DOCSLIB.ORG

Criterions, Prediction and Prevention of Loess Liquefaction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Criterions, Prediction and Prevention of Loess Liquefaction Missouri University of Science and Technology Scholars' Mine International Conferences on Recent Advances 2010 - Fifth International Conference on Recent in Geotechnical Earthquake Engineering and Advances in Geotechnical Earthquake Soil Dynamics Engineering and Soil Dynamics 27 May 2010, 8:45 am - 9:15 am Criterions, Prediction and Prevention of Loess Liquefaction Lanmin Wang Lanzhou Institute of Seismology, China Earthquake Administration, China Zhongxia Yuan Lanzhou Institute of Seismology, China Earthquake Administration, China Haimei Sun Lanzhou Institute of Seismology, China Earthquake Administration, China Jin Deng Lanzhou Institute of Seismology, China Earthquake Administration, China Follow this and additional works at: https://scholarsmine.mst.edu/icrageesd Part of the Geotechnical Engineering Commons Recommended Citation Wang, Lanmin; Yuan, Zhongxia; Sun, Haimei; and Deng, Jin, "Criterions, Prediction and Prevention of Loess Liquefaction" (2010). International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. 1. https://scholarsmine.mst.edu/icrageesd/05icrageesd/session12/1 This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License. This Article - Conference proceedings is brought to you for free and open access by Scholars' Mine. It has been accepted for inclusion in International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics by an authorized administrator of Scholars' Mine. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. CRITERIONS, PREDICTION AND PREVENTION OF LOESS LIQUEFACTION Lanmin Wang Zhongxia Yuan, Haimei Sun, Jin Deng Lanzhou Institute of Seismology, Lanzhou Institute of Seismology, China Earthquake Administration China Earthquake Administration Lanzhou, Gansu-China 730000 Lanzhou, Gansu-China 730000 ABSTRACT Although loess liquefaction is not very common during earthquakes in Northwest of China, it is disastrous if it happens. Both study and valid evidence from Haiyuan 8.5 Earthquake in 1920 and Tajikistan 5.9 Earthquake in 1989 have proved that loess liquefaction could be very disastrous under certain conditions. In this paper, the criterions of loess liquefaction are discussed to show that unlike typical liquefaction of sand, loess which falls into the category of both silt clay and clayey silt has unique characteristics during liquefaction test. To predict liquefaction of loess, a simple method based on laboratory test and field evidences using GIS is proposed. The prediction results and corresponding measure have been adopted in Seismic Design Code for Buildings in Lanzhou Urban Area. Finally, recent approach of treatment of loess with chemicals methods is developed, which may have some application implication as an simple and feasible treatment method against liquefaction of loess. INTRODUCTION Loess is widely distributed in Northwest of China, where along the hillside. Even 50 years later, the flow trace of the Loess Plateau, with 400,000 square kilometers, is the largest loess can still be identified in the field. In 1990, based on field plateau of loess in the world. The plateau is covered by thick investigation, an overall assessment of loess liquefaction were loess layer, which is from tens meters to more than 500 meters. given by Bai et al. (Bai, 1990), since then there comes a great Lanzhou, Gansu area, with completely developed loess layer interest for loess liquefaction study. Wang Lanmin performed and large deposit thickness, has been named as “the thickest dynamic triaxial test of loess liquefaction and made inversion loess sedimentation area in the world” and represents the analyses of the three cases, which shows that the PGAs typical geological characteristics of the loess layer in China. triggering loess liquefaction during the Haiyuan earthquake, New Madrid earthquake and Tajik earthquake are respectively For a long period, liquefaction of silt soils including loess is around 380gal, 240gals and 150gals. not recognized even if there were some study and it is often controversial. This attitude changed during 1990’s. Loess Liquefaction of loess is unique in many ways. First of all, it is liquefaction is not very common but surely observed during a flow type of liquefaction. That is, under the effect of cyclic earthquakes in Northwest of China and other part of the world loading, the pore water pressure in loess rises, effective stress like Tajikistan and central states of Untied States (Ishihara, is down and large amount of residual strain develops, finally, 1990; Hwang and Wang, 2000). During Haiyuan 8.5 loess loses its strength and became mud flow. The amount of Earthquake in 1920, Tajikistan 5.9 Earthquake in 1989 and residual strain as it is shown in dynamic test could easily be much earlier, the New Madrid earthquake in 1811-1812, there more than 10%, which is really huge. The loess sample after were loess liquefaction which caused landslides of