccentrically with respect to the axis of the injection pressure measuring device 1 and a single injection liquid passage is provided on the opposite side, the pressure applied to the lower surface This distribution is not axisymmetric, and a moment that tilts the injection pressure measuring device 1 acts, which is likely to cause damage to the rubber tube 43 of the air packer, the signal cable 30, the vinyl tube 33 for the air packer, and the like.

  There are several types of pressure sensors 57, but here, a metal strain gauge pressure sensor that is inexpensive and easily available is employed. The metal strain gauge type pressure sensor has one built-in strain gauge and two lead signal lead wires, and four strain gauges and four lead signal lead wires. In the form, the latter, which does not require a bridge box, was adopted. A commercially available product with a maximum measuring pressure of 10 MPa class, a mounting screw diameter of 8 mm, a head maximum diameter of 15 mm, and an overall height of 24 mm.

Next, an assembly / disassembly method of the injection pressure measuring apparatus 1 according to the present embodiment will be described.
Assembly is performed according to the following procedure.
Two or four strain gauge pressure sensors 57 with a signal lead wire having an appropriate length are screwed and fixed to the flange 61 using the two-surface width 58a of the head 58. These signal lead wires 57 a are connected to the signal lead wire through hole 50 of the lower housing 45 following the signal lead wire through hole 60 of the pressure sensor housing 54, and then the pressure sensor 57 attached to the flange 61. In the state where the head 58 is aligned with the infusion solution branch passage 55 and the bolt through holes 64, 65 provided on the flange 61 and the pressure sensor housing 54, respectively, the center of the lower end of the pressure sensor housing 54 And the flange 61 and the pressure sensor housing 54 are held together. In this state, the signal lead wire through hole 60 of the pressure sensor housing 54 is connected to the signal of the lower housing 45 while preventing the signal lead wire 57a previously passed through the two through holes 60 and 50 from being loosened excessively. The flange 61 and the pressure sensor housing 54 are fastened together and fixed to the lower housing 45 with bolts 63 while being aligned with the lead wire through holes 50.

Next, the signal lead wire 57a that protrudes upward and inside from the through hole 50 of the lower housing 45 is passed through the interior of the packer hose 40 from the bottom to the top, and in this state, the lower housing 45 side is fixed, The lower base 42 of the packer hose 45 is screwed to the lower housing 45 by slowly turning so as not to damage the signal lead wire 57a.
When the screw connection is completed, the end of the signal lead wire 57a is formed into a small eyeball shape so that it can be easily hooked with a hook later, for example. On the circumference of the upper end surface of the upper cap 41 of the packer hose 40 that is just under the signal cable through hole 26 of the upper housing 20 when the screw connection between the upper housing 20 and the upper cap 41 of the packer hose 40 that has been examined in advance is completed. In order to prevent the eyeball-shaped end of the signal lead wire 57a from coming into contact with the thread of the female screw 38 of the upper housing 20 and damaging it when the two screws are joined, Fix the packer hose 40 side. Next, the upper housing 20 to which the center tube 44 is screwed in advance is inserted into the guide hole 46 of the lower housing 45 through the center tube 44 through the inside of the packer hose 40 through which the signal lead wire 57a passes. Slowly turn to screw them together. In this way, the frictional force acting on the outer surface of the signal lead wire 57a passed through the narrow gap between the packer hose 40 and the center tube 44 and the slowly rotating center tube 44 is negligible. The wire 57a is not wound around the center tube 44 or entangled and is not damaged.

  In this state, since the eyeball-shaped end portion of the temporarily secured signal lead wire 57a is located directly below the signal cable through hole 26 of the upper housing 20, a signal is output from the signal cable outlet 23 of the cutout portion 22 of the upper housing 20. For example, a thin wire whose tip is formed in a hook shape is inserted into the cable through hole 26, the hook is hooked on the eyeball at the end of the signal lead wire 57a, and the signal lead wire 57a is pulled out.

