scholarly journals Influence of Water Content on the Mechanical Parameters of the Intact Rock and Rock Mass

2018 ◽  
Author(s):  
Balázs Vásárhelyi ◽  
Morteza Davarpanah
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Rock Mass ◽  
Internal Friction ◽  
Water Content ◽  
Uniaxial Compressive Strength ◽  
Water Saturation ◽  
Friction Angle ◽  
Intact Rock ◽  
Mechanical Parameters

The goal of this paper is to present the influence of the water saturation of the intact rock on different mechanical parameters, such as internal friction angle, cohesion, Hoek-Brown constant (mi ). Analyzing the previously published results, it was found that due to water saturation both the uniaxial compressive strength and tensile strength decrease similarly, i.e. the ratio of these two values is constant, thus the internal friction angle does not change but only the cohesion. Likewise, Hoek-Brown constant (mi ) remains constant; it is independent on the moisture content.The ratio of the elastic modulus and the uniaxial compressive strength of the intact rock is also calculated. According to the laboratory results, this ratio (namely modulus ratio) is also independent on the water content.It is shown that the mechanical parameters of the rock mass (such as compressive strength, tensile strength, deformation modulus) similarly depend on the water content than the intact rock.

scholarly journals Geotechnical and geomechanical characteristics of the rocks along tunnel of Kulekhani III Hydro-electric Project

2016 ◽  
Vol 50 (1) ◽  
pp. 39-50
Author(s):  
Suman Panthee ◽  
Mahesh Khanal ◽  
T. N. Singh
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Rock Mass ◽  
Young’S Modulus ◽  
Uniaxial Compressive Strength ◽  
Friction Angle ◽  
Geotechnical Properties ◽  
Intact Rock ◽  
Geomechanical Properties ◽  
Rock Types

 Geotechnical and geomechanical properties are important to understand tunnel behaviour and they differ according to rock types. Therefore, tunnel passing through different rock types is selected for the present study. The tunnel alignment of Kulekhani III hydroelectric project crosses five stratigraphic formations which compriseing eight lithological units. The rocks of the area have most dominantly three sets of joints in which the foliation plane is prominent. In geotechnical study of intact rock, seven geotechnical properties - viz unit weight (γ), uniaxial compressive strength (σci), tensile strength (σti), young’s modulus (Ei), poison’s ratio (ν), friction angle (ci) and cohesion ( i) were measured in lab and on the basis of the intact rock properties five geotechnical properties - uniaxial compressive strength (σcm), tensile strength (σtm), young’s modulus (Em), friction angle (cm) and cohesion ( m) of rock mass were determined. RMR, Q and GSI were used for geomechanical classification and the distributions of the geomechanical class values were studied. The relationship between UCS of rock mass and geomechanical classifications RMR and Q were studied for all rock types. Quite similar results were observed with both RMR and Q systems. The trend of correlations of each rock type with both classification systems follows almost analogous order. Power type continuous equation is observed for Q and exponential type relation is obtained for RMR. The general trend of correlation of UCS rock mass with RMR and Q is calculated which has R2 more than 0.9. The observed relations were compared with empirical relations proposed by other researchers and the results of the present study lie between the upper and lower boundaries set by other researchers. Among them, harder rocks have better correlation than softer rocks. It is also observed that higher the poisson’s ratio of the rock shown higher the order of linear correlation of rock mass properties with its geomechanical properties.

An Experimental Study on the Mechanical Properties of Soils of the Landslide Induced by Rainfall

2011 ◽  
Vol 90-93 ◽  
pp. 1303-1306
Author(s):  
Dong Heng Hao ◽  
Jian Feng Qi ◽  
Bin Wang ◽  
Shu Qin Zhao
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Internal Friction ◽  
Water Content ◽  
Strain Softening ◽  
Friction Angle ◽  
Mechanical Parameters ◽  
Strain Stress ◽  
Geotechnical Tests ◽  
Sliding Zone

Geotechnical tests are performed to study the strain-stress behavior and mechanical parameters by using the automatic KTG triaxial shear apparatus. This study shows that the strain softening phenomenon emerges after the peak values of strain-stress relations appear for the sliding-body soils, and that the strain-stress relations are in the sate of strain hardening all the time for the sliding-zone soils although the water content keeps sameness. The variation laws of cohesion and internal friction angle with water content are respectively consistent with an exponential function and linear relation.

