To introduce students to the basic principles of soil mechanics. To develop their ability to apply these principles in the solution of simple practical problems in geotechnical engineering.

On successful completion of this module a student will be able to:
1 Understand the salient features of soil nature, soil characterisation and soil permeability
2 Understand the effective stress concept, determine the distribution of vertical total stress, pore pressure and vertical effective stress with depth
3 Apply the theory of one-dimensional consolidation to determine the development of settlement in foundations and geo-structures with time
4 Understand the principles of shear strength in a soil material and calculate the strength parameters by means of both laboratory and field-testing methods

Basic characteristics of soils: nature of soil; phase relationships; compaction; soil classification; sieve analysis and the Atterberg limits; correlation of engineering properties of shrinkage and swelling; frost heave.

Stresses within a soil: total stress; porewater pressure; and significance of the effective stress principle; Mohr's circle.

Permeability and flow: laboratory testing (constant and falling head permeameters); in situ testing; comparison of laboratory and in situ testing; artesian flow, critical hydraulic gradient, seepage force; one dimensional flow through layered strata; two dimensional seepage through isotropic and anisotropic soils; construction of flow nets by sketching and laboratory modelling.

Compression and consolidation: the spring and piston analogy; one dimensional and isotropic compression; Terzaghi's theory of one-dimensional consolidation; approximate solution for one dimensional consolidation; the odeometer test; formation of overconsolidated and normally consolidated clays; simple settlement calculations.

Shear strength: Coulomb failure criteria; the shear box and triaxial tests; the behaviour of loose and dense sands; the behaviour of normally and over consolidated clays; choice of strength parameters for short term and long term; the application of shear strength parameters to determine the stability of an infinite slope, earth pressures and the ultimate capacity of a footing.
Site investigation: objectives; in situ tests (vane and SPT); comparison of laboratory and in situ tests.

PROBLEM
Different soil typologies can be found in real applications, such as (1) the feasibility study for the excavation of a tunnel for a tube line, typically at large soil depth and very long distance; and (2) the choice of the foundation system for a residential building on a given soil. The design of engineering works (e.g., foundation systems of buildings) has to take into account the behaviour of the existing soil. Soil behaviour can be influenced by several external conditions (e.g., load increase) and the design choices depend on these conditions. In order to design a proper structural system, the mechanical properties of soil under different conditions have to be evaluated by means of both theoretical methods and experimental tests. Soil features allow choosing the best solution for structures in terms of engineering performance and economic impact.

LABORATORY SESSIONS
The students will attend some laboratory experiments. Some experimental tests will be performed in order to define the main features of a soil typology (e.g., sand soil). Different external conditions (e.g., seepage and consolidation phenomena) will be simulated in the laboratory in order to record the soil behaviour under different likely situations. The students will prepare a laboratory report that includes all the performed experiments.

COURSEWORK
The students will produce a laboratory report about the experimental activities performed during the laboratory sessions. In this report, they will compare the soil behaviour under different external conditions and they will have a better understanding of the soil mechanics. The discussion about the experimental outcomes (e.g., soil strength) will demonstrate the influence of the investigated external factors on the design choices in geotechnical engineering.

LECTURES
The lectures will introduce the students to the nature of soil as well as to its basic characteristics. A detailed description of soil behaviour under different loads and external condition (e.g., seepage and consolidation phenomena) will be provided. The lectures will provide the description of some experimental tests for soil mechanical properties as well as the methods for defining soil properties by using the experimental outcomes.

TUTORIALS
The Module will provide tutorials classes in order to improve students understanding of soil mechanics. After the lectures some questions will be given to the students and the solutions/answers will be explained/discussed during the tutorial classes.

Exam - 70% LO - 1-4. Pass mark - 30% 2 hours. Closed book exam.

Lab report - 30% LO - 1-4. Pass mark - 30% 1,500 words. Laboratory report based on experimental tests.

Students are required to pass all components. The overall mark should be lareger than 40%.

Nature of FORMATIVE assessment supporting student learning Studio Assignments and laboratory sessions, Mock exam