scholarly journals Initial investigation of the intrinsic geomechanical properties of soils in area of landslide Černá Pole

2019 ◽  
Author(s):  
Karolína Faktorová ◽  
Juraj Chalmovský ◽  
Pavel Koudela ◽  
Lumír Míča
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Laboratory Tests ◽  
Triaxial Tests ◽  
Geomechanical Properties ◽  
Important Type ◽  
Initial Investigation ◽  
Loading And Unloading ◽  
Oedometer Tests

One of the most important type of Brno’s subsoil is Miocene’s clay. Mechanical properties of these clays were already studied by various methods, authors, in several locations. These parameters, however, varies across the locations and therefore new data are needed to further refineme them. The objective of the laboratory tests presented in this paper was to determine shear strength and compressibility parameters on reconstituted samples, locality Černá Pole. Stiffness parameters for primary loading and unloading – reloading were obtained from series of oedometer tests. Consolidated undrained triaxial tests were performed for evaluation of soil critical shear strength. Obtained results were compared with another available data.

scholarly journals Three-dimensional numerical simulation of mechanical properties of soil-tire mixture by discrete element method

2019 ◽  
Vol 92 ◽  
pp. 14011
Author(s):  
Mohsen Asadi ◽  
Ahmad Mahboubi
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Damping Ratio ◽  
Strain Curve ◽  
Young Modulus ◽  
Engineering Properties ◽  
Triaxial Tests ◽  
Sand Particle ◽  
Arithmetic Average ◽  
Harmonic Average

Soil engineering properties can be improved employing different methods. Among them is mixing soil with tire derived additives (TDA). TDAs generally increase some parameters of mixture such as damping ratio, permeability, ductility and also in some cases shear strength. Various properties of TDAs from mechanical properties to their geometry can affect the mixture behavior. In this paper using the YADE platform, simulations of triaxial tests on sand tire mixtures are presented. To take compressibility into consideration, each rubber crumb particle is made of several spheres connected elastically to each other. For sand particle generation the clump technique was employed. Shapes of both sand and rubber particles are inspired from real grains. As properties of sand and rubber are different, especially Young modulus, rubber sand interaction is considered as soft rigid contact. Therefor harmonic average and arithmetic average was used to compute contact Young modulus (and then stiffness). The model was validated by comparison of results of triaxial tests simulation on pure rubber sample with literature ones which both exhibited linear stress-strain curve. Then triaxial tests with different sand to rubber ratio were simulated to see whether harmonic average or arithmetic average gives the best match to literature. The results show shear strength reduces by decreasing of sand to rubber ratio. This is the same as what is reported in literature.

scholarly journals The effect of temperature on the mechanical properties and workability of rock salt

2019 ◽  
Vol 2 (1) ◽  
pp. 384-393
Author(s):  
Piotr Małkowski ◽  
Łukasz Bednarek ◽  
Krzysztof Kotwica ◽  
Grzegorz Stopka
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Temperature Increase ◽  
Laboratory Tests ◽  
Effect Of Temperature ◽  
Transverse Strain ◽  
Salt Rock ◽  
The Road ◽  
Salt Mining

Abstract Underground salt mining accounts for about 16 percent of the total salt production worldwide. When excavating salt rock, the cutters of the road header come into contact with the rock. This produces friction and, consequently, a rise in temperature. Generally, as temperature increases, salt gradually loses its plasticity. The extent of these alterations depends on the presence of other minerals in the rock. This paper presents the results of laboratory tests on regularly shaped samples of salt. An analysis was performed of the results of compressive, tensile and induced-shear strength, and of Young's modulus, Poisson's ratio, cuttability index and side chipping angle. The testing was conducted on samples with a temperature of about 20°C and samples heated to 50°C and 80°C. The tests showed that as temperature increased, so did compressive and tensile strength, and longitudinal and transverse strain of salt. The temperature increase caused, however, a decrease in shear strength. The cuttability index and the side chipping angle also decreased when the heated samples were being cut. The percentage changes in the parameters within the 60-degree temperature range were as high as several dozen percent.

Variation of Mechanical Properties of Soft Marine Clay With Methane Gas Content

2013 ◽  
Author(s):  
Raúl Nava Castro ◽  
Jean M. E. Audibert ◽  
Willard DeGroff ◽  
Kuat C. Gan ◽  
Paul Ruckman
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Soil Structure ◽  
Load Transfer ◽  
Gas Bubbles ◽  
Gas Content ◽  
Triaxial Tests ◽  
Marine Clay ◽  
Methane Gas ◽  
Partial Load

To quantify the effects of methane gas on mechanical properties of soft marine clay, an exhaustive laboratory testing program was developed using zeolite to uniformly disseminate gas bubbles inside the clay matrix. Results from controlled rate-of-strain (CRS) tests indicated that as the gas content increases, there is a reduction in the interpreted preconsolidation pressure, although the rigidity of the clay with more gas increased throughout the test. Minivane test results indicated that the undisturbed shear strength decreases as the amount of methane gas increases, while the residual and remolded strengths remain practically unchanged, i.e., are independent of the gas content. Similarly results from triaxial tests indicated that the undisturbed shear strength is reduced as the gas content increases, but there was no change in the failure mode. Interestingly, the normalized shear strength increased for the clay with gas, when the samples were tested at 100 percent of deformation per hour. It is theorized that the methane gas bubbles interact with both the clay platelets and the pore water, and, to certain point, bear part of the load, thus modifying the distribution of the load in the soil structure; that is to say, there is a partial load transfer from the gas bubbles to the soil structure, as the clay particles confine the methane gas.

