CIVIL 322 – GEOMECHANICS 2
(15 Points, FC 2016)
COURSE CO-ORDINATOR: Prof MICHAEL PENDER
Room 1.1102, ext. 87919, Email:
Dr RYAN YAN
Room 1.???, ext. ????, Email:
TIMES: Wednesday 4.00 – 5.00 1.439
Thursday 4.00 – 5.00 1.439
Friday 4.00 – 5.00 1.439
(There will be roughly one tutorial session for every two lectures, but these will be taken as convenient and appropriate at any of the times shown above and not identified with a particular timetable slot.)
Office hours: M J Pender Monday & Wednesday 2:00-3:00pm 1.1102
R Yan
PHILOSOPHY:
This course, following on from Geomechanics 1, completes the basis for the application of the principles of geomechanics in geotechnical engineering. The combined purpose of both Geomechanics 1 and Geomechanics 2 is to present sufficient fundamental ideas to prepare the way for the subsequent electives: Geomechanics 3, Foundation Engineering, Slope Engineering. The three courses: Introductory Engineering Geology, Geomechanics 1, and Geomechanics 2 are intended to provide the core geotechnical knowledge thought to be essential for all graduates in Civil Engineering or Environmental Engineering. Two significant aspects of the teaching of Geomechanics 1 and Geomechanics 2 are:
(i) the importance placed on observation of real soil behaviour in the laboratory
(ii) illustrations of the application of the principles in geotechnical design contexts, albeit simple ones.
LABORATORY:
Schedule to be announced Geomechanics laboratory located on Level 1.
Two laboratory sessions, each of 2 hours, are part of the paper:
· Consolidation testing and soil compressibility
· Consolidated drained (CD) test on dry sand
A journal (not a formal report) will be required from each student for each of the laboratory exercises. The journals will be inspected and, when satisfactory, signed-off. The laboratory sessions are an integral part of the course and satisfactory performance, ie attendance at the assigned laboratory sessions and the completion of the journal report, is required and will constitute up to 5% of the final grade.
A laboratory journal must contain: (i) the processed results of the laboratory tests, (ii) the tabulated results (pre-formatted blank table sheets are provided) and, where appropriate, plots of the results, and (iii) interpretive comments on the significance of the results obtained. The deadline for the journal reports is 2 weeks after the date of the laboratory session.
ASSESSMENT:
Final Exam: 2 hours 70%
Test: 1 hour 15% Monday May 02 at 6.00 pm. Rooms to be advised. The marked scripts will be available at the Student Services stall (level 3) from Tuesday 10 May. Student ID is required to collect your script.
Group Design Project: 10% Deadline Tuesday April 26 at 12.00 noon (hand-in at the Student Services Stall). Marking for the design project will be allocated on the basis of 1/3 for effort, 1/3 for insight, and 1/3 for the results. The marked projects will be available at the Student Services Stall.
Laboratory Reports: 5%
Homework: Assignments will be set, roughly weekly. These will not carry any assessment towards the final grade but will, if handed in, be noted and the completion of these will be used in assessing cases for conceded, compassionate and aegrotat passes.
LEARNING OBJECTIVES:
The major topics to be covered in the paper are:
· Slope stability (continuing from the rock slope stability work in Geomechanics 1)
· Magnitude and rate of the consolidation settlement
· Earth pressures on soil retaining structures
· Bearing capacity of shallow foundations
In covering the above material it is intended that the student will:
· become familiar with the terminology and understand the principles of geomechanics associated with each topic
· appreciate how to apply the understanding gained in geotechnical design (developed through the set assignments and the design project)
· develop a deepening appreciation of geomechanics as a coherent body of knowledge
· become aware of how geomechanics relates to other aspects of mechanics utilised in Civil Engineering and Environmental Engineering.
COURSE OUTLINE:
The main headings for each of the topic areas in the course are:
· Slope stability:
Slope stability in uniform soil – planar and curved failure surfaces
Stability charts for various drainage and groundwater conditions
Special cases – vertical slope in a saturated clay, the infinite slope
Method of slices – Ordinary and Bishop methods using a spreadsheet or similar tool
· Earth pressures on soil retaining structures:
Earth pressures generated by cohesionless soil on smooth and rough walls – active and passive
Effect of earthquake loading
Earth pressures generated by cohesive soils
Earth pressure distribution in terms of soil shear strength parameters
In situ and at-rest earth pressures
· Bearing capacity of shallow foundations:
Mechanisms of bearing capacity failure
Terzaghi bearing capacity equation
Effect of foundation shape and embedment on foundation bearing capacity
Bearing capacity factor of safety and compensated foundations
Application to gravity retaining walls
· Magnitude and rate of the consolidation settlement:
Mechanism of settlement – consolidation a time dependent process
Laboratory oedometer test
Derivation of the equation for one dimensional consolidation
Solution of the consolidation equation
Application of the consolidation equation solution:
time for consolidation settlement
interpretation of laboratory oedometer test results
Subsurface vertical stresses generated by surface loads
Settlement estimation in layered soil deposits
Time allocation:
Being a 10 point paper with laboratory work the total contact time available is 30 hours for lectures and tutorials as well as 4 hours for laboratory. It is proposed to divide this among the topic headings in the following way:
· Stability of slopes 6 sessions
· Lateral earth pressures and retaining structures 8 sessions
· Bearing capacity of shallow foundations 6 sessions
· Consolidation of clay layers and settlement of foundations 9 sessions
· Summary and revision 1 session
TEXTS:
A set of preprinted notes is available for the course. This is the main teaching resource, students are expected to purchase this. It will be available at the start of lectures.
The recommended text (supplementary reading) is Craig (four copies are available on short loan from the Engineering Library) which provides useful supplementary reading for the hand-out teaching materials. In addition the following are on Desk Copy in the Engineering Library:
Craig, R. F. “Soil Mechanics”, Spon, 2004.
(Call number: TA710 .C685 2004)
Wesley, L. D. “Fundamentals of Soil Mechanics for Sedimentary and Residual soils” Wiley 2010.
(Call number: TA709.5 W47 2010)
Lancellotta, R. “Geotechnical Engineering”, Balkema, 1995.
(Call number: 624.13 L22)
Terzaghi, K., Peck, R. B. & Mesri, G. “Soil Mechanics in Engineering Practice”, Wiley 1996.
(Call number: 624.131 T33s 1996)
Powrie, W. “Soil Mechanics”, E&FN Spon, 1997.
(Call number: 624.131 P87)