CN113218735A

CN113218735A - Triaxial test saturated sample loading method for soil

Info

Publication number: CN113218735A
Application number: CN202110503660.1A
Authority: CN
Inventors: 强毅; 覃荣高; 张小凌; 曹广祝
Original assignee: Kunming University of Science and Technology
Current assignee: Kunming University of Science and Technology
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2021-08-06
Anticipated expiration: 2041-05-10
Also published as: CN113218735B

Abstract

The invention discloses a triaxial test saturated sample loading method for soil, which comprises a stainless steel barrel and a plastic film, wherein the plastic film is arranged in an inner cavity of the stainless steel barrel, a plurality of balls are uniformly distributed between the plastic film and the stainless steel barrel, a soil sample barrel is arranged in the inner cavity of the plastic film, the soil sample barrel is in a three-piece arrangement, and a tightening hoop is arranged in the center of the outer side wall of the soil sample barrel. The invention has convenient sample loading operation on the sample, and can effectively improve the saturation of the sample loading soil, thereby effectively reducing errors and improving the precision of the sample during the experiment; the device can restore the real mechanical parameters of the soil sample in the field more truly, thereby providing more reliable theoretical data for the research of slope stability. The invention has the advantages of high sample saturation and high precision.

Description

Triaxial test saturated sample loading method for soil

Technical Field

The invention relates to the technical field of geotechnical engineering, in particular to a triaxial test saturated sample loading method for soil.

Background

The shear strength is the strength limit when an external force is vertical to the axis of the material and has a shearing action on the material; or to the maximum ability to resist shear failure. The shear strength of the soil refers to the ultimate strength of the soil to resist shear damage, is an important mechanical property of the soil, and is also the calculation of soil pressure, the calculation of the stability of the side slope of the earth dam and the fillingThe shear strength of the soil can be calculated by the following formula according to parameters required by calculation of the strength of the filling body and the like:

wherein phi is an internal friction angle, and c is cohesive force of soil, and is a factor of shear strength of the soil. The total stress internal friction angle and the effective stress internal friction angle can be obtained by direct shear test or triaxial compression test determination of soil according to different test methods and analysis methods. The influence factors of the shear strength of the soil mainly include the composition of the soil, the compactness and the water content of the soil, the stress state of the soil and the like. In the prior art, the saturation of the sample is low during operation, so that the precision of data is reduced, the error is large, and the use of the data is not facilitated.

Disclosure of Invention

The invention provides a soil triaxial test saturated sample loading method, which aims to overcome the defects of low saturation and large data error in the prior art. The soil triaxial test saturated sample loading method has the characteristics of high sample saturation, high precision and the like.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a triaxial test saturator of soil, includes the stainless steel bucket, the inner chamber of stainless steel bucket is provided with plastic film, evenly distributed is provided with a plurality of ball between plastic film and the stainless steel bucket, plastic film's inner chamber is provided with soil sample bucket, soil sample bucket is three lamella settings, the lateral wall center of soil sample bucket is provided with the lock hoop, all be provided with splint on the upper and lower lateral wall of soil sample bucket, logical groove has all been seted up at the lateral wall center of splint, it all is provided with the permeable stone to lead to the inslot, two be provided with the pull rod near the right side between the splint, pull rod and lower side splint fixed connection, swing joint between pull rod and the upside splint, the top swing joint of pull rod has the knob, the stainless steel bucket has seted up the screw thread on being close to the lateral wall of top surface, threaded connection has the bung on the top surface.

Preferably, the diameter of the ball is 0.45 mm.

Preferably, the top surface of the stainless steel barrel is fixedly connected with a waterproof rubber ring.

Preferably, lead to the groove cross-section and be the convex setting, the permeable stone all is located and is close to soil sample bucket one side setting.

Preferably, the center of the top surface of the barrel cover is fixedly connected with a handle.

