Experimental Study on the Mechanical Properties and Disintegration Resistance of Microbially Solidified Granite Residual Soil

Xiao, Xueli; Fang, Caixing; Dong, Feng; Wang, Yuxin

doi:10.3390/cryst12020132

Cited by 7 publications

(6 citation statements)

References 32 publications

(40 reference statements)

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“…The use of a double medium culture promotes the production of high urease bacterial fluid, which is crucial for soil sample consolidation. The research on the reinforcement of granite residual soil shows that th the soil after reinforcement increases by 115.43%, and the internal friction an slightly [26]. The effect of reinforcement is lower than that of this test.…”

Section: Shearing Strengthmentioning

confidence: 56%

“…The cohesion and friction angle of groups JR and JK are significantly improved, especially in group JR; the peristaltic pump grouting has little disturbance on soil samples and is most effective for transporting colony and cementing fluid into the lower soil mass, with the best consolidation effect. The research on the reinforcement of granite residual soil shows that the cohesion of the soil after reinforcement increases by 115.43%, and the internal friction angle decreases slightly [26]. The effect of reinforcement is lower than that of this test.…”

Section: Shearing Strengthmentioning

confidence: 64%

“…In the application of granite residual soil reinforcement, Wang et al discovered that bio-cementation forms a surface coating on granite residual soils, which leads to the hydraulic conductivity by 90.9% from the initial value, and the erosion rate can be reduced by 95.2% [25]. Liang et al's research found that the internal friction angle of MICP-treated granite residual soil increased by 10% under a moisture content of 30%, while its cohesion increased by 218% [26]. Moreover, Zhu et al conducted a study on the effectiveness of adding calcium lignosulfonate to improve the microbial growth environment and pore structure of granite residual soil.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Strength and Mechanism of Granite Residual Soil Strengthened by Microbial-Induced Calcite Precipitation Technology

Wang,

Li,

Chen

et al. 2023

Applied Sciences

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High rainfall environmental conditions can easily cause erosion or collapse of the granite residual soil slope. However, traditional slope reinforcement methods have drawbacks such as poor landscape effect, high energy consumption of raw materials, and environmental pollution. This study studied the application of microbial-induced calcite precipitation (MICP) in the reinforcement of granite residual soil. The consolidation effect of various methods was investigated, and the influence of cementing liquid concentration and pH value on consolidation under optimal curing conditions was explored. The results showed that the bacteria concentration reached OD600 = 3.0 and urease activity was 31.64 mM/min, which positively impact the production of calcium carbonate and the stability of crystal morphology. In addition, the soaking method was found to have the most effective consolidation effect on the surface soil samples, with the lowest disintegration rate. On the other hand, the peristaltic pump grouting method is the most effective in strengthening depth. This method resulted in a 513.65% increase in unconfined compressive strength (UCS), a 297.98% increase in cohesion, and a 101.75% increase in internal friction angle. This study also found that after seven rounds of grouting, the highest UCS was achieved in consolidated soil samples with a 0.5 mol/L cementing solution concentration, reaching 1.602 MPa. The UCS of soil samples increases as the pH value of the cementing fluid increases within the range of 6–8. As the pH value reaches 8–9, the strength increases and stabilizes gradually. These research findings can serve as an experimental basis for strengthening granite residual soil slopes and a guide for improving microbial geotechnical strengthening methods.

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Section: Shearing Strengthmentioning

confidence: 56%

Section: Shearing Strengthmentioning

confidence: 64%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Strength and Mechanism of Granite Residual Soil Strengthened by Microbial-Induced Calcite Precipitation Technology

Wang,

Li,

Chen

et al. 2023

Applied Sciences

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“…A large amount of polypropylene fibers were difficult to distribute evenly in the PFCSs, so fibers tended to form clusters and entangled with each other, damaging the overall structure of the soil [31]. Nevertheless, the main reason for the increase in cohesion of the CS was the production of C-S-H colloids [32], which could improve the overall integrity and performance of the soil. However, the too-high polypropylene fiber content could reduce the binding ability of cement, thus reducing the inter-particle interaction forces in the soil [33].…”

Section: Cohesion Due To Varying Cement Contentsmentioning

confidence: 99%

The Influence of Different Curing Environments on the Mechanical Properties and Reinforcement Mechanism of Dredger Fill Stabilized with Cement and Polypropylene Fibers

