Plane strain shear strength of unsaturated fiber-reinforced fine-grained soils

Abstract

Discrete randomly distributed fibers are commonly used to improve the engineering characteristics of the soil and thus soil properties such as shear strength, compressibility, density, and hydraulic conductivity. Most studies have so far focused on describing the behavior of soils containing randomly distributed fibers under dried or saturated conditions. However, the water table may seasonally fluctuate, thus generating unsaturated soil conditions. Therefore, a better understanding of the hydro-mechanical properties of unsaturated improved soils is of high necessity. In this research, the shear strength parameters of fine-grained soils were evaluated using the biaxial device available at Ruhr Universität Bochum. The applied device was modified to test unsaturated fine-grained soils with various degrees of saturation using axis translation and vapor equilibrium techniques. The experiments were conducted on fine soils containing 0, 0.5, and 1% fiber contents under a wide range of matric suctions. The ductile behavior was more noticeable in samples with lower suctions and higher straw contents. Furthermore, the shear strength of both unreinforced and reinforced fine-grained soils considerably increased by an increase in the suction. Finally, shear band inclination increased by the suction while decreasing by straw content.

Shear strength characteristics of basalt fiber-reinforced loess

“…The main reason to explain the phenomenon is that with increasing of FC , the fiber number increased, which resulted in the more contact points between fiber and soil particles. Due to fibers can limit deformation of soil particles through anchoring effect, thereby result in improved the sample strength and prevent sample damage 22 , 23 .

Figure 3 Effect of FC on the stress–strain curves ( a ) FL = 4 mm; ( b ) FL = 8 mm; ( c ) FL = 12 mm; ( d ) FL = 16 mm.

…”

“…Tamassoki et al 22 stated that 3% content of activated carbon and coir fiber can significantly improved the compressive strength, while 2% content can remarkably enhanced the shear strength of lateritic soil. Soleimani-Fard et al 23 revealed that discrete distributed fibers can significantly improved the shear strength, compressive, and hydraulic conductivity of fiber-reinforced fine-grained soil. Malekzadeh and Bilsel 24 reported that the addition of polypropylene fiber can significantly decreased the swell-shrink of expansive soil, and shrinkage limit increased more than 50%.…”

Analysis of basalt fiber reinforcement on static shear properties of Beibu Gulf sea sand

“…With the development 1335 (2024) 012011 IOP Publishing doi:10.1088/1755-1315/1335/1/012011 2 of the fiber industry, cost-effective chemical fiber products have been increasingly used in the engineering field; thus, fiber reinforcement as a new type of geotechnical reinforcement technology has received wide attention. At present, most researchers at home and abroad have studied the influence of fiber reinforcement on the mechanical properties of sand by conducting triaxial compression tests [24][25][26][27][28], direct shear tests [29][30][31], and unconfined compressive strength tests [32][33][34][35] and have achieved interesting research results. The most commonly used fiber materials include polypropylene fibers [36][37][38][39], carbon fibers [40][41], and glass fibers [42][43][44][45].…”