A triaxial test saturated sample loading method for soil comprises the following steps:

s1: according to the standard 19.3.2 middle-exhaust saturation method of GB/T50123-2019 geotechnical test method, vertically placing a plastic film into water in a true saturator container, wrapping a sample saturator in the water in the true saturator container by using the plastic film, and ensuring that the water submerges the sample saturator and no air bubble exists between the plastic film and the sample saturator;

s2: taking a stainless steel barrel with a detachable sealing cover and a diameter and a height which are larger than 1cm of a pressure chamber as a freezing barrel, putting a stainless steel ball with a diameter of 0.45mm at the bottom of the container, putting a sample saturator wrapped with a plastic film into the stainless steel barrel in water in a true saturator container, and putting the stainless steel ball with a diameter of 0.45mm between the sample saturator and the wall of the stainless steel barrel to enable the sample saturator to be positioned in the middle of the stainless steel barrel;

s3: putting a stainless steel ball with the diameter of 0.45mm on a sample saturator in a stainless steel barrel, filling water with the stainless steel ball and taking out the stainless steel ball from the water surface, filling a waterproof rubber ring, and tightly covering a barrel cover;

s4: the tightly covered stainless steel barrel is placed into a freezing chamber of a refrigerator until water is completely frozen between the stainless steel barrel and a sample saturator, but the sample is frozen within 0.5CM of the outer side;

s5: taking out the stainless steel barrel from the freezing layer of the refrigerator, wrapping the stainless steel barrel with a hot towel, pouring out the sample saturator, stripping off the plastic film and ice outside the sample saturator, and collecting the stainless steel balls stripped off together for secondary use;

s6: wrapping the sample saturator by the hot towel for about 30 seconds, unwrapping the sample saturator, loading the sample according to the GB/T50123-2019 geotechnical test method standard 19.4, wherein no water seeps in the loading process, loading the sample within 6 minutes, and keeping the saturation of the loaded sample consistent with the saturation of the saturated sample.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention has convenient sample loading operation on the sample, and can effectively improve the saturation of the sample loading soil, thereby effectively reducing errors and improving the precision of the sample during the experiment;

2. the device can restore the real mechanical parameters of the soil sample in the field more truly, thereby providing more reliable theoretical data for the research of slope stability.

Drawings

FIG. 1 is a schematic view of the internal structure of the present invention;

fig. 2 is a schematic view of the internal cross-sectional structure of the present invention.

Reference numbers in the figures: 1. a stainless steel barrel; 2. a plastic film; 3. a ball bearing; 4. a soil sample barrel; 5. tightening; 6. a splint; 7. a through groove; 8. a pull rod; 9. a knob; 10. a barrel cover; 11. a waterproof rubber ring; 12. a permeable stone; 13. a handle.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

Referring to fig. 1-2, the present invention provides a technical solution: a triaxial test saturator for soil comprises a stainless steel barrel 1, a plastic film 2 is arranged in an inner cavity of the stainless steel barrel 1, a plurality of balls 3 are uniformly distributed between the plastic film 2 and the stainless steel barrel 1, the diameter of each ball 3 is 0.45mm, a soil sample barrel 4 is arranged in the inner cavity of the plastic film 2, the soil sample barrel 4 is in a three-piece arrangement, a tightening hoop 5 is arranged at the center of the outer side wall of the soil sample barrel 4, clamping plates 6 are arranged on the upper and lower side walls of the soil sample barrel 4, through grooves 7 are formed in the centers of the side walls of the clamping plates 6, permeable stones 12 are arranged in the through grooves 7, the cross sections of the through grooves 7 are in a convex arrangement, the permeable stones 12 are arranged at one side close to the soil sample barrel 4, a pull rod 8 is arranged between the two clamping plates 6 close to the right side, the pull rod 8 is fixedly connected with the lower clamping plates 6, the pull rod, the outer side wall of the stainless steel barrel 1 close to the top surface is provided with threads, the top surface of the stainless steel barrel 1 is connected with the barrel cover 10 through the threads, the top surface of the stainless steel barrel 1 is fixedly connected with a waterproof rubber ring 11, water leakage can be effectively avoided, the using effect is good, and the top surface center of the barrel cover 10 is fixedly connected with the handle 13, so that the stainless steel barrel is convenient to operate and use.