Wang,

et al. 2023

Materials

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An effective method widely used in geotechnical engineering to solve the shrinkage and cracking issues in cement-stabilized soil (CS) is evenly mixing randomly distributed fibers into it. Dredger fills stabilized with cement and polypropylene fibers (PFCSs) are exposed to rainwater immersion and seawater erosion in coastal areas, influencing their mechanical performance and durability. In this study, direct shear and consolidation compression tests were conducted to investigate the influence of different curing environments on the mechanical properties and compressive behavior of PFCSs. Dominance and regression analyses were used to study the impact of each factor under different curing regimes. The reinforcement mechanism of different curing environments was also explored using scanning electron microscopy (SEM) imaging. The results show that the cohesion and elastic modulus of the specimens cured in seawater were reduced compared with those cured in freshwater and standard curing environments. The best fiber content for the strength and compressive modulus of PFCSs was determined to be 0.9% of the mass of dredged fill. The results of value-added contributions and the relative importance of each factor in different curing environments show that the overall average contribution of cement content in the seawater curing environment is reduced by 6.79% compared to the freshwater environment. Multiple linear regression models were developed, effectively describing the quantitative relationships of different properties under different curing conditions. Further, the shear strength was improved by the coupling effect of soil particles, a C-S-H gel, and polypropylene fibers in the PFCSs. However, the shear strength of the PFCSs was reduced due to the structural damage of the specimens in the freshwater and seawater curing environments.

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“…GRS is considered a problematic regional soil due to its unique geological origin, specific composition, and structural characteristics. It has unique geological engineering properties, such as being easy to disturb and a tendency to disintegrate when immersed in water [3][4][5]. The mechanical properties and stability of GRS are significantly affected by water.…”

Section: Introductionmentioning

confidence: 99%

Disintegration Characteristics of Remolded Granite Residual Soil with Different Moisture Contents

Chen,

Zhou,

et al. 2023

Sustainability

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Granite residual soil (GRS) has prominent disintegration characteristics which have induced various geological disasters and engineering problems. The initial moisture content is believed to affect the disintegration of GRS significantly. To explore the effects of the initial moisture content on the soil disintegration characteristics and disintegration mechanism, disintegration tests were performed on remolded GRS with different initial moisture contents via the balance method, and the quantitative disintegration indices were corrected, considering the effects of water-absorption weight gain, in combination with a parallel water-absorption test. The disintegration characteristics and mechanism were thoroughly investigated, starting with the disintegration process curves and disintegration morphology, and combined with strength theory, X-ray diffraction (XRD) and X-ray fluorescence (XRF), the matric suction test, and the triaxial shear test. The results are as follows. (1) The corrected method improves the accuracy of the quantitative disintegration evaluation. (2) During the two disintegration stages, the forms of disintegration are dispersive fragmentation and progressive or block separation, and the soil matric suction and weakening of intergranular joining forces, respectively, are the drivers of disintegration. The first stage is usually completed within 1.5–2 min, and the disintegration ratio is usually within 20%. (3) The trends of change within the disintegration during the two stages show opposite water-content-dependent modes, and the soil samples with lower moisture contents have better water stability and slower disintegration in the second stage. The average disintegration rate of the soil with a moisture content of 24.4% in the first and second stages was approximately 1/5 and 13 times, respectively, that of the soil with a moisture content of 6.1%; these values can be rendered as 0.049%/s and 0.82%/s, respectively. The results provide some theoretical references for soil and water conservation and engineering applications in the GRS field.

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Experimental Study on the Mechanical Properties and Disintegration Resistance of Microbially Solidified Granite Residual Soil

Cited by 7 publications

References 32 publications

Strength and Mechanism of Granite Residual Soil Strengthened by Microbial-Induced Calcite Precipitation Technology

Strength and Mechanism of Granite Residual Soil Strengthened by Microbial-Induced Calcite Precipitation Technology

The Influence of Different Curing Environments on the Mechanical Properties and Reinforcement Mechanism of Dredger Fill Stabilized with Cement and Polypropylene Fibers

Disintegration Characteristics of Remolded Granite Residual Soil with Different Moisture Contents

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