Yukon River bridge landslide: Preliminary geologic and geotechnical evaluation

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What does this data set describe?

Title:
Yukon River bridge landslide: Preliminary geologic and geotechnical evaluation
Abstract:
This report presents the findings of a geologic and geotechnical evaluation of a landslide at the Yukon River bridge (the E.L. Patton Bridge). The Yukon River bridge landslide occurred in fall 2012 between approximately 375 and 575 feet west of the bridge. Although there was no damage to the bridge foundation, the landslide's close proximity to the bridge and concerns over additional failures prompted multiple evaluations, including landslide documentation, drainage assessments, and geotechnical studies. This report was prepared to convey the general characteristics of the rock mass, characteristics of rock discontinuities, and the geomorphic expression of the 2012 landslide in the vicinity of the bridge. We determined that the fractured bedrock and steep slopes in the bridge vicinity are prone to slope failure. However, this assessment should be considered preliminary and should not be used to determine areas of potential future slope instabilities. A significant amount of additional exploration and slope stability analysis is required to fully understand the landslide hazard in the area of the bridge, as well as the potential for reactivation and/or expansion of the 2012 landslide into adjacent slopes.
Supplemental_Information:
The geospatial data file provided in this digital data distribution package is a compilation of the manuscript tables 1 and 2. The table headers and data organization have been slightly modified to make the data readily accessible to users who wish to view outcrop locations and descriptions via GIS or other software. The DGGS metadata standard extends the FGDC standard to include elements that are required to facilitate our internal data management. These elements, referred to as "layers," group and describe files that have intrinsic logical or topological relationships and correspond to subdirectories within the data distribution package. The metadata layer provides the metadata, codesets, or other documentation files applicable to all layers. Attribute information for each data layer is described in this metadata file under the "Entity_and_Attribute_Information" section. Data layer contents: >sample-location-details: GPS coordinates and rock mass properties for each outcrop field station.
  1. How should this data set be cited?

    Koehler, R.D., Reger, R.D., Sicard, K.R., and Spangler, E.R., 2013, Yukon River bridge landslide: Preliminary geologic and geotechnical evaluation: Preliminary Interpretive Report PIR 2013-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 69 p.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -149.732431
    East_Bounding_Coordinate: -149.720385
    North_Bounding_Coordinate: 65.875738
    South_Bounding_Coordinate: 65.872301

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 2013
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: ASCII tabular files, report

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a point data set.

    2. What coordinate system is used to represent geographic features?

      The horizontal datum used is World Geodetic System of 1984.
      The ellipsoid used is World Geodetic System of 1984.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257223563.

  7. How does the data set describe geographic features?

    pir2013-6-sample-location-details
    GPS coordinates and rock mass properties for each outcrop field station. (Source: Alaska Division of Geological & Geophysical Surveys)

    Station_Number
    Label assigned to identify the station. (Source: Alaska Division of Geological & Geophysical Surveys)

    ValueDefinition
    NULLBlank (NULL) field values indicate that this value was not recorded.

    Alphanumeric characters which correlate to field-data collection sheets provided in Appendix B of the manuscript

    Latitude
    Latitude, WGS84 (Source: Alaska Division of Geological & Geophysical Surveys)

    ValueDefinition
    NULLBlank (NULL) field values indicate that this value was not recorded.

    Range of values
    Minimum:65.87230104
    Maximum:65.87573804
    Units:decimal degrees

    Longitude
    Longitude, WGS84 (Source: Alaska Division of Geological & Geophysical Surveys)

    ValueDefinition
    NULLBlank (NULL) field values indicate that this value was not recorded.

    Range of values
    Minimum:-149.732431
    Maximum:-149.720385
    Units:decimal degrees

    Description
    Description of the station location (Source: Alaska Division of Geological & Geophysical Surveys)

    ValueDefinition
    NULLBlank (NULL) field values indicate that this value was not recorded.

    A station number (and GPS waypoint) was not recorded for area between the stations 10 and 11. However, we did record observations in this area.

    Lithology
    Description of the rock type (Source: Alaska Division of Geological & Geophysical Surveys)

    Free text, terminology is generally consistent with: Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., ed., 2005, Glossary of Geology: American Geological Institute, 799 p.

    Color
    Color of the rock, a delimited list of options is provided in data sheet template. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.

    Grain_Size
    Color of the rock, a delimited list of options is provided in data sheet template. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.

    Compressive_Strength
    General assessed compressive strength of rock at the station, classification parameters and a delimited list of options are provided in data sheet template. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.

    Weathering
    State of weathering, a delimited list of options is provided in data sheet template. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.

    Fabric
    General pattern of discontinuities throughout the outcrop, a delimited list of options provided is in data sheet template. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.

    Block_Size
    General size of the rock blocks that are defined by outcrop fabric; classification parameters and a delimited list of options are provided in data sheet template. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.

    Num_Discontinuity_Sets
    Discontinuity is a collective term used here to describe breaks in the outcrop surface; these may include: joints, fractures, bedding planes, rock cleavage, foliation, shear zones etc. This value provides a count of intersecting discontinuities found at each outcrop. (Source: Alaska Division of Geological & Geophysical Surveys)

    Formal codeset
    Codeset Name:Alaska field rock classification and structural mapping guide, rock mass description data sheet
    Codeset Source:Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, ADOT&PF Geotechnical Procedures Manual, 31 p.