s1: according to the standard 19.3.2 middle pumping saturation method of GB/T50123-2019 geotechnical test method, vertically placing the plastic film 2 into water in a true saturator container, wrapping the sample saturator with the plastic film 2 in the water in the true saturator container, and ensuring that the water submerges the sample saturator and no air bubble exists between the plastic film 2 and the sample saturator;

s2: taking a stainless steel barrel 1 with a detachable sealing cover and a diameter and a height which are larger than 1cm of a pressure chamber as a freezing barrel, putting a stainless steel ball 3 with a diameter of 0.45mm at the bottom of the container, putting a sample saturator wrapped with a plastic film 2 into the stainless steel barrel 1 in water in a true saturator container, and putting the stainless steel ball 3 with a diameter of 0.45mm between the sample saturator and the wall of the stainless steel barrel 1 to enable the sample saturator to be arranged at the middle position of the stainless steel barrel 1;

s3: putting a stainless steel ball 3 with the diameter of 0.45mm on a sample saturator in a stainless steel barrel 1, filling water with the stainless steel ball and lifting the stainless steel ball to the water surface, padding a waterproof rubber ring 11, and tightly covering a barrel cover 10;

s4: the tightly covered stainless steel barrel 1 is put into a refrigerator freezing chamber until water is completely frozen between the stainless steel barrel 1 and a sample saturator, but the sample is frozen within 0.5CM of the outer side, taking a Yunnan red clay sample as an example: at the room temperature of 20 ℃, the mixture needs to be frozen in a refrigerator of minus 38 ℃ for 3 hours;

s5: taking out the stainless steel barrel 1 from the freezing layer of the refrigerator, wrapping the stainless steel barrel 1 with a hot towel, pouring out the sample saturator, stripping the plastic film 2 and ice outside the sample saturator, and collecting and leaving the stainless steel ball 3 stripped together for secondary use;

The working principle is as follows: when the device is used, according to the standard 19.3.2 air suction saturation method of GB/T50123-2019 geotechnical test method, a plastic film 2 is vertically placed into water in a container of a true saturator, the sample saturator is wrapped by the plastic film 2 in the water in the container of the true saturator, the sample saturator is submerged in the water if no air bubble exists between the plastic film 2 and the sample saturator, a stainless steel barrel 1 with a detachable sealing cover and a diameter which is 1cm larger than that of a pressure chamber is taken as a freezing barrel, a stainless steel ball 3 with the diameter of 0.45mm is placed at the bottom of the container, the sample saturator wrapped by the plastic film 2 is placed into a stainless steel barrel 1 in the water in the container of the true saturator, the stainless steel ball 3 with the diameter of 0.45mm is placed between the sample saturator and the wall of the stainless steel barrel 1, the stainless steel ball 3 with the diameter of 0.45mm is placed in the middle of the sample saturator in the stainless steel barrel 1, the method comprises the steps of opening upwards, filling water, lifting out of the water surface, padding with a waterproof rubber ring 11, tightly covering a barrel cover 10, placing a tightly covered stainless steel barrel 1 into a refrigerator freezing chamber until the water between the stainless steel barrel 1 and a sample saturator is completely frozen, but the sample is frozen within 0.5CM outside, taking out the stainless steel barrel 1 from a freezing layer of the refrigerator, wrapping the stainless steel barrel 1 with a hot towel, pouring out the sample saturator, stripping off the ice outside of a plastic film 2 and the sample saturator, collecting and leaving the stripped stainless steel ball 3 for a second time, wrapping the sample saturator with the hot towel for about 30 seconds, unfastening the sample saturator, loading the sample according to GB/T50123 and 2019 geotechnical test method standard 19.4, wherein no water seeps out in the loading process, the sample is loaded within 6 minutes, and the saturation of the loaded sample is consistent with the saturated sample.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A soil triaxial test saturator, comprising a stainless steel barrel (1), characterized in that: the inner cavity of the stainless steel barrel (1) is provided with a plastic film (2), the plastic film (2) and stainless steel A plurality of balls (3) are evenly distributed among the buckets (1), and a soil sample bucket (4) is arranged in the inner cavity of the plastic film (2). The center of the outer side wall of the soil sample bucket (4) is provided with a tightening hoop (5), the upper and lower side walls of the soil sample bucket (4) are provided with splints (6), and the center of the side wall of the splint (6) Both are provided with through grooves (7), and permeable stones (12) are arranged in the through grooves (7), and a pull rod (8) is arranged between the two splints (6) near the right side, and the pull rod ( 8) It is fixedly connected to the lower splint (6), the draw rod (8) is movably connected to the upper splint (6), the top of the draw rod (8) is movably connected with a knob (9), and the stainless steel barrel (1) Threads are provided on the outer side wall close to the top surface, and the top surface of the stainless steel bucket (1) is threadedly connected with a bucket cover (10).

