CN204924988U - Three large -scale bearing appearance devices of coarse -grained soil suitable for CT scan - Google Patents

Abstract

The utility model provides a three large -scale bearing appearance devices of coarse -grained soil suitable for CT scan, including hold a kind base, down porous disk, go up porous disk, sample cap, by the semi -circular sheetmetal of two block splittings form to the die sinking. The lower part of holding kind base is equipped with matches the circular boss of pegging graft with large -scale triaxial apparatus base, and the upper portion of holding kind base is equipped with first circular recess, down is equipped with first water guide air conduction channel, the embedding of lower porous disk to the bottom of circular boss along the recess center first circular recess forms a circular plane and is used for sample bottom contact. Water inlet on the base of first water guide air conduction channel and large -scale triaxial apparatus is linked together, holds kind base side upper portion and establishes the first arc recess of round along a hoop and be used for the ligature rubber membrane, installs on holding kind base through mounting detachably the die sinking. The utility model discloses can dismantlement of triaxial apparatus base and installation be followed to the sample conveniently, the CT scan of triaxial test front and back sample can be realized to acquire the thin sight structural information of the experimental front and back soil body.

Description

Coarse-grained soil large-scale three-bearing sample device suitable for CT scanning

technical field

The utility model relates to the technical field of soil mechanics laboratory testing, in particular to a coarse-grained soil large-scale three-bearing-like device suitable for CT scanning.

Background technique

Coarse-grained soil refers to the soil-rock mixture whose particle size (mass ratio) is greater than 50% with a particle size of 0.075mm-60mm. Coarse-grained soils are widely distributed and abundant in nature. Coarse-grained soil is the main dam material for earth-rock dams and one of the main research objects of soil mechanics. Large-scale triaxial test is the main method to study the strength and deformation characteristics of coarse-grained soil, and the determination of soil parameters by triaxial test has become an important basis for geotechnical engineering design. Coarse-grained soil has the discrete characteristics of bulk materials. It is a macroscopic phenomenological method to study the mechanical behavior of coarse-grained soil simply by triaxial test. Therefore, it is necessary to study the control mechanism behind these macroscopic laws and the corresponding mesoscopic characteristics of the sample. The change of the soil is particularly important. CT scanning technology has been widely used in the field of rock and soil testing in recent years because it can non-destructively, dynamically and quantitatively obtain the mesostructure information of the soil. When observing the mesoscopic structure of soil, it is required that the sample can be easily removed from the triaxial instrument. The device carrying the triaxial sample is light in weight and easy to carry. There should be no metal in the scanning area, and it can be installed on the triaxial instrument after scanning. Continue to carry out saturated consolidation shear tests on the instrument.

The large-scale triaxial sample of coarse-grained soil adopts a cylindrical sample. During the sample preparation, the sample is often prepared on a triaxial tester. A split circular membrane and a rubber membrane are installed on the base of the pressure chamber, and the rubber membrane is used to hold the rubber membrane. One end is fastened to the base of the pressure chamber, and the permeable plate connected to the base is often embedded on the base, and the rubber film covers the permeable plate. After sample preparation, vacuumize to ensure that the sample is upright. After the sample preparation is completed, the pressure chamber base and the test When CT scanning is performed on the sample, since the base of the pressure chamber is heavy and bulky and is made of metal, X-rays cannot penetrate and cannot be scanned together with the base, which requires the sample to be scanned from the base After the CT scanning is completed, the sample can be installed on the base of the triaxial instrument, and a series of tests such as water head saturation will be carried out. Therefore, to explore and implement a new large-scale triaxial sample bearing device for coarse-grained soil suitable for CT scanning and its use method, to realize CT scanning of the sample before and after the triaxial test of coarse-grained soil, so as to obtain the fine details of the soil before and after the test. Observational structural information has important practical significance.

Utility model content

The utility model aims at the deficiencies of the existing sample preparation technology, and provides a coarse-grained soil large-scale three-bearing sample device suitable for CT scanning. It is disassembled and installed from the base of the triaxial instrument, and it is guaranteed to be airtight. The structure is simple and light. It can realize CT scanning of the sample before and after the triaxial test, so as to obtain the mesoscopic structure information of the soil before and after the test.

