Experimental Study on Physical Mechanical Properties and Microstructure of Diatomite Soil in Zhejiang Province, China

Lei Gao,Omar Abdulhafidh,Mingjun Gao,Yi Luo,Yingeng Kang

doi:10.3390/app12010387

Lei Gao, Omar Abdulhafidh + Show 3 more

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https://doi.org/10.3390/app12010387

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Abstract

Diatomite soil is a kind of bio-siliceous soil with complex composition and special structure, the physical and mechanical properties of diatomite soil are very important for the engineering project. In this paper, the physical properties, mechanical properties, and microstructure of diatomite soil in Zhejiang Province are studied by geotechnical tests and microscopic tests from the macroscopic and microscopic perspective. The results show that: (1) The diatomite soil has special properties different from other soils, including small particle size, low specific gravity value, high liquid-plastic limit, and low compressibility, and the strength indexes c and φ of diatomite soil will decrease with an increase in soil water content; (2) in the triaxial test, when the dry density of diatomite soil increases from 1.30 g/cm3 to 1.50 g/cm3, the effective internal friction angle of diatomite soil increases from 5.6° to 14.5° and the effective cohesion increases from 30.9 kPa to 49.6 kPa. The stress–strain curve of diatomite soil changes from weak softening type to weak hardening type when the confining pressure is above 200 kPa; (3) the diatomite soil has high porosity due to its unique microstructure; it is rich in aluminum oxides and minerals, which will greatly reduce the engineering performance of diatomite soil.

Highlights

Academic Editor: Claudio DeDiatomite soil is a kind of porous siliceous soil, which is formed by the accumulation of diatoms and other plant remains
Considering the high natural water content of diatomite soil, the entry of water molecules breaks the overlapping cell structure composed of silicon, aluminum, and oxygen, which leads to a softening effect and volume expansion of diatomite soil
The physical properties, mechanical properties, and microstructure of diatomite soil in Zhejiang Province are studied through a series of geotechnical engineering tests in this paper

Summary

Introduction

Academic Editor: Claudio DeDiatomite soil is a kind of porous siliceous soil, which is formed by the accumulation of diatoms and other plant remains. There are abundant diatomite soil resources in the world, it is estimated that the geological reserves of diatomite soil in the world are at least two billion tons. It is mainly distributed in China, the United States, Denmark, France, and other places [1,2]. Diatomite soil has special structural and chemical stability, which is characterized by soft texture, high adsorption, high porosity, and low density [3]. At present, it is often used as an adsorption material in the chemical industry [4,5,6]. The main component of diatomite soil is SiO2 , and it contains more clay minerals, detritus, and organic matter [7,8,9]

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