scholarly journals Influence of Compaction on the Properties of Remolded Cemented Sands

2021 ◽  
Author(s):  
Aseel R. AL-Sanea ◽  
◽  
Nabil F. Ismael ◽  
Keyword(s):  
Shear Strength ◽  
Model Tests ◽  
Soil Parameters ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Compacted Soils ◽  
Relative Compaction ◽  
Test Soil ◽  
Cemented Sands

The properties and behaviour of compacted cemented sands in Kuwait were examined by laboratory and model tests. Upon excavation the cementation bonds are destroyed and the material, locally known as gatch, is transformed into clayey sands with fines content (<0.075 mm) ranging from 20% to 40%. Testing included basic properties, compaction, permeability, direct shear and consolidation tests. Model tests were also carried out on a circular plate loaded on compacted soils to failure. The test soil was compacted to a relative compaction of 85%, 90%, 95% and 100%. The results indicate a significant decrease in the ultimate bearing capacity and the shear strength parameters c, ϕ, and an increase in the compressibility parameters Cc, Cs and the permeability as the relative compaction decreases from 100% to 85%. The rate of variation of the various soil parameters with relative compaction is examined.

scholarly journals Mechanical Behaviour of Reinforced Sand with Natural Curauá Fibers through Full Scale Direct Shear Tests

2019 ◽  
Vol 92 ◽  
pp. 12003
Author(s):  
Leila Maria Coelho de Carvalho ◽  
Michelé Dal Toé Casagrande
Keyword(s):  
Shear Strength ◽  
Sandy Soil ◽  
Soil Reinforcement ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Shear Tests ◽  
Strength Parameters ◽  
Direct Shear Tests ◽  
Soil Shear Strength ◽  
Curaua Fibers

Inclusion of natural fibers (sisal, curauá, coco fiber and others) for soil improvement has been the study object in diverse geotechnical areas and it is a topic of growing interest, within the research area of new geotechnical materials. The state of the art in this subject highlights excellent results as soil strength parameters improve and post-cracking strength (toughness) increase. Soil reinforcement technique with fibers is established in the technology of composite materials, this being a combination of two or more materials presenting properties that the component materials do not possess on their own. The aim of this paper is to study the mechanical behaviour of sand-fiber composite by inserting natural curauá fibers into a sandy matrix, with different fiber contents. The fibers were randomly distributed in the soil mass. The experimental program included physical and mechanical characterization of the composites, using full-scale direct shear tests, with samples measuring 30 x 30 cm and 15 cm high. Direct shear tests were carried out using fibers with 25 mm length and 0.5 and 0.75% fiber content (relative to the soil dry weight). The specimens also presented a relative density of 50% and moisture content of 10%. It was sought to establish a pattern behaviour so that the addition of curauá fiber influence can be explained, thus, comparing with the sandy soil shear strength parameters. Inclusion of natural curauá fibers as soil reinforcement presented satisfactory results, as an increase in the soil shear strength parameters was observed when compared with sandy soil results.

Study on Shear Strength Experiments Base on the Modified Direct Shear Apparatus for Unsaturated Soils

2013 ◽  
Vol 438-439 ◽  
pp. 1176-1180 ◽  
Author(s):  
Gao Feng Chen ◽  
Ying Fa Lv ◽  
Zhi Huai Huang ◽  
Yan Chang
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Friction Angle ◽  
Soil Samples ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
General Internal ◽  
Direct Shear Apparatus

The unconsolidated-undrained fast shear tests of saturated-unsaturated remolded soil samples under different moisture content which is 1.1%, 10.1%, 14.9%, 19.9%, 24.2%, 29.9%, 37.7% respectively, and normal stress which is 50kPa, 100kPa, 200kPa, 300kPa, 400kPa respectively, were studied by the modified SDJ-1-type strain direct shear apparatus and U.S. Lab VIEW data acquisition system. The shear strength parameters of unsaturated soil samples, i.e. general cohesion and general internal friction angle were obtained based on Mohr-Coulomb strength theory. The test results showed that the general cohesion firstly increased and then reduced with the moisture content increasing, and the general internal friction angle increased with the moisture content decreasing. The function between the general shear strength parameters and the moisture content was studied. The concept of general shear strength parameters was proposed in the paper, and would provide a simple and practical method to obtain the strength parameters for engineering practice.

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