2 . The soil triaxial test saturator according to claim 1 , wherein the diameter of the ball ( 3 ) is 0.45 mm. 3 .

3 . The soil triaxial test saturator according to claim 1 , wherein a waterproof rubber ring ( 11 ) is fixedly connected on the top surface of the stainless steel barrel ( 1 ). 4 .

4. A soil triaxial test saturator according to claim 1, wherein the cross section of the through groove (7) is convex, and the permeable stones (12) are located near the soil sample bucket ( 4) One side setting.

5 . The soil triaxial test saturator according to claim 1 , wherein a handle ( 13 ) is fixedly connected to the center of the top surface of the barrel cover ( 10 ). 6 .

6. the triaxial test saturated sample loading method of a kind of soil according to any one of claims 1-5, is characterized in that, comprises the following steps:

S1: According to GB/T 50123-2019 Geotechnical Test Method Standard 19.3.2, after the air-saturation method, the plastic film (2) is placed vertically into the water in the true saturator container, and the plastic film (2) is placed in the water in the true saturator container. Wrap the sample saturator with the film (2), make sure that the water submerges the sample saturator, and there are no air bubbles between the plastic film (2) and the sample saturator;

S2: Take a stainless steel bucket (1) with a detachable sealing cover whose diameter and height are both greater than 1 cm of the pressure chamber as a freezing bucket, put a stainless steel ball (3) with a diameter of 0.45 mm at the bottom of the container, and place it in the water in the true saturator container. Put the sample saturator wrapped with plastic film (2) into the stainless steel barrel (1), and put a stainless steel ball (3) with a diameter of 0.45mm between the sample saturator and the wall of the stainless steel barrel (1) to saturate the sample. The device is in the middle of the stainless steel barrel (1);

S3: Put a stainless steel ball (3) with a diameter of 0.45mm on the sample saturator in the stainless steel bucket (1), with the opening facing upwards and filling with water to lift the water surface, pad the waterproof rubber ring (11), and close the bucket lid (10) tightly ;

S4: Put the tightly covered stainless steel bucket (1) into the freezer of the refrigerator until the water between the stainless steel bucket (1) and the sample saturator is completely frozen, but the sample is only frozen within 0.5CM outside;

S5: Take out the stainless steel bucket (1) from the freezing layer of the refrigerator, wrap the stainless steel bucket (1) with a hot towel, pour out the sample saturator, peel off the plastic film (2) and the ice outside the sample saturator, and peel off the stainless steel together The balls (3) are collected and left for next use;

S6: Wrap the sample saturator with a hot towel for about 30 seconds, untie the sample saturator, and install the sample according to GB/T 50123-2019 Geotechnical Test Method Standard 19.4. There is no water seepage during the sampling process, and the sample is installed within 6 minutes. The saturation of the loaded sample is the same as that of the saturated sample.