報告者：蕭鈺 指導 老師 ：倪春發 老師 2010/12/16

1. Field evidenceof pore pressure diffusionin clayey soils pronetolandslidingBerti, M., Simoni, A., 2010Journal of Geophysical Research,115, 報告者：蕭鈺 指導老師：倪春發 老師 2010/12/16

2. Outline 1.Introduction 2.Rocca Pitigliana Test Site 3.Monitoring System 4.Hydrologic Modeling 5.Results and Discussion 6. Conclusions

3. Introduction

4. 1. [Dhakal and Sidle, 2004; Iverson, 2000;Rosso et al., 2006; Montgomery and Dietrich , 1994] developed simple, explicit equations with few input parameters 2. [Iverson and Major 1987] first proposed that a simple model for vertical diffusive propagation can be used to interpret the wet‐season groundwater response in a large earth flow body. 3. [ Baum and Reid 1995] discovered that surface infiltration can saturate the landslide body in just a few days,and that the saturated soil responds rapidly to heavy rainfall.

5. 1. To illustrate the hydrologic behavior of weathered clayey soils overlying a clay‐shale bedrock. 2. To evaluate the capability of the one‐dimensional (1‐D) linear‐diffusion model. 3. To compare the calibrated hydraulic parameters with those measured by field and laboratory tests. 4. To compare the performance of linear‐diffusion and different models

6. Rocca Pitigliana Test Site

8. Monitoring System

11. Hydrologic Modeling

12. Hydraulic Parameters of the Soil D：hydraulic diffusivity K：hydraulic conductivity C：specific moisture capacity ψ：pressure head Saturated Aquifer

13. Linear‐Diffusion Model ψ ： pressure head D0： Saturatedhydraulic diffusivity α：slope angle

14. Results and Discussion

18. Conclusions

19. 1. The pressure waves advance vertically downward through the fully saturated soil at high speed (the observed velocity is 200 times greater than the advective front velocity) and become slower and smoother with depth. 2.The short‐term behavior of the clay cover can be well reproduced using the 1‐D linear‐diffusion model proposed by Iverson [2000]. The model loses its predictive capabilities when applied outside its validity domain or when surface ponding occurs 3.The utility of a linear‐diffusion model in the framework of areal slope stability assessment is rather limited.

20. Thanks for your attention