GEOLOGIC HAZARDS of the ZION NATIONAL PARK GEOLOGIC-HAZARD STUDY AREA, WASHINGTON and KANE COUNTIES, UTAH by William R

Total Page:16

File Type:pdf, Size:1020Kb

GEOLOGIC HAZARDS of the ZION NATIONAL PARK GEOLOGIC-HAZARD STUDY AREA, WASHINGTON and KANE COUNTIES, UTAH by William R GEOLOGIC HAZARDS OF THE ZION NATIONAL PARK GEOLOGIC-HAZARD STUDY AREA, WASHINGTON AND KANE COUNTIES, UTAH by William R. Lund, Tyler R. Knudsen, and David L. Sharrow SPECIAL STUDY 133 UTAH GEOLOGICAL SURVEY a division of UTAH DEPARTMENT OF NATURAL RESOURCES 2010 GEOLOGIC HAZARDS OF THE ZION NATIONAL PARK GEOLOGIC-HAZARD STUDY AREA, WASHINGTON AND KANE COUNTIES, UTAH by William R. Lund, Tyler R. Knudsen, and David L. Sharrow Cover Image: Dump truck crushed by rock fall on November 23, 1947, in Zion National Park (photo courtesy of the National Park Service). ISBN 978-1-55791-833-8 SPECIAL STUDY 133 UTAH GEOLOGICAL SURVEY a division of UTAH DEPARTMENT OF NATURAL RESOURCES 2010 STATE OF UTAH Gary R. Herbert, Governor DEPARTMENT OF NATURAL RESOURCES Michael Styler, Executive Director UTAH GEOLOGICAL SURVEY Richard G. Allis, Director PUBLICATIONS contact Natural Resources Map & Bookstore 1594 W. North Temple Salt Lake City, UT 84116 telephone: 801-537-3320 toll-free: 1-888-UTAH MAP Web site: mapstore.utah.gov email: [email protected] UTAH GEOLOGICAL SURVEY contact 1594 W. North Temple, Suite 3110 Salt Lake City, UT 84116 telephone: 801-537-3300 Web site: geology.utah.gov Although this product represents the work of professional scientists, the Utah Department of Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding its suitability for a particular use. The Utah Department of Natural Resources, Utah Geological Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or consequential damages with respect to claims by users of this product. CHAPTER CONTENTS Chapter 1 - Introduction ABSTRACT .....................................................................................................................................................................................3 PURPOSE ........................................................................................................................................................................................ 3 BACKGROUND ............................................................................................................................................................................. 4 SCOPE OF WORK ..........................................................................................................................................................................5 SETTING ......................................................................................................................................................................................... 6 GEOLOGY ...................................................................................................................................................................................... 7 RELATIVE IMPORTANCE OF GEOLOGIC HAZARDS IN THE STUDY AREA ....................................................................11 ADDITIONAL INFORMATION AND GUIDELINES ................................................................................................................ 12 ACKNOWLEDGMENTS ............................................................................................................................................................. 12 REFERENCES .............................................................................................................................................................................. 12 Chapter 2 – Flood and Debris-Flow Hazards INTRODUCTION ......................................................................................................................................................................... 16 SOURCES OF INFORMATION ................................................................................................................................................... 16 FLOOD TYPES ............................................................................................................................................................................. 16 Riverine Floods ......................................................................................................................................................................... 16 Flash Floods ............................................................................................................................................................................. 17 Debris Flows ............................................................................................................................................................................. 17 Sheetfloods ................................................................................................................................................................................18 Unintentional Water Release from Water-Retention Structures ................................................................................................18 Flooding Associated with Rock-Fall or Landslide Dams ......................................................................................................... 20 FLOOD DISCHARGE AND FREQUENCY ESTIMATES ........................................................................................................ 20 FLOOD-PRONE-AREA CLASSIFICATION ...............................................................................................................................20 National Flood Insurance Program 100-Year Flood Map .........................................................................................................20 National Park Service “Floodplain” Map ................................................................................................................................. 21 Summary of Flood Hazard to Existing National Park Service Facilities in Zion Canyon ....................................................... 21 Other Flood-Prone Areas .......................................................................................................................................................... 21 USING THE MAP ......................................................................................................................................................................... 23 MAP LIMITATIONS ..................................................................................................................................................................... 