Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an installation method, a disassembly method and a use method of a hollow cylindrical sample.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the installation method of the sample preparation device of the hollow cylindrical sample comprises the following steps:
step 1, placing a drainage chassis 4 on a test rack 7, and keeping the drainage chassis 4 horizontal;
step 2, uniformly coating a layer of vacuum sealing grease on the edge of the four-petal inner cylinder assembly 101, aligning and folding the four-petal inner cylinder assembly 101, and inserting the four-petal inner cylinder assembly into an inner cylinder clamping groove 402 of the drainage chassis 4;
step 3, uniformly coating a layer of vacuum sealing grease on the edge of the matched water-permeable top cover 3, and clamping the vacuum sealing grease into a fixing groove 102 at the top end of the inner cylinder assembly 101;
step 4, wetting circular filter paper with the diameter of 60mm, and flatly attaching the circular filter paper to the water-permeable top cover 3; wetting a filter paper strip with the width of 10-12mm, and flatly attaching the filter paper strip to the water permeable hole 103 of the inner cylinder assembly 101; aims to accelerate the drainage of the soil sample and prevent fine particles in the soil from being filtered out; the assembly of the inner cylinder 1 is completed;
step 5, placing the sealing washer 6 into the outer cylinder clamping groove 401 of the drainage chassis 4;
step 6, uniformly coating a layer of vacuum sealing grease on the inner sides of the limiting grooves 205 of the two-petal outer cylinder consolidation component 201, folding the two-petal outer cylinder consolidation component 201, extending bolts into bolt holes of two adjacent locking blocks 204 to fix the two-petal outer cylinder consolidation component 201 into a whole, and completing the assembly of the consolidation outer cylinder 2;
step 7, vertically inserting the assembled consolidation outer cylinder 2 into an outer cylinder clamping groove 401 of the drainage base 4, aligning the fixing hole A203 and the fixing hole B404, adjusting the fixation holes to be completely attached to the drainage base 4, fixing the consolidation outer cylinder 2 on the drainage chassis 4 through bolts, and connecting the consolidation outer cylinder 2 and the drainage chassis 4 through the bolts; and finishing the installation of the sample preparation device of the hollow cylindrical sample.
The use method of the sample preparation device for the hollow cylindrical sample comprises the following steps:
step 1, air-drying a soil sample; spreading the soil sample obtained on site into a thin layer of 0.5-0.8 cm, spreading on clean kraft paper, placing in a shady, dry and ventilated place, and turning over once every 1 hour to accelerate the drying of the soil sample;
step 2, removing impurities from the soil sample; placing the air-dried soil sample on a rubber plate, and grinding the soil sample by using wood, wherein the gravel cannot be crushed in the grinding process; sieving the rolled soil sample by a sieve with 2mm holes to remove larger impurities in the soil sample;
step 3, drying the soil sample; flatly spreading the soil sample without impurities into a drying box, drying at 105-110 ℃, weighing the soil sample once every two hours, and when the drying time is not less than 8 hours and the change difference of the soil sample weight weighed each time is within 0.02%, determining that the soil sample is completely dried;
step 4, slurry preparation; weighing 1000g of the dried soil sample by using an electronic scale, putting the dried soil sample into a preparation barrel, adding a small amount of airless water in a plurality of times, and stirring by using a stirring rod until the slurry flows uniformly and has no caking; continuously adding the airless water until the water content reaches 1.8-2.5 times of liquid limit; the distance between the liquid level and the water filling port in the whole water adding process is not more than 3cm, so that the air is reduced;
step 5, mud is subjected to material sealing; sealing a material preparation barrel filled with the slurry by using a preservative film, sealing the material for 15 hours to uniformly mix water and soil, and vibrating once every 3 hours to remove bubbles in the slurry;
step 7, injecting slurry; the smoldered slurry is injected into the installed sample preparation device at a constant speed by using a funnel and a rubber tube, the vertical distance between the mouth of the rubber tube and the liquid level of the slurry is not higher than 3cm in the grouting process so as to prevent air from being mixed in, and the sample preparation device is vibrated slightly;
step 8, pressurizing and solidifying or/and vacuum pumping;
and 9, observing the water quantity change in the measuring cylinder 9, when the water discharge reaches a preset value, selectively closing the vacuum pump 10 according to actual conditions, waiting for the vacuum negative pressure in the device to be slowly discharged to 0kPa, and standing the device for 1 hour so as to facilitate the disassembly of the subsequent sample preparation device.