nearly liquefaction test is very soft and cannot stand on itself without horizontal layers and other types of geotechnical hazard. leaving for desiccation of certain amount of time. The shape of Villages were buried and hundreds of lives lost for the cases of sample, which is a normal cylinder before liquefaction test, China and Tajikistan. Investigation and records have shown turns into a bulged form at the bottom (Fig.1). This indicates that Haiyuan earthquake caused the rise of the underground that loess samples turns into a mud flow due to liquefaction. water of nearly 4-5 meters, which led to liquefaction in Late An interesting feature of microstructure of loess after Pleistocene(Q3) loess layer at depth of 14-16m. The sliding liquefaction test is the formation of many round holes, which distance reached a maximum of 1.5km of the super stratum do not observed in sample before test. The diameter of these Paper No. OSP 11 1 round holes is from 60 to 200 micron(Fig.2 ). Because of its liquefaction, the pores were damaged and the particles regular shape, it has to do with the pore water movement. We rearranged to contact more closely each other. assume that there are two reasons for the formation of such round holes: 1. during the test there are collapse of Since 1990’s liquefaction of Loess has been an hot topic and microstructure which formed a larger pore, 2. the pore water on the front of scientific exploration. Wang L.M et al (1996, movement using such holes as main channel, and thus they are 1999) carried comprehensive study on the liquefaction also subjected to pore water pressure, which is homogenous, characteristics of loess liquefaction and its mechanism. Also, the homogenous pore water pressure caused these holes to sit explosion is applied to show that loess liquefaction is have a round shape. This phenomenon also indicates that possible. Yang Zhenmao et al. (2004) studied the pore because of low permeability of loess, pore water movement is pressure increase characteristics and steady state strength. quite uneven at different parts of the sample, most of the pore Yuan Zhongxia et al. (2004) studied on mechanism and water running through the channels composed with the round discrimination criterion of loess liquefaction and regarded that holes and channels connecting or around them. loess liquefaction is a “ flow type” and has large deformation. Liao Shengxiu, Chen Juhong (2007) using hard evidence from site, showed that long duration of mechanical vibration of pile driver caused liquefaction of loess field. Wang L.M et al. (2007) applied the research results into practices through drafted “Seismic Design Code for Buildings in Lanzhou Urban Area”, which is the first local engineering specification for the discrimination and treatment of loess liquefaction. The loess liquefaction is fall into the category of liquefaction of silt-clay mixtures as the term used by American scientists. Prakash et al. (1998) proved that PI and initial void ratio are two relatively independent parameters, which decide whether the loess could liquefies or not. And the age and structure decide the pattern of pore pressure increase during liquefaction. The development of pore pressure and strain Fig.1 Loess samples after liquefaction test during loess liquefaction are different from that of sand under the cyclic loading. Boulanger and Idriss (2006) divided the liquefaction behavior into “sand-like” and “clay-like”. This through new light on study of liquefaction of loess and draw a clear line on problems and type of silt soils that were debatable as far as liquefaction is concerned. Although liquefaction mechanism and behaviors of loess have been studied, there is also some no well established test procedures and criteria to assess liquefaction potential or treat loess ground for liquefaction. With the development of urbanization and agriculture irrigation, the area of saturated loess and loess with high water content has been enlarging. There is a very high probability to liquefy loess under the earthquake with certain intensity. So there is still urgent need to study loess liquefaction and clarify some of the filed where 600μm which it still not well accepted or recognized. Fig.2 Microstructure of loess after liquefaction (Magnification factor: 100) TEST OF LOESS LIQEFACTION There is a major difference between liquefaction of sand and that of loess. For sand liquefaction, it is the result of Most laboratory loess liquefaction tests have been done on the densification of sand structure which forced some portion of electromagnetic dynamic triaxial instrument in Lanzhou water move out from the skeleton and even rise up. But for Institute of Seismology (LIS) before 2006. The instrument has loess, because of its low permeability, water cannot move as some disadvantages, such as, lacking of back pressure for freely as it is in sand. As a result, the pore water pressure saturation, open-loop control and which makes the test process buildup applies shear stress to loess structure and causes it to rather awkward sometimes.