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    This report presents the findings of a geologic and geotechnical evaluation of a landslide at the Yukon River bridge, conducted by the State of Alaska, Division of Geological & Geophysical Surveys (DGGS) through a reimbursable services agreement with the State of Alaska Department of Transportation & Public Facilities (ADOT&PF). De Anne S. P. Stevens provided a technical review of the report.

  3. To whom should users address questions about the data?

    Alaska Division of Geological & Geophysical Surveys
    GIS Manager
    3354 College Road
    Fairbanks, AK 99709-3707
    USA

    (907)451-5020 (voice)
    dggsgis@alaska.gov

    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays


Why was the data set created?

This report was prepared to convey the general characteristics of the rock mass, characteristics of rock discontinuities, and the geomorphic expression of the 2012 landslide in the vicinity of the Yukon River bridge. However, this assessment should be considered preliminary and should not be used to determine areas of potential future slope instabilities. A significant amount of additional exploration and slope stability analysis is required to fully understand the landslide hazard in the area of the bridge, as well as the potential for reactivation and/or expansion of the 2012 landslide into adjacent slopes.


How was the data set created?

  1. From what previous works were the data drawn?

    Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003 (source 1 of 2)
    Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003, Alaska field rock classification and structural mapping guide: State of Alaska, Alaska.

    Type_of_Source_Media: paper
    Source_Contribution:
    geotechnical - geomorphic observations and preliminary interpretation

    Barton, Nick, 1978 (source 2 of 2)
    Barton, Nick, 1978, Suggested methods for the quantitative description of discontinuities in rock masses: International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts v. 15, no. 6, p. 319-368, Pergamon, Oxford-New York, International.

    Type_of_Source_Media: paper
    Source_Contribution:
    geotechnical - geomorphic observations and preliminary interpretation

  2. How were the data generated, processed, and modified?

    Date: 2013 (process 1 of 1)
    Geotechnical - geomorphic observations and preliminary interpretation - The Yukon River bridge landslide field review was performed August 25-29, 2013, by Rich Koehler, Karri Sicard, and Eleanor Spangler of DGGS and Richard 'Dick' Reger of Reger's Geologic Consulting. Bedrock outcrops along the base of the Yukon River bluff were inspected for the presence of faults, fractures, shears or weathering zones, and/or other features that could provide information from which to infer subsurface conditions of bedrock farther upslope. Quantitative descriptions of rock mass and discontinuity data are based on the methodology of Barton (1978). Rock mass and discontinuity survey data sheets from the Alaska Field Rock Classification and Structural Mapping Guide (ADOT&PF, 2003) were used to record the field observations. Key rock characteristics that were documented include lithology, color, grain size, field compressive strength, rock mass fabric, block size, and state of weathering. Discontinuity surveys at each outcrop station include information on type of discontinuity, dip, dip direction, persistence, termination, aperture, nature of filling, strength of filling, surface roughness, surface shape, waviness, joint roughness coefficient, and presence of water. Detailed definitions for each of these parameters are provided in ADOT&PF (2003). Discontinuity orientations were measured with a Brunton compass, using standard geologic field techniques. We compiled the field data and LiDAR observations into a preliminary report that summarizes the general characteristics of the rock mass, characteristics of rock discontinuities, and the geomorphic expression of the 2012 landslide and the surrounding area.

    Data sources used in this process:

    • Alaska Department of Transportation & Public Facilities (ADOT&PF), 2003
    • Barton, Nick, 1978

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    The attributes listed in this dataset were transcribed from field-data collection sheets. The field-data sheets were also scanned and included as an appendix to the manuscript. The geologic interpretations presented in this report have undergone technical review by a geologist of comparable technical expertise. We incorporated the reviewer's suggestions into the final draft when deemed appropriate.

  2. How accurate are the geographic locations?

    We assigned a "station number" to each outcrop discussed in this report. Near the center of each outcrop, we recorded a single GPS waypoint to approximate the location of each "station." A station number (and GPS waypoint) was not recorded for the area between the stations 10 and 11. However, we did record observations in this area.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    Users should note that this table is a compilation of the information provided in tables 1 and 2 to the manuscript. These tables provide only the outcrop locations and rock mass values. To see all of the outcrop measurements and descriptions, users should refer to the field-data sheets (see Appendix B of the manuscript).

  5. How consistent are the relationships among the observations, including topology?

    not applicable


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
Use_Constraints:
Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.

  1. Who distributes the data set? (Distributor 1 of 1)

    Alaska Division of Geological & Geophysical Surveys
    3354 College Road
    Fairbanks, AK 99709-3707
    USA

    (907)451-5020 (voice)
    (907)451-5050 (FAX)
    dggspubs@alaska.gov

    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our website (<http://www.dggs.alaska.gov>) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
  2. What's the catalog number I need to order this data set?

    PIR 2013-6

  3. What legal disclaimers am I supposed to read?

    The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 29-Oct-2013
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Metadata Manager
3354 College Road
Fairbanks, AK 99709-3707
USA

(907)451-5020 (voice)

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


Generated by mp version 2.9.21 on Tue Oct 29 12:14:59 2013