Determination of shear strength properties of coarse-grained materials for stone column

ce/papers ◽  
2018 ◽  
Vol 2 (2-3) ◽  
pp. 791-796
Author(s):  
Monika SULOVSKA ◽  
Jakub STACHO
Keyword(s):  
Shear Strength ◽  
Strength Properties ◽  
Coarse Grained ◽  
Stone Column

scholarly journals Determining the Shear Strength Properties of a Soil-geogrid Interface Using a Large-scale Direct Shear Test Apparatus

2020 ◽  
Author(s):  
Jakub Stacho ◽  
Monika Sulovska ◽  
Ivan Slavik
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Large Scale ◽  
Direct Shear Test ◽  
Shear Test ◽  
Strength Properties ◽  
Coarse Grained ◽  
Direct Shear ◽  
Test Apparatus ◽  
Fine Gravel

The paper deals with the laboratory testing of coarse-grained soils that are reinforced using a geogrid. The shear strength properties were determined using a large-scale direct shear test apparatus. The tests were executed on original as well as on reinforced soil, when the geogrid was placed on a sliding surface, which permitted determining the shear strength properties of the soil-geogrid interface. The aim of the tests was to determine the interface shear strength coefficient α, which represents the ratio of the shear strength of the soil-geogrid interface to the unreinforced soil. The tests were executed on 3 samples of coarse-grained materials, i.e., poorly graded sand, poorly graded fine gravel and poorly graded medium gravel. Two types of geogrids were tested, i.e., a woven polyester geogrid and a stiff polypropylene geogrid. The results of the laboratory tests on the medium gravel showed that the reduction coefficient α reached higher values in the case of the stiff polypropylene geogrid. In the cases of the fine gravel and sand, the values of the interface coefficient α were similar to each other. The shear strength of the interface was reduced or was similar to the shear strength of unreinforced soil in a peak shear stress state, but significantly increased with horizontal deformations, especially for the fine gravel and sand. The largest value of the coefficient α was measured in the critical shear stress state. Based on the results of the testing, a correlation which allows for determining the optimal grain size distribution was obtained.

Stiffness and strength properties of five paperboards and their moisture dependency

TAPPI Journal ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 71-85
Author(s):  
GUSTAV MARIN ◽  
MIKAEL NYGARDS ◽  
SOREN OSTLUND
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Shear Strength ◽  
Three Dimensional ◽  
Strength Properties ◽  
Bending Stiffness ◽  
Moisture Ratio ◽  
Machine Direction ◽  
Product Series

Five commercial multiply folding boxboards made on the same paperboard machine have been analyzed. The paperboards were from the same product series but had different grammage (235, 255, 270, 315, 340 g/m2) and different bending stiffness. The paperboards are normally used to make packages, and because the bending stiffness and grammage varies, the performance of the packages will differ. Finite element simulations can be used to predict these differences, but for this to occur, the stiffness and strength properties need to be deter-mined. For efficient determination of the three-dimensional properties in the machine direction (MD), cross direction (CD), and Z direction (ZD), it is proposed that the paperboard should be characterized using in-plane tension, ZD-tension, shear strength profiles, and two-point bending. The proposed setups have been used to determine stiff-ness and strength properties at different relative humidity (20,% 50%, 70%, and 90% RH), and the mechanical proper-ties have been evaluated as a function of moisture ratio. There was a linear relation between mechanical properties and moisture ratio for each paperboard. When the data was normalized with respect to the standard climate (50% RH) and plotted as a function of moisture ratio, it was shown that the normalized mechanical properties for all paperboards coincided along one single line and could therefore be expressed as a linear function of moisture ratio and two constants. Consequently, it is possible to obtain the mechanical properties of a paperboard by knowing the structural prop-erties for the preferred level of RH and the mechanical property for the standard climate (50% RH and 23°C).

scholarly journals Influence of Binding Rates on Strength Properties of Moulding Sands with the GEOPOL Binder

2014 ◽  
Vol 14 (1) ◽  
pp. 37-40 ◽  
Author(s):  
M. Holtzer ◽  
D. Drożyński ◽  
A. Bobrowski ◽  
W. Plaza
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Bending Strength ◽  
Strength Properties ◽  
Technological Properties ◽  
Inorganic Binder ◽  
Splitting Strength ◽  
Moulding Sand ◽  
Tensile And Bending Strength

Abstract The results of investigations of moulding sands with an inorganic binder called GEOPOL, developed by the SAND TEAM Company are presented in the paper. Hardeners of various hardening rates are used for moulding sands with this binder. The main aim of investigations was determination of the influence of the hardening rate of moulding sands with the GEOPOL binder on technological properties of these sands (bending strength, tensile strength, permeability and grindability). In addition, the final strength of moulding sands of the selected compositions was determined by two methods: by splitting strength and shear strength measurements. No essential influence of the hardening rate on such parameters as: permeability, grindability and final strength was found. However, the sand in which the slowest hardener (SA 72) were used, after 1 hour of holding, had the tensile and bending strength practically zero. Thus, the time needed for taking to pieces the mould made of such moulding sand will be 1.5 - 2 hours.

scholarly journals Wybrane zagadnienia dotyczące budowy tuneli z wykorzystaniem zmechanizowanych tarcz zawiesinowych

2019 ◽  
Vol 28 (3) ◽  
pp. 488-499
Author(s):  
Krzysztof Michalczuk ◽  
Mirosław Lipiński ◽  
Małgorzata Wdowska
Keyword(s):  
Shear Strength ◽  
Tunnel Boring Machine ◽  
Coarse Grained ◽  
Geotechnical Parameters ◽  
Soil Layers ◽  
Fine Grained ◽  
Tunnel Boring ◽  
A Site ◽  
Slurry Shield

The major criteria which determine selection of tunneling technology with use of tunnel boring machine (TBM) technique concern geotechnical an hydrogeological conditions of a site. When subsoil strata does not consist of rock the soils are group in two categories, i.e. coarse grained and fine grained soils. Determination of geotechnical parameters pertinent to the problem of tunneling requires individual approach in each case. In case of slurry shield technique, calculations of pressure required for face support should account for real loading conditions. In particular, with respect to shear strength, drainage conditions should be properly accounted for. Thus determined shear strength should be assigned to properly distinguished soil layers. The proper division of soil strata into soil layers is also discussed in the paper.

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