Ballast Direct Shear Testing

2014 ◽  
Author(s):  
Timothy D. Stark ◽  
Robert H. Swan ◽  
Zehong Yuan
Keyword(s):  
Shear Strength ◽  
Test Procedure ◽  
Strength Properties ◽  
Specimen Size ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Railroad Track ◽  
Dead Weight ◽  
Shear Box ◽  
Direct Shear Testing

This paper summarizes the appropriate equipment and test procedure for ballast shear strength testing using the direct shear method (ASTM D3080 and D5321) and presents some typical results. To accomplish this ballast testing, a full-scale direct shear box was developed that can accommodate an approximately 1 m (3 feet) wide and 0.6 m (2 feet) deep specimen, which is much larger than current shear boxes used for ballast testing. This larger specimen size resulted in significant differences in measured shear behavior and shear strength parameters. The shear strength properties of the ballast under typical as-placed conditions are determined herein using the new shear box and normal stresses applied through dead weight loading that are representative of railroad track conditions. Effects of direct shear specimen size and confining normal stress are demonstrated using a typical angular granite ballast and the results are compared to published ballast shear strength data.

scholarly journals Experimental Study on Shear Strength Parameters of Soil Mixed with Glass Fiber

2019 ◽  
Vol 4 (6) ◽  
pp. 124-128
Author(s):  
Mohamad Farouk Abd-elmagied
Keyword(s):  
Shear Strength ◽  
Strength Properties ◽  
Vital Role ◽  
Peak Shear Strength ◽  
Shear Strength Parameters ◽  
Fiber Glass ◽  
Strength Parameters ◽  
Sample Weight ◽  
Strain Behavior ◽  
Shear Box

Determining the shear strength properties of the soil is a vital step in investigation its stress-strain behavior. Moreover, suction plays a vital role in the shear strength of the unsaturated soil. This paper investigates the influence of the fiber glass on the shear strength parameters of (c-ɸ) soil with different ratios. To achieve this purpose, the samples of (c- ɸ) soil from El-Fardos gardens housing compound, Benha city, Egypt, were prepared at their maximum dry densities with corresponding optimum moisture content. Direct shear box test of 60 x 60 mm under a relentless rate of 1 mm/min was employed with the proposed range of ASTM D 3080. Different fiber glass ratios of 0.1, 0.50 and 1.00 % of soil sample weight were used. The results confirmed that the peak shear strength parameters increased with increasing the fiber ratio.

Interface shear strength properties of geogrid-reinforced steel slags using a large-scale direct shear testing apparatus

2020 ◽  
Vol 48 (5) ◽  
pp. 625-633 ◽  
Author(s):  
Farshid Maghool ◽  
Arul Arulrajah ◽  
Mehdi Mirzababaei ◽  
Cherdsak Suksiripattanapong ◽  
Suksun Horpibulsuk
Keyword(s):  
Shear Strength ◽  
Large Scale ◽  
Strength Properties ◽  
Direct Shear ◽  
Shear Testing ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Testing Apparatus ◽  
Reinforced Steel ◽  
Direct Shear Testing

Effect of Sample Size on TDA Shear Strength Parameters in Direct Shear Tests

2020 ◽  
Vol 2674 (9) ◽  
pp. 1110-1119 ◽  
Author(s):  
Khaled Zahran ◽  
Hany El Naggar
Keyword(s):  
Shear Strength ◽  
Shear Test ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Shear Tests ◽  
Strength Parameters ◽  
Angle Of Internal Friction ◽  
Direct Shear Tests ◽  
Shear Box ◽  
Box Dimensions

Tire-derived aggregate (TDA), a relatively new construction material, has been gaining acceptance as a backfill material for embankments, trenches, and earth-retaining structures because of its lightweight and excellent geotechnical properties. Type A TDA has a basic geometric shape, with particles approximately 12 to 100 mm in size. As a result of the simplicity and accuracy of the direct shear test, most laboratories choose this test in preference to more complex tests. However, TDA requires large-scale direct shear apparatus because of the consistently large size of its particles, and few facilities own this type of apparatus. Depending on the shear box dimensions, the aspect ratio of the particle size to the box dimensions may lead to variations in the shear strength results of the sample being evaluated. This research focuses on studying the effect of TDA sample size on the shear strength results of direct shear tests by using five different shear box sizes. The findings show that the angle of internal friction increases slightly as the dimensions of the shear box decrease. It was found that the maximum variation in the angle of internal friction and the cohesion results of the different shear boxes was only 1.9° and 2.4 kPa, respectively. These differences should be taken into consideration when TDA shear test results are used in the geotechnical design. It is recommended that a shear box with an aspect ratio (W/Dmax) greater than or equal to 4 should be used when evaluating the shear strength parameters of TDA.

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.

Specimen Size and Scale Effects of Direct Shear Box Tests of Sands

2006 ◽  
Vol 29 (6) ◽  
pp. 100312 ◽  
Author(s):  
L David Suits ◽  
TC Sheahan ◽  
AB Cerato ◽  
AJ Lutenegger
Keyword(s):  
Scale Effects ◽  
Specimen Size ◽  
Direct Shear ◽  
Shear Box
Sign in / Sign up

Export Citation Format

Share Document