Influence of acid environment on Collapsibility of Loess

¹ Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China.
² School of Civil Engineering and Architecture, Xi’an University of Technology, Xi’an 710048, China.

^* Corresponding author’s e-mail: ningli@xaut.edu.cn

Abstract

Cemented connection of loess is an important internal factor of loess collapsibility, which has a direct impact on its collapsibility. In this study, different concentrations of nitric acid were added to the immersion solution of loess collapsibility test, and the collapsibility sensitivity indexes of loess, such as collapsibility coefficient, stability time and collapsibility rate, were tested under acidic environment and different pressures. At the same time, scanning electron microscope was used to observe the changes of pore and structure of soil samples before and after the test. The test results show that in acid solution, the collapsibility coefficient of collapsible loess increases more under low pressure, and the collapsibility stability time of collapsible loess increases under different pressures. Loess has different collapsibility sensitive pressure range in aqueous solution and acidic solution. The structural strength of collapsible loess has an important influence on the depth of collapsible loess.