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Combined display of all available logs of ASDSO Dam Safety Toolbox. You can narrow down the view by selecting a log type, the username (case-sensitive), or the affected page (also case-sensitive).

16:44, 16 December 2022 Grichards talk contribs created page Change Management (Created page with " __NOTOC__ Category:Construction ---- Approved designs should be followed with any changes being approved prior to implementation. The construction manager may authorize that minor variations in the work do not involve a contract amount adjustment. Work variations should also be consistent with overall intent of the design and documentation of such authorizations should...")
16:28, 16 December 2022 Grichards talk contribs deleted page Engineering Oversight (content was: " __NOTOC__ Category:Construction ----  Paragraph text ==Engineering Oversight Responsibilities== * Site Inspection * Shop Inspection * Quality Assurance/Quality Control ==Trainings== {{Video Icon}} On-D...", and the only contributor was "Grichards" (talk))
16:26, 16 December 2022 Grichards talk contribs deleted page Quality Assurance/Quality Control (content was: " __NOTOC__ Category:Engineering Oversight ----  Paragraph text ==Best Practices Resources== {{Document Icon}} Engineering Guidelines for the Evaluation of Hydropower Projects: Chapter 7- Construction Quality Control...", and the only contributor was "Grichards" (talk))
15:30, 16 December 2022 Grichards talk contribs created page Specifications (Created page with "__NOTOC__ Category:Home ---- {{Picture  |image=const1.jpg  |link=  |caption=Construction of an embankment dam. }}  "Some of the potential problems that could occur during construction can be reduced by clear, concise specifications and clear, concise instructions to cont...")
22:27, 15 December 2022 Grichards talk contribs deleted page Federal Guidelines for Dam Safety (content was: "__NOTOC__ ==Federal Guidelines for Dam Safety (2011)== ===Abstract=== "These guidelines apply to Federal practices for dams with a direct Federal interest and are not intended to supplant or otherwise conflict with State or local government responsibilities for safety of dams under their jurisdiction." ===Link to Document=== ===Errata Previous Versions=== ===Pre...", and the only contributor was "Rmanwaring" (talk))
22:18, 15 December 2022 Grichards talk contribs created page Support of Excavation (Created page with " __NOTOC__ Category:Construction ---- {{Picture  |image=SOE.png  |link=  |caption=Temporary Shoring Wall }} Construction of deep excavations must be made prior to a modification to the existing structure or new structure can be built. When excavations have the potential t...")
22:18, 15 December 2022 Grichards talk contribs created page File:SOE.png
22:18, 15 December 2022 Grichards talk contribs uploaded File:SOE.png
00:02, 15 December 2022 Grichards talk contribs created page Reservoir-triggered Seismicity (Created page with "__NOTOC__ Category: Seismic ---- If the proposed reservoir is substantial in volume or active faults cross near the reservoir area, then potential for reservoir-triggered seismicity (RTS) should be evaluated. RTS is the idea that the added weight of the reservoir or pore pressure distribution increases the frequency of earthquakes in areas of high seismic activity OR may cause earthquakes in areas thought to be seismically inactive. RTS has been observed in dams over...")
00:01, 15 December 2022 Grichards talk contribs created page Seiches (Created page with "__NOTOC__ Category: Seismic ---- A seiche is a standing wave that forms in an enclosed body of water that has the potential to generate hazardous fluctuation in the reservoir level. Assessment of seiche hazard considers the oscillatory motions of water generated by strong ground shaking, and the probabilities of the events occurring. <!-- For information on notation for in text citations visit https://www.mediawiki.org/wiki/Help:Cite Or simply enclose the citation...")
23:58, 14 December 2022 Grichards talk contribs created page Deterministic Seismic Analysis (Created page with "__NOTOC__ Category: Seismic ---- In the deterministic approach, individual earthquake scenarios (earthquake magnitude and location) are developed for each relevant seismic source and a specified ground motion probability level is selected (by tradition, it is either 0 or 1 standard deviation above the median). Based on the earthquake location, the distance to the site is computed. Given the magnitude, distance, and number of standard deviations for the ground motion,...")
