CN112834403A - Penetration test method - Google Patents

Penetration test method Download PDF

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Publication number
CN112834403A
CN112834403A CN202110014722.2A CN202110014722A CN112834403A CN 112834403 A CN112834403 A CN 112834403A CN 202110014722 A CN202110014722 A CN 202110014722A CN 112834403 A CN112834403 A CN 112834403A
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test
air pressure
water pressure
assembly
soil sample
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CN202110014722.2A
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CN112834403B (en
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高文元
郭小红
郭建涛
姚再峰
刘医硕
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China State Construction Engineering Corp Ltd CSCEC
China State Construction Engineering Industry Technology Research Institute
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China State Construction Engineering Corp Ltd CSCEC
China State Construction Engineering Industry Technology Research Institute
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/08Investigating permeability, pore-volume, or surface area of porous materials
    • G01N15/0806Details, e.g. sample holders, mounting samples for testing
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/08Investigating permeability, pore-volume, or surface area of porous materials
    • G01N15/082Investigating permeability by forcing a fluid through a sample
    • G01N15/0826Investigating permeability by forcing a fluid through a sample and measuring fluid flow rate, i.e. permeation rate or pressure change

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  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Biochemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Fluid Mechanics (AREA)
  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

The application discloses a penetration test method, which comprises the following steps: arranging a filter assembly in the test barrel, and enabling the periphery of the filter assembly to be abutted against the inner surface of the side wall of the test barrel; filling a test soil sample on the filter assembly, loading a pneumatic curtain assembly in the process of filling the test soil sample, and enabling the periphery of the pneumatic curtain assembly to be abutted against the inner surface of the side wall of the test barrel, wherein the pneumatic curtain assembly is used for forming a pneumatic curtain layer in the test soil sample; and connecting a test component with the test barrel, and carrying out a penetration test on the test soil sample.

Description

Penetration test method
Technical Field
The application relates to the field of soil sample penetration tests, in particular to a penetration test method.
Background
The water-rich weak stratum has the characteristics of high water pressure, low bearing capacity, weak stability, complex seepage path, various distribution and formation forms and the like, so the engineering requirement of the tunnel engineering in the water-rich weak stratum is stricter compared with other soil qualities, the construction process is often accompanied with structural or geological disasters, and major accidents are also sometimes caused.
Therefore, in order to realize the research and development of the construction process of the tunnel engineering in the water-rich weak stratum, the permeation rule of the pressurized gas in the water-rich stratum and the grouting curtain and the water-resisting mechanism of the pressurized gas need to be determined. According to the related specification of section 16 in the geotechnical test standard (GBT 50123-2019), for the purpose of testing the water-proof condition of the air pressure curtain, the test equipment available at the present stage is generally constant-head test equipment and variable-head test equipment, however, the above two test equipment have great differences in the test soil sample, space size and test method and limitations of new technology research, and are specifically embodied in the following aspects:
1. the conventional test equipment cannot meet the test conditions of the air pressure curtain, the application of air pressure load is not considered at the beginning of the test design, the test is only limited to liquid-solid coupling dimension, and the dimension which is called as solid-liquid-gas three-phase coupling dimension cannot be expanded;
2. the constant head test equipment is suitable for coarse-grained soil and the variable head test is suitable for fine-grained soil, the water-rich soft soil layer has a complex structure and is often accompanied with an interlayer, and a single device cannot accurately test the soil sample of the water-rich soft soil layer;
3. the permeation path of the gas in the test soil sample cannot be observed, and a microscopic observation method is lacked;
4. the conventional test equipment has very small size, obvious size effect and side wall effect, and the remaking of the soil sample destroys the original soil loading structure and can not accurately measure the real condition of the permeability of the soil body;
5. the handling of the large-volume test soil sample is not considered, and the operation of changing the working condition is difficult; and
6. the test device is not transparent, and the informatization and visualization degrees are not high.
In view of the above technical problems, no effective solution has been proposed at present.
Disclosure of Invention
The present disclosure provides a penetration test method to at least solve the above technical problems in the prior art.
According to an embodiment of the present application, there is provided a penetration test method including: arranging a filter assembly in the test barrel, and enabling the periphery of the filter assembly to be abutted against the inner surface of the side wall of the test barrel; filling a test soil sample on the filter assembly, loading an air pressure curtain assembly in the process of filling the test soil sample, and enabling the periphery of the air pressure curtain assembly to be abutted against the inner surface of the side wall of the test barrel, wherein the air pressure curtain assembly is used for forming an air pressure curtain layer in the test soil sample; and connecting the test assembly with the test barrel, and performing a penetration test on the test soil sample.
Thereby through the technical scheme of this embodiment, solved the above-mentioned technical problem that exists among the prior art to this embodiment is applicable to the infiltration experiment under the full type soil sample under the atmospheric pressure curtain effect, has following advantage:
1. the device can accommodate large-volume stratified soil samples, is suitable for permeability tests of soils with different physical properties, and is flexible in measuring point arrangement and modularized in installation;
2. the device can realize convenient loading and unloading of the large-volume soil sample, and save the test time;
3. the air curtain can be loaded, and the air pressure water-resisting mechanism can be researched;
physical observation of the penetration degree can be realized, and the diffusion degree of the gas in the soil body can be easily and qualitatively expressed;
5. the air pressure curtain component can realize self reference through the structure of a grouting curtain, an air pressure curtain and a grouting curtain without a contrast test; and
6. and 3, data acquisition is realized, and errors of manual measurement are reduced.
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
Some specific embodiments of the present application will be described in detail hereinafter by way of illustration and not limitation with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:
FIG. 1 is a schematic perspective view of an permeation test apparatus according to an embodiment of the present application;
FIG. 2 is a schematic external view of a test barrel of the permeation test apparatus according to an embodiment of the present application;
FIG. 3 is a schematic view of an air pressure output component of an air pressure curtain assembly according to an embodiment of the present application;
FIG. 4 is a schematic view of a test site on a test bucket of a pneumatic curtain assembly according to an embodiment of the present application;
FIGS. 5 and 6 are schematic views showing the assembly of the penetration test apparatus according to the present embodiment in the case of conducting a coarse soil test; and
FIGS. 7 and 8 are schematic views showing the assembly of the penetration test apparatus according to the present embodiment when a fine soil test is performed; and
FIG. 9 is a flow chart of a permeation test method according to an embodiment of the present application.
Detailed Description
It should be noted that, in the present disclosure, the embodiments and features of the embodiments may be combined with each other without conflict. The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
In order to make the technical solutions of the present disclosure better understood by those skilled in the art, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only some embodiments of the present disclosure, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.
It should be noted that the terms "first," "second," and the like in the description and claims of the present disclosure and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances for describing the embodiments of the disclosure herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
FIG. 1 is a schematic perspective view of an permeation test apparatus according to the first aspect of the present embodiment. Referring to fig. 1, according to a first aspect of embodiments of the present application, there is provided an permeation test apparatus including: test bucket 1, filter assembly 6 and test subassembly. The test barrel 1 is used for accommodating a test soil sample for carrying out a penetration test; the filter assembly 6 is arranged in the test barrel 1, and the periphery of the filter assembly 6 is abutted against the inner surface of the side wall of the test barrel 1 and is used for filtering moisture in the test soil sample; and the test component is connected with the test barrel 1 and is used for performing a penetration test on the test soil sample. And wherein, still be provided with the atmospheric pressure curtain subassembly 5 that is located filter assembly 6 top in the experimental bucket 1, the periphery of atmospheric pressure curtain subassembly 5 and the interior surface butt of experimental bucket 1 lateral wall for form the atmospheric pressure curtain layer in experimental soil sample.
