CN106644649A - Triaxial sample preparation device for hammer-type rockfill materials and use method - Google Patents

Abstract

The invention discloses a hammer-type rockfill material triaxial sample preparation device and a use method. The hammer-type rockfill triaxial sample preparation device includes a sample preparation mechanism and a compaction mechanism, and the sample preparation mechanism includes a split mold, a collar, a base, a permeable plate, a permeable stone, a rubber sleeve, and an O-ring and a vacuum pump, the compaction device includes a compaction hammer, a compaction pad, a guide rod, a measuring rod, a guide rod locator and a test ruler. The present invention realizes the molding of the bulk rockfill material sample through the rubber sleeve adsorbed on the sample preparation cylinder, utilizes the mutual cooperation between the guide rod, the measuring rod and the test ruler to realize the uniform layered sample preparation of the rockfill material, and finally, the two mechanisms With high-efficiency cooperation, the sample production of continuous graded piles and single graded rockfill materials is realized, and the purpose of sample making is independent of the triaxial compression instrument and the produced samples have good uniformity.

Description

A hammer-type rockfill material triaxial sample preparation device and its application method

technical field

The invention relates to the field of civil and water conservancy engineering tests, in particular to a rockfill material triaxial test sample preparation device and a use method thereof.

Background technique

The proportion of clean energy in total energy is increasing year by year, and hydropower energy is an important part of clean energy. Hydroelectric power generation is mainly achieved through water storage in dams. Soil and rockfill materials are important construction materials for dam foundations. During engineering construction, tamping and rolling methods are used to make soil and stone materials reach their engineering design density, and the shear strength of dense soil and stone materials It is an important parameter for the stability of the dam foundation, and the shear strength parameter is mainly obtained through indoor triaxial tests on the scaled-down soil and rock. The indoor triaxial sample is made by layered compaction method with the control of sample density as the index. Since the soil and rock are non-viscous bulk materials, the samples are generally made on a triaxial testing machine. After the production is completed, a triaxial test is carried out. This method of sample making reduces the utilization rate of the triaxial testing machine and prolongs a set The time required for the test, and when layered samples are used, the compaction height of each layer of the sample is not easy to measure accurately, resulting in poor sample uniformity and large density dispersion, so that the accuracy of the triaxial test results cannot be obtained. Guaranteed, it cannot truly reflect the real mechanical parameters of soil and rock. Due to the rise of self-compacting concrete, rockfill concrete and cemented granular materials have become a new type of environmentally friendly dam foundation material. The construction technology of this dam foundation is to use high-performance self-compacting concrete to fill the pores of the rockfill material. The foundation material of the dam foundation is continuously graded. The earth-rock material is transformed into a poorly graded rockfill material. The degree of improvement of the shear strength of the cemented granular material relative to the rockfill material is an important reference index for selecting the type of self-compacting concrete. Therefore, it is particularly important to perform triaxial tests on the rockfill material. Based on the above situation, there is an urgent need for a new type of rockfill material triaxial sample production device and method of use, in order to achieve the purpose of high sample uniformity, uniform compactness and mass production of samples independently of the testing machine.

Contents of the invention

The purpose of implementing the present invention is to propose a hammer-type rockfill material triaxial sample preparation device, using the sample preparation mechanism and compaction mechanism of the device, to realize different gradation rockfill materials independently from the triaxial testing machine for sample preparation. The purpose of sample preparation is to improve sample production efficiency and reduce triaxial test time, while ensuring high sample uniformity and uniform density. In order to achieve the above object, the present invention adopts the following technical scheme: a hammer-type rockfill triaxial sample preparation device, comprising: a sample preparation mechanism, including a split mold, a collar, a base, a permeable plate, a permeable stone, Rubber sleeves, O-rings and vacuum pumps, the inside of the split mold is engraved with thread-like indentations, the permeable plate can be embedded in the groove of the base; , a guide rod, a measuring rod, a guide rod fixer, a test ruler, the guide rod and the compacting backing plate are connected by a metal ball fixed at the end of the guide rod.