23 HAZARD REDUCTION ...............................................................................................................................................................23 REFERENCES .............................................................................................................................................................................. 25 Chapter 3 – Rock-Fall Hazard INTRODUCTION ......................................................................................................................................................................... 30 SOURCES OF INFORMATION ................................................................................................................................................... 30 ROCK-FALL SOURCES............................................................................................................................................................... 30 ROCK- FALL-HAZARD CLASSIFICATION ............................................................................................................................. 32 USING THE MAP ......................................................................................................................................................................... 33 MAP LIMITATIONS ..................................................................................................................................................................... 33 HAZARD REDUCTION ...............................................................................................................................................................33 REFERENCES .............................................................................................................................................................................. 34 Chapter 4 – Landslide Hazard INTRODUCTION ......................................................................................................................................................................... 38 SOURCES OF INFORMATION ................................................................................................................................................... 38 LANDSLIDE CAUSES .................................................................................................................................................................38 LANDSLIDE TYPES AND PROCESSES ................................................................................................................................... 39 LANDSLIDES IN THE ZION NATIONAL PARK GEOLOGIC-HAZARD STUDY AREA ..................................................... 41 Sentinel Landslide .....................................................................................................................................................................41 Zion–Mount Carmel Highway Switchbacks Landslide ............................................................................................................ 42 Kolob Canyons Scenic Drive Landslides ................................................................................................................................
Recommended publications
  • The Wasatch Fault
    The WasatchWasatchThe FaultFault UtahUtah Geological Geological Survey Survey PublicPublic Information Information Series Series 40 40 11 9 9 9 9 6 6 The WasatchWasatchThe FaultFault CONTENTS The ups and downs of the Wasatch fault . .1 What is the Wasatch fault? . .1 Where is the Wasatch fault? Globally ............................................................................................2 Regionally . .2 Locally .............................................................................................4 Surface expressions (how to recognize the fault) . .5 Land use - your fault? . .8 At a glance - geological relationships . .10 Earthquakes ..........................................................................................12 When/how often? . .14 Howbig? .........................................................................................15 Earthquake hazards . .15 Future probability of the "big one" . .16 Where to get additional information . .17 Selected bibliography . .17 Acknowledgments Text by Sandra N. Eldredge. Design and graphics by Vicky Clarke. Special thanks to: Walter Arabasz of the University of Utah Seismograph Stations for per- mission to reproduce photographs on p. 6, 9, II; Utah State University for permission to use the satellite image mosaic on the cover; Rebecca Hylland for her assistance; Gary Christenson, Kimm Harty, William Lund, Edith (Deedee) O'Brien, and Christine Wilkerson for their reviews; and James Parker for drafting. Research supported by the U.S. Geological Survey (USGS), Department
    [Show full text]
  • Ron Blakey, Publications (Does Not Include Abstracts)
    Ron Blakey, Publications (does not include abstracts) The publications listed below were mainly produced during my tenure as a member of the Geology Department at Northern Arizona University. Those after 2009 represent ongoing research as Professor Emeritus. (PDF) – A PDF is available for this paper. Send me an email and I'll attach to return email Blakey, R.C., 1973, Stratigraphy and origin of the Moenkopi Formation of southeastern Utah: Mountain Geologist, vol. 10, no. 1, p. 1 17. Blakey, R.C., 1974, Stratigraphic and depositional analysis of the Moenkopi Formation, Southeastern Utah: Utah Geological Survey Bulletin 104, 81 p. Blakey, R.C., 1977, Petroliferous lithosomes in the Moenkopi Formation, Southern Utah: Utah Geology, vol. 4, no. 2, p. 67 84. Blakey, R.C., 1979, Oil impregnated carbonate rocks of the Timpoweap Member Moenkopi Formation, Hurricane Cliffs area, Utah and Arizona: Utah Geology, vol. 6, no. 1, p. 45 54. Blakey, R.C., 1979, Stratigraphy of the Supai Group (Pennsylvanian Permian), Mogollon Rim, Arizona: in Carboniferous Stratigraphy of the Grand Canyon Country, northern Arizona and southern Nevada, Field Trip No. 13, Ninth International Congress of Carboniferous Stratigraphy and Geology, p. 89 109. Blakey, R.C., 1979, Lower Permian stratigraphy of the southern Colorado Plateau: in Four Corners Geological Society, Guidebook to the Permian of the Colorado Plateau, p. 115 129. (PDF) Blakey, R.C., 1980, Pennsylvanian and Early Permian paleogeography, southern Colorado Plateau and vicinity: in Paleozoic Paleogeography of west central United States, Rocky Mountain Section, Society of Economic Paleontologists and Mineralogists, p. 239 258. Blakey, R.C., Peterson, F., Caputo, M.V., Geesaman, R., and Voorhees, B., 1983, Paleogeography of Middle Jurassic continental, shoreline, and shallow marine sedimentation, southern Utah: Mesozoic PaleogeogÂraphy of west central United States, Rocky Mountain Section of Society of Economic Paleontologists and Mineralogists (Symposium), p.
