CN111877299A

CN111877299A - High-precision pore water pressure gauge based on sealing membrane

Info

Publication number: CN111877299A
Application number: CN202010781042.9A
Authority: CN
Inventors: 郭万里; 李威; 武颖利; 侯锐; 刘武斌; 朱玥妍; 雷银拴; 李小梅; 席月鹏; 顾行文; 杨汜; 任国峰; 李召阳
Original assignee: Nanjing Hydraulic Research Institute of National Energy Administration Ministry of Transport Ministry of Water Resources
Current assignee: Nanjing Hydraulic Research Institute of National Energy Administration Ministry of Transport Ministry of Water Resources
Priority date: 2020-08-06
Filing date: 2020-08-06
Publication date: 2020-11-03
Anticipated expiration: 2040-08-06
Also published as: CN111877299B

Abstract

The invention relates to a high-precision pore water pressure gauge based on a sealing membrane, which comprises a top cover, an upper shell, a protective shell, a permeable stone, a lower shell, a bottom cover, an external connection line and a pressure sensor, wherein the top cover is connected with the upper shell; the pressure sensor is arranged in the lower shell, the permeable stone is arranged between the upper shell and the lower shell, the protective shell is arranged on the outer side of the permeable stone, and two ends of the protective shell are respectively arranged on the outer sides of the upper shell and the lower shell; the invention adopts the protective shell structure, avoids the direct contact of the permeable stone and the soil body, and the permeable stone is not easy to be silted up and damaged; the vent holes are formed in the top cover, the shell and the upper part of the protective shell, so that air in the pore water pressure gauge can be conveniently discharged, and the measurement accuracy is improved; the flexible film is adopted to wrap the pressure sensor, no air water is filled between the pressure sensor and the flexible film, and pore water is not in direct contact with the pressure sensor, so that the influence of air in the pore water on a measurement result is avoided, and the measurement precision is improved.

Description

High-precision pore water pressure gauge based on sealing membrane

Technical Field

The invention relates to the technical field of engineering monitoring, in particular to a high-precision pore water pressure gauge based on a sealing membrane.

Background

The pore water pressure gauge is a professional device for monitoring the pore water pressure in the fields of engineering construction such as foundation pit engineering, foundation engineering, dam engineering and the like, wherein the monitoring of the underground pore water pressure is carried out in the construction process and after the construction. The most commonly used pore water pressure gauges include a vibrating wire type pore water pressure gauge and an air pressure type pore water pressure gauge, and the principle of the pore water pressure gauge is that pore water penetrates through a water permeable material to act on an induction diaphragm, and then related physical phenomena are induced through the deformation of the induction diaphragm. The vibrating string type pore water pressure gauge is taken as an example, the working principle is that pore water enters through a permeable stone and acts on a sensor pressure sensing membrane, the pressure sensing membrane deforms under the action of pressure to cause vibration of vibrating strings, and the pore water pressure can be obtained through measuring the corresponding response of the vibrating strings and through conversion.

At present, many pore water pressure meters for measuring pore water pressure exist at home and abroad, but the existing pore water pressure meters generally have the following problems:

1. when the existing pore water pressure gauge is embedded in soil, the permeable stone is in direct contact with the soil body, so that the clogging condition is easy to occur, and when the soil pressure is higher, the permeable stone can be damaged;

2. when the existing pore water pressure gauge is used for measuring, pore water in a soil layer permeates through the permeable stone and directly acts on an induction diaphragm of the pressure sensor, and air in the pore water usually has great influence on a measuring result;

3. the existing pore water pressure gauge generally does not consider the exhaust condition, and the air in the pore water pressure gauge is not easy to exhaust, so that the measurement result is influenced;

4. the existing pore water pressure gauge is difficult to disassemble, and the permeable stones are difficult to replace when being blocked and damaged, and the pore water pressure gauge needs to be wholly placed into water for saturation when being saturated.

The problems of the existing pore water pressure gauge directly affect the accuracy of measured data and the convenience of use and operation, so that the development of the high-precision pore water pressure gauge for solving the problems in the prior art is of great significance.