As described in the background art, the water-rich weak stratum has the characteristics of high water pressure, low bearing capacity, weak stability, complex seepage path, various distribution and formation forms and the like, so that the engineering requirements of the tunnel engineering of the water-rich weak stratum are stricter compared with other soil qualities, the construction process is often accompanied with structural or geological disasters, and major accidents sometimes occur. Therefore, in order to realize the research and development of the construction process of the tunnel engineering in the water-rich weak stratum, the permeation rule of the pressurized gas in the water-rich stratum and the grouting curtain and the water-resisting mechanism of the pressurized gas need to be determined. However, the existing test equipment cannot meet the test conditions of the air pressure curtain, the application of air pressure load is not considered at the beginning of the test design, the test is only limited to the liquid-solid coupling dimension, and the extension to the solid-liquid-gas three-phase coupling dimension cannot be realized.
In order to solve the technical problem, the penetration test apparatus of the present embodiment is provided with an air pressure curtain assembly 5 in the test barrel 1 for accommodating the test soil sample, and the periphery of the air pressure curtain assembly 5 abuts against the inner surface of the side wall of the test barrel 1, so as to achieve the sealing effect. And the air pressure curtain assembly 5 is used to form an air pressure curtain layer in the test soil sample.
Therefore, when the penetration test equipment described in the embodiment is used for performing a penetration test on a soil sample, the test condition of the air pressure curtain can be met, an air pressure load is applied in the test process, and the test is expanded to a solid-liquid-gas three-phase coupling dimension, so that the technical problem that the existing test equipment is only limited to the test of the liquid-solid coupling dimension and cannot expand the solid-liquid-gas three-phase coupling dimension is solved.
In addition, the test bucket 1 may be made of, for example, a colorless and transparent acryl material, so that the test bucket 1 can visually show the process of the test to the user. Therefore, the technical problems that the existing test equipment is not transparent and has low informatization and visualization degrees are solved.
Alternatively, as shown with reference to FIG. 1, the pneumatic drapery assembly 5 includes: a first grouting curtain part 510, a pneumatic output part 520 and a second grouting curtain part 530. Wherein the air pressure output part 520 is used for applying a predetermined air pressure to the test soil samples at both sides of the air pressure curtain assembly 5; and the first grouting curtain part 510 and the second grouting curtain part 530 are respectively disposed at upper and lower sides of the air pressure output part 520, for simulating a formation grouting consolidation effect.
Specifically, referring to fig. 1 and 2, the air pressure output part 520 may be connected to an air source through an air inlet pipe 523 shown in fig. 2, for example, so as to apply a predetermined air pressure to the test soil samples at both sides of the air pressure curtain assembly 5. And the first grouting curtain part 520 and the second grouting curtain part 530 can simulate the consolidation effect of the stratum grouting, so that an air pressure curtain cabin is formed between the first grouting curtain part 520 and the second grouting curtain part 530, and the effect of the air pressure curtain is simulated to the test soil samples at both sides of the air pressure curtain component 5.
And preferably a colored liquid is disposed within the pneumatic output member 520. That is, in the initial condition, the colored liquid which is not easily diffused is stored in the air pressure output member 520 in advance. In the test process, colored liquid can be injected into the test soil sample through the air pressure output component 520, and then the air pump is switched to inject air, so that the visual observation of the permeation height of the gas in the soil sample is realized.
Alternatively, as shown in FIG. 1, the first grouting curtain part 510 and the second grouting curtain part 530 include: grouting curtains 511 and 531 and grouting curtain frames 512 and 532, wherein the grouting curtain frames 512 and 532 are used for sealing the grouting curtains 511 and 531 with the inner surface of the sidewall of the test bucket 1. Thus, in this way, airtightness between the grouting curtain parts 510 and 530 and the sidewall of the test bucket 1 can be maintained, thereby better simulating the effect of the grouting curtain at both sides of the air pressure output part 520.
Further optionally, grouting drapery frames 512 and 532 include: outer collars 5121 and 5321 abutting against the inner surface of the side wall of the test tub 1; and inner clamping rings 5122 and 5322 for clamping grouting curtains 511 and 531 in cooperation with the outer clamping rings 5121 and 5321. And wherein the outer peripheries of the outer races 5121 and 5321 are wrapped with the seal rings 5123 and 5323. Thus, in this way, airtightness between the grouting curtain parts 510 and 530 and the sidewall of the test bucket 1 can be better achieved, thereby better simulating the effect of the grouting curtain at both sides of the air pressure output part 520. And, preferably, the sealing rings 5123 and 5323 are silicone sealing rings.
Optionally, grouting curtains 511 and 531 include: geotextiles 5111 and 5311; and a consolidation slurry disposed on the geotextiles 5111 and 5311, wherein a slit is formed on the consolidation slurry. Specifically, the grouting curtains 511 and 531 are formed by: the geotextile 5111 or 5311 is immersed in a common grouting slurry (e.g., a cement slurry or a bi-slurry) and the consolidation slurry is subjected to a crushing process after the slurry is consolidated to form gaps in the consolidation slurry. Therefore, the defects of non-overlapping and non-occlusion after the slurry is diffused can be truly simulated by the method. Preferably, the geotextile 5111 or 5311 is a geotextile.
Alternatively, as shown in fig. 3, the air pressure output part 520 includes a pipe plate 521 wound in a disc shape and an air inlet pipe 523, and an air hole 522 is formed on a side wall of the pipe plate 521. One end of the pipe disc 521 located at the inner side is blocked, and the other end of the pipe disc 521 is connected with the air inlet pipe 523. The air inlet pipe 523 is configured to be capable of protruding out of the test bucket 1 through a through hole of a test site (e.g., the test site 304a) of the test bucket 1. In this way, the injection of gas into the test soil sample in the horizontal plane is thus achieved. And preferably, the hole diameter of the air hole 522 is gradually increased in a direction from the outside of the pipe disc 521 to the inside of the pipe disc 521. Thus, the injection of the gas can be ensured to be uniform.
Further preferably, the air inlet pipe 523 is connected to a through hole of the first test site 304a of the pneumatic curtain assembly 5 through a stuffing box joint 541. Thereby maintaining the tightness between the air inlet pipe 523 and the through hole of the first test site 304 a. And is withdrawn from the pneumatic curtain assembly 5 through the loose stuffing box joint 541 after the test, facilitating the rapid unloading of the soil sample. Preferably, vaseline is interposed between the test tub 1 and the test soil sample, thereby eliminating the influence of the sidewall effect on the permeability while increasing the smoothness of the inner surface of the sidewall of the test tub 1.
Optionally, referring to fig. 4, a plurality of test sites 301a to 308a and 301b to 308b with different heights are disposed on the sidewall of the test barrel 1, and through holes penetrating through the sidewall of the test barrel 1 are disposed at the test sites 301a to 308a and 301b to 308b, and connection members 311a to 318a and 311b to 318b are disposed on the through holes for connecting the test assemblies. And the test assembly comprises test assemblies used for different test projects, wherein the test points corresponding to the test assemblies used for the different test projects are different.