    [Show full text]
  • PALEOSEISMIC INVESTIGATION of the NORTHERN WEBER SEGMENT of the WASATCH FAULT ZONE at the RICE CREEK TRENCH SITE, NORTH OGDEN, UTAH by Christopher B
    Paleoseismology of Utah, Volume 18 PALEOSEISMIC INVESTIGATION OF THE NORTHERN WEBER SEGMENT OF THE WASATCH FAULT ZONE AT THE RICE CREEK TRENCH SITE, NORTH OGDEN, UTAH by Christopher B. DuRoss, Stephen F. Personius, Anthony J. Crone, Greg N. McDonald, and David J. Lidke SPECIAL STUDY 130 Utah Geological Survey UTAH GEOLOGICAL SURVEY a division of UTAH DEPARTMENT OF NATURAL RESOURCES 2009 Paleoseismology of Utah, Volume 18 PALEOSEISMIC INVESTIGATION OF THE NORTHERN WEBER SEGMENT OF THE WASATCH FAULT ZONE AT THE RICE CREEK TRENCH SITE, NORTH OGDEN, UTAH by Christopher B. DuRoss1, Stephen F. Personius2, Anthony J. Crone2, Greg N. McDonald1, and David J. Lidke2 1Utah Geological Survey 2U.S. Geological Survey Cover photo: Rice Creek trench site; view is to the east. ISBN 1-55791-819-8 SPECIAL STUDY 130 Utah Geological Survey UTAH GEOLOGICAL SURVEY a division of UTAH DEPARTMENT OF NATURAL RESOURCES 2009 STATE OF UTAH Gary R. Herbert, Governor DEPARTMENT OF NATURAL RESOURCES Michael Styler, Executive Director UTAH GEOLOGICAL SURVEY Richard G. Allis, Director PUBLICATIONS contact Natural Resources Map & Bookstore 1594 W. North Temple Salt Lake City, UT 84116 telephone: 801-537-3320 toll-free: 1-888-UTAH MAP Web site: mapstore.utah.gov email: [email protected] UTAH GEOLOGICAL SURVEY contact 1594 W. North Temple, Suite 3110 Salt Lake City, UT 84116 telephone: 801-537-3300 Web site: geology.utah.gov Although this product represents the work of professional scientists, the Utah Department of Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding its suitability for a particular use. The Utah Department of Natural Resources, Utah Geological Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or consequential damages with respect to claims by users of this product.
    [Show full text]
  • The Mormon Pioneer National Heritage Area
    Museums M 191 MPNHA Absorb the Old West through anti, U hundreds of interactive N displays of pioneer history, orth Mormon heritage, outlaw T 84642 stories, and nature and UNDER THE RIM M Artists, Artisans, Crafters wildlife. Experience a new Big Water ain understanding of the settlers Big Water Visitor Center Museum/Grand Inspired by this rugged who shaped the social, Staircase Escalante National Monument Pal landscape, the artists and cultural and historic life crafters of the area are and lore of the American Kanab Grand Staircase Escalante National winners of the Best of West. Museum hours vary His Monument Geo Arc State Award. Handmade Kanab Heritage House by season. Call ahead His treasures include porcelain for schedule (See Visitor Kanab Heritage Museum Mt. Carmel dolls and carved wooden Information box at right). Kanab Visitor Center Museum The Old Rock Church Gallery Art caricatures, antique HEADWatERS BOULDER LOOP / furniture reproductions, Circleville HEADWatERS contemporary woodcraft, LittlE DEnmarK Butch Cassidy’s Childhood Home His HEritagE AREA MARKERS pottery, appliqued western Fairview Mormon Pioneer National Heritage Old Rock Schoolhouse, Marysvale clothing, hand tooled boots Art Hatch Fairview Museum and Art His Area Markers showing local travel Escalante Tithing Office, 1884 William Derby Johnson, Jr., House and saddles, unique jewelry, Daughters of Utah Pioneers Museum His maps and historic sites. Historic Red Brick Homes (Cole’s Hotel), 1884, Kanab Native American crafts, Fountain Green Open by appointment M. Parker (Butch Cassidy), Perry Lodge, Home to the Move Stars fine art and more. Beautiful Mt. Pleasant, corner of Main Street and Hwy 89 objects and memorable Fountain Green Daughters of Utah Pioneers Marysvale Cabin, c.