Disclosure of Invention

In view of this, the present application aims to provide a high-precision pore water pressure gauge based on a sealing film, so as to avoid the permeable stone from directly contacting with the soil body, facilitate the discharge of the air inside the pore water pressure gauge, avoid the influence of the gas in the pore water on the measurement result, and improve the measurement precision.

In order to achieve the above object, the present application provides the following technical solutions.

A high-precision pore water pressure gauge based on a sealing membrane comprises a top cover, an upper shell, a protective shell, a permeable stone, a lower shell, a bottom cover, an external connection line and a pressure sensor; the pressure sensor is arranged inside the lower shell;

the permeable stone is arranged between the upper shell and the lower shell, the protective shell is arranged on the outer side of the permeable stone, and two ends of the protective shell are respectively arranged on the outer sides of the upper shell and the lower shell;

the top cover is fixed at one end of the upper shell and one end of the protective shell, and the bottom cover is fixed at one end of the lower shell.

Preferably, upper portion shell, protective housing, permeable stone, lower part shell are the loop configuration, the top cap below is provided with central screw, lower part shell top be provided with the fixed screw hole of central screw, so that upper portion shell, protective housing, permeable stone, lower part shell are together fixed.

Preferably, the protective shell is of a splicing structure and comprises 2 symmetrical half-ring bodies.

Preferably, the protective shell is provided with protrusions and water inlet holes at the periphery of the contact end of the protective shell and the lower shell, and clamping grooves corresponding to the protrusions are formed at the periphery of the lower shell, so that the protective shell is fixedly connected with the lower shell, and the protective shell is ensured to have enough rigidity under the action of soil pressure; the inlet opening is used for realizing that pore water gets into in the protective housing, gets into through the permeable stone and acts on pressure sensor.

Preferably, the lower casing is provided with a plurality of through holes on the one end top surface that is close to the permeable stone to make things convenient for inside water of manometer to circulate from top to bottom.

Preferably, a first exhaust hole is formed in the top cover to facilitate the exhaust of air inside the pressure gauge.

Preferably, the top of upper portion shell is provided with the second exhaust hole all around, be provided with on the protective housing with the third exhaust hole that the second exhaust hole corresponds to make things convenient for the inside air of pressure gauge to discharge.

Preferably, the pressure gauge further comprises a flexible membrane wrapped around the pressure sensor, the gap between the flexible membrane and the pressure sensor being filled with airless water.

Preferably, the pressure sensor comprises a pressure sensing diaphragm, a shell, a permanent magnet and a coil, an iron block, a vibrating wire and a vibrating wire fixing body, wherein the pressure sensing diaphragm is arranged close to the end of the permeable stone.

Preferably, the flexible membrane is not subjected to any tension, and is only used for transmitting the outside pressure to the airless water between the flexible membrane and the pressure sensor, so that the pressure is transmitted by the contact of the airless water and the pressure sensing membrane, and the pressure measurement is completed.

The beneficial technical effects obtained by the invention are as follows:

1) the invention solves the problems in the prior art, adopts the protective shell structure, avoids the direct contact of the permeable stone and the soil body, and prevents the permeable stone from clogging and damaging; the structure is simple, the disassembly is convenient, the reliability is strong, and the applicability is wide;

2) according to the invention, the flexible film is adopted to wrap the pressure sensor, the airless water is filled between the flexible film and the pressure sensor, the pore pressure is measured through the path of pore water-flexible film-airless water-pressure sensor, the pore water is not in direct contact with the pressure sensor, the influence of gas in the pore water on the measurement result is avoided, and the measurement precision is improved;

3) the vent holes are formed in the top cover, the shell and the upper part of the protective shell, so that air in the pore water pressure gauge can be conveniently discharged, and the measurement accuracy can be improved.

The foregoing description is only an overview of the technical solutions of the present application, so that the technical means of the present application can be more clearly understood and the present application can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present application more clearly understood, the following detailed description is made with reference to the preferred embodiments of the present application and the accompanying drawings.