As described in the background art, the water-rich soft soil layer has a complex structure, often accompanied by the occurrence of an interlayer, and a single device cannot accurately test the soil sample of the water-rich soft soil layer. In view of this, referring to fig. 2 and 4, the permeation test apparatus of the present embodiment is provided with a plurality of test sites 301a to 308a and 301b to 308b having different heights on the side wall of the test bucket 1, and the test sites 301a to 308a and 301b to 308b are provided with through holes penetrating the side wall of the test bucket 1. Therefore, different test assemblies are arranged at test points with different heights, and tests of different projects can be performed. For example, the test soil sample may be subjected to a penetration test of coarse soil and a penetration test of fine soil.
Preferably, the connection parts 311a to 318a and 311b to 318b are male screw joints.
And preferably, the permeation test apparatus further includes a sealing member 320 for connecting the connection members 311a to 318a, 311b to 318b and sealing the through-holes. Therefore, in the penetration experiment, the test point without the component can be sealed by the sealing part 320. Specifically, the sealing member 320 may be, for example, a sealing cap.
Optionally, the plurality of test sites 301 a-308 a, 301 b-308 b comprises a plurality of pairs of test sites disposed at different heights, wherein each pair of test sites is disposed at the same height of the test bucket 1 (preferably, oppositely disposed with respect to the axis of the test bucket 1). Preferably, the test sites of adjacent heights have a predetermined height difference therebetween and have an angular deviation of a predetermined angle with respect to the axial center of the test bucket.
Referring specifically to fig. 2 and 4, a plurality of test sites 301a to 308a and 301b to 308b are provided in pairs at different heights on the side wall of the test bucket 1. Accordingly, by providing the test sites in pairs, the air pressure injection of the air pressure output part 520 and the same-layer measurement of the seepage flow rate and the water pressure of the air pressure curtain assembly 5 can be realized on the same layer.
And preferably, the height difference between the mutually adjacent test point positions is 100mm, and the horizontal dislocation is sequentially carried out in the same direction by 15 degrees, so that the test components arranged at different test point positions in the test process are not interfered with each other.
Optionally, the test assembly comprises a test assembly for performing coarse earth tests and/or a test assembly for performing fine earth tests. Thus, the coarse-grained soil penetration test and/or the fine-grained soil penetration test can be carried out on the same test soil sample.
Preferably, with reference to fig. 5 and 6, the assembly for performing a coarse soil test comprises: water pressure sensors 9a to 9c, drain pipes 10a and 10b, and flow sensors 11a and 11 b. The water pressure sensors 9a to 9c include: the first water pressure sensor 9a and the second water pressure sensor 9b are respectively connected with through holes of a second test point position 307a and a third test point position 305a which are positioned at different heights above the air pressure curtain component 5; and a third water pressure sensor 9c connected to the through hole of the fourth test site 302a between the air pressure curtain assembly 5 and the filter assembly 6. The drain pipes 10a and 10b include: the first drainage pipe 10a is connected with a through hole of the fifth test site 304b provided with the air pressure curtain component 5; and a second drain pipe 10b connected to a through hole of a sixth test site 301a disposed below the filter assembly 6. The flow sensors 11a and 11b include: a first flow sensor 11a provided in the first drain pipe 10 a; and a second flow sensor 11b provided in the second drain pipe 10 b. Wherein the fifth test site location 304b is located at the same height of the test bucket 1 as the first test site location 304a (e.g., opposite the first test site location 304 a).
Alternatively, referring to fig. 7 and 8, a test assembly for conducting fine grain soil tests includes: overflow pipe 2, first tee fitting 12a, second tee fitting 12b, first pressure tube 13a, second pressure tube 13b, first water pressure sensor 9a and second water pressure sensor 9 b. The overflow pipe 2 is arranged on the side wall of the test barrel 1 and is higher than the test points 301 a-308 a and 301 b-308 b; the first pressure pipe 13a and the first water pressure sensor 9a are connected with the connecting part 314b of the fifth test site position 304b through the first tee joint pipe 12 a; and the second pressure pipe 13b and the second water pressure sensor 9b are connected with the connecting part 311a of the sixth test site 301a below the filter assembly through the second tee pipe 12 b. Wherein the fifth test site location 304b is located at the same height of the test bucket 1 as the first test site location 304a (e.g., opposite the first test site location 304 a).
Further alternatively, as shown with reference to fig. 1, the filter assembly 6 comprises: a geotextile 610; and a geotextile frame 620 for sealing the geotextile 610 with the inner surface of the sidewall of the test tub 1. And further, the geotextile frame 620 includes: an outer clamping ring 621 abutting against the inner surface of the side wall of the test barrel 1; and an inner grip ring 622 for cooperating with the outer grip ring 621 to grip the geotextile 610. And the outer periphery of the outer clamping ring 621 is wrapped with a sealing ring 623. And further preferably, the sealing ring 623 may be a silicone sealing ring. Thereby through above structure, can be so that the internal surface of filter assembly 6 and experimental bucket 1 lateral wall forms seal structure to can further guarantee experimental accuracy. Preferably, geotextile 610 is a geotextile.
Optionally, the barrel diameter of the test barrel 1 is larger than 600mm and the height is larger than 1 m. Therefore, the test barrel 1 can contain a large-volume test soil sample, so that an original soil structure can be kept as much as possible, and the real situation of the soil permeability can be accurately measured.
Optionally, referring to fig. 1, the permeation testing apparatus further includes a bottom plate assembly 7 disposed at the bottom of the testing barrel 1, wherein the bottom plate assembly 7 includes: a bottom plate 701, wherein the periphery of the bottom plate 701 abuts against the inner surface of the side wall of the test bucket 1; and a sealing bead 702 disposed around the periphery of the bottom plate 701. And preferably, the base plate 701 is made of an acryl material. And optionally water-permeable pebbles are arranged between the floor module 7 and the filter module 6.
Optionally, referring to fig. 1, the permeation testing apparatus further comprises a support ring 4, wherein the support ring 4 abuts against the inner surface of the sidewall of the testing barrel 1 and is disposed below the bottom plate assembly 7 for supporting the bottom plate assembly 7.
Alternatively, referring to fig. 1 and 2, the penetration test apparatus further includes a binding band 8, wherein the binding band 8 is provided on the outer surface of the sidewall of the test bucket 1, and corresponds to the position of the support ring 4. The side wall of the test bucket 1 can be tightened by the binding bands 8, and inward pressure is applied to the support ring 4 to compress the support ring 4, so that the support ring 4 can be fixed in the test bucket 1 and support the bottom plate assembly 7.
And in this way, the base plate assembly 7 can be detached from the bottom of the test tub 1, so that when the test soil sample needs to be detached after the test is completed, the test soil sample, the filter assembly 6 and the air pressure curtain assembly 5 can be sequentially detached from the bottom of the test tub 1 after detaching the base plate assembly 7. Therefore, the loading and unloading of the large-volume soil sample can be conveniently realized, and the test operation is simpler and more convenient. And preferably, during the test, lubricating oil can be smeared on the inner surface of the side wall of the test bucket 1, so that the air pressure curtain assembly 5, the filter assembly 6 and the bottom plate assembly 7 form a movable seal with the side wall of the test bucket 1. And the inner surface of the sidewall of the test bucket 1 is smoothly arranged so as to ensure the sliding of the air pressure curtain assembly 5, the filter assembly 6 and the bottom plate assembly 7.
