CN211927461U - Tool for preparing hollow cylindrical sandy soil sample by sand rain method - Google Patents

Abstract

The utility model discloses a tool for preparing a hollow cylindrical sandy soil sample by a sand rain method, which comprises a cylindrical sample inner die (1), a cylindrical sample outer die (2) and a cylindrical base (3), and also comprises a funnel base (4), an annular bayonet (5) and a rotating fan blade (6); rotatory fan blade (6) and annular bayonet socket (5) combination form controllable sand outlet, and the sample outer mould (2) and the sample between the mould (1) clearance corresponding, mould (2) upper end sealing connection outside funnel base (4) lower extreme and the sample, upper end opening, the middle part holds the controllable sand outlet that rotatory fan blade (6) and annular bayonet socket (5) combination formed. The utility model discloses the system utensil of hollow cylinder sand sample is prepared to the sand rain method, and the sand hoop distributes evenly, relative closely knit degree control is accurate.

Description

Tool for preparing hollow cylindrical sandy soil sample by sand rain method

Technical Field

The utility model belongs to the technical field of geotechnical test instrument equipment, especially a sand rain legal system is equipped with device of hollow cylinder sandy soil sample.

Background

The hollow cylindrical sandy soil sample is used for researching the continuous rotation problem of a main stress shaft of a soil body through a hollow cylindrical torsional shear apparatus (HCA).

The sand rain method is one of the commonly used sand sample preparation methods. Based on the process of soil formation, sand is dropped into the jig from a certain height (so as to control the dropping speed) through the hopper. The sand sample thus produced more closely resembles the natural form of sand. Through research and comparison with other sample preparation methods, such as an insertion and tamping method, a vibration method and a compaction method, the sample prepared by the sand rain method generally shows a shrinkage reduction state in a triaxial test. Therefore, the sand rain method sample is an effective sample preparation scheme for researching various indexes of a sand layer formed by wind load and water flow deposition and researching the shrinkage reduction characteristic of sand. The sand rain method is convenient when being applied to the traditional solid sample jig, and can obtain an ideal relative compactness sample by being assisted with a compactor.

The structure of the existing hollow cylindrical sample preparation jig is shown in fig. 1, and the common structure size is 100mm in outer diameter, 60mm in inner diameter and 200mm in height. The device comprises a cylindrical sample inner die 1, a cylindrical sample outer die 2 and a cylindrical base 3. The sample inner mold 1 is a cylinder formed by four-flap side walls to form a sample inner cavity, and the sample outer mold 2 is a cylinder formed by three-flap side walls (commonly called three-flap in the art) to form a sample outer wall. The sample inner die 1 is concentrically arranged in the sample outer die 2, and the lower ends of the sample inner die and the sample outer die are fixedly connected with the base 3.

When adopting sand rain method sand preparation appearance, when needing to sieve the sand with the help of the funnel, because of current hollow cylinder appearance preparation tool annular mouth is narrower, funnel neck diameter and annular mouth size differ little, appear blocking easily when leading to rotatory injection soil appearance to can not guarantee that the surface of sand sample is on a water flat line, can't let its distribution even, relative closely knit degree uncontrollable, seriously influenced the dynamic characteristic research of sand under complicated stress route.

Disclosure of Invention

An object of the utility model is to provide a sand rain legal system of preparing hollow cylinder sandy soil sample possesses, and the sandy soil hoop distributes evenly, relative closely knit degree control is accurate.

Realize the utility model discloses the technical solution of purpose does:

a tool for preparing a hollow cylindrical sandy soil sample by a sand rain method comprises a cylindrical sample inner die 1, a cylindrical sample outer die 2 and a cylindrical base 3, and further comprises a funnel base 4, an annular bayonet 5 and a rotating fan blade 6; rotating fan blade 6 forms controllable sand outlet with the combination of annular bayonet 5, and is corresponding with the clearance between outer mould 2 of sample and the sample inner mould 1, 4 lower extremes of funnel base and the outer mould 2 upper end sealing connection of sample, upper end opening, the middle part holds the controllable sand outlet that rotating fan blade 6 and the combination of annular bayonet 5 formed.

