Data-Based Real-Time Moisture Modeling in Unsaturated Expansive Subgrade in Texas

Ahmed, Asif; Hossain, Sahadat; Khan, Mohammad Sadik; Shishani, Aya

doi:10.1177/0361198118772960

Cited by 11 publications

(6 citation statements)

References 16 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is generally accepted that the water content, void ratio and type of clay minerals in the soil are the main factors affecting the volume change potential of the soil [3][4][5]. On average, expansive soils in the United States incur more financial losses to the nation's infrastructure than earthquakes, floods, hurricanes, and tornadoes combined [6,7].…”

Section: Introductionmentioning

confidence: 99%

Coupled Effect of Wet-Dry Cycles and Rainfall on Highway Slope Made of Yazoo Clay

2019

View full text Add to dashboard Cite

Expansive Yazoo clay soil is susceptible to volumetric deformation and is dominant in central Mississippi and other neighboring southern states of the United States. Recurring shrink-swell behavior causes a significant problem to infrastructures in the area. Although Yazoo clay causes a significant problem in the deep southern states, limited study has been conducted on the behavior of Yazoo clay, especially in the presence of rainfall. The objective of this current study is to investigate the coupled effect of changes in void ratio due to wet-dry cycles and rainfall on the stability of highway slopes made of Yazoo clay. The finite element method in Plaxis 2D by Bentley System (https://www.plaxis.com/) has been utilized to investigate the coupled effect of changes in mechanical properties and rainfall using flow-deformation and stability analysis. Reconstituted expansive clay soil samples were used for the laboratory experiment. The reconstituted Yazoo clay samples were subjected to 3, 5, and 7 wetting and drying cycles in an enclosed chamber for a 24-h period. The axial deformation of the samples and the change in void ratios at each number of the cycle was closely monitored. The strength change at each wet and dry cycle was also investigated and used for slope stability analysis in the presence of rainfall. The test results indicate that the void ratio increases with the increasing number of wet-dry cycles. A continuous increment in void ratios from 0.99 in an undisturbed state with no wet-dry cycle to 1.49 at the 7th wet-dry cycle, indicating a 48.9% increase, as the wetting and drying cycle increases was recorded; in turn, decreasing the cohesion of the soil by 77%. The factor of safety considering the effect of two total rainfall periods of Rv = 126.2 mm (2 h) and Rv = 271.7 mm (3 days) reduced from 1.7 to 1.2 and 1.68 to 1.02, considering the effect of the 7th wet-dry cycle at the topsoil. The changes in the void ratio due to the wetting and drying cycle of Yazoo clay soil reduces the shear strength to a fully softened condition, increasing the possibility of slope failure. This condition further worsens in the presence of a perched water condition due to the infiltration of rain water.

show abstract

Section: Introductionmentioning

confidence: 99%

Coupled Effect of Wet-Dry Cycles and Rainfall on Highway Slope Made of Yazoo Clay

2019

View full text Add to dashboard Cite

show abstract

“…Khan et al [26] proposes a model using the Winkler foundation theory to analyze the pavement by considering it as a beam resting on expansive soil. Application of the developed models will facilitate noninvasive estimations of the response of soil strength and stiffness properties to variations in moisture [23].…”

Section: Resultsmentioning

confidence: 99%

A Review of Mathematical Models for Performance Prediction of Flexible Paving on Expansive Soils

Rivetti¹,

Margalho²,

Albuquerque³

et al. 2020

Blucher Engineering Proceedings

View full text Add to dashboard Cite

The presence of expansive soils in road works is linked to deformations, which causes an increase in the need for maintenance. There is monitoring software, however, they do not take into account parameters of the behavior of expansive soils. In this sense, a mathematical model with inputs of expansive soil parameters, are essential to reduce production and maintenance costs. This study aims to seek, through a systematic literature review, scientific publications, and patents that include mathematical models capable of evaluating the performance of pavements through the behavior of expansive soils. It was observed that there are few publications related to the theme and the models found do not take into account specific parameters of the behavior of expansive soils.

show abstract

“…A report showed that 60% of China's expressways require major repairs or renovations after 10~12 years of service, and 17% require such repairs after 6~8 years, indicating a shorter-than-expected service life for expressways [1]. Studies have found that subgrade moisture is one of the main causes of this problem [2][3][4]. Typically, the subgrade is compacted at its optimal moisture content to achieve optimal performance.…”

Section: Introductionmentioning

confidence: 99%

A Numerical Simulation of Moisture Reduction in Fine Soil Subgrade with Wicking Geotextiles

Ma,

Feng,

Wang

et al. 2024

Materials

View full text Add to dashboard Cite

A new wicking geotextile is proposed to control the water content of fine-grained soil subgrade. By comparing the spatial distribution of volumetric water content and matric suction before and after the installation of the wicking geotextile, the effectiveness of the geotextile in controlling the subgrade humidity is evaluated. Firstly, the hydraulic parameters of the wicking geotextile are obtained through laboratory tests using a pressure plate apparatus. Then, a numerical model for water flow in the subgrade is established using COMSOL to obtain the spatial distribution characteristics of humidity in the subgrade under different groundwater levels (2~8 m). The results show the wicking geotextile exhibits strong hydrophilicity, low water retention, and high horizontal permeability. Compared to the subgrade without geotextile, the water content of the soil above the geotextile decreases significantly by 7.6~9.6% at groundwater levels of 4~8m, while the saturation decreases by 18.3~23.0%, and the matric suction increases by 2~2.3 times. The wicking fabric functions as an effective drainage material to serve as a capillary barrier in the cross-plane direction and an effective drainage tunnel to transport water in the in-plane direction. The dynamic resilient modulus of the subgrade increases by 23.2~43.6%. The wicking geotextile effectively absorbs and drains weakly bound water in unsaturated soil due to the matric suction difference and its horizontal drainage capacity to improve the bearing capacity of the subgrade. It suggests that using wicking geotextile for drainage and reinforcement in fine-grained soil subgrades with groundwater levels ranging from 4 to 8 m is beneficial.

show abstract

Data-Based Real-Time Moisture Modeling in Unsaturated Expansive Subgrade in Texas

Cited by 11 publications

References 16 publications

Coupled Effect of Wet-Dry Cycles and Rainfall on Highway Slope Made of Yazoo Clay

Coupled Effect of Wet-Dry Cycles and Rainfall on Highway Slope Made of Yazoo Clay

A Review of Mathematical Models for Performance Prediction of Flexible Paving on Expansive Soils

A Numerical Simulation of Moisture Reduction in Fine Soil Subgrade with Wicking Geotextiles

Contact Info

Product

Resources

About