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Influence of Stress and Hydraulic History on Water Retention Curveof Natural Loessin the Suction Range of 0-367.5MPa

Tiangang Lan¹, Mengyuan Ma¹, Shifeng Lu¹, Ling Xu^1,*

1 Department of Civil Engineering, School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi'an, Shaanxi, 710049, China

* Corresponding Author: Ling Xu. Email:

The International Conference on Computational & Experimental Engineering and Sciences 2024, 29(1), 1-1. https://doi.org/10.32604/icces.2024.010867

Abstract

Natural loess is a kind of kaolin wind-deposited soil.Thedifferent layers of loess experienced different overburden pressures and wetting-drying cycles, resulting in different water retention behaviors.The axis translation technique and the vapor equilibrium technique to determine the water retention behaviorof the three different sediment depth natural loess during drying and wettingprocess. In addition, the microstructure evolution experienced wetting and drying cycles also characterized by mercury intrusion porosimetry. The saturation and air entry value increased with the sediment depth increased because deeper sediment depth means lower initial void ratio. Thewaterretentioncurveshowsthatthereisalmost nohysteresis observed around the naturalsuction,and in relatively low suction range (0-450 kPa) has a larger degree of hysteresis than the larger suction range(3.29 MPa-367.5 MPa). The three different sediment depth loess exhibiteddifferent average degrees of hysteresis, this is mainly because the different sediment depth loess has experienced different in-situ hydraulic history(seasonal changes,change of water table).The microstructure evolution was investigated bymercury intrusion porosimetry. It appeared thatthe cumulative intrusion void ratio is increased after wetting-drying cycles, and the drying-wetting cycles mainly affect populationof small pores. This study can help us understand the memory of stress history and hydraulic history on the water retention curveof natural loess.

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