Preferably, the two split molds are provided with air suction ducts and the inner walls are engraved with spiral indentations, which is beneficial for the rubber sleeve to be tightly adsorbed on the inner wall of the sample preparation cylinder under the action of the vacuum pump.

Preferably, the two split molds respectively have a convex interface and a concave interface, the size of the concave interface is slightly larger than that of the convex interface, and a layer of elastic sealing gasket is contained in the concave interface.

Preferably, the permeable plate and the permeable stone have the same diameter, and the diameter of the lower end of the permeable plate is slightly smaller than the diameter of the base groove.

Preferably, the rubber membrane is 8cm longer than the common rubber membrane, so that the rubber membrane can be respectively fixed on the upper and lower permeable plates after the sample preparation is completed.

Preferably, the guide rod of the compacting hammer and the compacting backing plate are connected by a metal ball fixed at the end of the guide rod, and the diameter of the metal ball is larger than that of the guide rod.

Preferably, the measuring rod is a high-rigidity metal rod with a needle-shaped head, one end is fixed to the guide rod by a bolt, and the other end points to the height measuring ruler.

Preferably, the height of the test ruler can be adjusted in the vertical direction, and each compaction starts from 0 scale, which is easy to read.

The present invention also discloses a method for using the hammer-type triaxial sample preparation device for rockfill materials, including the following steps:

a. Put the base on a horizontal plane, place the permeable plate in the groove of the base, put the permeable stone on the permeable plate, put the rubber film on the bottom of the permeable plate, and fix the rubber film on the permeable plate with an O-ring , combine the split mold, and seal the split mold with a collar, turn the rubber film protruding from the outside of the sample preparation cylinder to the outer wall of the sample preparation cylinder and fix it with an O-ring, connect the suction conduit and the vacuum pump with a rubber tube, and extract the air for use The rubber film is tightly attached to the inner wall of the sample preparation cylinder;

b. Put the rockfill materials with a certain mass and evenly stirred into the rubber film, put the guide rod, compaction backing plate combination and compaction hammer, fix the position of the guide rod with a locator, adjust the height of the test ruler to make the compaction measurement The rod points to the 0 scale line, use the compaction hammer to compact the rock pile, and stop compaction when the measuring rod points to the set height;

c. Repeat step b until the height of the sample meets the test requirements. Put a permeable stone and a permeable plate on the top of the sample, place the compaction hammer on the surface of the permeable plate, stop vacuuming, remove the O-ring outside the sample preparation cylinder, and use The O-ring fixes the rubber membrane on the permeable plate;

d. After the test is completed, the components shall be dismantled in reverse order of assembly and the triaxial sample of the rockfill material shall be properly kept.

Compared with the existing rockfill material triaxial sample preparation method, the present invention has the following advantages:

In the hammer-type triaxial sample preparation device for rockfill materials involved in the present invention, the sample preparation mechanism and the compaction mechanism cooperate closely with each other to achieve high sample uniformity, uniform compactness, and mass production testing independently of the testing machine. The purpose of sampling; the two split molds are initially connected through a concave-convex interface, and then sealed with a collar, which is easy to assemble and disassemble the sample preparation cylinder, and at the same time can quickly extract the air between the sample preparation cylinder and the rubber membrane; The inner wall of the mold is engraved with thread-like dents, which is good for the rubber film to be tightly adsorbed on the inner wall of the sample preparation cylinder; the diameter of the permeable plate is slightly smaller than the diameter of the groove of the base, so that the sample can be taken out under slight artificial disturbance; the compaction hammer is guided The rod and the compaction backing plate are connected by a metal ball fixed at the end of the guide rod to ensure a more uniform force on the rockfill under compaction and a better uniformity of the sample; the cooperation of the measuring rod and the test ruler can accurately measure the compaction The height of the guide rod locator consists of two metal rods and buckles that can only rotate 90 degrees horizontally, which realizes the accuracy of positioning and the ease of disassembly of the device.