Compared with the prior art, the invention has the advantages that:
the method has the advantages that: the mounting and connection of the invention mostly adopt a mortise and tenon buckling mode, so that the soil sample can be more accurately close to the required standard size; a vacuum bin with higher tightness is formed, so that water and gas can be conveniently discharged, and the control on the water content is more accurate; and effectively reduced when tearing open the appearance disturbance degree to the soil sample, avoided carrying out the secondary cutting to soil sample inside and outside diameter, provide probably for once only making fast the saturated hollow cylinder sample that has the inside and outside diameter of international common standard.
The method has the advantages that: the invention combines two common slurry consolidation methods, exerts the advantages of the vacuum consolidation method of efficiently and uniformly discharging water and gas in the soil sample, and simultaneously adopts the pressurization consolidation to make up the defect of easily causing the soil sample to be in a hyperconjugation state in the vacuum consolidation, thereby greatly improving the consolidation efficiency, shortening the sample preparation period, and the prepared sample can better meet the requirements of actual tests. The improved consolidation device is simpler, more convenient and smaller, and effectively prevents the slurry layering phenomenon, so that the prepared sample is more uniform, and the comparative analysis of the hollow cylinder torsional shear test result is facilitated.
The method has the advantages that: the invention can realize the one-time rapid manufacture of saturated hollow cylindrical samples with domestic common standard inner and outer diameters of 60mm multiplied by 100 mm.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings, in order that the present disclosure may be more fully understood and fully conveyed to those skilled in the art. While the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the invention is not limited to the embodiments set forth herein.
The installation method of the sample preparation device of the hollow cylindrical sample comprises the following steps:
step 1, placing a drainage chassis 4 on a test rack 7, and keeping the drainage chassis 4 horizontal;
step 2, uniformly coating a layer of vacuum sealing grease on the edge of the four-petal inner cylinder assembly 101, aligning and folding the four-petal inner cylinder assembly 101, and inserting the four-petal inner cylinder assembly into an inner cylinder clamping groove 402 of the drainage chassis 4;
step 3, uniformly coating a layer of vacuum sealing grease on the edge of the matched water-permeable top cover 3, and clamping the vacuum sealing grease into a fixing groove 102 at the top end of the inner cylinder assembly 101;
step 4, wetting circular filter paper with the diameter of 60mm, and flatly attaching the circular filter paper to the water-permeable top cover 3; wetting a filter paper strip with the width of 10-12mm, and flatly attaching the filter paper strip to the water permeable hole 103 of the inner cylinder assembly 101; aims to accelerate the drainage of the soil sample and prevent fine particles in the soil from being filtered out; the assembly of the inner cylinder 1 is completed;
step 5, placing the sealing washer 6 into the outer cylinder clamping groove 401 of the drainage chassis 4;
step 6, uniformly coating a layer of vacuum sealing grease on the inner sides of the limiting grooves 205 of the two-petal outer cylinder consolidation component 201, folding the two-petal outer cylinder consolidation component 201, extending bolts into bolt holes of two adjacent locking blocks 204 to fix the two-petal outer cylinder consolidation component 201 into a whole, and completing the assembly of the consolidation outer cylinder 2;
step 7, vertically inserting the assembled consolidation outer cylinder 2 into an outer cylinder clamping groove 401 of the drainage base 4, aligning the fixing hole A203 and the fixing hole B404, adjusting the fixation holes to be completely attached to the drainage base 4, fixing the consolidation outer cylinder 2 on the drainage chassis 4 through bolts, and connecting the consolidation outer cylinder 2 and the drainage chassis 4 through the bolts; and finishing the installation of the sample preparation device of the hollow cylindrical sample.
