Three-dimensional Criterion for Predicting Peak Shear Strength of Matched Discontinuities with Different Joint Wall Strengths

Author(s):  
Zhi Cheng Tang ◽  
Zhi Fei Zhang ◽  
Yu-Yong Jiao
1999 ◽  
Vol 36 (2) ◽  
pp. 363-368 ◽  
Author(s):  
Daud W Rassam ◽  
David J Williams

A relationship describing the shear-strength profile of a desiccating soil deposit is essential for the purpose of analysis, especially when a numerical method is adopted where each zone in a discretised grid is assigned an elevation-dependent shear-strength value. The matric-suction profile of a desiccating soil deposit is nonlinear. Up to the air-entry value, an increase in matric suction is associated with a linear increase in shear strength. Beyond air entry, as the soil starts to desaturate, a nonlinear increase in shear strength occurs. The soil-water characteristic curve is stress dependent, as is the shear-strength gain as matric suction increases. In this paper, a three-dimensional, nonlinear regression analysis showed that a power-additive function is suitable to describe the variation of the shear strength of unsaturated soils with matric suction. The proposed function incorporates the effect of normal stress on the contribution of matric suction to the shear strength.Key words: air-entry value, matric suction, nonlinear regression, soil-water characteristic curve, tailings, unsaturated shear strength.


Author(s):  
Juncheng Gao ◽  
Menad Nait Amar ◽  
Mohammad Reza Motahari ◽  
Mahdi Hasanipanah ◽  
Danial Jahed Armaghani

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Enmao Quan ◽  
Yangsen Cao ◽  
Hongke Xu

To broaden the application of the basalt fiber in the preventive maintenance of asphalt pavement, this study investigated the bonding performance and evaluated the comprehensive performance of the basalt fiber asphalt macadam seal. Firstly, different types of basalt fiber asphalt macadam seal were prepared. The influences of content and length of the basalt fiber and dosage of emulsified asphalt on the bonding performance of the asphalt macadam seal were analyzed and compared. Next, by using the efficacy coefficient method, comprehensive performance considering both mechanical and economic characteristics of the basalt fiber asphalt macadam seal was evaluated. After that, reasonable content of each material was determined. Finally, the strengthening mechanism of the fiber on the bonding performance of macadam seals was revealed from a microscopic view. The results showed that compared with the ordinary asphalt macadam seal, the loss aggregate rate of the basalt fiber asphalt macadam seal was 11.0–30.5% lower, and the pull-out strength, shear strength, and torsional shear strength were 11.7–16.3%, 9.7–22.4%, and 4.2–20.6% higher, respectively. Considering the bonding performance and economic benefits, the optimal amount of emulsified asphalt and basalt fiber was 1.6 kg/m2 and 70 g/m2, respectively. Basalt fiber increased the cohesion of the asphalt material and improved the bonding performance of asphalt macadam seals through formation of the three-dimensional network structure. This study can provide reference to the application of basalt fibers in asphalt pavement maintenance.


2017 ◽  
Vol 88 ◽  
pp. 146-151 ◽  
Author(s):  
Boonchai Ukritchon ◽  
Kongkit Yingchaloenkitkhajorn ◽  
Suraparb Keawsawasvong

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