The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic structural diagram of a closed-film based high-precision pore water pressure gauge in one embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of a closed-film based high-precision pore water pressure gauge in one embodiment of the present disclosure;

FIG. 3 is a schematic structural diagram of a top cover in one embodiment of the present disclosure;

FIG. 4 is a schematic structural view of an upper housing in one embodiment of the present disclosure;

FIG. 5 is a schematic structural view of a half-ring of a protective shell according to an embodiment of the disclosure;

FIG. 6 is a schematic view of a permeable stone according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural view of a lower housing in one embodiment of the present disclosure;

FIG. 8 is a schematic view showing the assembly of a top cover, a protective shell, an upper shell, a permeable stone and a lower shell according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of a bottom cover and external wires according to an embodiment of the disclosure.

In the above drawings: 10. a top cover; 101. a first exhaust port; 102. a central screw; 20. an upper housing; 201. a second vent hole; 30. a protective shell; 301. a third vent hole; 302. a protrusion; 303. a water inlet hole; 40. a permeable stone; 50. a lower housing; 501. a threaded hole; 502. a through hole; 503. a card slot; 60. a bottom cover; 70. flexible film, 80, no water; 90. a pressure sensor; 901. a pressure-sensitive film; 902. a housing; 903. a permanent magnet and a coil; 904. an iron block; 905. vibrating wire; 906. a vibrating wire fixing body; 100. and (4) external connection of wires.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. In the following description, specific details such as specific configurations and components are provided only to help the embodiments of the present application be fully understood. Accordingly, it will be apparent to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, descriptions of well-known functions and constructions are omitted in the embodiments for clarity and conciseness.

It should be appreciated that reference throughout this specification to "one embodiment" or "the embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrase "one embodiment" or "the present embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Further, the present application may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, B exists alone, and A and B exist at the same time, and the term "/and" is used herein to describe another association object relationship, which means that two relationships may exist, for example, A/and B, may mean: a alone, and both a and B alone, and further, the character "/" in this document generally means that the former and latter associated objects are in an "or" relationship.

The term "at least one" herein is merely an association relationship describing an associated object, and means that there may be three relationships, for example, at least one of a and B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.

It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion.

Example 1

As shown in fig. 1 and 2, the high-precision pore water pressure gauge based on the closed membrane comprises a top cover 10, an upper shell 20, a protective shell 30, a permeable stone 40, a lower shell 50, a bottom cover 60, an external connection line 100 and a pressure sensor 90.

The permeable stone 40 is arranged between the upper shell 20 and the lower shell 50, the protective shell 30 is arranged outside the permeable stone 40, and two ends of the protective shell 30 are respectively arranged outside the upper shell 20 and the lower shell 50, so that the permeable stone 40 is prevented from directly contacting with the soil body and being silted or damaged under the action of soil pressure.

Further, the upper and

lower housings

20 and 50 are provided with notches at the ends contacting the porous stone 40, so that both ends of the porous stone 40 are fixed in the notches.

The top cover 10 is fixed to one end of the upper case 20 and the protective case 30, and the bottom cover 60 is fixed to one end of the lower case 50 by a screw coupling.

As shown in fig. 3-7, the upper casing 20, the protective casing 30, the permeable stone 40 and the lower casing 50 are all ring-shaped structures.

A central screw 102 is arranged below the top cover 10, and a threaded hole 501 fixed with the central screw 102 is arranged above the lower shell 50, so that the upper shell 20, the protective shell 30, the permeable stone 40 and the lower shell 50 are fixed together.

Further, a groove is formed below the top cover 10, the upper shell 20 and the protective shell 30 are close to one end of the top cover 10, and a fixing ring is arranged at one end of the upper shell 20 and is smaller than a fixing ring of the protective shell 30, so that one ends of the upper shell 20 and the protective shell 30 are fixed in the groove of the top cover 10.

Further, as shown in fig. 8, the protective shell 30 is a splicing structure, and includes 2 symmetrical half-rings, so as to facilitate disassembly and assembly.