Load more

Recommended publications
  • Seismic Pore Water Pressure Generation Models: Numerical Evaluation and Comparison
    th The 14 World Conference on Earthquake Engineering October 12-17, 2008, Beijing, China SEISMIC PORE WATER PRESSURE GENERATION MODELS: NUMERICAL EVALUATION AND COMPARISON S. Nabili 1 Y. Jafarian 2 and M.H. Baziar 3 ¹M.Sc, College of Civil Engineering, Iran University of Science and Technology, Tehran, Iran ² Ph.D. Candidates, College of Civil Engineering, Iran University of Science and Technology, Tehran, Iran ³ Professor, College of Civil Engineering, Iran University of Science and Technology, Tehran, Iran ABSTRACT: Researchers have attempted to model excess pore water pressure via numerical modeling, in order to estimate the potential of liquefaction. The attempt of this work is numerical evaluation of excess pore water pressure models using a fully coupled effective stress and uncoupled total stress analysis. For this aim, several cyclic and monotonic element tests and a level ground centrifuge test of VELACS project [1] were utilized. Equivalent linear and non linear numerical models were used to evaluate the excess pore water pressure. Comparing the excess pore pressure buildup time histories of the numerical and experimental models showed that the equivalent linear method can predict better the excess pore water pressure than the non linear approach, but it can not concern the presence of pore pressure in the calculation of the shear strain. KEYWORDS: Excess pore water pressure, effective stress, total stress, equivalent linear, non linear 1. INTRODUCTION Estimation of liquefaction is one of the main objectives in geotechnical engineering. For this purpose, several numerical and experimental methods have been proposed. An important stage to predict the liquefaction is the prediction of excess pore water pressure at a given point.
    [Show full text]
  • 2021 Oregon Seismic Hazard Database: Purpose and Methods
    State of Oregon Oregon Department of Geology and Mineral Industries Brad Avy, State Geologist DIGITAL DATA SERIES 2021 OREGON SEISMIC HAZARD DATABASE: PURPOSE AND METHODS By Ian P. Madin1, Jon J. Francyzk1, John M. Bauer2, and Carlie J.M. Azzopardi1 2021 1Oregon Department of Geology and Mineral Industries, 800 NE Oregon Street, Suite 965, Portland, OR 97232 2Principal, Bauer GIS Solutions, Portland, OR 97229 2021 Oregon Seismic Hazard Database: Purpose and Methods DISCLAIMER This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. Users of this information should review or consult the primary data and information sources to ascertain the usability of the information. This publication cannot substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from the results shown in the publication. WHAT’S IN THIS PUBLICATION? The Oregon Seismic Hazard Database, release 1 (OSHD-1.0), is the first comprehensive collection of seismic hazard data for Oregon. This publication consists of a geodatabase containing coseismic geohazard maps and quantitative ground shaking and ground deformation maps; a report describing the methods used to prepare the geodatabase, and map plates showing 1) the highest level of shaking (peak ground velocity) expected to occur with a 2% chance in the next 50 years, equivalent to the most severe shaking likely to occur once in 2,475 years; 2) median shaking levels expected from a suite of 30 magnitude 9 Cascadia subduction zone earthquake simulations; and 3) the probability of experiencing shaking of Modified Mercalli Intensity VII, which is the nominal threshold for structural damage to buildings.