The technical problem to be solved by the utility model is achieved through the following technical solutions:

A large-scale three-bearing sample device for coarse-grained soil suitable for CT scanning, including a sample-bearing base, a lower permeable plate, an upper permeable plate, a sample cap, and a split mold composed of two separated semicircular metal sheets. The lower part of the sample base is provided with a circular boss that matches with the base of the large triaxial instrument, the upper part of the sample base is provided with a first circular groove, along the center of the groove down to the bottom of the circular boss The first water guide and air guide channel, the lower permeable plate is embedded in the first circular groove to form a circular plane for contacting the bottom of the sample, the first water guide and air guide channel is connected to the water inlet on the base of the large triaxial instrument The upper part of the side of the sample base is provided with a first arc-shaped groove along the ring direction for binding the rubber film. The split mold is detachably installed on the sample base through the fixing piece. The second circular groove, the upper water-permeable plate is embedded in the second circular groove to form a circular plane for contacting the top of the sample, and the upper part of the sample cap side is provided with a fourth arc-shaped groove along the ring direction. For binding rubber film.

As mentioned above, the coarse-grained soil large-scale three-bearing device suitable for CT scanning is equipped with fixing plates from top to bottom at the joints of the split molds, and at least two bolt holes are set on the fixing plates on both sides, and the fixing parts pass through the two Corresponding bolt holes on the side fixing plates connect the two semicircular metal sheets into one.

For the coarse-grained soil large-scale three-bearing device suitable for CT scanning as described above, at least two reinforcement rings are arranged vertically on the split mold to increase the strength of the split mold.

As mentioned above, a coarse-grained soil large-scale three-bearing device suitable for CT scanning has a second arc-shaped groove in the inner circle of the bottom of the split mold for binding the rubber film.

As mentioned above, the coarse-grained soil large-scale three-bearing sample device suitable for CT scanning is provided with multiple bolt holes along the ring direction at the bottom of the split mold, and the first bolt holes are correspondingly arranged along the ring direction on the lower part of the side of the sample base. , the fixing member sequentially passes through the bolt holes of the split mold and the first bolt hole of the sample base to fix the split mold and the sample base.

For the coarse-grained soil large-scale three-bearing sample device suitable for CT scanning as described above, a downward third arc-shaped groove is arranged in the center of the top of the sample cap to match with the loading rod of the triaxial tester.

As mentioned above, the coarse-grained soil large-scale three-bearing sample device suitable for CT scanning, the sample base, the upper water-permeable plate, the lower water-permeable plate, and the sample cap can all be made of special aluminum alloy materials, which are light in weight and can withstand a certain load , X-rays can penetrate and can effectively reduce artifacts.

The beneficial effects of the utility model are: the utility model solves the problem that the sample is fixed to the base of the large triaxial pressure chamber during conventional triaxial sample preparation, and the base of the pressure chamber is heavy and bulky and cannot be scanned by CT. The new type can conveniently disassemble and install the sample from the base of the triaxial instrument, and ensure airtightness. The structure is simple and light. It can realize CT scanning of the sample before and after the triaxial test to obtain the mesoscopic structure of the soil before and after the test. information.

Description of drawings

Fig. 1 shows that the utility model is applicable to the front view of the coarse-grained soil large-scale three-bearing sample device of CT scanning;

Fig. 2 shows that the utility model is applicable to the top view of the sample base in the coarse-grained soil large-scale three-bearing sample device of CT scanning;

Fig. 3 shows that the utility model is applicable to the front view of the split mold in the coarse-grained soil large-scale three-bearing sample device of CT scanning;

Fig. 4 shows that the utility model is applicable to the top view of split mold in the coarse-grained soil large-scale three-bearing sample device of CT scanning;

Fig. 5 shows the top view of the sample cap in the coarse-grained soil large-scale three-bearing device of the present invention suitable for CT scanning.

In the figure: 1—large triaxial instrument base, 2—sample bearing base, 3—lower permeable plate, 4—half split mold, 5—upper permeable plate, 6—sample cap, 7—bottom sealing ring, 8—the first 1. Water guide and air guide channel, 9—first arc groove, 10—second arc groove, 11—fixing plate, 12—first fixing bolt, 13—reinforcing ring, 14—third arc groove , 15—the second water guide and air guide channel, 16—the upper sealing ring, 17—the fourth arc groove, 18—the first bolt hole, 19—the second bolt hole, 20—the second fixing bolt, 21—test Like, 22—rubber film.

Detailed ways

The technical solutions in the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the utility model.

Please refer to Figure 1 and Figure 2, the utility model provides a coarse-grained soil large-scale three-bearing device suitable for CT scanning, including a sample base 2, a lower permeable plate 3, a split mold 4, an upper permeable plate 5, a test Sample cap6.

