Soil consists of soil particles, water, and air. The engineering properties of soil are greatly influenced by the ratio of these components. Unsaturated soil mechanics is an essential part of geotechnical engineering, which is necessary to deal with problems related to disaster prevention and geoenvironment — such as rainfall induced slope failure and seepage in waste facilities. The purpose of this course is to provide knowledge of water and heat transfers, and strength and deformation of unsaturated soil.
Through the course, students will be able to:
- understand mechanism and modeling of water retention, governing equations for seepage, and infiltration control using soil water retention.
- understand heat transfer between the atmosphere and ground, thermal properties of unsaturated soil, governing equations for heat transfer, and use of heat insulation.
- understand contribution of suction to strength and deformation of unsaturated soil, and apply to problems of slope stability during rainfall.
- deliver a clear lecture based on their understanding of some papers on the topics above.
Unsaturated soil, Water retention, Seepage, Thermal properties, Slope stability
✔ Specialist skills | Intercultural skills | ✔ Communication skills | ✔ Critical thinking skills | ✔ Practical and/or problem-solving skills |
Lectures, exercises, and presentations. In lecture and exercise classes, attendance is confirmed by submission of assignments.
Course schedule | Required learning | |
---|---|---|
Class 1 | Porewater pressure in unsaturated soil | To understand porewater pressure in unsaturated soil |
Class 2 | Water retention and permeability | To understand mechanism of water retention and permeability in unsaturated condition |
Class 3 | Unsaturated seepage flow | To understand governing equations for unsaturated seepage flow and boundary conditions |
Class 4 | Exercise 1 | To do exercises on unsaturated seepage flow |
Class 5 | Application of unsaturated seepage flow – capillary barrier – | To understand infiltration control using difference in hydraulic properties of sand and gravel |
Class 6 | Heat transfer and thermal properties | To understand thermal properties of unsaturated soil and governing equations for heat flow |
Class 7 | Use of heat insulation of soil | To understand use of heat insulation of soil in various fields |
Class 8 | Presentation 1 | To read papers on unsaturated seepage flow and deliver a lecture |
Class 9 | Strength parameters | To understand contribution of suction to strength parameters |
Class 10 | Slope stability during rainfall | To understand slope stability analysis during rainfall infiltration |
Class 11 | Exercise 2 | To do exercises on slope stability of unsaturated soil |
Class 12 | Stress variables | To understand stress variables (effective stress) that control strength and deformation of unsaturated soil |
Class 13 | Presentation 2 | To read papers on mechanical behavior of unsaturated soil and deliver a lecture |
Class 14 | Summary | Lesson reviews, comments on assignments, and Q & A |
Students are expected to review each class and submit assignments. For presentation classes, students are required to prepare presentation slides and practice presentations.
Handouts and papers will be provided in class.
Fredlund, D. G., & Rahardjo, H. (1993). Soil mechanics for unsaturated soils. John Wiley & Sons.
Jury, W. A., & Horton, R. (2004). Soil physics. John Wiley & Sons.
地盤工学会不飽和地盤の挙動と評価編集委員会 (2005). 不飽和地盤の挙動と評価, 丸善出版 [in Japanese]
Assignments(40%),Presentations(40%),Attendance(20%)
No prerequisites are necessary, but enrollment in the related courses is desirable.
Mai Sawada(sawada.m.af[at]m.titech.ac.jp, 2798)