    [Show full text]
  • 5.4.5 Geological Hazards
    Section 5.4.5: Risk Assessment – Geological Hazards 5.4.5 Geological Hazards The following section provides the hazard profile (hazard description, location, extent, previous occurrences and losses, probability of future occurrences, and impact of climate change) and vulnerability assessment for the geological hazards in Sussex County. 2016 Plan Update Changes The hazard profile has been significantly enhanced to include a detailed hazard description, location, extent, previous occurrences, probability of future occurrence, and potential change in climate and its impacts on the geological hazards is discussed. The geological hazards is now located in Section 5 of the plan update. It includes landslide, land subsidence and sinkholes, all of which were profiled separately in the 2011 HMP. New and updated figures from federal and state agencies are incorporated. U.S. 2010 Census data was incorporated, where appropriate. Previous occurrences were updated with events that occurred between 2008 and 2015. A vulnerability assessment was conducted for the geological hazards and it now directly follows the hazard profile. 5.4.5.1 Profile Hazard Description Geological hazards are any geological or hydrological processes that pose a threat to humans and natural properties. Every year, severe natural events destroy infrastructure and cause injuries and deaths. Geologic hazards may include volcanic eruptions and other geothermal related features, earthquakes, landslides and other slope failures, mudflows, sinkhole collapses, snow avalanches, flooding, glacial surges and outburst floods, tsunamis, and shoreline movements. For the purpose of this HMP update, only landslides and land subsidence/sinkholes will be discussed in the Geological Hazard profile. Landslides According to the U.S.
    [Show full text]
  • Geologic Map of the Moriah Knoll Quadrangle, Northern Mohave County, Arizona
    U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Geologic map of the Moriah Knoll quadrangle, northern Mohave County, Arizona George H. Billingsley, Open-File Report 94-634 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. .S. Geological Survey, Flagstaff, Arizona 1994 1 INTRODUCTION The Moriah Knoll 7.5' quadrangle is located in northern Mohave County, northwestern Arizona. The quadrangle is about 48 km south of the Arizona/Utah State line and about 56 km southwest of Colorado City, Arizona, the nearest settlement (fig. 1). Elevations range from about 1,426 m (4,680 ft) in the northwest corner of the quadrangle to 2,007 m (6,585 ft) at Berry Knoll in the south-central edge of the quadrangle. Access to the area is by improved dirt road locally referred to as the Temple Trail. The Temple Trail branches south from the Navajo Trail. The Navajo Trail extends to Colorado City, Arizona (fig. 1). Several unimproved dirt roads lead from the Temple Trail to various locations within the quadrangle area. Travel on the Temple Trail can be done with 2 wheel drive vehicles, all other roads require a high-clearance vehicle, or 4 wheel drive in wet weather. The area is managed by the U.S. Bureau of Land Management, including about 4 sections belonging to the state of Arizona.