Seafloor Polymetallic Sulfides Mechanical Property Test

2014 ◽  
Vol 1015 ◽  
pp. 316-319
Author(s):  
Zhong Hua Huang ◽  
Shao Jun Liu ◽  
Ying Guang Xu ◽  
Wang Hu
Keyword(s):  
Compressive Strength ◽  
Internal Friction ◽  
Uniaxial Compressive Strength ◽  
Compression Strength ◽  
Triaxial Compression ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Test Method ◽  
Dry Density ◽  
Average Value

Seafloor polymetallic sulfide specimens were developed according to engineering rock test method standard (GB/T 50266-2013). Seafloor polymetallic sulfide wet density and dry density were tested. Uniaxial compressive strength and triaxial compression strength of seafloor polymetallic sulfide were tested using rock mechanics test system MTS 815. Elasticity modulus and Poisson's ratio of seafloor polymetallic sulfide were calculated based on specimens stress-strain curves. Cohesion and internal friction angle were calculated based on specimens triaxial test Mohr stress circle. Test results show that seafloor polymetallic sulfide dry density average value is 2.6 g/cm3, wet density average value is 2.94 g/cm3. Uniaxial compressive strength and triaxial compression strength of seafloor polymetallic sulfide are unstable. Average value of the uniaxial compressive strength is 10.243MPa. Average value of triaxial compression strength test peak load is 47.166KN. Cohesion is 2.447MPa and internal friction angle is 38.04o.

Variations in Mechanical Parameters of Rock Mass Affecting Shaft Lining / Zmiany Parametrów Mechanicznych Górotworu I Ich Wpływ Na Obudowę Szybową

2013 ◽  
Vol 58 (3) ◽  
pp. 629-642 ◽  
Author(s):  
Tadeusz Majcherczyk ◽  
Zbigniew Niedbalski ◽  
Daniel Wałach
Keyword(s):  
Rock Mass ◽  
Internal Friction ◽  
Soil Properties ◽  
Water Content ◽  
High Water Content ◽  
Mechanical Parameters ◽  
Mass System ◽  
Geomechanical Properties ◽  
Angle Of Internal Friction ◽  
Shaft Lining

Abstract The paper presents geomechanical properties of rock mass occurring in the initial section of shaft lining during its execution. The shaft being sunk is surrounded with cohesive soils, mainly clays with sand layers and silts. Such lithology causes that in various levels some parts of strata are saturated with water. This results in a considerable changeability of soil properties in time. With high water content, the soil is washed away leading to local loss of contact between shaft lining and surrounding soils. This, in turn, results in lack of proper support for curbs and shaft lining fracture in some sections. Engineering activity in such a case should embrace sealing injections in selected parts of the shaft in order to resume proper reinforcement in the lining-rock mass system. The studies of the soils surrounding shaft lining were supposed to help design curbs with increased bearing capacity. The tests of soils indicated that the angle of internal friction and cohesion do change not only at different depths but also at the same depth in different points of perimeter. It was also observed during the study that the mechanical parameters of the analyzed soils improve as the distance from the shaft lining increases, which clearly indicates change of soil properties in the direct neighborhood of the shaft. Considerable number of tests carried out in the study allowed to determine the relationship between water content and angle of internal friction or soil cohesion. The determined relationships can help to estimate change of soil properties under the influence of water with considerable precision. The reinforcement of curbs executed with the use of ground anchors allowed for further shaft sinking. The tests of concrete used in the shaft carried out in the analyzed section produced results similar to the values assumed in the project.

scholarly journals Mixing Ratios and Cementing Mechanism of Similar Silty Mudstone Materials for Model Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hong-Yuan Fu ◽  
Shuang-Xing Qi ◽  
Zhen-Ning Shi ◽  
Ling Zeng
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Water Content ◽  
Uniaxial Compressive Strength ◽  
Dominant Factor ◽  
Similar Material ◽  
Silty Mudstone ◽  
Mixing Ratios ◽  
Similar Materials