    [Show full text]
  • A Study of Unstable Slopes in Permafrost Areas: Alaskan Case Studies Used As a Training Tool
    A Study of Unstable Slopes in Permafrost Areas: Alaskan Case Studies Used as a Training Tool Item Type Report Authors Darrow, Margaret M.; Huang, Scott L.; Obermiller, Kyle Publisher Alaska University Transportation Center Download date 26/09/2021 04:55:55 Link to Item http://hdl.handle.net/11122/7546 A Study of Unstable Slopes in Permafrost Areas: Alaskan Case Studies Used as a Training Tool Final Report December 2011 Prepared by PI: Margaret M. Darrow, Ph.D. Co-PI: Scott L. Huang, Ph.D. Co-author: Kyle Obermiller Institute of Northern Engineering for Alaska University Transportation Center REPORT CONTENTS TABLE OF CONTENTS 1.0 INTRODUCTION ................................................................................................................ 1 2.0 REVIEW OF UNSTABLE SOIL SLOPES IN PERMAFROST AREAS ............................... 1 3.0 THE NELCHINA SLIDE ..................................................................................................... 2 4.0 THE RICH113 SLIDE ......................................................................................................... 5 5.0 THE CHITINA DUMP SLIDE .............................................................................................. 6 6.0 SUMMARY ......................................................................................................................... 9 7.0 REFERENCES ................................................................................................................. 10 i A STUDY OF UNSTABLE SLOPES IN PERMAFROST AREAS 1.0 INTRODUCTION
    [Show full text]
  • Recommended Guidelines for Liquefaction Evaluations Using Ground Motions from Probabilistic Seismic Hazard Analyses
    RECOMMENDED GUIDELINES FOR LIQUEFACTION EVALUATIONS USING GROUND MOTIONS FROM PROBABILISTIC SEISMIC HAZARD ANALYSES Report to the Oregon Department of Transportation June, 2005 Prepared by Stephen Dickenson Associate Professor Geotechnical Engineering Group Department of Civil, Construction and Environmental Engineering Oregon State University ODOT Liquefaction Hazard Assessment using Ground Motions from PSHA Page 2 ABSTRACT The assessment of liquefaction hazards for bridge sites requires thorough geotechnical site characterization and credible estimates of the ground motions anticipated for the exposure interval of interest. The ODOT Bridge Design and Drafting Manual specifies that the ground motions used for evaluation of liquefaction hazards must be obtained from probabilistic seismic hazard analyses (PSHA). This ground motion data is routinely obtained from the U.S. Geologocal Survey Seismic Hazard Mapping program, through its interactive web site and associated publications. The use of ground motion parameters derived from a PSHA for evaluations of liquefaction susceptibility and ground failure potential requires that the ground motion values that are indicated for the site are correlated to a specific earthquake magnitude. The individual seismic sources that contribute to the cumulative seismic hazard must therefore be accounted for individually. The process of hazard de-aggregation has been applied in PSHA to highlight the relative contributions of the various regional seismic sources to the ground motion parameter of interest. The use of de-aggregation procedures in PSHA is beneficial for liquefaction investigations because the contribution of each magnitude-distance pair on the overall seismic hazard can be readily determined. The difficulty in applying de-aggregated seismic hazard results for liquefaction studies is that the practitioner is confronted with numerous magnitude-distance pairs, each of which may yield different liquefaction hazard results.
    [Show full text]
  • The Distribution of Silty Soils in the Grayling Fingers Region of Michigan: Evidence for Loess Deposition Onto Frozen Ground
    Geomorphology 102 (2008) 287–296 Contents lists available at ScienceDirect Geomorphology journal homepage: www.elsevier.com/locate/geomorph The distribution of silty soils in the Grayling Fingers region of Michigan: Evidence for loess deposition onto frozen ground Randall J. Schaetzl ⁎ Department of Geography, 128 Geography Building, Michigan State University, East Lansing, MI, 48824-1117, USA ARTICLE INFO ABSTRACT Article history: This paper presents textural, geochemical, mineralogical, soils, and geomorphic data on the sediments of the Received 12 September 2007 Grayling Fingers region of northern Lower Michigan. The Fingers are mainly comprised of glaciofluvial Received in revised form 25 March 2008 sediment, capped by sandy till. The focus of this research is a thin silty cap that overlies the till and outwash; Accepted 26 March 2008 data presented here suggest that it is local-source loess, derived from the Port Huron outwash plain and its Available online 10 April 2008 down-river extension, the Mainstee River valley. The silt is geochemically and texturally unlike the glacial fl Keywords: sediments that underlie it and is located only on the attest parts of the Finger uplands and in the bottoms of Glacial geomorphology upland, dry kettles. On sloping sites, the silty cap is absent. The silt was probably deposited on the Fingers Loess during the Port Huron meltwater event; a loess deposit roughly 90 km down the Manistee River valley has a Permafrost comparable origin. Data suggest that the loess was only able to persist on upland surfaces that were either Kettles closed depressions (currently, dry kettles) or flat because of erosion during and after loess deposition.