    [Show full text]
  • Coastal and Other Hazards (Se)
    Goleta General Plan /Coastal Land Use Plan 5.0 Safety Element CHAPTER 5.0 SAFETY ELEMENT: COASTAL AND OTHER HAZARDS (SE) 5.1 INTRODUCTION General Plan Law Requirements [GP] The Safety Element is one of seven general Safety Element Policies plan elements mandated by state law. The SE 1: Safety in General scope of the Safety Element is specified in SE 2: Bluff Erosion and Retreat Section 65302 (g) of the California SE 3: Beach Erosion and Shoreline Hazards SE 4: Seismic and Seismically Induced Hazards Government Code as follows: SE 5: Soil and Slope Stability Hazards SE 6: Flood Hazards The general plan shall include a safety SE 7: Urban and Wildland Fire Hazards element for the protection of the SE 8: Oil and Gas Industry Hazards community from any unreasonable SE 9: Airport-Related Hazards. SE 10: Hazardous Materials and Facilities risks associated with the effects of SE 11: Emergency Preparedness seismically induced surface rupture, ground shaking, ground failure, tsunami, seiche, and dam failure; slope instability leading to mudslides and landslides; subsidence and other geologic hazards known to the legislative body; flooding; and wild land and urban fires. The safety element shall include mapping of known seismic and other geologic hazards. It shall also address evacuation routes, peak-load water supply requirements, and minimum road widths and clearances around structures, as those items relate to identified fire and geologic hazards. Coastal hazards such as bluff retreat and shoreline erosion are also addressed in this element, as are hazards associated with oil and gas production, processing, and transport. California Coastal Act Requirements [CP] The California Coastal Act (Coastal Act) requires new development to be sited and designed to minimize risks, ensure stability and structural integrity, and neither create nor contribute significantly to erosion or require the construction of new shoreline protective devices that would substantially alter natural landforms along coastal bluffs and cliffs.
    [Show full text]
  • Quaternary Tectonics of Utah with Emphasis on Earthquake-Hazard Characterization
    QUATERNARY TECTONICS OF UTAH WITH EMPHASIS ON EARTHQUAKE-HAZARD CHARACTERIZATION by Suzanne Hecker Utah Geologiral Survey BULLETIN 127 1993 UTAH GEOLOGICAL SURVEY a division of UTAH DEPARTMENT OF NATURAL RESOURCES 0 STATE OF UTAH Michael 0. Leavitt, Governor DEPARTMENT OF NATURAL RESOURCES Ted Stewart, Executive Director UTAH GEOLOGICAL SURVEY M. Lee Allison, Director UGSBoard Member Representing Lynnelle G. Eckels ................................................................................................... Mineral Industry Richard R. Kennedy ................................................................................................. Civil Engineering Jo Brandt .................................................................................................................. Public-at-Large C. Williatn Berge ...................................................................................................... Mineral Industry Russell C. Babcock, Jr.............................................................................................. Mineral Industry Jerry Golden ............................................................................................................. Mineral Industry Milton E. Wadsworth ............................................................................................... Economics-Business/Scientific Scott Hirschi, Director, Division of State Lands and Forestry .................................... Ex officio member UGS Editorial Staff J. Stringfellow .........................................................................................................
    [Show full text]
  • Tour Options~
    14848 Seven Oaks Lane Draper, UT 84020 1-888-517-EPIC [email protected] APMA Annual Scientific Meeting (The National) ~Tour Options~ Zion National Park 1 Day Tour 6-10am Depart Salt Lake City and travel to Zion 10am-5pm Zion National Park We will leave Springdale and head in to the park and enjoy our first hike together up to Emerald Pools. This mild warm up is a beautiful loop trail that will take us along a single track trail, past waterfalls and pools of cool blue water all nesting beneath the massive monolith cliffs of Zion. Afterward we will drive up canyon and walk two trails known as the Riverwalk and Big Bend. The Virgin River, descending from the upper plateau, has worked its way over time through the sandstone carving out the main Zion corridor. You’ll be amazed by the stunning views as we walk along the river. Following these hikes, we will stop for lunch at the Zion Lodge which sits in the park. After lunch, we will drive to the eastern side of the park and through the Carmel Tunnel which was carved out of the solid cliff face in the 1920’s. We will start first at Checkerboard Mesa where you can explore the massive sandstone monoliths. Lastly, we walk along the Overlook Trail until we reach the stunning viewpoint overlooking the entire canyon. 5-6pm Dinner 6-10pm Travel to Salt Lake City Arches National Park 1 Day Tour 6-10am Travel from Salt Lake City to Arches National 10am-5pm Arches National Park In Arches National Park, we begin at the Wall Street trail head.