23:57, 14 December 2022 Grichards talk contribs created page Probabilistic Seismic Analysis (Created page with " __NOTOC__ Category: Seismic ---- In the probabilistic approach, all possible and relevant deterministic earthquake scenarios (all possible magnitude and location combinations) are considered as well as all possible ground motion probability levels (a range of the number of standard deviations above or below the median). For each earthquake scenario, the distance to the site is computed and then the ground motions are computed for each number of standard deviations a...")
23:55, 14 December 2022 Grichards talk contribs created page Velocity Structure (Created page with "__NOTOC__ Category: Geologic and Tectonic Setting ---- The velocity structure is a generalized model of the earth’s crust using layers having different assumed seismic velocities. It is important in a SHA to have a well-defined velocity structure. Several parameters (''VS30'', ''Z1.0'', ''Z2.5'') are used in most attenuation relationships. The most important parameter is ''VS30'', which is defined as the shear wave velocity in the top 30 m...")
23:54, 14 December 2022 Grichards talk contribs created page Local Tectonic Setting (Created page with "__NOTOC__ Category: Geologic and Tectonic Setting ---- Clearly identifying and determining the activity level of faults within and adjacent to a project region is critical for development of the input parameters required to perform an SHA. An experienced seismologist should assess and summarize available literature to identify known seismic conditions in a region. The record of historical earthquakes should be evaluated to develop and verify recurrence parameters for...")
23:53, 14 December 2022 Grichards talk contribs created page Local Geologic Setting (Created page with "__NOTOC__ Category: Geologic and Tectonic Setting ---- An understanding of the rock units, stratigraphy, and geologic structure of a region, consistent with the global tectonic setting, needs to be developed to characterize the nature of the existing faults and potential seismic sources of a region. An experienced geologist should assess and summarize the known geologic and faulting conditions found in an available geologic literature, maps, and imagery. When geologi...")
23:53, 14 December 2022 Grichards talk contribs created page Global Geologic Setting and Plate Tectonics (Created page with "__NOTOC__ Category: Geologic and Tectonic Setting ---- A seismic hazard assessment should include an evaluation of the global geologic setting. Understanding the behavior and properties of the Earth's surface and underlying layers sets the stage for interpreting the local geologic setting. Global tectonics is the theory that the earth’s relatively low density crust (lithosphere) is composed of seven or eight major and several smaller rigid fragments. These te...")
23:46, 14 December 2022 Grichards talk contribs created page Ground Motion Characterization (Created page with "__NOTOC__ Category:Seismic ---- Normally ground motion prediction equations (GMPE) are selected from a published set of relationships. The relationships are selected based on one of the three main types of tectonic regimes: #Active Crustal #Subduction #Stable Continental <!-- For information on notation for in text citations visit https://www.mediawiki.org/wiki/Help:Cite Or simply enclose the citation as shown <ref> citation </ref> in the location of the in text m...")
23:43, 14 December 2022 Grichards talk contribs created page Background Seismicity (Created page with " __NOTOC__ Category:Seismic ---- Background zones and gridded seismicity are also types of areal sources. Background zones are used to model events that occur off of the known faults. Gridded seismicity uses a method of estimating activity rates and b-values by smoothing seismicity over a large region and assigning values to very small zones (or grids). <!-- For information on notation for in text citations visit https://www.mediawiki.org/wiki/Help:Cite Or simply...")
23:40, 14 December 2022 Grichards talk contribs deleted page Fault Geometry (content was: "__NOTOC__ ----  The fault geometry includes the coordinates in map view, cross-section (depth), width, and the dip.  {{Citations}}...")