Referring to fig. 5, the protective shell 30 is provided with a protrusion 302 and a water inlet 303 around a contact end with the lower shell 50, and a slot 503 corresponding to the protrusion 302 is provided around the lower shell 50, so that the protective shell 30 is fixedly connected with the lower shell 50, and the protective shell 30 has sufficient rigidity under the action of soil pressure; the water inlet 303 is used for allowing pore water to enter the protective shell 30 and act on the pressure sensor 90 through the permeable stone 40.

Furthermore, the protrusion 302 and the clamping groove 503 are both of annular structures, so that the assembly is convenient, and the stability is good after the installation.

Referring to fig. 7, the lower housing 50 is provided with a plurality of through holes 502 on a top surface of an end thereof adjacent to the permeable stone 40 to facilitate the water flow in the pressure gauge.

Further, referring to fig. 3, the top cover 10 is provided with a first vent hole 101 to facilitate the venting of air inside the pressure gauge during use.

Further, referring to fig. 8, second vent holes 201 are formed around the top end of the upper housing 20, and third vent holes 301 corresponding to the second vent holes 201 are formed in the protective housing 30, so that air inside the pressure gauge can be conveniently exhausted when the pressure gauge is used.

Further, the sizes of the first exhaust hole 101, the second exhaust hole 201 and the third exhaust hole 301 are small enough to prevent soil particles from entering and blocking the exhaust holes.

The pressure sensor 90 is disposed inside the lower housing 50, the pressure sensor 90 is a commercially available pressure sensor, the pressure sensor 90 is connected to an external wire 100, and the external wire 100 passes through the bottom cover 60, as shown in fig. 9.

Example 2

Based on the above embodiment 1, the same points are not repeated, and the difference is that, referring to fig. 2, the pressure gauge further includes a flexible membrane 70, the flexible membrane 70 is disposed in the lower housing 50 and wrapped around the pressure sensor 90, and the gap between the flexible membrane 70 and the pressure sensor 90 is filled with the airless water 80.

The pressure sensor 90 comprises a pressure sensing diaphragm 901, a shell 902, a permanent magnet and coil 903, an iron block 904, a vibrating wire 905 and a vibrating wire fixing body 906, wherein the pressure sensing diaphragm 901 is arranged at the end close to the permeable stone 40.

The flexible membrane 70 itself does not bear any tension, and is only used for transmitting the outside pressure to the airless water 80 between the flexible membrane 70 and the pressure sensor 90, and further the pressure is transmitted by the contact of the airless water 80 and the pressure sensing membrane 901, so as to complete the pressure measurement.

The pore water acts on the flexible membrane 70 by applying pressure, then the flexible membrane 70 transmits the pressure to the airless water 80 and further to the pressure sensor 90, and the pore water is not in direct contact with the pressure sensor 90, so that the influence of gas in the pore water pressure gauge on the measurement result can be effectively avoided.

In this embodiment, the flexible membrane 70, the pressure sensor 90, the airless water 80 and the bottom cover 60 are not detachable after being assembled, and the rest of the components including the top cover 10, the upper housing 20, the protective housing 30 and the permeable stone 40 are detachable for inspection, saturation, replacement, etc.

The high-precision pore water pressure gauge based on the closed membrane solves the problems in the prior art, and adopts the structure of the protective shell 30 to prevent the permeable stone 40 from directly contacting with the soil body, so that the permeable stone 40 is difficult to block and damage; the vent holes are formed in the top cover 10, the shell and the upper part of the protective shell 30, so that air in the pore water pressure gauge can be conveniently discharged, and the measurement accuracy can be improved; the pressure sensor 90 is wrapped by the flexible membrane 70, the airless water 80 is filled between the flexible membrane 70 and the pressure sensor 90, the pore pressure is measured through the path of the pore water-the flexible membrane 70-the airless water 80-the pressure sensor 90, the pore water is not in direct contact with the pressure sensor 90, the influence of gas in the pore water on the measurement result is avoided, and the measurement precision is improved; and the structure is simple, the disassembly is convenient, the reliability is strong, and the applicability is wide.