    [Show full text]
  • CPT-Geoenviron-Guide-2Nd-Edition
    Engineering Units Multiples Micro (P) = 10-6 Milli (m) = 10-3 Kilo (k) = 10+3 Mega (M) = 10+6 Imperial Units SI Units Length feet (ft) meter (m) Area square feet (ft2) square meter (m2) Force pounds (p) Newton (N) Pressure/Stress pounds/foot2 (psf) Pascal (Pa) = (N/m2) Multiple Units Length inches (in) millimeter (mm) Area square feet (ft2) square millimeter (mm2) Force ton (t) kilonewton (kN) Pressure/Stress pounds/inch2 (psi) kilonewton/meter2 kPa) tons/foot2 (tsf) meganewton/meter2 (MPa) Conversion Factors Force: 1 ton = 9.8 kN 1 kg = 9.8 N Pressure/Stress 1kg/cm2 = 100 kPa = 100 kN/m2 = 1 bar 1 tsf = 96 kPa (~100 kPa = 0.1 MPa) 1 t/m2 ~ 10 kPa 14.5 psi = 100 kPa 2.31 foot of water = 1 psi 1 meter of water = 10 kPa Derived Values from CPT Friction ratio: Rf = (fs/qt) x 100% Corrected cone resistance: qt = qc + u2(1-a) Net cone resistance: qn = qt – Vvo Excess pore pressure: 'u = u2 – u0 Pore pressure ratio: Bq = 'u / qn Normalized excess pore pressure: U = (ut – u0) / (ui – u0) where: ut is the pore pressure at time t in a dissipation test, and ui is the initial pore pressure at the start of the dissipation test Guide to Cone Penetration Testing for Geo-Environmental Engineering By P. K. Robertson and K.L. Cabal (Robertson) Gregg Drilling & Testing, Inc. 2nd Edition December 2008 Gregg Drilling & Testing, Inc. Corporate Headquarters 2726 Walnut Avenue Signal Hill, California 90755 Telephone: (562) 427-6899 Fax: (562) 427-3314 E-mail: [email protected] Website: www.greggdrilling.com The publisher and the author make no warranties or representations of any kind concerning the accuracy or suitability of the information contained in this guide for any purpose and cannot accept any legal responsibility for any errors or omissions that may have been made.
    [Show full text]
  • 1. Geology and Seismic Hazards
    8 PUBLIC SAFETY ELEMENT As required by State law, the Public Safety Element addresses the protection of the community from unreasonable risks from natural and manmade haz- ards. This Element provides information about risks in the Eden Area and delineates policies designed to prepare and protect the community as much as possible from the effects of: ♦ Geologic hazards, including earthquakes, ground-shaking, liquefaction and landslides. ♦ Flooding, including dam failures and inundation, tsunamis and seiches. ♦ Wildland fires. ♦ Hazardous materials. This Element also contains information and policies regarding general emer- gency preparedness. Each section includes background information on the particular hazard followed by goals, policies and actions designed to minimize risk for Eden Area residents. The Public Safety Element establishes mechanisms to prepare for and reduce death, injuries and damage to property from public safety hazards like flood- ing, fires and seismic events. Hazards are an unavoidable aspect of life, and the Public Safety Element cannot eliminate risk completely. Instead, the Element contains policies to create an acceptable level of risk. 1. GEOLOGY AND SEISMIC HAZARDS Earthquakes and secondary seismic hazards such as ground-shaking, liquefac- tion and landslides are the primary geologic hazards in the Eden Area. This section provides background on the seismic hazards that affect the Eden Area and includes goals, policies and actions to minimize these risks. 8-1 COUNTY OF ALAMEDA EDEN AREA GENERAL PLAN PUBLIC SAFETY ELEMENT A. Background Information As is the case in most of California, the Eden Area is subject to risks from seismic activity. The Eden Area is located in the San Andreas Fault Zone, one of the most seismically-active regions in the United States, which has generated numerous moderate to strong earthquakes in northern California and in the San Francisco Bay Area.