Alternatively, as shown in fig. 1 and 2, the penetration test apparatus further includes a tightening mechanism 801 provided to the binding band 8 for tightening the binding band 8.
Furthermore, according to a second aspect of embodiments of the present application, there is provided a method of conducting a penetration test on a test soil sample, wherein fig. 9 shows a schematic flow diagram of the method. Referring to fig. 9, the method includes:
s902: arranging a filter assembly 6 in the test barrel 1, and enabling the periphery of the filter assembly 6 to be abutted against the inner surface of the side wall of the test barrel 1;
s904: filling a test soil sample on the filter assembly 6, loading the air pressure curtain assembly 5 in the process of filling the test soil sample, and enabling the periphery of the air pressure curtain assembly 5 to be abutted against the inner surface of the side wall of the test barrel 1, wherein the air pressure curtain assembly 5 is used for forming an air pressure curtain layer in the test soil sample; and
s906: and connecting the test assembly with the test barrel 1, and performing a penetration test on the test soil sample.
Therefore, the test method described in this embodiment loads the air pressure curtain assembly 5 in the process of filling the test soil sample, so that when the penetration test of the soil sample is performed by using the penetration test apparatus described in this embodiment, the test condition of the air pressure curtain can be satisfied, the air pressure load is applied in the test process, and the test is extended to the solid-liquid-gas three-phase coupling dimension, thereby solving the technical problem that the existing test apparatus is only limited to the test of the liquid-solid coupling dimension and cannot extend the solid-liquid-gas three-phase coupling dimension.
In addition, the test bucket 1 may be made of, for example, a colorless and transparent acryl material, so that the test bucket 1 can visually show the process of the test to the user. Therefore, the technical problems that the existing test equipment is not transparent and has low informatization and visualization degrees are solved.
Optionally, the method further comprises, prior to loading the pneumatic drapery assembly 5, making the pneumatic drapery assembly 5 by: making a first grouting curtain part 510 of the air pressure curtain assembly 5, wherein the first grouting curtain part 510 is used for simulating the grouting consolidation effect of the stratum; making an air pressure output part 520 of the air pressure curtain assembly 5, wherein the air pressure output part 520 is used for applying preset air pressure to the test soil samples at two sides of the air pressure curtain assembly 5; and making a second grouting curtain part 530 of the pneumatic curtain assembly 5, wherein the second grouting curtain part 530 is used for simulating the grouting consolidation effect of the stratum.
Thus, a predetermined air pressure can be applied to the test soil samples on both sides of the air pressure curtain assembly 5 during the test. And the first grouting curtain part 520 and the second grouting curtain part 530 can simulate the consolidation effect of stratum grouting, so that an air pressure curtain cabin is formed between the first grouting curtain part 520 and the second grouting curtain part 530, and the effect of the air pressure curtain is simulated to the test soil samples at two sides of the air pressure curtain component 5. And further preferably, the operation of loading the pneumatic curtain assembly 5 includes loading the second grouting curtain part 530, the pneumatic output part 520 and the first grouting curtain part 510 in order from the bottom up.
Optionally, referring to fig. 2 and 4, the method further comprises: a plurality of test point positions 301 a-308 a and 301 b-308 b with different heights are arranged on the side wall of the test barrel 1; through holes penetrating through the side wall of the test barrel 1 are arranged at the test point positions 301a to 308a and 301b to 308 b; and connecting the test components for different test items with the through holes of the corresponding test point positions 301a to 308a and 301b to 308b of the test barrel 1 respectively to perform different test items.
In the test method of the embodiment, the plurality of test sites 301a to 308a and 301b to 308b with different heights are arranged on the side wall of the test barrel 1, and the through holes penetrating through the side wall of the test barrel 1 are arranged at the test sites 301a to 308a and 301b to 308b, so that different test assemblies are arranged at the test sites with different heights, and tests of different projects can be performed. For example, the test soil sample may be subjected to a penetration test of coarse soil and a penetration test of fine soil.
Preferably, the test modules for different test items may be connected to the through-holes of the respective test sites 301a to 308a, 301b to 308b of the test bucket 1 through the respective connection members 311a to 318a, 311b to 318 b. The coupling members 311a to 318a, 311b to 318b may be male screws, for example.
Further, the operation of loading the pneumatic drapery assembly 5 further includes: the air inlet pipe 523 of the air pressure output part 520 is extended out of the test bucket 1 through the through hole of the corresponding first test site 304 a.
Optionally, the operation of connecting the test assembly with the test barrel 1 and performing the penetration test on the test soil sample by using the test assembly includes: connecting a test assembly for performing a coarse-grained soil test with the test barrel 1, and performing a coarse-grained soil penetration test on a test soil sample; and/or connecting a test assembly for performing a fine-grained soil test with the test barrel 1, and performing a fine-grained soil penetration test on the test soil sample.
Alternatively, referring to fig. 5 and 6, the operation of connecting a test assembly for performing a coarse soil test with the test tub 1 includes: connecting the first water pressure sensor 9a with a through hole of a second test site 307a above the air pressure curtain assembly 5, and connecting the second water pressure sensor 9b with a through hole of a third test site 305a above the air pressure curtain assembly 5; connecting a third water pressure sensor 9c with a through hole of a fourth test site 302a between the air pressure curtain assembly 5 and the filter assembly 6; connecting the first drain pipe 10a with the through hole of the fifth test site 304 b; connecting the second drain pipe 10b with a through hole of a sixth test site 301a arranged below the filter assembly 6; a first flow sensor 11a is provided in the first drain pipe 10 a; and a second flow sensor 11b is provided in the second drain pipe 10 b. The fifth test site position 304b and the first test site position 304a are disposed at the same height of the test bucket 1, for example, the fifth test unit 304b is disposed opposite to the first test site position 304 a.
Further, referring to fig. 5 and 6, the operation of performing the coarse soil penetration test on the test soil sample includes: injecting water into the test barrel 1; closing the second drain pipe 10b and opening the first drain pipe 10 a; detecting the water pressure at the second test site 307a via the first water pressure sensor 9a, the water pressure at the third test site 305a via the second water pressure sensor 9b, and the flow rate at the fifth test site 304b via the first flow sensor 11 a; and determining a first permeability coefficient of the test soil sample according to data detected by the first water pressure sensor 9a, the second water pressure sensor 9b and the first flow sensor 11 a.