Compared with the prior art, the utility model, it is showing the advantage and is:

1. the sand is distributed uniformly in the circumferential direction: the sand outlets uniformly arranged along the annular direction of the utility model can lead the sandy soil to fall to the bottom of the jig from the same height at the same time and at the same speed, thus leading the sandy soil samples to be uniformly distributed along the annular direction;

2. the relative compactness is accurately controlled: the falling speed of the sandy soil is controlled by controlling the size of the sand outlet, so that the relative compactness of the sandy soil sample is more accurately controlled.

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Drawings

Fig. 1 is a schematic structural view of a hollow cylindrical sample preparation jig in the prior art.

Fig. 2 is a schematic view of the three-dimensional structure of the tool for preparing the hollow cylindrical sandy soil sample by the novel sand rain method.

Fig. 3 is a vertical cross-sectional view of fig. 2.

Fig. 4 is a top view of fig. 2.

Figure 5 is a vertical cross-sectional view of the hopper base of figure 2.

Figure 6 is a vertical cross-sectional view of the annular bayonet of figure 2.

Fig. 7 is a vertical cross-sectional view of the rotating fan blade of fig. 2.

Fig. 8 is a top view of fig. 7.

In the figure, 1, a sample inner mould has four petals to form a hollow cylinder to form a sample inner cavity, 2, a sample outer mould has three petals, 3, a base, 4, a funnel base, 5, an annular bayonet, 6, a rotating fan blade,

41 wide-mouth funnel, 42 platforms, 43 sample guide ring, 51 upper annular bayonet, 52 lower annular bayonet, 61 blade group, 62 cylinder, 63 screw thread.

Detailed Description

The utility model discloses a mould utensil of hollow cylinder sand and soil sample is prepared to molding sand rain method, including mould 1, the outer mould 2 of cylinder sample and cylindric base 3 in the cylinder sample as shown in figure 1.

As shown in fig. 2, 3 and 4, as an improvement point of the present invention, the tool for preparing a hollow cylindrical sandy soil sample by a new sand rain method further comprises a funnel base 4, an annular bayonet 5 and a rotating fan blade 6;

rotating fan blade 6 forms controllable sand outlet with the combination of annular bayonet 5, and is corresponding with the clearance between outer mould 2 of sample and the sample inner mould 1, 4 lower extremes of funnel base and the outer mould 2 upper end sealing connection of sample, upper end opening, the middle part holds the controllable sand outlet that rotating fan blade 6 and the combination of annular bayonet 5 formed.

The utility model can make the sand fall to the bottom of the jig from the same height at the same time and at the same speed through the controllable sand outlet, so that the sand samples are uniformly distributed along the ring shape; the falling speed of the sandy soil is controlled by controlling the size of the sand outlet, so that the relative compactness of the sandy soil sample is more accurately controlled.

As shown in fig. 5, the funnel base 4 preferably includes a wide-mouth funnel 41, a landing 42, and a sample guide ring 43;

the inner side of the abutment 42 is hermetically and fixedly connected with the upper end of the sample guide ring 43, and the outer side of the abutment is hermetically and fixedly connected with the lower end of the wide-mouth funnel 41;

the inner diameter of the sample guide ring 43 is the same as the inner diameter of the sample outer mold 2.

As shown in fig. 6, the annular bayonet 5 comprises an upper bayonet 51 and a lower bayonet 52;

the upper bayonet 51 and the lower bayonet 52 are circular rings with the same shape, and a plurality of gaps are uniformly arranged in the circumferential direction of the circular rings;

the upper bayonet 51 and the lower bayonet 52 are oppositely overlapped up and down, the peripheries of the upper bayonet 51 and the lower bayonet 52 are fixedly and hermetically connected, a horizontal circular cavity is formed in the middle of the upper bayonet 51 and the lower bayonet 52, and gaps between the upper bayonet 51 and the lower bayonet 52 are opposite up and down;

the lower bayonet 52 is fixed to the landing 42.

As shown in fig. 7 and 8, the rotating fan blade 6 includes a blade set 61, a cylinder 62 and an external thread 63;

the blade group 61 is a plurality of fan-shaped blades uniformly arranged along the circumferential direction of the circular ring, and the number and the positions of the plurality of fan-shaped blades correspond to the number and the positions of the gaps arranged along the circumferential direction of the upper bayonet 51;

the inner side of the circular ring of the blade group 61 is fixedly and hermetically connected with the lower end of the cylinder 62;

the external thread 63 is sleeved on the outer side of the upper part of the cylinder 62;

the blade group 61 is rotatably arranged in a horizontal circular cavity formed by the upper bayonet 51 and the lower bayonet 52;

the outer diameter of the cylinder 62 is the same as the outer diameter of the mold 1 in the sample.