    [Show full text]
  • Bray 2011 Pseudostatic Slope Stability Procedure Paper
    Paper No. Theme Lecture 1 PSEUDOSTATIC SLOPE STABILITY PROCEDURE Jonathan D. BRAY 1 and Thaleia TRAVASAROU2 ABSTRACT Pseudostatic slope stability procedures can be employed in a straightforward manner, and thus, their use in engineering practice is appealing. The magnitude of the seismic coefficient that is applied to the potential sliding mass to represent the destabilizing effect of the earthquake shaking is a critical component of the procedure. It is often selected based on precedence, regulatory design guidance, and engineering judgment. However, the selection of the design value of the seismic coefficient employed in pseudostatic slope stability analysis should be based on the seismic hazard and the amount of seismic displacement that constitutes satisfactory performance for the project. The seismic coefficient should have a rational basis that depends on the seismic hazard and the allowable amount of calculated seismically induced permanent displacement. The recommended pseudostatic slope stability procedure requires that the engineer develops the project-specific allowable level of seismic displacement. The site- dependent seismic demand is characterized by the 5% damped elastic design spectral acceleration at the degraded period of the potential sliding mass as well as other key parameters. The level of uncertainty in the estimates of the seismic demand and displacement can be handled through the use of different percentile estimates of these values. Thus, the engineer can properly incorporate the amount of seismic displacement judged to be allowable and the seismic hazard at the site in the selection of the seismic coefficient. Keywords: Dam; Earthquake; Permanent Displacements; Reliability; Seismic Slope Stability INTRODUCTION Pseudostatic slope stability procedures are often used in engineering practice to evaluate the seismic performance of earth structures and natural slopes.
    [Show full text]
  • Living on Shaky Ground: How to Survive Earthquakes and Tsunamis
    HOW TO SURVIVE EARTHQUAKES AND TSUNAMIS IN OREGON DAMAGE IN doWNTOWN KLAMATH FALLS FRom A MAGNITUde 6.0 EARTHQUAke IN 1993 TSUNAMI DAMAGE IN SEASIde FRom THE 1964GR EAT ALASKAN EARTHQUAke 1 Oregon Emergency Management Copyright 2009, Humboldt Earthquake Education Center at Humboldt State University. Adapted and reproduced with permission by Oregon Emergency You Can Prepare for the Management with help from the Oregon Department of Geology and Mineral Industries. Reproduction by permission only. Next Quake or Tsunami Disclaimer This document is intended to promote earthquake and tsunami readiness. It is based on the best SOME PEOplE THINK it is not worth preparing for an earthquake or a tsunami currently available scientific, engineering, and sociological because whether you survive or not is up to chance. NOT SO! Most Oregon research. Following its suggestions, however, does not guarantee the safety of an individual or of a structure. buildings will survive even a large earthquake, and so will you, especially if you follow the simple guidelines in this handbook and start preparing today. Prepared by the Humboldt Earthquake Education Center and the Redwood Coast Tsunami Work Group (RCTWG), If you know how to recognize the warning signs of a tsunami and understand in cooperation with the California Earthquake Authority what to do, you will survive that too—but you need to know what to do ahead (CEA), California Emergency Management Agency (Cal EMA), Federal Emergency Management Agency (FEMA), of time! California Geological Survey (CGS), Department of This handbook will help you prepare for earthquakes and tsunamis in Oregon. Interior United States Geological Survey (USGS), the National Oceanographic and Atmospheric Administration It explains how you can prepare for, survive, and recover from them.
    [Show full text]
  • Beyond the Angle of Repose: a Review and Synthesis of Landslide Processes in Response to Rapid Uplift, Eel River, Northern Eel River, Northern California
    Portland State University PDXScholar Geology Faculty Publications and Presentations Geology 2-23-2015 Beyond the Angle of Repose: A Review and Synthesis of Landslide Processes in Response to Rapid Uplift, Eel River, Northern Eel River, Northern California Joshua J. Roering University of Oregon Benjamin H. Mackey University of Canterbury Alexander L. Handwerger University of Oregon Adam M. Booth Portland State University, [email protected] Follow this and additional works at: https://pdxscholar.library.pdx.edu/geology_fac David A. Schmidt Univ Persityart of of the W Geologyashington Commons , Geomorphology Commons, and the Geophysics and Seismology Commons Let us know how access to this document benefits ou.y See next page for additional authors Citation Details Roering, Joshua J., Mackey, Benjamin H., Handwerger, Alexander L., Booth, Adam M., Schmidt, David A., Bennett, Georgina L., Cerovski-Darriau, Corina, Beyond the angle of repose: A review and synthesis of landslide pro-cesses in response to rapid uplift, Eel River, Northern California, Geomorphology (2015), doi: 10.1016/j.geomorph.2015.02.013 This Post-Print is brought to you for free and open access. It has been accepted for inclusion in Geology Faculty Publications and Presentations by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Authors Joshua J. Roering, Benjamin H. Mackey, Alexander L. Handwerger, Adam M. Booth, David A. Schmidt, Georgina L. Bennett, and Corina Cerovski-Darriau This post-print is available at PDXScholar: https://pdxscholar.library.pdx.edu/geology_fac/75 ACCEPTED MANUSCRIPT Beyond the angle of repose: A review and synthesis of landslide processes in response to rapid uplift, Eel River, Northern California Joshua J.
