~ 582 ~ ISSN Print: 2394-7500 ISSN Online: 2394-5869 Impact Factor: 5.2 IJAR 2015; 1(13): 582-585 www.allresearchjournal.com Received: 20-10-2015 Accepted: 21-11-2015 Gouri Mohan L Assistant Professor, Dept of Civil Engineering, Bishop Jerome Institute, Kollam Santhini S Lal Assistant Professor, Dept of Civil Engineering, Bishop Jerome Institute, Kollam Dr. KK Abdul Rasheed Associate Professor, Dept of Mechanical Engineering, TKM College of Engineering, Kollam Dr. Reebu Zachariah Koshy Professor, Dept of Civil Engineering, TKM College of Engineering, Kollam Correspondence Gouri Mohan L Assistant Professor, Dept of Civil Engineering, Bishop Jerome Institute, Kollam Theoretical study on constitutive modelling of frozen soils Gouri Mohan L, Santhini S Lal, Dr. KK Abdul Rasheed, Dr. Reebu Zachariah Koshy Abstract Artificial Ground Freezing techniques eliminate the need for structural supports during the course of an excavation, as frozen ground is solid and waterproof. At present, it is adopted as an effective way to deal with various construction ground control challenges such as the mitigation of seepage infiltration into tunnels and shaft excavations; or ground strengthening for excavation. In-depth knowledge of the frozen soil characteristics through experiments and the development of suitable constitutive models that suit the geological conditions of our country are necessary to predict the strength and behaviour of the frozen soils. This paper presents a review on the various constitutive models used in soil analysis. Authors hope that this article will help to develop better understanding of frozen soil properties and emphasize the need for accurate constitutive models incorporating the characteristics of soils in our country. Keywords: Artificial Ground Freezing, Constitutive Modelling, Mohr Coulomb criteria, Drucker Prager Model Introduction The technique of Artificial Ground Freezing (AGF) is now commonly used in the cold regions of the world. Extension and improvement of transportation networks in densely populated areas with thickly packed infrastructure is becoming unavoidable now-a-days, especially in urban areas. An alarming increase in the population of vehicles is creating severe traffic congestion. Hence this will surely be a promising ground improvement technique in the coming years all around the World as infrastructural expansion is possible only through underground space exploration. Artificial Ground Freezing is gaining importance because of its advantage in eliminating the need for structural supports during the course of excavation. In this method, the strong solid frozen barrier created around the zone of excavation prevents the intrusion of water into the area of excavation thereby creating a safe working environment for labourers. In all other existing excavation methods, there are possibilities of dangers creeping in due to various reasons during the progress of the work. AGF involves circulating refrigerated liquid through a series of subsurface pipes to freeze the ground temporarily around the zone of excavation until the work is completed as shown in fig 1. Most of the theoretical and experimental studies in the cold regions are conducted on soils which are in the naturally frozen state. All the available literature and existing models are based on these results. For introducing the AGF technique for any underground construction in our country, a thorough knowledge of the geotechnical characteristics of soils, especially in the frozen state, is necessary. The intrinsic material properties such as moisture content, organic matter, air bubbles, grain size, salts and externally imposed testing conditions such as strain-rate, stress and strain history, temperature and confining pressure governs the mechanical behaviour of frozen soil. Constitutive Models in Soil Analysis When frozen soil is subjected to loading, the uniaxial stress strain curve exhibits an elasto- plastic behaviour. So constitutive models are required for studying the behaviour of soil subjected to loading. Soil is a complicated material that behaves non-linearly and often shows anisotropic and time dependent behaviour when subjected to stresses. Generally, soil behaves differently in primary loading, unloading and reloading. International Journal of Applied Research 2015; 1(13): 582-585