Experimental Studies on the Basic Friction Angle of Planar Rock Surfaces by Tilt Test

2018 ◽  
Vol 47 (1) ◽  
pp. 20170308 ◽  
Author(s):  
Ning Zhang ◽  
Charlie C. Li ◽  
Aizhong Lu ◽  
Xuguang Chen ◽  
Dejun Liu ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Friction Angle ◽  
Tilt Test ◽  
Basic Friction Angle

scholarly journals The Friction Angle of the Leiyang Marble Surface after Exposure to High Temperature

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Meng Hong Peng ◽  
Man Huang
Keyword(s):  
Surface Condition ◽  
Surface Friction ◽  
Friction Angle ◽  
Effect Of Temperature ◽  
Tilt Test ◽  
Rock Surface ◽  
Sliding Angle ◽  
Normal Loading ◽  
Basic Friction Angle ◽  
Marble Surface

There is a lack of information about the temperature-dependent nature of the rock surface, which is one of the essential parameters to predict the surface friction. In the present study, we experimentally study the effect of temperature on the basic friction angle of the marble surface through the direct shear test under the low normal loading condition and tilting test (Stimpson/disk tilt test). The basic friction angle gradually decreases with the increase in temperature from 20°C to 600°C for the two kinds of the tilting test. The results indicate that the Stimpson test on samples with the length-to-diameter ratio of 2 can be more reliable to estimate the basic friction angle of the rock surface after exposure to high temperatures. The results illustrate that the sliding angle depends on the surface condition. With the increase in the repetitive measurements, the sliding angle decreases as the marble surface is cleaned, and the parameter increases as the marble surface is not cleaned.

scholarly journals Determination of the basic friction angle ϕb of joints using the field tilt test: results of various “fast” tests on outcrops

2021 ◽  
Vol 833 (1) ◽  
pp. 012048
Author(s):  
L Jordá-Bordehore ◽  
L Alejano ◽  
R Tomás ◽  
S C Loaiza ◽  
M T García ◽  
...  
Keyword(s):  
Friction Angle ◽  
Tilt Test ◽  
Test Results ◽  
Basic Friction Angle

scholarly journals Characterization and Modeling Study on Softening and Seepage Behavior of Weakly Cemented Sandy Mudstone after Water Injection

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Junting Guo ◽  
Teng Teng ◽  
Xiaoyan Zhu ◽  
Yuming Wang ◽  
Zhaolong Li ◽  
...  
Keyword(s):  
Water Saturation ◽  
Water Injection ◽  
Experimental Studies ◽  
Friction Angle ◽  
Engineering Practice ◽  
Permeability Evolution ◽  
Exponential Relationship ◽  
Softening Effect ◽  
Negative Exponential ◽  
Sandy Mudstone

Water injection-induced rock softening and the associated water seepage characteristics are the common and basic problems in underground reservoir construction and the prevention of mine water disaster. In this paper, a series of experimental studies was carried out to investigate these characteristics with the weakly cemented sandy mudstone collected from Shendong Buertai coal mine, China. The characteristics of water softening and the stress-seepage interactions in water-saturated weakly cemented sandy mudstone were directly obtained. Then, a modification method of the constitutive model for rock mass considering the softening effect and a stress-damage-driven model for permeability evolution were established. Research results show that water saturation reduces the tensile strength, compressive strength, and cohesion by 56% and reduces the elastic modulus by 28%. The hydraulic effects on Poisson’s ratio and internal friction angle are negligible. The relationship between the permeability of weakly cemented sandy mudstone with complete compaction deformation is to be divided into three stages of seepage shielding, seepage surge, and seepage recovery. Rock permeability in each stage has a negative exponential relationship with the effective stress. This research provides a theoretical basis for the researches of hydromechanical couplings on weakly cemented sandy mudstone, which is insightful for rock engineering practice.

scholarly journals Shear Parameters of Rammed Earth Material: Results from Different Approaches

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
R. El-Nabouch ◽  
Q.-B. Bui ◽  
P. Perrotin ◽  
O. Plé
Keyword(s):  
Numerical Model ◽  
Seismic Performance ◽  
Numerical Models ◽  
Construction Material ◽  
Experimental Studies ◽  
Friction Angle ◽  
Rammed Earth ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Experimental Values

