ENGINEERING TRIPOS PART IB - 2012/2013

PAPER 8 - SELECTED TOPICS (3)

Civil & Structural

Design & Construction of Underground Space

Leader: Professor K. Soga / Dr. C. Burgoyne

Timing: Weeks 1-4 Easter term

Structure: 14 lectures + 2 examples classes, 4 lectures/week

AIMS

The aims of this course are to:

• Act as a shop window for the techniques and technologies of civil engineering seen as a practical and scientific discipline.
• Create interest in the design and construction of underground facilities, with illustrations from recent schemes, and in so doing highlight the role of the professional.
• Introduce the materials of underground construction: soil, and reinforced concrete.
• Introduce the principles of soil mechanics, and to demonstrate their application to the design of structures underground.

OBJECTIVES

Students who have taken the course should be able to:

• Select a method of underground construction which will be appropriate to some specified set of ground conditions.
• Relate soil voids ratio to its bulk density, and calculate vertical stresses.
• Interpret tests to determine the strength of soils, so as to obtain appropriate "undrained" (single-phase) or "drained" (dual-phase) parameters.
• Use Mohr circles of stress to calculate the possible bounds to the lateral earth pressure: "active" (minimal) and "passive" (maximal).
• Use active and passive pressures to dimension satisfactory earth retaining walls, and calculate shear forces and bending moments.
• Calculate the design flexural strength of reinforced concrete sections, using appropriate material properties.
• Outline the internal stress-distribution in reinforced concrete walls, and make proposals for shear reinforcement.
• Discuss the detailing of reinforced concrete retaining walls constructed in various ways.
• Discuss the factors influencing design and construction of bored tunnels in urban areas.
• Illustrate the handling of uncertainty and risk in construction underground.

SYLLABUS (Book References)

1. Granular Materials (3L)

References

(1) 1-26, 63-79, 93-96

(2) 1-30, 46-64, 165-170

• 1.1. Geology, rock, soil
• 1.2. Pores & water, density, geostatic stresses
• 1.3. Effective stress and pore water pressure
• 1.4. Strength in shear and compression
• 1.5. Effective internal friction, dilatancy, critical state
• 1.6. Tests for the shear strength of soils: shear box, triaxal

2. Earth Pressures (3L)

References

(1) 272-284, 295-307

(2) 243-250

• 2.1. Earth pressure and thrust on retaining walls
• 2.2. Coulomb's kinematical method using wedge mechanisms
• 2.3. Rankine's statical method using Mohr's circles of stress
• 2.4. Active and passive limits to possible earth pressures
• 2.5. The influence of water in sands and clays
• 2.6. Drained and undrained soil behaviour

3. Geotechnical Design of Underground Space (3L)

References

(1) 357-376, 409-430

233-242, 269-271, 341-375

• 3.1. Site investigation and ground characterisation
• 3.2. Permissible soil strength, design earth pressures
• 3.3. Designing a retaining wall: stability and equilibrium, factors of safety
• 3.4. Cut and cover, and top-down construction of reinforced concrete, case histories.
• 3.5. Tunnelling: design and construction
• 3.6. Tunnelling: stability, ground movements, case histories.

4. Reinforced Concrete (3L)

References

(3) 1-2, 18-28, 85-119

• 4.1. Simple theory for the bending of a concrete beam
• 4.2. Shear force and bending moment distribution in walls.
• 4.3. Longitudinal and shear reinforcement
• 4.4. Design, detailing and construction of reinforced concrete
• 4.5. Analysis and design of underground structures

5. Design and Construction of Underground Space (2L)

Reference

Please see the Booklist for Part IB Courses for references for this module.

Last updated: May 2012