The lower part of the sample-bearing base 2 is provided with a circular boss that is matched with the large-scale triaxial instrument base 1, and the upper part of the sample-bearing base 2 is provided with a downwardly recessed first circular groove. From the center of the groove down to the bottom of the circular boss, there is a first water-guiding and air-guiding channel 8, and the lower water-permeable plate 3 is embedded in the first circular groove to form a circular plane with a diameter of 300 mm for contacting the bottom of the sample. . The top of the base 1 of the large triaxial instrument is provided with a groove matching the circular boss, and the circular boss is inserted into the groove for matching connection. The first water guide and air guide channel 8 can be connected with the water inlet on the base 1 of the large triaxial instrument, and can be sealed with the lower sealing ring 7 . The upper part of the side of the sample base 2 is circumferentially provided with a circle of first arc-shaped grooves 9 for binding the rubber film 22, and the lower part of the side of the sample base 2 is evenly provided with six first bolt holes 18 along the circumferential direction for Fix with split mold 4.

Please refer to Fig. 3 and Fig. 4 further. The split mold 4 is composed of two semicircular metal sheets, and fixing plates 11 are respectively arranged at the joints thereof from top to bottom, and 4 second bolts are evenly arranged on the fixing plates 11 on both sides. Hole 19, four fixing parts (such as the first fixing bolt 12) pass through the corresponding second bolt holes 19 on the fixing plates 11 on both sides to connect two semicircular metal sheets into one, while the split mold 4 is vertically Three reinforcement rings 13 are arranged at equal intervals to increase the strength of the split mold 4 . A circle of second arc-shaped grooves 10 is arranged in the bottom of the split mold 4 to bind the rubber film 22 . 6 bolt holes are arranged circumferentially symmetrically at the bottom of the split mold 4, and correspond to the first bolt holes 18 of the sample holder base 2, and the split mold 4 and the bearing are connected with a fixing member (such as the second fixing bolt 20). The sample base 2 is fixed, and the split mold 4 can be matched with the above-mentioned sample base 2 and the large triaxial instrument base 1. It can be understood that the bottom of the split mold 4 is set on the upper round table of the large triaxial base 1, and the sample base 2 is installed on the upper round table of the large triaxial base 1, the sample base 2, and the upper part of the large triaxial base 1 The outer diameter of the round table is adapted to the inner diameter of the split mold 4.

Fig. 5 shows the top view of sample cap in the utility model, and the bottom of sample cap 6 is provided with the second circular groove (as shown in Figure 1) that diameter is 260mm, goes up to sample along the groove center The top of the cap 6 is provided with a "Z" shaped second water guide and air guide channel 15, and the end can be sealed with an upper sealing ring 16. The upper water-permeable plate 5 is embedded in the second circular groove to form a circular plane with a diameter of 300 mm for contacting the top of the sample. The center of the top of the sample cap 6 is provided with a downward third arc-shaped groove 14 for Matching with the loading rod of the triaxial tester, a fourth arc-shaped groove 17 is arranged on the upper part of the side of the sample cap 6 along the circumference for binding the rubber film 22 .

In the utility model, the sample bearing base 2, the upper permeable plate 3, the lower permeable plate 5, and the sample cap 6 can all be made of special aluminum alloy materials, which are light in weight, able to bear a certain load, and capable of penetrating X-rays and effectively Features that reduce artifacts.

The utility model is applicable to the use method of the coarse-grained soil large-scale three-bearing sample device of CT scanning specifically as follows:

Step 1. Sample preparation: Insert the sample holder base 2 on the large triaxial instrument base 1, insert the lower permeable plate 3 on the sample holder base 2, and then use a rubber belt to place the rubber film 22 on the first arc of the sample holder 2. Tighten the 9 places of the shaped groove with the sample base 2, then install the split mold 4 on the triaxial base 1, fix the two joints of the split mold 4 with the first fixing bolt 12, and turn the rubber film 22 outwards On the split mold 4, make it straight and close to the inner wall of the split mold 4, prepare the soil material according to the regulations of SL237-053-1999, and vibrate the soil material according to the multi-layer wet compaction method until it is installed Finish the last layer, level the surface, add the upper permeable plate 5 and the sample cap 6, tighten the rubber film 22 at the fourth arc groove 17 on the sample cap 6;

Wherein when the split mold 4 is fixed with the sample base 2, the bolt holes of the split mold 4 correspond to the first bolt holes 18 of the sample base 2, and are fixed with the second fixing bolt 20.