Wherein the first permeability coefficient may be calculated, for example, by the following formula:
Figure BDA0002886445980000101
Figure BDA0002886445980000102
in the formula: k is a radical ofT1Testing the permeability coefficient (cm/s) of the original soil sample at the water temperature T ℃;
q is the amount of permeated water (cm) in t seconds3) Detected by the first flow sensor 11 a;
L1is the seepage diameter (cm) and is equal to the test soil sample height between the centers of the manometers of the test point positions 307a and 305 a;
a is the cross-sectional area (cm) of the test soil sample2);
t is time(s);
H1the water head height difference (cm) between the water pressure sensors 9a and 9b can be obtained by conversion according to the water pressure difference measured by the water pressure sensors 9a and 9 b;
k20the permeability coefficient (cm/s) of the test soil sample at the standard temperature (20 ℃);
ηTthe coefficient of kinetic viscosity of water at T ℃ (1 × 10)-6kPa·s);
η20The coefficient of dynamic viscosity of water at 20 ℃ (1 × 10)-6kPa·s)。
Further, the operation of performing the coarse-grained soil penetration test on the test soil sample further comprises: closing the first drain pipe 10a and opening the second drain pipe 10 b; detecting the water pressure at the second test site 307a via the first water pressure sensor 9a, the water pressure at the third test site 305a via the second water pressure sensor 9b, the water pressure at the fourth test site 302a via the third water pressure sensor 9c, and the flow at the sixth test site 301a via the second flow sensor 11 b; and determining a second permeability coefficient of the test soil sample according to the data detected by the first water pressure sensor 9a, the second water pressure sensor 9b, the third water pressure sensor 9c and the second flow sensor 11 b.
The second permeability coefficient can be calculated by the following equations (3) to (5).
Figure BDA0002886445980000111
Figure BDA0002886445980000112
Figure BDA0002886445980000113
kT2The permeability coefficient (cm/s) of the air pressure curtain is tested at the water temperature T ℃;
kT3the comprehensive permeability coefficient (cm/s) of a test soil layer and a grouting and air pressure curtain at the water temperature T ℃, namely a second permeability coefficient;
l2 is the seepage diameter (cm), equal to the test soil sample height between the centers of the manometers of test sites 305a and 302 a;
H2the head height difference (cm) between the water pressure sensors 9a and 9c may beAnd the water pressure difference is converted according to the water pressure difference measured by the water pressure sensors 9a and 9 c.
Further, the operation of performing the coarse-grained soil penetration test on the test soil sample further comprises: injecting a colored liquid into the air pressure output part 520 and then applying air pressure to the air pressure output part 520; the relationship between the permeation height of the colored liquid and the air pressure of the air pressure curtain assembly and the relationship between the second permeability coefficient of the test soil sample and the air pressure of the air pressure curtain assembly are determined according to the air pressure applied to the air pressure output part 520, the permeation height of the colored liquid, the water pressure detected by the first water pressure sensor 9a, the water pressure detected by the second water pressure sensor 9b, the water pressure detected by the third water pressure sensor 9c and the flow rate detected by the second flow sensor 11 b. Wherein the second permeability coefficient can be calculated using the above-mentioned formulas (3) to (5).
Further, the water pressure sensors 9a to 9c may preferably be water pressure transducers. The flow sensors 11a and 11b may be clamp-on flow sensors 10. Further preferably, the water pressure sensors 9 a-9 c are connected to the connection members 317a, 315a and 312a of the respective test sites 307a, 305a and 302a through the tee fittings 12 a-12 c, respectively. Referring to fig. 5, the one ends 1202 of the three-way pipes 12a to 12c connected to the water pressure sensors 9a to 9c and the one ends connected to the through holes are opened, and the one ends 1201 not connected to the water pressure sensors 9a to 9c and the through holes are closed.
And further preferably, when the coarse soil test is performed, the number of pairs of test points above the air pressure curtain assembly 5 is not less than 3 pairs, and the number of pairs of test points below the air pressure curtain assembly 5 is not less than 1 pair. And the test point corresponding to the first and second water pressure sensors 9a and 9b is not the test point 308a or 308b closest to the upper edge of the test tub 1. In addition, in the case of performing the coarse soil test, an overflow pipe 2 is provided on the side wall of the test bucket 1, and the overflow pipe 2 is provided at a position higher than the test sites 301a to 308a and 301b to 308 b. Thereby can adjust the flood peak height in experimental bucket 1 through overflow pipe 2, maintain flood peak height invariant.
Therefore, through the arrangement, when the coarse-grained soil test is carried out, the logarithm of the test point positions above the air pressure curtain component 5 is more than or equal to 3 pairs. Then 2 test points which are not closest to the upper edge of the test barrel 1 are selected (the test points 305 a-307 a and 305 b-307 b are selected), and the tee pipes 12a and 12b and the water pressure sensors 9a and 9b are connected. Each tee 12a and 12b is provided with a valve. During the coarse soil test, the valve at the end of the tee pipes 12a and 12b not connected with the water pressure sensors 9a and 9b is in a closed state. The pneumatic curtain assembly 5 is arranged at corresponding test sites 304a and 304b according to the setting height of the lower soil layer, and the test sites 304a and 304b are respectively connected with the stuffing box joint 541 and the water outlet pipe 10 a. The stuffing box joint 541 is used for meeting the requirement of air tightness when the air inlet pipe 523 of the air pressure output component 520 penetrates through the test barrel 1, and the water outlet pipe 10a is provided with a clamp type flow sensor 11a for monitoring the seepage water flow. The logarithm of the test point position of the soil layer below the air pressure curtain component 5 is more than or equal to 1 pair, and for example, the test point position 302a is connected with a water pressure transmitter 9c through a tee pipe fitting 12c, and the water pressure condition at the test point position 302a is monitored. The permeable pebble layer is arranged at the test point positions 301a and 301b at the bottommost edge, the test point position 301a is connected with the water outlet pipe 10b, and the water outlet pipe 10b is provided with a clamp type flow sensor 11b for monitoring the water seepage flow condition of the air pressure curtain in the water-resisting state.
Alternatively, referring to fig. 7 and 8, the operation of connecting a test assembly for fine soil testing to a test bucket 1 includes: connecting the overflow pipe 2 with through holes which are arranged on the side wall of the test barrel 1 and are higher than the test points 301 a-308 a and 301 b-308 b; connecting the first tee fitting 12a with the through bore of the fifth test site location 304 b; connecting the second tee pipe 12b with a through hole of a sixth test site 301a disposed below the filter assembly 6; connecting a first pressure pipe 13a and a first water pressure sensor 9a with a first tee pipe 12 a; and a second pressure pipe 13b and a second water pressure sensor 9b are connected to the second tee pipe 12 b. Wherein the fifth test site location 304b is located at the same height of the test bucket 1 as the first test site location 304 a. Preferably, the fifth test site location 304b is disposed opposite the first test site location 304 a.
Further, referring to fig. 7 and 8, the operation of performing the fine soil infiltration test on the test soil sample includes: injecting water into the test barrel 1; opening the first tee 12a and the second tee 12b until the first tee 12a and the second tee 12b are closed after the water in the first pressure tube 13a and the second pressure tube 13b overflows; stopping injecting water into the test barrel 1, and starting the first three-way pipe fitting 12 a; and detecting the change data of the water pressure of the fifth test site 304b along with time through the first water pressure sensor 9a, and determining a third permeability coefficient of the test soil sample according to the change data detected by the first water pressure sensor 9 a.
Wherein the third permeability coefficient may be calculated, for example, by the formula:
Figure BDA0002886445980000131
Figure BDA0002886445980000132
a is a sectional area (cm) of the pressure pipes 13a, 13b2);
L is the seepage diameter (cm) and is equal to the height of the test soil sample;
Hb1the initial head (cm) of the overflow pipe 2;
Hb2the head (cm) at the termination of the first pressure pipe 13 a.