The metal lead wires corresponding to the signal lead wire 57a drawn out to the outside and the end portion of the signal cable 30 through which the end portions of the signal nut 57, the O-ring 28, and the connector 27 are passed through the central portion in advance. Connecting. The connection may be made with a plug and socket that can be easily connected and disconnected. However, since the diameter increases, it is desirable to connect with brazing and waterproof.
When the connection between the signal cable 30 and the signal lead wire 57a is completed, the connecting portion 31 is pushed into the signal cable through hole 26 and held. Next, while holding the signal cable 30 and its connecting portion 31 so as not to rotate, the connector 27 passing through the signal cable 30 is screwed into the signal cable outlet 23 into the hole in the center, and then the signal cable 30 is passed in advance. The O-ring 28 is pulled down and fitted into the groove at the top of the connector 27, and the cap nut 29 is tightened into the screw portion at the top of the connector 27. The state after tightening is shown in FIG. By doing so, it is possible to prevent leakage of internal high-pressure air from the outer surface of the signal cable 30, intrusion of external muddy water or injected liquid, and extraction of the signal cable due to internal high-pressure air.

  To connect the notch 22 of the upper housing 20 to the air supply / exhaust port 24 of the air packer vinyl tube 33, first, a connector 32 having a narrow tube 34 having a throttle hole 35 in the center is screwed into the air supply / exhaust port 24. The inner diameter portion of the end portion of the air packer vinyl tube 33 that has passed through the center portion of the cap nut 37 and the caulking piece 36 in advance is fitted into the thin tube 34, and the caulking piece 36 is pulled down until it contacts the upper portion of the connector 32 in this state. Then, the cap nut 37 is tightened to complete the process. The state after assembly is shown in FIG.

  For disassembly, first, the cap nut 29 of the connector 27 of the signal cable 30 is removed, and the cap nut 29 and the O-ring 28 are pulled upward while the signal cable 30 is passed. In this state, the connector 27 is rotated and pulled away from the upper housing 20 while holding the connection portion 31 between the signal cable 30 and the signal lead wire 57a so as not to rotate. Next, the connection portion 31 between the signal cable 30 and the signal lead wire 57 a is pulled out from the signal cable through hole 26, the signal cable 30 and the signal lead wire 57 a are disconnected, and the signal lead wire 57 a is connected to the signal cable through hole 26. The screw connection between the upper housing 20 and the upper cap 41 of the packer hose 40 is separated while being pushed down to the connecting pocket portion 25.

  Thereafter, disassembly may be performed in the reverse order of assembly.

It is a longitudinal section showing an injection pressure measuring device at the time of grouting concerning one embodiment of the present invention. It is AA sectional drawing of FIG. It is a bottom view of FIG. It is sectional drawing of the connector part for signal cable drawer | drawing-out of FIG. It is sectional drawing of the edge part connector of the vinyl tube for air packers of FIG. FIG. 2 is a longitudinal sectional view in which an injection liquid discharge port and a pressure sensor in FIG. 1 are each eccentric. It is a figure showing a general grout injection system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection pressure measuring apparatus 10 Injection rod 11 Injection liquid channel | path 20 Upper housing 21 Channel | path 22 Notch part 23 Signal cable outlet 24 Packer air supply / exhaust port 25 Pocket part 26 Signal cable through-hole 27 Signal cable connector 30 Signal cable 31 Connection part 33 Air packer vinyl tube 34 Narrow tube 35 Air throttle hole 36 Caulking piece 38 Female thread 40 Packer hose 41 Upper base 42 Lower base 43 Rubber tube 44 Center tube 45 Lower housing 46 Guide holes 47, 48, 49 Groove 50 Signal lead wire through hole 51 , 52 O-ring 53 Dust seal 54 Pressure sensor housing 55 Branch passage 56 Pocket portion 57 Pressure sensor 57a Signal lead wire 58 Head 59 Pressure sensing portion 61 Flange 62 Discharge port 63 Bolt 64, 65 Bolt through hole

Claims (6)