    [Show full text]
  • BAER) Assessment Specialist Report, Phase 2 – GEOLOGIC HAZARDS
    Burned Area Emergency Response (BAER) Assessment Specialist Report, Phase 2 – GEOLOGIC HAZARDS Thomas Fire, Los Padres National Forest January 2018 Allen King – Geologist, Los Padres NF (retired) Dennis Veich – Forest Geologist, Shasta-Trinity NF Fire-damaged Tree near Chismahoo Mountain “When rain starts to fall, people in higher risk basins should be prepared to evacuate. Do not remain in, near or below burned areas at the base of canyons, even during light rain. Stay away from small streams that could become raging rivers in the blink of an eye. If the forecast calls for heavy rains through the night, homes may not be safe places if they are located in or near drainage areas and within a mile of the mountain front. Roads can suddenly become blocked with mud and debris, and can wash out at stream crossings. It is important to pay strong attention to warnings from local emergency responders and weather advisories.” -Sue Cannon, USGS Landslide Hazards Program, 2003 INTRODUCTION The Thomas Fire started on December 4, 2017, near the Thomas Aquinas College (east end of Sulphur Mountain), Ventura County, California. The fire is still considered to be active and as of January 12th, 2018, it is estimated to have burned 281,900 acres and is 92% contained. Approximately 181,300 acres within the burn area are National Forest lands (~64%); 98,200 acres are private (~35%); and 2,400 acres (~1%) are a combination of state and county properties. Although tremendous down-slope/down-drainage resources and values and lives are recognized and kept in mind during our analysis, this report addresses the effects of the Thomas Fire and the associated Values At Risk (VARs) ONLY on Forest Service lands, since the other lands are being evaluated by teams of Cal Fire scientists and other agencies.
    [Show full text]
  • Zion Scenic Byway Interpretive Plan FINAL
    Zion Scenic Byway Interpretive Plan FINAL Prepared for: Zion Canyon Corridor Council February, 2015 i Table of Contents Acknowledgements ................................................................................................................................................... iv 1. Introduction and Project Overview........................................................................................................................ 1 Partners and Stakeholders ................................................................................................................................. 3 Interpretive Plan Process.................................................................................................................................... 4 2. Research and Gathering Existing Data ................................................................................................................... 5 “Listening to Springdale - Identifying Visions for Springdale” Project .................................................................. 5 Interpretive Sites Field Review ........................................................................................................................... 6 Other Coordination ............................................................................................................................................ 6 3. Marketing and Audience Analysis.......................................................................................................................... 7 Zion Scenic Byway Corridor
    [Show full text]
  • Seismic Design Guidelines Appendix B: Geotechnical
    Mandatory Retrofit Program for Non-Ductile Concrete Buildings And Pre-Northridge Steel Moment Frame Buildings Ordinance 17-1011 SEISMIC DESIGN GUIDELINES APPENDIX B ISSUED NOVEMBER 8, 2019 REVISED SEPTEMBER 25, 2020 APPENDIX B: GEOTECHNICAL / GEOLOGICAL REPORT REQUIREMENTS 1.0 INTRODUCTION ASCE 41 geotechnical/geological report requirements for seismic evaluation and retrofit design varies greatly based on the amount of as-built information obtained and type of existing foundation system. The following document is intended to help clarify geotechnical / geological requirements of Ordinance 17-1011 for Non-Ductile Concrete and Pre-Northridge Steel Moment Frames. It is noted that all geotechnical / geological reports shall be signed and stamped by a California licensed Geotechnical Engineer and by a California licensed Geologist (if applicable). 2.0 SEISMIC SITE HAZARD The following frequently asked questions and answers are intended to clarify the scope and requirements of the seismic site hazard requirements of Ordinance 17-1011. 2.1 When is a site-specific seismic hazard determination required? A site-specific seismic hazard procedure is required when: a. The building is located on Site Class E soils and the mapped BSE-2N Sxs>2.0 or b. The building is located on Site Class F soils, unless Ss<0.20. In addition, a site-specific hazard is required to scale records when performing a non- linear dynamic time-history analysis. [Ref. ASCE 41 Section 2.4]. 2.2 When scaling a suite of acceleration records, is there a required or preferred scaling method? A site-specific response spectra shall be developed per ASCE 41 Section 2.4.2.1 requirements.
    [Show full text]