The use method of the sample preparation device for the hollow cylindrical sample comprises the following steps:
step 1, air-drying a soil sample; spreading the soil sample obtained on site into a thin layer of 0.5-0.8 cm, spreading on clean kraft paper, placing in a shady, dry and ventilated place, and turning over once every 1 hour to accelerate the drying of the soil sample;
step 2, removing impurities from the soil sample; placing the air-dried soil sample on a rubber plate, and grinding the soil sample by using wood, wherein the gravel cannot be crushed in the grinding process; sieving the rolled soil sample by a sieve with 2mm holes to remove larger impurities in the soil sample;
step 3, drying the soil sample; and flatly spreading the soil sample without impurities into a drying box, drying at 105-110 ℃, weighing the soil sample once every two hours, and when the drying time is not less than 8 hours and the change difference of the soil sample weight weighed each time is within 0.02%, determining that the soil sample is completely dried. Note: the above specification applies to soils having an organic content of no more than 5% by mass of the dry soil sample; if the organic matter content in the soil sample is 5-10%, the drying temperature is set to 65-70 ℃.
Step 4, slurry preparation; weighing 1000g of the dried soil sample by using an electronic scale, putting the dried soil sample into a preparation barrel, adding a small amount of airless water in a plurality of times, and stirring by using a stirring rod until the slurry flows uniformly and has no caking; continuously adding the airless water until the water content reaches 1.8-2.5 times of liquid limit; the distance between the liquid level and the water filling port in the whole water adding process is not more than 3cm, so that the air is reduced;
step 5, mud is subjected to material sealing; sealing a material preparation barrel filled with the slurry by using a preservative film, sealing the material for 15 hours to uniformly mix water and soil, and vibrating once every 3 hours to remove bubbles in the slurry;
step 7, injecting slurry; the smoldered slurry is injected into the installed sample preparation device at a constant speed by using a funnel and a rubber tube, the vertical distance between the mouth of the rubber tube and the liquid level of the slurry is not higher than 3cm in the grouting process so as to prevent air from being mixed in, and the sample preparation device is vibrated slightly;
step 8, pressurizing and solidifying or/and vacuum pumping;
step 8.1, pressurizing and consolidating; the water collecting hole 403 of the drainage chassis 4 is connected with the water-gas separating device 8, and the bottom of the water-gas separating device 8 is also connected with the measuring cylinder 9; attaching the wet filter paper to one side of a pressure-bearing cover 5, smearing Vaseline on the side surface of the pressure-bearing cover 5, vertically placing the pressure-bearing cover 5 above a sample preparation device after grouting is finished, and placing a corresponding balance weight on the pressure-bearing cover 5 according to the permeability of a soil sample;
step 8.2, vacuum suction; a water collecting hole 403 of the drainage chassis 4 is connected with a water-gas separating device (8), the water-gas separating device 8 is selectively connected with a vacuum pump 10, and the bottom of the water-gas separating device 8 is also connected with a measuring cylinder 9; starting a power supply of the vacuum pump 10, and applying negative pressure in stages according to 20kPa, 40kPa, 60kPa and 80 kPa; the purpose is to guarantee that seepage is stable in the soil sample, avoids the inside atress inequality of soil sample to cause the defect of system appearance.
And 9, observing the water quantity change in the measuring cylinder 9, when the water discharge reaches a preset value, selectively closing the vacuum pump 10 according to actual conditions, waiting for the vacuum negative pressure in the device to be slowly discharged to 0kPa, and standing the device for 1 hour so as to facilitate the disassembly of the subsequent sample preparation device.