Rammed earth (RE) is a construction material which is manufactured by compacting the soil in a formwork, in different layers. Several recent studies have investigated this material. The seismic performance of RE buildings is an important topic which needs to be carefully investigated. The complex numerical model seems a performant approach to investigate the seismic performance of a whole building. To correctly establish the model, the shear parameters of the material, which are the cohesion and the friction angle, should be identified. This paper first presents experimental studies on the shear parameters of RE through the direct shear tests, at two different scales. The differences of the results at different scales are analyzed. Then, the obtained experimental values are used in a numerical model to simulate the shear behavior of RE walls which are loaded by a constant vertical stress and pushed horizontally on the top. From the obtained results, the values for numerical models are recommended.

An Experimental Study on the Mechanical Characteristics of Sandstone-Like Material with Preset Filling Joints

2013 ◽  
Vol 353-356 ◽  
pp. 644-649
Author(s):  
Xin Yu Liu ◽  
Ai Hua Liu ◽  
Bang Biao Wu
Keyword(s):  
Internal Friction ◽  
Uniaxial Compression ◽  
Shear Failure ◽  
Experimental Studies ◽  
Deformation Modulus ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Filling Material ◽  
Shear Tests ◽  
Intact Specimen

This paper investigates the strength and deformation characteristics of the sandstone-like material containing the preset filling joints. The test specimens are designed with different height-diameter ratio. The uniaxial compression and shear tests were performed during the experimental studies. The results show that: (1) the failure models of the 3 kinds specimens including ones without joints, ones with "cruciform" joints and ones with "intersecting parallels" joints are similar to the general trend, e.g. X-shaped conjugated single-slope shear failure and single-slope shear failure under compression and shear tests ; (2) under uniaxial compression, the performance of intact specimen is clearly affected by its size, and the strength of jointed one is significantly affected by the weakening of the structure. This impact depends on the joints conditions, e.g. joint density, with filling material or without filling material; (3) Deformation modulus E and Cohesion c have no significant change for the 2 kinds jointed specimens, but the internal friction angle is obviously affected by joints and their fillings. The internal friction angle decreases rapidly with the increase of joints number.

scholarly journals Experimental Studies and Analysis on Mobilization of the Cohesionless Sediments Through Alluvial Channel: A Review

2021 ◽  
Vol 7 (5) ◽  
pp. 915-936
Author(s):  
Akash Anand ◽  
Mubeen Beg ◽  
Neeraj Kumar
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Lift Force ◽  
Experimental Studies ◽  
Friction Angle ◽  
Force Balance ◽  
Complete Analysis ◽  
Rough Boundary ◽  
Fluid Forces ◽  
River Bed

Entrainment of river bed particles by turbulent flow is a core matter of study in river hydrodynamics. It is of great interest to river engineers to evaluate the shear stress for initiating river bed motion. The main objective is to calculate transport rates for bed load, to predict changes in bed level which are scoured or aggraded and to design a stable channel. Forces acting upon the particle especially fluid forces which give a major role in the incipient motion of the particle on the rough boundary. For calculation generally use shield’s diagram but some other modified methods and approaches are discussed. Modeling criteria are discussed for the hydraulically smooth and rough boundary depending on Reynolds number. In the past, experimental studies on tractive shear stress have been done by many researchers but consideration of lift force to analyze the movement of sediment is very limited. For suspended load transport, a detailed analysis of lift force is required. Based on the study it has been observed that shear stress depends on channel slope not only due to gravitational force but also many other factors like drag force, lift force, friction angle, fluctuations, velocity profile, etc. Complete analysis of these factors provides slope dependency over shear stress. To improve past studies, some factors have been discussed, to give a more correct force balance equation. This is very difficult task to analyze more and more variable’s dependency on the slope. Consideration of the possible number of variable holds complete analysis of experimental study. This paper also reviews the effect of particle Reynolds number and relative submergence over critical shield stress. Doi: 10.28991/cej-2021-03091700 Full Text: PDF

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