Prediction of Post-Yield Strain from Loading and Unloading Phases of Pressuremeter, Triaxial, and Consolidation Test Curves for Sustainable Embankment Design

Sustainability

Abdeliazim Mustafa Mohamed¹  Safeer Abbas²  Wasim Abbass²  Mubashir Aziz³  Dina Mohamed Fathi⁴  Zia ur Rehman⁵  Ammad Hassan Khan⁵  Zubair Masoud⁶ 

[1] Department of Civil Engineering, Prince Sattam Bin Abdulaziz University, Alkharj 16273, Saudi Arabia;Department of Civil Engineering, University of Engineering and Technology Lahore, Lahore 54890, Pakistan;Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia;Department of Structure Engineering and Construction Management, Future University, Cairo 11835, Egypt;Department of Transportation Engineering and Management, University of Engineering and Technology, Lahore 54890, Pakistan;Independent Researcher, Lahore 54810, Pakistan;

关键词: geotechnical engineering;    clay;    sustainability;    embankments;    strain;    stress;   

DOI  :  10.3390/su14052535

来源: DOAJ

【 摘 要 】

Exponential development of post-yield strain (Ԑ_post) is a pivotal indicator of failure in embankments constructed on soft saturated clays. This paper characterizes saturated clay stratum comprising very soft to very stiff stratigraphy, with plasticity index (PI) ranging from 19% to 31%, by performing widely used geotechnical engineering tests, i.e., the prebored pressuremeter (PMT) test, the triaxial (TXL) test, and constant-rate-of-strain (CRS) consolidation. PMT, TXL, and CRS tests were performed at a strain rate range of 0.18%/min to 0.21%/min to explore the yield stress (σ′_y), the pre-yield strain (Ԑ_pre), and the post-yield strain (Ԑ_post). Results indicate that Ԑ_post/Ԑ_pre for PMT, TXL, and CRS stress–strain curves range from 2.7 to 19 in the loading phase and 2 to 21 in the unloading phase. An exponential increase in Ԑ_post/Ԑ_pre is observed in the range of 10 to 21 for very soft to soft clay which is congruent with the realistic sustainable range of 4 to 30 for embankment failure on soft clays worldwide. The evaluated Ԑ_post/Ԑ_pre can be applied for sustainable prediction of post-failure evolution of strains in embankments on soft clays. Simplistic correlations are developed for approximation and prediction of Ԑ_post as a function of σ′_y, Ԑ_pre and maximum applied pressure (P_max) for loading and unloading phases with reasonable accuracy. The intuitive zone of critical ℇ_post is quantified for impending failure in embankments for maximum applied pressure (P_max), ranging from 36 kPa to 100 kPa for very soft to soft clay for use in sustainable embankment design and construction. Variation in predicted versus measured results of an individual site is observed to be within ±10% of line of equality.

【 授权许可】

Unknown