Further, the operation of performing the fine soil penetration test on the test soil sample further comprises: closing first tee 12a and opening second tee 12 b; and detecting the change data of the water pressure along with the time through the second water pressure sensor 9b, and determining the fourth permeability coefficient of the test soil sample according to the change data detected by the second water pressure sensor 9 b.
Wherein the fourth permeability coefficient may be calculated, for example, according to equation (8) described below.
Figure BDA0002886445980000133
Hb3The head (cm) at the termination of the second pressure pipe 13 b.
Optionally, the operation of performing a fine soil penetration test on the test soil sample further includes: replenishing the water level in the first and second pressure pipes 13a and 13b to a preset height; injecting a colored liquid into the air pressure output part 520 and then applying air pressure to the air pressure output part 520; the first tee pipe 12a is opened, and the relationship between the permeation height of the colored liquid and the air pressure of the air pressure curtain assembly and the relationship between the fourth permeability coefficient of the test soil sample and the air pressure to the air pressure curtain assembly are determined according to the air pressure applied to the air pressure output part 520, the permeation height of the colored liquid and the water pressure detected by the second water pressure sensor 9 b. Wherein the fourth permeability coefficient may be calculated, for example, according to equation (8) described above.
And preferably the height of the top ends of the first and second pressure tubes 13a and 13b is higher than the height of the overflow tube 2 in case of connection to the test sites 304b and 301 a.
Therefore, in the fine soil testing, the logarithm of the test point positions above the air pressure curtain component 5 is more than or equal to 2 pairs, and the air pressure curtain component 5 is arranged at the corresponding test point positions 304a and 304b according to the setting height of the lower soil layer. Test site 304a is connected to stuffing box joint 541 and test site 304b is connected to hydraulic transmitter 9a and pressure tube 13a via tee 12 a. The stuffing box joint 541 is used for meeting the requirement of air tightness when the air inlet pipe 523 of the air pressure output component 520 passes through the test barrel 1. A hydraulic transducer 9a and a pressure tube 13a are connected to the tee 12a at the test site location 304b, wherein the preset head height in the pressure tube 13a is greater than the central level position of the overflow tube 2. The logarithm of the retaining test point positions of the soil layer below the air pressure curtain component is more than or equal to 1 pair. Wherein a layer of water-permeable pebbles is arranged at the position of the lowermost test sites 301a and 301 b. The test site 301a is connected with a tee 12b, and the hydraulic transmitter 9b and the pressure pipe 13b are arranged at the same water head height as the test site 304 b.
Thereby through the technical scheme of this embodiment, solved the above-mentioned technical problem that exists among the prior art to this embodiment is applicable to the infiltration experiment under the full type soil sample under the atmospheric pressure curtain effect, has following advantage:
1. the device can accommodate large-volume stratified soil samples, is suitable for permeability tests of soils with different physical properties, and is flexible in measuring point arrangement and modularized in installation;
2. the device can realize convenient loading and unloading of the large-volume soil sample, and save the test time;
3. the air curtain can be loaded, and the air pressure water-resisting mechanism can be researched;
physical observation of the penetration degree can be realized, and the diffusion degree of the gas in the soil body can be easily and qualitatively expressed;
5. the air pressure curtain component can realize self reference through a structure of a grouting curtain, an air pressure curtain and a grouting curtain without a contrast test;
6. and 3, data acquisition is realized, and errors of manual measurement are reduced.
The following detailed description of the test method according to the second aspect of this embodiment is given below:
firstly, test equipment installation:
s102: collecting undisturbed soil, and preparing a test soil sample;
s104: preparing an assembled air pressure curtain component 5, a filtering component 6 and a bottom plate component 7;
s106: installing sealing caps 320 at the test point positions 301 a-308 a and 301 b-308 b, smearing a layer of lubricating oil on the inner wall of the test barrel 1, supporting by using the support ring 4 after installing the bottom plate assembly 7, tensioning the binding bands 8 to increase the contact pressure between the inner wall of the test barrel 1 and the outer wall of the support ring 4, and then detecting whether the test device leaks water;
s108: a filtering component 6 is arranged after the saturated permeable pebble layer is prepared;
s110: filling a lower layer test soil sample of the pneumatic curtain, smearing Vaseline on the corresponding inner wall position of the test barrel 1 before filling, filling the test soil sample in layers, and ensuring the saturated state of the test soil sample;
s112: installing the air pressure curtain component 5 (i.e. the grouting curtain components 510 and 530 and the air pressure output component 520), screwing the air inlet pipe 523 of the air pressure output component 520 through the corresponding test point 304a (i.e. the first test point) by using the stuffing box joint 541, filling the air pressure curtain layer (corresponding to the air pressure curtain component 5) with water-permeable fine sand, and simultaneously ensuring that the lower part of the upper grouting curtain (i.e. the grouting curtain 511 of the first grouting curtain component 510) is completely immersed in the water;
s114: before filling the upper layer of the air pressure curtain test soil sample, smearing Vaseline on the corresponding inner wall position of the test barrel 1, then filling the test soil sample in a layered mode to ensure the saturated state of the soil sample until the preset height is reached, and arranging a layer of gravel on the top surface of the soil sample.
Step two, coarse-grained soil testing step S202: under the condition of continuous water injection, replacing the sealing cap 320 with hydraulic pressure transmitters 9 a-9 c (namely first to third hydraulic pressure sensors) connected through tee pipes 12 a-12 c (namely first to third tee pipes) at preset test points 307a (namely second test point), 305a (namely third test point) and 302a (namely fourth test point), wherein the valves of the tee pipes 12 a-12 c are completely opened until the gas in the tee pipes 12 a-12 c is completely discharged and water overflows, and then closing the valves at the ends of the tee pipes 12 a-12 c which are not connected with the hydraulic pressure transmitters;
s204: under the condition of continuous water filling, replacing the sealing cap 320 with the drainage pipes 10a (namely, a first drainage pipe) and 10b (namely, a second drainage pipe) at preset drainage positions 304b (namely, a fifth test point) and 301a (namely, a sixth test point) and arranging flow sensors 11a and 11b on the drainage pipes 10a and 10 b;
s206: detecting whether the data of the water pressure transmitter is the real water pressure height of the corresponding test point position, and performing a test after no error exists;
s208: the water drainage pipe 10b at the position of the permeable pebble layer is closed, the water pressure of the test points 307a and 305a of the test soil sample at the upper layer of the air pressure curtain is detected through the water pressure transmitters 9a and 9b, and the flow of the test point 304b is detected through the flow sensor 11 a. And calculating the permeability coefficient (i.e. a first permeability coefficient) of the test soil sample according to the water pressure detected by the water pressure transmitters 9a and 9b and the flow detected by the flow sensor 11 a;
wherein the permeability coefficient can be calculated according to the following formula:
Figure BDA0002886445980000151
Figure BDA0002886445980000152
in the formula: k is a radical ofT1Testing the permeability coefficient (cm/s) of the original soil sample at the water temperature T ℃;
q is the amount of permeated water (cm) in t seconds3) Detected by the flow sensor 11 a;
L1the seepage diameter (cm) is equal to the height of a test soil sample between the centers of two pressure measuring holes 307a and 305 a;
a is the cross-sectional area (cm) of the test soil sample2);
t is time(s);
H1the water head height difference (cm) between the water pressure transmitters 9a and 9b can be obtained by conversion according to the water pressure difference measured by the water pressure transmitters 9a and 9 b;
