Deformation History of a Landslide Slip Zone in Light of Soil Microstructure

Abstract

Research Article| February 01, 2004 Deformation History of a Landslide Slip Zone in Light of Soil Microstructure BAO-PING WEN; BAO-PING WEN 12Department of Hydraulic and Hydropower Engineering, Tsinghua University, Beijing 100084, China Search for other works by this author on: GSW Google Scholar ADNAN AYDIN ADNAN AYDIN 3Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China Search for other works by this author on: GSW Google Scholar Author and Article Information BAO-PING WEN 12Department of Hydraulic and Hydropower Engineering, Tsinghua University, Beijing 100084, China ADNAN AYDIN 3Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China Publisher: Association of Environmental & Engineering Geologists First Online: 02 Mar 2017 Online ISSN: 1558-9161 Print ISSN: 1078-7275 © 2004 Association of Engineering Geologists Environmental & Engineering Geoscience (2004) 10 (2): 123–149. https://doi.org/10.2113/10.2.123 Article history First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation BAO-PING WEN, ADNAN AYDIN; Deformation History of a Landslide Slip Zone in Light of Soil Microstructure. Environmental & Engineering Geoscience 2004;; 10 (2): 123–149. doi: https://doi.org/10.2113/10.2.123 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Abstract The microstructure of a slip zone from a recent landslide was investigated by combined optical microscopy (OPM) and backscattered electron microscopy (BEM) techniques. Along the toe of the slope, the slip zone consisted of two distinct segments, formed a) along a pre-existing slip zone and b) through completely decomposed granite (CDG), both of which comprise composite soils. The microstructural features were systematically captured, quantified, and analyzed using an advanced image-analysis system. It is shown that variations in density, porosity, presence of matching fragments of coarse particles, abundance of tabular aggregates and plates of kaolinite and particle alignment are significant indicators of the deformation history of the slip zone. The results indicate that multiple processes concurred in the course of deformation: compaction and dilation, cataclasis and comminution, and particle rearrangement. Such deformation features of the natural composite soils are fundamentally different from the relatively simple soils commonly used in laboratory studies. The extent of each process depends on the particle-size distribution and stress level that prevailed at time of failure. The particle movement and microstructural evolution of the slip zone could be described as particulate flow through simultaneous bulk simple shear and pure shear. Depending on their relative abundance, fine particles play an important but variable role in the development of the slip zone and the mobilization of its shear resistance to deformation. Reactivation and/or prolonged deformation evidently change the deformation behavior of the pre-existing slip zone. In general, shape-preferred orientation of particles occurs where they are obviously aligned. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.