The above description is only a preferred embodiment of the present invention, and it is not intended to limit the scope of the present invention, and various modifications and changes may be made by those skilled in the art. Variations, modifications, substitutions, integrations and parameter changes of the embodiments may be made without departing from the principle and spirit of the invention, which may be within the spirit and principle of the invention, by conventional substitution or may realize the same function.

Claims

1. A high-precision pore water pressure gauge based on a closed membrane is characterized by comprising a top cover (10), an upper shell (20), a protective shell (30), a permeable stone (40), a lower shell (50), a bottom cover (60), an external connection wire (100) and a pressure sensor (90); the pressure sensor (90) is disposed inside the lower housing (50);

the permeable stone (40) is arranged between the upper shell (20) and the lower shell (50), the protective shell (30) is arranged on the outer side of the permeable stone (40), and two ends of the protective shell are respectively arranged on the outer sides of the upper shell (20) and the lower shell (50);

the top cover (10) is fixed at one end of the upper shell (20) and the protective shell (30), and the bottom cover (60) is fixed at one end of the lower shell (50).

2. The closed-membrane-based high-precision pore water pressure gauge is characterized in that the upper shell (20), the protective shell (30), the permeable stone (40) and the lower shell (50) are all of annular structures, a central screw (102) is arranged below the top cover (10), and a threaded hole (501) fixed with the central screw (102) is arranged above the lower shell (50), so that the upper shell (20), the protective shell (30), the permeable stone (40) and the lower shell (50) are fixed together.

3. Closed-film-based high-precision pore water pressure gauge according to claim 2, characterized in that the protective shell (30) is a spliced structure comprising 2 symmetrical half-rings.

4. The closed membrane-based high-precision pore water pressure gauge is characterized in that the protective shell (30) is provided with a bulge (302) and a water inlet hole (303) at the periphery of the contact end of the protective shell (30) and the lower shell (50), and a clamping groove (503) corresponding to the bulge (302) is arranged at the periphery of the lower shell (50) so that the protective shell (30) is fixedly connected with the lower shell (50) and the protective shell (30) has enough rigidity under the action of soil pressure; the water inlet hole (303) is used for enabling pore water to enter the protective shell (30) and act on the pressure sensor (90) through the permeable stone (40).

5. The closed-membrane based high-precision pore water pressure gauge according to claim 1, wherein the lower housing (50) is provided with a plurality of through holes (502) on the top surface of one end near the permeable stone (40) to facilitate the water flow up and down inside the pressure gauge.

6. The closing film based high precision pore water pressure gauge according to claim 1, characterized in that the top cover (10) is provided with a first vent hole (101) to facilitate the venting of the air inside the pressure gauge.

7. The closed membrane-based high-precision pore water pressure gauge is characterized in that second vent holes (201) are formed in the periphery of the top end of the upper shell (20), and third vent holes (301) corresponding to the second vent holes (201) are formed in the protective shell (30) so that air inside the pressure gauge can be conveniently exhausted.

8. The closed-film based high precision pore water pressure gauge according to claim 1, characterized in that the pressure gauge further comprises a flexible film (70), the flexible film (70) is wrapped around the pressure sensor (90), and the gap between the flexible film (70) and the pressure sensor (90) is filled with airless water (80).

9. The closed-film-based high-precision pore water pressure gauge according to claim 8, wherein the pressure sensor (90) comprises a pressure sensing diaphragm (901), a shell (902), a permanent magnet and coil (903), an iron block (904), a vibrating wire (905) and a vibrating wire fixing body (906), and the pressure sensing diaphragm (901) is arranged at the end close to the permeable stone (40).

10. The closed-film based high-precision pore water pressure gauge according to claim 9, wherein the flexible film (70) is not subjected to any tension by itself, and is only used for transmitting outside pressure to the non-aqueous liquid (80) between the flexible film (70) and the pressure sensor (90), and further transmitting pressure by the contact of the non-aqueous liquid (80) and the pressure sensing film (901) to complete pressure measurement.