k20the permeability coefficient (cm/s) of the soil sample at the standard temperature (20 ℃);
ηTthe coefficient of kinetic viscosity of water at T ℃ (1 × 10)-6kPa·s);
η20The coefficient of dynamic viscosity of water at 20 ℃ (1 × 10)-6kPa·s)。
S210: closing the drainage pipe 10a at the position 304b of the air pressure curtain layer, simultaneously opening the drainage pipe 10b of the permeable pebble layer, detecting the water pressure of the test points 307a and 305a of the soil sample at the upper layer of the air pressure curtain through the water pressure transducers 9a and 9b, detecting the water pressure of the test point 302a of the soil sample at the lower layer of the air pressure curtain through the water pressure transducer 9c, and measuring the drainage flow of the test point 301a of the soil sample at the lower layer of the air pressure curtain through the flow sensor 11 b. The permeability coefficient (and the second permeability coefficient) of "test soil sample + initial grouting curtain + initial air pressure curtain layer" is obtained by calculation according to the water pressure detected by the water pressure transmitters 9a to 9c and the flow detected by the flow sensor 11b, wherein the permeability coefficient can be calculated according to the following equations (3) to (5):
Figure BDA0002886445980000161
Figure BDA0002886445980000162
Figure BDA0002886445980000163
kT2the permeability coefficient (cm/s) of the air pressure curtain is tested at the water temperature T ℃;
kT3the comprehensive permeability coefficient (cm/s) of a test soil layer and a grouting and air pressure curtain at the water temperature T ℃, namely a second permeability coefficient;
L2is the seepage diameter (cm) and is equal to the test soil sample height between the centers of the pressure measuring holes of the test point positions 305a and 302 a;
H2the water head height difference (cm) between the water pressure transmitters 9a and 9c can be obtained by conversion according to the water pressure difference measured by the water pressure transmitters 9a and 9 c;
s212: slowly injecting colored liquid into the air pressure output component 520, wherein the volume of the colored liquid is the volume of the air pressure curtain layer minus the volume of the air pressure output component 520, and then switching the air pressure;
s214: monitoring the air pressure of the air pressure curtain, the permeation height of the colored liquid, the water pressure of the test points 307a, 305a and 302a and the change data of the drainage flow at the bottom of the equipment (namely the drainage flow at the test point 301a) along with time, and finally obtaining data of 'the permeation height of the colored liquid-air pressure curtain pressure' and 'the permeability coefficient-air pressure curtain pressure', wherein the permeability coefficient can be calculated by the formula in the step S210;
s216: eliminating the influence of the initial grouting curtain, the initial air pressure curtain and the sidewall effect through the penetration series theory (for example, the difference value can be calculated by referring to the penetration coefficient calculated in the step S214 and the penetration coefficient calculated in the step S210, and the difference value can eliminate the influence of the initial grouting curtain, the initial air pressure curtain and the sidewall effect);
s218: after the test is finished, the water source is closed, the stuffing box joint 541 is loosened, the air pressure output part 520 is extracted, the binding band at the bottom of the test barrel 1 is loosened, the soil sample and various feeding assemblies in the test barrel 1 are integrally separated and unloaded, finally, the test point position is dismantled, the equipment components are cleaned, and the next group of test is carried out.
Thirdly, fine soil testing step S302: the pressure pipes 13a and 13b are flexible pipes, so that the overall height is lower than that of the overflow pipe in the initial state, under the condition of continuous water filling, the sealing caps 320 of the preset test points (304b and 301a) are replaced by the hydraulic pressure transmitters 9a and 9b and the pressure pipes 13a and 13b which are connected through the tee pipes 12a and 12b, and the valves of the tee pipes 12a and 12b are installed to be completely opened until the valves of the tee pipes 12a and 12b are closed after water in the pressure pipes 13a and 13b overflows, and the pressure pipes are restored to the vertical original length;
s304: closing a water source, opening a valve of the tee pipe fitting 12a at the position of the air pressure curtain layer (the test point position 304b), detecting the change data of the water pressure at the test point position 30b along with the time through the water pressure transmitter 9a, and calculating to obtain a third permeability coefficient of the test soil sample, wherein the third permeability coefficient can be calculated according to the following formula:
Figure BDA0002886445980000171
Figure BDA0002886445980000172
a is a sectional area (cm) of the pressure pipes 13a, 13b2);
L is the seepage diameter (cm) and is equal to the height of the test soil sample;
Hb1the initial head (cm) of the overflow pipe 2;
Hb2the head (cm) at the termination of the pressure pipe 13 a;
s306: closing a valve of a tee pipe fitting 12a at the position of the air pressure curtain layer, opening a valve of a tee pipe fitting 12b at the position of the water permeable pebble layer (the test point position 301a), detecting the change data of the water pressure at the test point position 301a along with time through a water pressure transmitter 9b, and obtaining the permeability coefficient (namely, a fourth permeability coefficient) of the test soil sample, the initial grouting curtain and the initial air pressure curtain layer through calculation, wherein the permeability coefficient can be calculated according to the following formula (8), for example:
Figure BDA0002886445980000173
Hb3the head (cm) at the termination of the pressure pipe 13 b;
s308: respectively replenishing the water level in the pressure pipes and recovering to the preset height;
s310: slowly injecting colored liquid into the air pressure output component 520, wherein the volume of the colored liquid is the volume of the air pressure curtain layer minus the volume of the air pressure output component 520, and then switching the air pressure;
s312: opening a valve of the three-way pipe fitting 12a at the position of the air pressure curtain layer (namely the test point position 304b), detecting data of the air pressure of air pressure curtain layer injection, the colored liquid permeation height and the water pressure of the permeable pebble test point position 301a along with time, and finally obtaining data of 'colored liquid permeation height-air pressure curtain pressure intensity' and 'permeability coefficient-air pressure curtain pressure intensity', wherein the permeability coefficient can be calculated by referring to the formula in the step S306;
s314: eliminating the influence of the initial grouting curtain, the initial air pressure curtain and the side wall effect through the penetration series theory (for example, the influence of the initial grouting curtain, the initial air pressure curtain and the side wall effect can be eliminated by calculating the difference value of the penetration coefficients calculated in the steps S312 and S306);
s316: and disassembling and cleaning the test device in the same step with the coarse-grained soil, and carrying out the next group of tests.
The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
In the description of the present disclosure, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are presented only for the convenience of describing and simplifying the disclosure, and in the absence of a contrary indication, these directional terms are not intended to indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the disclosure; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.
The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A method of conducting a penetration test on a test soil sample, comprising:
arranging a filter assembly (6) in the test barrel (1), and enabling the periphery of the filter assembly (6) to be abutted against the inner surface of the side wall of the test barrel (1);
filling a test soil sample on the filter assembly (6), loading a pneumatic curtain assembly (5) in the process of filling the test soil sample, and enabling the periphery of the pneumatic curtain assembly (5) to be abutted with the inner surface of the side wall of the test barrel (1), wherein the pneumatic curtain assembly (5) is used for forming a pneumatic curtain layer in the test soil sample; and
and connecting a test component with the test barrel (1), and carrying out a penetration test on the test soil sample.