The similarity model test is one of the important means to study the engineering properties of soft rock. This study aims to develop similar materials for silty mudstone, which has characteristics of low strength and water expansion, based on traditional materials including gypsum, barite powder, clay minerals, and distilled water. The orthogonal design method was used to determine the mixing ratios of the similar materials. The density, uniaxial compressive strength, tensile strength, elastic modulus, and Poisson’s ratio were selected as control indicators of the similar materials. The results show that the water content is the dominant factor for the density, tensile strength, elastic modulus, and Poisson’s ratio of the similar materials of silty mudstone, while the gypsum content is the dominant factor for the uniaxial compressive strength. The physical and mechanical properties of the similar material samples with water content of 19%, barite powder ratio of 32%, and gypsum mass of 250 g show good similarity to those of the raw silty mudstone. The water absorption and expansibility of similar materials with clay mineral ratio of 12% are consistent with those of the raw silty mudstone. The scanning electron microscopy (SEM) observation indicates that the similar material with optimal mixing ratios exhibits a similar microstructure to that of silty mudstone.

Effect of Clay Dosage on Mechanical Properties of Plastic Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 664-667 ◽  
Author(s):  
Qiao Yan Guan ◽  
Peng Zhang
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Elastic Modulus ◽  
Internal Friction ◽  
Friction Angle ◽  
Splitting Tensile Strength ◽  
Plastic Concrete

A designed experimental study has been conducted to investigate the effect of clay dosage on mechanical properties of plastic concrete. The mechanical properties include compressive strength, splitting tensile strength, shear strength and elastic modulus. On the basis of the experimental results of the specimens of eight sets of mix proportions, the mechanism of action of clay on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of decrease in the compressive strength, splitting tensile strength, shear strength and elastic modulus of plastic concrete with the increase of clay dosage. However, the internal friction angle of the shear specimens is increasing gradually with the increase of clay dosage. Further, the clay appears can improve the ductility of plastic concrete and this can help plastic concrete to bear larger deformation before failure.

scholarly journals Determination of Mechanical Properties of Altered Dacite by Laboratory Methods

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 813
Author(s):  
Veljko Rupar ◽  
Vladimir Čebašek ◽  
Vladimir Milisavljević ◽  
Dejan Stevanović ◽  
Nikola Živanović
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rock Mass ◽  
Uniaxial Compressive Strength ◽  
Rock Material ◽  
Strength Parameter ◽  
Gradual Transition ◽  
Strength Parameters ◽  
Triaxial Compressive Strength ◽  
Heterogeneous Rock

This paper presents a methodology for determining the uniaxial and triaxial compressive strength of heterogeneous material composed of dacite (D) and altered dacite (AD). A zone of gradual transition from altered dacite to dacite was observed in the rock mass. The mechanical properties of the rock material in that zone were determined by laboratory tests of composite samples that consisted of rock material discs. However, the functional dependence on the strength parameter alteration of the rock material (UCS, intact UCS of the rock material, and mi) with an increase in the participation of “weaker” rock material was determined based on the test results of uniaxial and triaxial compressive strength. The participation of altered dacite directly affects the mode and mechanism of failure during testing. Uniaxial compressive strength (σciUCS) and intact uniaxial compressive strength (σciTX) decrease exponentially with increased AD volumetric participation. The critical ratio at which the uniaxial compressive strength of the composite sample equals the strength of the uniform AD sample was at a percentage of 30% AD. Comparison of the obtained exponential equation with practical suggestions shows a good correspondence. The suggested methodology for determining heterogeneous rock mass strength parameters allows us to determine the influence of rock material heterogeneity on the values σciUCS, σciTX, and constant mi. Obtained σciTX and constant mi dependences define more reliable rock material strength parameter values, which can be used, along with rock mass classification systems, as a basis for assessing rock mass parameters. Therefore, it is possible to predict the strength parameters of the heterogeneous rock mass at the transition of hard (D) and weak rock (AD) based on all calculated strength parameters for different participation of AD.

Characterization of Shear Strength and Interface Friction of Organic Soil

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Friction Angle ◽  
Structural Materials ◽  
Organic Soil ◽  
Internal Friction Angle ◽  
Interface Friction

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

Sign in / Sign up

Export Citation Format

Share Document