Because the external diameter of drum 62 is the same with the external diameter of mould 1 in the sample, the internal diameter of sample guide ring 43 is the same with the internal diameter of mould 2 outside the sample, thereby make blading 61 arrange in the sample between mould 1 and the mould 2 outside the sample, rotate external screw thread 63, make drum 62 drive blading 61, with last bayonet 51 and lower bayonet 52 cooperation, form controllable sand outlet, the whereabouts height and the time of effective control sand, make the sand sample along annular evenly distributed, and come the speed of control sand whereabouts through the size of control sand outlet, thereby the relative compactness of more accurate control sand sample.

The working process of the tool for preparing the hollow cylindrical sandy soil sample by the novel sand rain method is described in detail below.

Firstly, the thread 61 of the rotary fan blade 6 is poked to enable the sand outlet of the annular bayonet 5 to be in a closed state.

Next, the sand weighed in layers is injected by rotation along the wide-mouth funnel 41 of the funnel base 4. After the injection, the sand surface is lightly scraped.

The thread 61 is then slowly shifted to control the sand outlet sand production rate. After the threads 61 are shifted to an ideal position according to the required sand production speed, the jig is knocked by rubber hammers one by one (the times are determined according to the required relative compactness) so that sand grains fall at the required speed.

And finally, when all the sand particles in the wide-mouth funnel 41 fall into the sample outer mold 2, stopping knocking, closing the sand outlet, injecting sand, and repeating the operation until the sand required by weighing is filled.

Claims (4)

1. The utility model provides a sand rain legal system is equipped with system utensil of hollow cylinder sand soil sample, includes cylinder sample inner mould (1), outer mould (2) of cylinder sample and cylindric base (3), its characterized in that:

the funnel comprises a funnel base (4), an annular bayonet (5) and a rotating fan blade (6);

rotatory fan blade (6) and annular bayonet socket (5) combination form controllable sand outlet, and the sample outer mould (2) and the sample between the mould (1) clearance corresponding, mould (2) upper end sealing connection outside funnel base (4) lower extreme and the sample, upper end opening, the middle part holds the controllable sand outlet that rotatory fan blade (6) and annular bayonet socket (5) combination formed.

2. The tool of claim 1, wherein:

the funnel base (4) comprises a wide-mouth funnel (41), a platform (42) and a sample guide ring (43);

the inner side of the platform (42) is hermetically and fixedly connected with the upper end of the sample guide ring (43), and the outer side of the platform is hermetically and fixedly connected with the lower end of the wide-mouth funnel (41);

the inner diameter of the sample guide ring (43) is the same as that of the sample outer die (2).

3. The tool of claim 2, wherein:

the annular bayonet (5) comprises an upper bayonet (51) and a lower bayonet (52);

the upper bayonet (51) and the lower bayonet (52) are circular rings with the same shape, and a plurality of gaps are uniformly arranged in the circumferential direction of the circular rings;

the upper bayonet (51) and the lower bayonet (52) are oppositely overlapped up and down, the peripheries of the upper bayonet and the lower bayonet are fixedly and hermetically connected, a horizontal circular cavity is formed in the middle of the upper bayonet and the lower bayonet, and gaps between the upper bayonet (51) and the lower bayonet (52) are opposite up and down;

the lower bayonet (52) is fixed on the platform (42).

4. The tool of claim 3, wherein:

the rotating fan blade (6) comprises a blade group (61), a cylinder (62) and an external thread (63);

the blade group (61) is a plurality of fan-shaped blades uniformly arranged along the circumferential direction of the circular ring, and the number and the positions of the fan-shaped blades correspond to the number and the positions of gaps arranged in the circumferential direction of the upper bayonet (51);

the inner side of the circular ring of the blade group (61) is fixedly and hermetically connected with the lower end of the cylinder (62);

the external thread (63) is sleeved on the outer side of the upper part of the cylinder (62);

the blade group (61) is rotatably arranged in a horizontal circular cavity formed by the upper bayonet (51) and the lower bayonet (52);

the outer diameter of the cylinder (62) is the same as the outer diameter of the sample inner mold (1).

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