2. The method of claim 1, further comprising, prior to loading the pneumatic drapery assembly (5), making the pneumatic drapery assembly (5) by:
making a first grouting curtain part (510) of the pneumatic curtain assembly (5), wherein the first grouting curtain part (510) is used for simulating a stratum grouting consolidation effect;
making an air pressure output part (520) of the air pressure curtain assembly (5), wherein the air pressure output part (520) is used for applying preset air pressure to test soil samples on two sides of the air pressure curtain assembly (5); and
making a second grouting curtain part (530) of the pneumatic curtain assembly (5), wherein the second grouting curtain part (530) is used for simulating the grouting consolidation effect of the stratum.
3. The method of claim 2, wherein the operation of loading the pneumatic drapery assembly (5) includes loading the second grouting drapery component (530), the pneumatic output component (520), and the first grouting drapery component (510) sequentially in bottom-up order.
4. The method of claim 3, further comprising:
a plurality of test sites (301 a-308 a, 301 b-308 b) with different heights are arranged on the side wall of the test barrel (1); and
through holes penetrating through the side wall of the test barrel (1) are arranged at the test point positions (301 a-308 a, 301 b-308 b);
and respectively connecting the test components for different test items with the through holes of the corresponding test point positions (301 a-308 a, 301 b-308 b) of the test barrel (1) to perform different test items.
5. The method of claim 4, wherein the operation of loading the pneumatic drapery assembly (5) further comprises: and (3) enabling the air inlet pipe (523) of the air pressure output component (520) to penetrate through the through hole of the corresponding first test site (304a) and extend out of the test barrel (1).
6. The method according to claim 5, characterized in that the operation of connecting the test assembly to the test tub (1) and carrying out the penetration test of the test soil sample with the test assembly comprises:
connecting a test component for performing a coarse-grained soil test with the test barrel (1), and performing a coarse-grained soil penetration test on the test soil sample; and/or
Connecting a test component for performing a fine-grained soil test with the test barrel (1), and performing a fine-grained soil penetration test on the test soil sample.
7. The method according to claim 6, characterized in that the operation of connecting a test assembly for carrying out a coarse soil test with the test tub (1) comprises:
connecting a first water pressure sensor (9a) to a through hole of a second test site (307a) above the pneumatic drapery assembly (5) and a second water pressure sensor (9b) to a through hole of a third test site (305a) above the pneumatic drapery assembly (5);
connecting a third water pressure sensor (9c) to a through hole of a fourth test site (302a) between the air pressure curtain assembly (5) and the filter assembly (6);
connecting a first drain pipe (10a) with a through hole of a fifth test site (304b), wherein the fifth test site (304b) and the first test site (304a) are arranged at the same height of the test tub (1);
connecting a second drain pipe (10b) with a through hole of a sixth test site (301a) arranged below the filter assembly (6);
arranging a first flow sensor (11a) at the first drain pipe (10 a); and
a second flow sensor (11b) is provided in the second drain pipe (10 b).
8. The method of claim 7, wherein the act of conducting a coarse soil penetration test on the test soil sample comprises:
injecting water into the test barrel (1);
closing the second drain pipe (10b) and opening the first drain pipe (10 a);
detecting the water pressure at the second test site (307a) by the first water pressure sensor (9a), the water pressure at the third test site (305a) by the second water pressure sensor (9b), and the flow rate at the fifth test site (304b) by the first flow rate sensor (11 a); and
determining a first permeability coefficient of the test soil sample according to the data detected by the first water pressure sensor (9a), the second water pressure sensor (9b) and the first flow sensor (11a), and wherein
The operation of performing a coarse-grained soil penetration test on the test soil sample further comprises:
closing the first drain pipe (10a) and opening the second drain pipe (10 b);
-detecting the water pressure of said second test site (307a) by means of said first water pressure sensor (9a), -detecting the water pressure of said third test site (305a) by means of said second water pressure sensor (9b), -detecting the water pressure of said fourth test site (302a) by means of said third water pressure sensor (9c), and-detecting the flow of said sixth test site (301a) by means of said second flow sensor (11 b); and
determining a second permeability coefficient of the test soil sample according to data detected by the first water pressure sensor (9a), the second water pressure sensor (9b), the third water pressure sensor (9c) and the second flow sensor (11b), and wherein
The operation of performing a coarse-grained soil penetration test on the test soil sample further comprises:
injecting a colored liquid into the air pressure output component (520) and then applying air pressure to the air pressure output component (520);
determining a relationship between the penetration height of the colored liquid and the air pressure of the air pressure curtain assembly and a relationship between the second permeability coefficient of the test soil sample and the air pressure of the air pressure curtain assembly according to the air pressure applied to the air pressure output part (520), the penetration height of the colored liquid, the water pressure detected by the first water pressure sensor (9a), the water pressure detected by the second water pressure sensor (9b), the water pressure detected by the third water pressure sensor (9c) and the flow rate detected by the second flow rate sensor (11 b).
9. A method according to claim 6, characterized in that the operation of connecting a test assembly for fine soil testing to the test bucket (1) comprises:
connecting an overflow pipe (2) with through holes which are arranged on the side wall of the test barrel (1) and are higher than the test point positions (301 a-308 a, 301 b-308 b);
connecting a first tee fitting (12a) with a through-hole of a fifth test site (304b), wherein the fifth test site (304b) is located at the same height of the test tub (1) as the first test site (304 a);
connecting a second tee pipe fitting (12b) with a through hole of a sixth test site (301a) disposed below the filter assembly (6);
connecting a first pressure pipe (13a) and a first water pressure sensor (9a) with the first tee fitting (12 a); and
connecting a second pressure pipe (13b) and a second water pressure sensor (9b) to the second tee fitting (12 b).
10. The method of claim 9, wherein the act of conducting a fine-grained soil infiltration test on the test soil sample comprises:
injecting water into the test barrel (1);
opening the first tee (12a) and the second tee (12b) until after water within the first pressure tube (13a) and the second pressure tube (13b) has spilled, closing the first tee (12a) and the second tee (12 b);
stopping injecting water into the test barrel (1) and opening the first three-way pipe fitting (12 a); and
detecting the variation data of the water pressure of the fifth test site (304b) with time through the first water pressure sensor (9a), and determining a third permeability coefficient of the test soil sample according to the variation data detected by the first water pressure sensor (9a), and the method is characterized in that
The operation of performing a fine soil penetration test on the test soil sample further comprises:
closing the first tee (12a) and opening the second tee (12 b); and
detecting the change data of the water pressure of the sixth test site (301a) along with the time through the second water pressure sensor (9b), and determining the fourth permeability coefficient of the test soil sample according to the change data detected by the second water pressure sensor (9b), and the water pressure change data is characterized in that
The operation of performing a fine soil penetration test on the test soil sample further comprises:
replenishing the water level in the first pressure pipe (13a) and the second pressure pipe (13b) to a preset height;
injecting a colored liquid into the air pressure output component (520) and then applying air pressure to the air pressure output component (520);
opening the first tee pipe (12a), and determining the relationship between the permeation height of the colored liquid and the air pressure of the air pressure curtain assembly and the relationship between the fourth permeability coefficient of the test soil sample and the air pressure to the air pressure curtain assembly according to the air pressure applied to the air pressure output part (520), the permeation height of the colored liquid and the water pressure detected by the second water pressure sensor (9 b).
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