Description of drawings

Fig. 1 is a kind of hammer type rockfill material triaxial sample preparation device of the present invention

Fig. 2 is the schematic diagram of rockfill material sample in the embodiment of the present invention

Fig. 3 is the structural representation of guide rod locator in the embodiment of the present invention

Fig. 4 is a schematic diagram of the structure of the permeable plate in the embodiment of the present invention

Fig. 5 is a schematic diagram of the split mold structure in the embodiment of the present invention

Figure 6 is a schematic structural view of the guide rod and the compaction pad in the embodiment of the present invention

Among them, 1-test ruler, 2-measuring rod, 3-rubber membrane, 4-O-ring, 5-collar, 6-suction duct, 7-split mold, 8-permeable stone, 9-base, 10- Permeable board, 11-stone pile, 12-compaction backing plate, 13-compaction hammer, 14-compaction hammer guide rod, 15-U-shaped buckle, 16-guide rod locator, 17-vacuum pump, 18-metal round ball.

detailed description:

Embodiments of the present invention are described in detail below in conjunction with the accompanying drawings:

Figure 1, Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6 show a hammer-type rockfill material triaxial sample preparation device, including 1-test ruler, 2-measuring rod, 3-rubber film, 4-O-ring, 5-collar, 6-exhaust duct, 7-split mold, 8-permeable stone, 9-base, 10-permeable board, 11-rock-filling material, 12-compaction backing plate, 13 - compaction hammer, 14- compaction hammer guide rod, 15- U-shaped buckle, 16- guide rod locator, 17- vacuum pump, 18- metal ball.

In the present invention, the sample preparation mechanism includes two split molds 7, the convex interface of the split mold 7 matches the size of the concave interface, and the split mold 7 is first formed by the convex and concave interfaces. sample preparation cylinder, and then use the collar 5 to seamlessly connect the two split molds 7; The diameter of the lower end of the lower end is slightly smaller than the diameter of the groove of the base 9, and the rubber sleeve 3 is fixed on the raised end of the water-permeable plate 10 with the O-ring 4; the length of the rubber membrane 3 is longer than that of the split mold 7. During the process, the rubber membrane 7 is turned outward on the outer wall of the sample preparation cylinder and fixed with an O-ring 4; the guide rod 14 and the compaction gasket 12 are connected through the metal ball 18 fixed at the bottom end of the guide rod 14; Rod locator 16 includes two metal rods that can rotate horizontally by 90 degrees. The outermost configuration of the metal rods is a semicircular metal ring, and the two metal rods are connected by two buckles 15; the test ruler 1 It can be pulled up and down; the compaction hammer 13 moves up and down along the guide rod 14 between the compaction height measuring rod 2 and the compaction backing plate 12 .

As shown in Figure 1, Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6, the base 9 is first placed on a horizontal plane, and then the sample preparation mechanism is assembled. After the assembly of the sample preparation barrel is completed, the rubber membrane 3 and Air between sample cylinders. Further put the weighed rockfill material 11 into the sample preparation cylinder, put the combination of the guide rod 14 and the compaction gasket 12 on the surface of the rockfill material, put the compaction hammer 13 along the guide rod 14, and fix the measuring rod 2 On the upper end of the guide rod 14, rotate the locator 16 so that the guide rod 14 is placed in the ring of the locating rod, connect the two locating rods with a U-shaped buckle 15, adjust the height of the test ruler 1, and make the direction of the measuring rod 2 0 tick marks.

The test steps are roughly as follows:

a. Put the base on a horizontal plane, place the permeable plate in the groove of the base, put the permeable stone on the permeable plate, put the rubber film on the bottom of the permeable plate, and fix the rubber film on the permeable plate with an O-ring , combine the split mold, and seal the split mold with a collar, turn the rubber film protruding from the outside of the sample preparation cylinder to the outer wall of the sample preparation cylinder and fix it with an O-ring, connect the suction conduit and the vacuum pump with a rubber tube, and extract the air for use The rubber film is tightly attached to the inner wall of the sample preparation cylinder;

b. Put the rockfill materials with a certain mass and evenly stirred into the rubber film, put the guide rod, compaction backing plate combination and compaction hammer, fix the position of the guide rod with a locator, adjust the height of the test ruler to make the compaction measurement The rod points to the 0 scale line, use the compaction hammer to compact the rock pile, and stop compaction when the measuring rod points to the set height;

c. Repeat step b until the height of the sample meets the test requirements. Put a permeable stone and a permeable plate on the top of the sample, place the compaction hammer on the surface of the permeable plate, stop vacuuming, remove the O-ring outside the sample preparation cylinder, and use The O-ring fixes the rubber membrane on the permeable plate;

d. After the test is completed, the components shall be dismantled in reverse order of assembly and the triaxial sample of the rockfill material shall be properly kept.