    [Show full text]
  • Earthquake/Landslide Death Scene Investigation Supplement
    Death Scene Investigation Supplement EARTHQUAKE/LANDSLIDE 1 DECEDENT PERSONAL DETAILS Last Name: First Name: Sex: Law Enforcement Case Number (if available): Male Female ME/C Case Number (if available): Law Enforcement Agency (if applicable): Date of Birth: Date of Death: Estimated Found Known MM DD YYYY MM DD YYYY Location of Injury (physical address, including ZIP code): 2 LOCATION OF THE DECEDENT Was the decedent found INDOORS? Yes No Complete 2A: OUTDOORS In what part of residence or building was the decedent found? Did the incident destroy the location? Yes No Unknown Did the incident collapse the walls or ceiling of the location? Yes No Unknown 2A OUTDOORS Was the decedent found OUTDOORS? Yes No Go to Section 3: Information about Circumstances of Death Any evidence the person was previously in a... Structure? Yes No Unknown Vehicle? Yes No Unknown 3 INFORMATION ABOUT CIRCUMSTANCES OF DEATH Does the cause of death appear to be due to any of the following? Select all potential causes of death. Complete all corresponding sections, THEN go to Section 7. Injury – Struck by (e.g., falling object)/Blunt force/Burns Complete Section 4: Injury Questions Motor Vehicle Crash Complete Section 5: Motor Vehicle Crash Questions Other (e.g., exacerbation of chronic diseases) Complete Section 6: Other Non-Injury Causes Questions 1 4 INJURY QUESTIONS How did the injury occur? Check all that apply: Hit by or struck against (Describe) Crushed (Describe) Asphyxia (Describe) Cut/laceration/impaled (Describe) Electric current or burn (Describe) Burn and/or
    [Show full text]
  • Pore Pressure Response During Failure in Soils
    Pore pressure response during failure in soils EDWIN L. HARP U.S. Geological Survey, 345 Middlefield Road, M.S. 998, Menlo Park, California 94025 WADE G. WELLS II U.S. Forest Service, Forest Fire Laboratory, 4955 Canyon Crest Drive, Riverside, California 92507 JOHN G. SARMIENTO Wahler Associates, P.O. Box 10023, Palo Alto, California 94303 111 45' ABSTRACT Three experiments were performed on natural slopes to investi- gate variations of soil pore-water pressure during induced slope fail- ure. Two sites in the Wasatch Range, Utah, and one site in the San Dimas Experimental Forest of southern California were forced to fail by artificial subsurface irrigation. The sites were instrumented with electronic piezometers and displacement meters to record induced pore pressures and movements of the slopes during failure. Piezome- ter records show a consistent trend of increasing pressure during the early stages of infiltration and abrupt decreases in pressure from 5 to 50 minutes before failure. Displacement meters failed to register the amount of movement, due to location and ineffectual coupling of meter pins to soil. Observations during the experiments indicate that fractures and macropores controlled the flow of water through the slope and that both water-flow paths and permeability within the slopes were not constant in space or time but changed continually during the course of the experiments. INTRODUCTION The mechanism most generally ascribed (for example, Campbell, 1975, p. 18-20) to account for rainfall-induced failure in soils indicates that an increase in the pore-water pressure within the soil mantle results in a reduction of the normal effective stresses within the material.
    [Show full text]