Effect of Temperature on Swelling Pressure and Compressibility of Soil

Master's Thesis , 2018 , 53 Pages , Grade: 9.36

Engineering - Geotechnology

Construction of building on clay soil is highly risky due to its poor strength. Clayey soil creates many problems to the Geotechnical Engineers primarily because of repeated change of moisture content. Normally, these soils increase in size and swell when they absorb water and reduce in size and shrink when they become dry. Volume change in soil leads to distortions in the form of settlement due to contraction as a result of dryness or in the form of expansion due to swelling as a result of the absorption of water. There may be the need for soil treatment to improve the engineering properties of such soil. Compacted bentonite is often used as a buffer materials and for radioactive waste disposal system. A good understanding of the hydro-mechanical behavior of clay soil is essential to ensure safe disposal.

The present study reports the results on the effects of temperature on swelling pressure and compressibility characteristics of soil. In this study, two different type of soils were used. One of them was a bentonite (liquid limit = 139%) procured from Bikaner, Rajasthan another one was Rourkela local soil (liquid limit = 35%). A new oedometer was designed and developed in-house to carry out consolidation and swelling pressure tests at a higher temperature. Swelling pressures tests on compacted bentonite specimens of targeted dry density of 1.6 Mg/m3 were conducted under constant volume condition for the temperature range between 25 to 90 0C. Compressibility tests at various temperatures for both soils were conducted using distilled water as the saturating fluid.
It observed that high temperature caused an increase in swelling pressure and compressibility index of bentonite soil. There is no effect of temperature on compressibility index of Rourkela local soil.

Contents

1 Introduction
1.1 Background and motivation
1.2 Objective of the work
1.3 Book Overview

2 Literature Review
2.1 Introduction
2.2 Identification of expansive soil
2.3 Structure of clay mineral
2.3.1 Kaolinite
2.3.2 Illite
2.3.3 Montmorillonite
2.4 Structure of compacted bentonite
2.5 Forces and charges in clay system
2.6 Particle association in Clay
2.7 Swelling Mechanism in Clay
2.8 Swelling pressure
2.8.1 Swelling pressure testing in Laboratory
2.8.2 Swelling pressure measurement devices
2.9 Compressibility behavior of bentonite
2.10 Effect of higher temperature on swelling and compressibility

3 Material and Methods
3.1 Properties of Soil studied
3.1.1 XRD Analysis
3.1.2 SEM Analysis
3.2 Modified oedometer
3.3 Swelling Pressure Test
3.3.1 Experimental setup
3.3.2 Constant volume swelling pressure test
3.4 Consolidation Test
3.4.1 Experimental setup
3.4.2 Methodology to Measure Compressibility

4 Result and Discussion
4.1 Swelling Pressure Test Result
4.2 Compressibility Test Result

5 Conclusions and Scope for Further Study
5.1 Conclusions
5.2 Scope for Further Study

References

• College: National Institute of Technology, Rourkela
• Grade: 9.36
• Author: Ahsan Rabbani (Author)
• Publication Year: 2018
• Pages: 53
• Catalog Number: V425569
• ISBN (eBook): 9783668708648
• ISBN (Book): 9783668708655
• Language: English
• Tags: effect, temperature, swelling, pressure, compressibility, soil