  An injection pressure measuring apparatus for grouting, characterized in that a pressure sensor capable of directly measuring the pressure in the injection section of the injection hole is arranged at the lower end of the air packer provided at the tip of the injection rod. A lower housing screwed to the lower end of the packer hose;
A flange equipped with a pressure sensor capable of directly measuring the pressure in the injection section of the injection hole;
A housing having a pocket for accommodating the head of the pressure sensor;
The lower housing and the housing have a through hole through which a signal lead wire of the pressure sensor passes.
The flange and the housing are fastened together with bolts on the lower surface of the lower housing with the flanges arranged at the lower part of the housing,
When assembling the lower housing, the flange, and the housing, the through holes of both housings are communicated, and the signal lead wire is passed in the longitudinal direction via the through holes,
An apparatus for measuring an injection pressure during grouting, wherein when the lower housing, the flange, and the housing are disassembled, the signal lead wire is pulled out in the longitudinal direction through the through hole. An upper housing screwed to the lower end of the injection rod;
A packer hose screwed to the lower end of the upper housing;
A lower housing screwed to the lower end of the packer hose;
One end is fixed to the internal passage of the upper housing, and the center tube is disposed across the internal passages of the packer hose and the lower housing;
A flange equipped with a pressure sensor capable of directly measuring the pressure in the injection section of the injection hole;
A housing having a pocket for accommodating the head of the pressure sensor;
The upper housing has a signal cable outlet connected to the signal lead of the pressure sensor, an air packer air supply / exhaust port, a signal cable through hole, and an air passage.
In the signal cable through hole, a connection portion between the signal cable and the signal lead wire is formed,
The packer hose has a gap in the longitudinal direction through which the signal lead wire communicates with the signal cable through hole, between the center tube and the internal passage.
The lower housing and the housing have a through hole through which the signal lead wire passes,
The flange and the housing are fastened together with bolts on the lower surface of the lower housing with the flanges arranged at the lower part of the housing,
When assembling the lower housing, the flange, and the housing, the through holes of both housings are communicated, and the signal lead wire is passed in the longitudinal direction via the through holes,
An apparatus for measuring an injection pressure during grouting, wherein when the lower housing, the flange, and the housing are disassembled, the signal lead wire is pulled out in the longitudinal direction through the through hole. In the grout injection pressure measuring device according to any one of claims 1 to 3,
The tip of the flange and the housing is branched into a plurality of passages for the injected liquid inside the center tube disposed inside the packer hose, and the plurality of passages are divided into respective passage cross-sectional areas. Equally, the sum of the cross-sectional areas is not made smaller than the cross-sectional area of the passage of the injection liquid, and is arranged at the same pitch on the same circumference, and the discharge liquid is discharged to the upper part of the injection section of the injection hole. Form an exit,
The pressure sensor is disposed at the center of the injection pressure measuring device and surrounded by the plurality of branched passages. The injection pressure measuring device at the time of grouting. In the grout injection pressure measuring device according to any one of claims 2 to 4,
A guide hole having a groove for mounting an O-ring and a dust seal is provided on the inner peripheral surface of the inner passage of the lower housing, and the guide hole is extended through the central portion of the packer hose. The center tube passing therethrough is rotatably and slidably attached in the longitudinal direction, and when the packer hose is expanded in the injection hole between the lower end surface of the guide hole and the lower end portion of the center tube, and the injection section An apparatus for measuring an injection pressure during grouting, wherein an interval is provided so that the lower end portion of the center tube does not reach the lower end surface of the guide hole when the injection solution is pumped into the inside. In the method for connecting and disconnecting the signal lead wire and the signal cable of the pressure sensor in the injection pressure measuring device at the time of grout according to claim 3,
When assembling the injection pressure measuring device, the signal lead wire of the pressure sensor that has passed through the through hole in the injection pressure measuring device and the internal gap of the air packer is pulled out from the signal cable through hole in the upper housing, and measured on the ground. Connected to the signal cable connected to the device, then push the connecting portion into the signal cable through hole, fix and seal with the connector, hold in the signal cable through hole,
When disassembling the injection pressure measuring device, the connecting portion is pulled out from the held signal cable through hole, the signal cable and the signal lead wire are separated, and the signal lead wire is routed through the signal cable. A method of connecting / disconnecting a signal lead wire of a pressure sensor and a signal cable, wherein the upper housing and the packer hose, which are screwed together in a state of being pushed into a hole, are separated.

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