Step 2. Separation of the sample from the base 1 of the triaxial pressure chamber: turn on the vacuum pump to pump air from the top of the sample to make the sample stand upright, and quickly put a sealing ring on the end of the second water-conducting and air-conducting channel 15 on the sample cap 16 seal, then disassemble the second fixing bolt 20 between the split mold 4 and the sample base 2, separate the sample 21 from the triaxial pressure chamber base 1, and disassemble the split mold 4;

Step 3, CT scan: Seal the end of the first water-guiding and air-guiding channel 8 on the sample base 2 with the lower sealing ring 7, together with the sample base 2, the upper water-permeable plate 3, the lower water-permeable plate 5 and the sample cap 6 Transported together to the CT machine for CT scanning;

Step 4, triaxial compression test: After the CT scan is completed, the sample is transported and installed on the base 1 of the triaxial instrument, the sealing ring 7 and the lower sealing ring 16 are removed, and the bottom end of the rubber film 22 is placed on the The second arc-shaped groove 10 of the split mold 4 is fastened to the pressure chamber base 1, continue vacuuming, open the water inlet valve, and the sample is under negative pressure, and the water passes through the water inlet hole on the pressure chamber base 1, The first water-guiding and air-guiding channel 8, the sample 21, and the second water-guiding and air-guiding channel 15 gradually saturate the sample from bottom to top. After the sample is saturated, carry out triaxial compression according to the regulations of SL237-060-1999, etc. test.

After the triaxial compression test is completed, the sample can still be scanned by CT according to the above method.

The beneficial effect of the utility model is that the utility model solves the problem that the sample is fixed to the base of the large triaxial pressure chamber during the conventional triaxial sample preparation, and the base of the pressure chamber is heavy and bulky and cannot be scanned by CT. The new type can conveniently disassemble and install the sample from the base of the triaxial instrument, and ensure airtightness. The structure is simple and light. It can realize CT scanning of the sample before and after the triaxial test to obtain the mesoscopic structure of the soil before and after the test. information.

The above is only a specific embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any skilled person in the technical field can easily think of changes within the technical scope disclosed in the utility model Or replacement, all should be covered within the scope of protection of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (7)

1. A coarse-grained soil large-scale three-bearing sample device suitable for CT scanning, comprising a sample base (2), a lower permeable plate (3), an upper permeable plate (5), and a sample cap (6), characterized in that : It also includes a split mold (4) composed of two separate semicircular metal sheets, the bottom of the sample base (2) is provided with a circular boss that is mated with the large triaxial instrument base (1), The upper part of the sample base is provided with a first circular groove, along the center of the groove down to the bottom of the circular boss is provided with a first water guide and air guide channel (8), and the lower permeable plate (3) is embedded in the second A circular groove forms a circular plane for contacting the bottom of the sample, the first water guide and air guide channel (8) communicates with the water inlet on the base (1) of the large triaxial instrument, the sample holder base (2) A circle of the first arc-shaped groove (9) is arranged in the upper part of the side along the ring direction for binding the rubber film (22). The bottom of the sample cap (6) is provided with a second circular groove, and the upper permeable plate (5) is embedded in the second circular groove to form a circular plane for contacting the top of the sample. The side of the sample cap (6) A circle of fourth arc-shaped grooves (17) is arranged circumferentially on the upper part of the edge for binding the rubber film (22). 2. the coarse-grained soil large-scale three-bearing sample device suitable for CT scanning as claimed in claim 1, is characterized in that: the joint of split mold (4) is respectively provided with fixed plate (11) from top to bottom, and both sides At least two bolt holes are arranged on the fixing plate (11), and the fixing piece passes through the corresponding bolt holes on the fixing plates (11) on both sides to connect the two semicircular metal sheets into one. 3. the coarse-grained soil large-scale three-bearing sample device that is applicable to CT scanning as claimed in claim 1, is characterized in that: at least two reinforcement rings (13) are set along the vertical etc. in the split mold (4), to increase the Strength of mold opening (4). 4. the coarse-grained soil large-scale three-bearing sample device suitable for CT scanning as claimed in claim 1, is characterized in that: the inner circle of the bottom of the split mold (4) is provided with a second arc-shaped groove (10) for For binding rubber film (22). 5. the coarse-grained soil large-scale three-bearing sample device applicable to CT scanning as claimed in claim 1, is characterized in that: a plurality of bolt holes are arranged circumferentially at the bottom of the split mold (4), and the sample base (2 ) are provided with first bolt holes (18) correspondingly along the ring direction, and the fixing parts pass through the bolt holes of the split mold (4) and the first bolt holes (18) of the sample base (2) in turn to Die opening (4) and sample base (2) are fixed. 6. the coarse-grained soil large-scale three-bearing sample device applicable to CT scanning as claimed in claim 1, is characterized in that: the center of the sample cap (6) top is provided with a downward third arc-shaped groove (14), Used to match the loading rod of the triaxial tester. 7. The coarse-grained soil large-scale three-bearing sample device suitable for CT scanning as claimed in claim 1, characterized in that: the sample base (2), the upper water-permeable plate (3), the lower water-permeable plate (5), the sample The cap (6) can be made of special aluminum alloy material, which is light in weight, can bear a certain load, can penetrate X-rays and can effectively reduce artifacts.