scholarly journals Undrained shear strength of Lisbon Miocene clay: a reappraisal based on triaxial and pressuremeter test results

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mafalda Lopes Laranjo ◽  
Manuel Matos Fernandes
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Physical And Mechanical Properties ◽  
Undrained Shear Strength ◽  
Triaxial Tests ◽  
Relevant Parameter ◽  
List Type ◽  
Test Results ◽  
Overconsolidated Clays ◽  
Undrained Shear

Abstract Undrained shear strength plays a fundamental role on the behaviour of clays. In overconsolidated clays, this parameter is largely influenced by test conditions, namely consolidation stress. “Prazeres Clay” is a Miocene overconsolidated formation, that can be found in a significant part of Lisbon area. Over the last decades a number of very relevant constructions have generated a large database for physical and mechanical properties of Miocene clays. Included in a broader study at the Faculty of Engineering of Porto University about Miocene clay’s physical and mechanical properties, existing data was gathered, treated and critically analysed, in order to establish a useful framework for geotechnical designers. This paper presents the results obtained for undrained shear strength, obtained from triaxial tests and Ménard Pressuremeter tests. It addresses the main difficulties associated with test’s interpretation and presents a discussion on how theoretical values relate to experimental ones. The paper proposes a range of variation for Prazeres Clay’ undrained shear strength based on a significant amount of test results, that is considered to be useful for geotechnical design. Article Highlights Undrained Shear strength is a relevant parameter for clays, and is usually derived from triaxial tests For overconsolidated clays, this parameter is highly dependent on preconsolidation stress, and on its relation to in situ stress. Based on a significant set of data, the paper presents a simple methodology for estimating this parameter

Pénétromètre à chute libre: Impact et pénétration dans des argiles reconstituées

1985 ◽  
Vol 22 (1) ◽  
pp. 129-135 ◽  
Author(s):  
D. Levacher
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Key Words ◽  
Laboratory Tests ◽  
Free Fall ◽  
Test Series ◽  
Dynamic Resistance ◽  
In Situ Testing

The use of a free-fall penetrometer for the determination of the in situ mechanical properties of reconstituted clays is presented. The penetrometer is equipped with an accelerometer for measuring continuously the acceleration or the deceleration. The equipment is relatively simple and the test is fast. The usefulness of such a test is demonstrated, and its adaptation to in situ testing is easy to achieve. Laboratory tests indicate that the shear strength can be directly computed as a function of depth. The penetrometer, as developed, can reach a depth of 0.50 m, but it is possible to achieve greater depths with some modifications. The results presented pertain to a few test series on reconstituted clays, with impact velocities up to 8 m/s. Key words: penetrometer, impact, reconstituted clays, tests, dynamic resistance, cohesion. [Journal translation]

Study on the Hoek-Brown Parameters under Loading and Unloading Triaxial Laboratory Tests

2011 ◽  
Vol 250-253 ◽  
pp. 2074-2078
Author(s):  
Jun Zheng He ◽  
Zai Quan Wang ◽  
Jin Shan Bai ◽  
Li Ming Zhang
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Laboratory Tests ◽  
Shear Failure ◽  
Shear Fracture ◽  
Material Constant ◽  
Triaxial Tests ◽  
Rock Samples ◽  
Loading And Unloading ◽  
Failure Conditions

Based on the brittle fracture theory of composite crack, and then overlapping the stresses at the end region of a crack under tension-shear or compression-shear failure conditions, the relationships of parameters in rock macroscopic and microscopic are determined by combining the Hoek-Brown failure criterion. There are many valuable conclusions through a series of loading and unloading triaxial laboratory tests on rock samples. The tension-shear fracture under the unloading triaxial tests at pre-peak is different from the compression-shear fracture under the loading triaxial tests. The Hoek-Brown criterion for rock is applicable and validity under the condition of loading triaxial tests. Because the uniaxial compressive strength is not the fundamental characteristic of rock, the virtual uniaxial compressive strength is proposed for the first time considering the unloading problem. Comparing with the loading tests, the Hoek-Brown material parameters of rock samples change greatly under unloading at pre-peak, and the virtual uniaxial compressive strength improves and Hoek-Brown material constant m reduces.

LABORATORY TESTS OF THE PHYSICAL-MECHANICAL PROPERTIES OF MATERIALS FOR REMEDIAL JOBS

2020 ◽  
pp. 58-63
Author(s):  
M.A. Druzhinin ◽  
◽  
G.V. Okromelidze ◽  
O.V. Garshina ◽  
I.A. Kudimov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Mechanical Properties Of Materials ◽  
Properties Of Materials

ALUMINUM 220

Alloy Digest ◽  
1962 ◽  
Vol 11 (3) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Heat Treating ◽  
Casting Alloy ◽  
Aluminum Casting ◽  
Aluminum Casting Alloy ◽  
Temperature Performance ◽  
Aluminum Company

Abstract ALUMINUM 220 is a 10% magnesium-aluminum casting alloy having the highest combination of mechanical properties, corrosion resistance and machinability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-112. Producer or source: Aluminum Company of America.

ALUMINUM 2011

Alloy Digest ◽  
1978 ◽  
Vol 27 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Temperature Performance ◽  
Screw Machine ◽  
Aluminum Copper Alloy

Abstract ALUMINUM 2011 is an age-hardenable aluminum-copper alloy to which lead and bismuth are added to make it a free-machining alloy. It has good mechanical properties and was designed primarily for the manufacture of screw-machine products. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-32. Producer or source: Various aluminum companies. Originally published October 1955, revised December 1978.

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