It should be emphasized that: the above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are valid. Still belong to the scope of the technical solution of the present invention.

Claims (10)

1. the axle sample sample preparation device of a kind of hammer formula stockpile three, it is characterised in that：The described axle sample of hammer formula stockpile three Sample preparation device includes：

Sample preparation mechanism, including split cavity, the collar, base, porous disc, permeable stone, rubber sleeve, O-ring and vavuum pump, described two Piece split cavity has respectively female and male interface, after the tentatively connection of concavo-convex interface, is sealed by the collar, described rubber Bottom porous disc is fixed in set bottom, and top is fixed on sample preparation cylinder outside and split cavity is tightly depended in the presence of vavuum pump Inwall, on described split cavity inwall screw-shaped indenture is carved with.

Real machine structure, including compaction hammer are hit, real backing plate, guide post, measurement bar, guide post position indicator and test chi is hit, described leads Connect a metal ball and be embedded in bar end and hit inside real backing plate, described measurement bar one end is secured by bolts in guiding Bar, the other end points to test chi.

2. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described two Piece split cavity has respectively symmetry female and male interface, and notching dimension is slightly larger than tang size, recess midsole layer bullet Property pad, the collar effect under realize that split cavity is combined closely.

3. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described is right Die sinking inwall is carved with helical form indenture, indenture not insertion upper/lower terminal face.

4. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described is saturating Water plate upper end is circular protrusions end, and the lower end diameter that there is the groove with protruding end with diameter, porous disc lower end bottom surface is slightly less than bottom The diameter of seat groove.

5. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described rubber Gum cover is fixed on porous disc by o-ring.

6. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described is saturating Water plate surrounding and center are uniformly distributed the permeable hole of a diameter of 2mm.

7. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described leads It is connected by being fixed on the metal ball of guide post end with hitting between real backing plate to bar.

8. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described survey Gauge rod is high rigidity metallic rod, and head is needle-like.

9. the axle sample sample preparation device of a kind of hammer formula stockpile three according to claim 1, it is characterised in that：Described leads It is only capable of horizontally rotating 90 degree of metallic rods by two to bar position indicator and corresponding U-shaped buckle is constituted, two metallic rod direction of rotation On the contrary.

10. the using method of the axle sample sample preparation device of a kind of hammer formula stockpile three, it is characterised in that：Using claim 1 to The axle sample sample preparation device of hammer formula stockpile three described in claim 9, comprises the steps：

A, base is put on horizontal plane, porous disc is positioned in base groove, permeable stone is put on porous disc, by rubber Glue film sleeve is fixed on rubber membrane on porous disc to porous disc bottom with O-ring, combines split cavity, and with the collar by split cavity Sealing, turns to sample preparation drum outer wall and is fixed with O-ring the rubber membrane stretched out outside sample preparation cylinder, and with rubber tube suction catheters are connected And vavuum pump, extracting air makes rubber membrane tightly depend on sample preparation cylinder inwall；

B, the stockpile that will press certain mass and uniform stirring load in rubber membrane, be put into guide post with hit real backing plate assembly with And compaction hammer, with position indicator fixed guide pole position, adjust test chi and highly make to hit actual measurement gauge rod and point to 0 graduation mark, using hitting Real hammering reality stockpile, stops hitting reality when measurement bar points to the height of setting；

C, repeat step b reach test requirements document up to specimen height, permeable stone and porous disc are put at the top of sample, compaction hammer Permeable plate surface is placed on, stops vacuumizing, remove the O-ring outside sample preparation cylinder, and rubber membrane is fixed on porous disc with O-ring On；

D, test are finished, and are removed part successively and are kept properly the axle sample of stockpile three by assembling reverse order.