A method for disassembling a sample preparation device of a hollow cylindrical sample comprises the following steps:
step 1, dismounting instruments required by pressurization consolidation or/and vacuum suction, dismounting bolts between two sections of consolidation outer cylinder assemblies 201, dismounting bolts between a consolidation outer cylinder 2 and a drainage chassis 4, and taking down the drainage chassis 4;
step 2, vertically placing the device with the drainage chassis 4 removed, carefully opening the two sections of the consolidation outer cylinder assemblies 201 towards two sides, and taking down the consolidation outer cylinder assemblies 201;
step 3, cutting the soil sample from the upper part until the water-permeable top cover 3 is completely leaked out, and taking down the water-permeable top cover 3;
step 4, peeling the four-petal inner cylinder assembly 101 outwards in sequence, and taking out carefully;
and 5, cutting the soil sample to a specified height to obtain a standard hollow cylindrical sample meeting the test requirements, wherein the standard hollow cylindrical sample has the specification of the inner diameter multiplied by the outer diameter multiplied by the height: 60 mm. times.100 mm. times.200 mm.
A sample preparation device for a hollow cylindrical sample comprises an inner cylinder 1, a consolidation outer cylinder 2, a water permeable top cover 3 and a drainage chassis 4.
The inner cylinder 1 comprises four inner cylinder components 101 which are arranged in an arc shape, and the four inner cylinder components 101 are combined into the inner cylinder 1 with a hollow inner part; the bottom of the inner cylinder assembly 101 is flat, fixing grooves 102 which are concave in a convex shape are formed in the top of the inner cylinder assembly, and the fixing grooves 102 which are opposite to each other on the left side and the right side are integrally formed into a cross shape; a plurality of water permeable holes 103 penetrating through the inner cylinder 1 are uniformly distributed on the side surface of the inner cylinder component 101 at intervals; the bottom of the inner cylinder 1 is integrally placed in the drainage chassis 4.
The consolidation outer cylinder 2 comprises two semi-circular consolidation outer cylinder components 201, the bottom of the consolidation outer cylinder components 201 is provided with a fixing table 202 in an outward convex shape, and the fixing table 202 is provided with a fixing hole A203 penetrating through the fixing table 202; the top of the consolidation outer cylinder component 201 is provided with a locking block 204 which is convex and provided with bolt holes, after the two sections of consolidation outer cylinder components 201 are oppositely placed, bolts extend into the bolt holes of the two adjacent locking blocks 204 to fix the two sections of consolidation outer cylinder components 201 into a whole; one side of the consolidation outer cylinder 2 is provided with an inward concave limiting groove 205, the other side is provided with an outward convex limiting block 206, and the limiting groove 205 and the limiting block 206 are mutually connected in a clamping way; the bottom of the consolidation outer cylinder 2 is integrally placed in the drainage chassis 4.
The outer edge profile of the water permeable top cover 3 is consistent with the hollow outer edge profile of the top of the inner cylinder 1, the water permeable top cover 3 is detachably arranged at the top of the inner cylinder 1, and a through hole is formed in the center of the water permeable top cover 3.
The whole body of the drainage chassis 4 is disc-shaped, a water collecting hole 403 penetrating through the drainage chassis 4 is formed in the drainage chassis 4, an inner concave inner cylinder clamping groove 402 is formed in the outer side of the water collecting hole 403, an inner concave outer cylinder clamping groove 401 is formed in the outer side of the inner cylinder clamping groove 402, and fixing holes B404 matched with the fixing holes A203 are uniformly distributed on the drainage chassis 4 at intervals.
The sample preparation device of the hollow cylindrical sample further comprises a pressure bearing cover 5, the pressure bearing cover 5 is integrally disc-shaped, and the outer diameter of the pressure bearing cover 5 is smaller than the inner diameter of the consolidation outer cylinder 2.
The sample preparation device for the hollow cylindrical sample further comprises a sealing washer 6, and the sealing washer 6 is placed in the clamping groove 401 of the outer cylinder.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described above with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the above detailed description of the embodiments of the invention presented in the drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.