23:40, 14 December 2022 Grichards talk contribs deleted page Mechanism (content was: "__NOTOC__ ----  Each fault should have a specified mechanism: normal, reverse (thrust) or strike-slip. Normal and reverse faulting are examples of dip-slip, where the displacement along the fault is in the direction of dip and movement involves a vertical component. Norma...", and the only contributor was "Rmanwaring" (talk))
23:38, 14 December 2022 Grichards talk contribs deleted page Magnitude Distribution (content was: "__NOTOC__ ----  The magnitude distribution is a probability density function (pdf) that describes the relative number of large magnitude, moderate and small magnitude earthquakes that occur on a seismic source. There are two forms of the magnitude density functions that...", and the only contributor was "Rmanwaring" (talk))
23:37, 14 December 2022 Grichards talk contribs deleted page Activity Rate (content was: "__NOTOC__ ----  There are two common approaches for estimating activity rates on seismic sources: historical seismicity and geologic information. ==Examples== {{Website Icon}} ==Best Practices Resources== {{Document Icon}} ==Trainings== {{Video Icon}} <!-- For info...", and the only contributor was "Rmanwaring" (talk))
23:20, 14 December 2022 Grichards talk contribs deleted page Local Geologic Setting (content was: "__NOTOC__ Category:Geologic and Tectonic Setting ----  An understanding of the rock units, stratigraphy, and geologic structure of a region, consistent with the global tectonic setting, needs to be developed to characterize the nature of the existing faults and potential seismic sources of a region. An experienced geologist should assess and summarize the known geologic and...")
23:20, 14 December 2022 Grichards talk contribs deleted page Local Tectonic Setting (content was: "__NOTOC__ Category:Geologic and Tectonic Setting ----  Clearly identifying and determining the activity level of faults within and adjacent to a project region is critical for development of the input parameters required to perform an SHA. An experienced seismologist should assess and summarize available literature to identify known seismic conditions in a region. The recor...")
23:20, 14 December 2022 Grichards talk contribs deleted page Velocity Structure (content was: "__NOTOC__ Category:Geologic and Tectonic Setting ----  The velocity structure is a generalized model of the earth’s crust using layers having different assumed seismic velocities. It is important in a SHA to have a well-defined velocity structure. Several parameters (''VS30'', ''Z1.0'', ''Z2.5'') are used in most attenuation relationships. The most important pa...")
23:11, 14 December 2022 Grichards talk contribs created page Feasibility (PGA from USGS) (Created page with "__NOTOC__ Category:Seismic ---- “The scope of the seismic hazard study at a site depends on the seismicity of a region or site-specific considerations, the types of structures involved, and the consequences of failure. The design and evaluation of dams for earthquake loading should be based on a comparable level of study and analysis for each phase of the study (seismotectonic, geological, site, geotechnical, and structural investigations) and that level of...")
19:13, 14 December 2022 Grichards talk contribs created page Serviceability (Created page with " __NOTOC__ Category:Structural Design Considerations ----  "Most dams have expected service lives of 100 years or more. This lengthy life span and the frequently harsh service environment pose long term maintenance, repair and upgrade problems. To the extent practicable, the design should anticipate these problems and...")
18:56, 14 December 2022 Grichards talk contribs created page Structural Steel (Created page with " __NOTOC__ Category:Structural Design Considerations ----  Structural steel is most commonly used for gated structures. "Gates are composed primarily of structural steel and are generally of welded fabrication. Structural members are typically rolled sections; however, welded built-up girders may be...")
18:06, 14 December 2022 Grichards talk contribs created page Bearing Capacity (Created page with " __NOTOC__ Category:Global Stability of a Dam ---- "Analytical methods, traditional bearing capacity equations, field tests, and laboratory tests are all used to determine the bearing capacity of soil and rock. The allowable bearing capacity is defined as the maximum pressure that can be permitted on a foundation soil or rock mass giving consideration to all pertinent fa...")
18:05, 14 December 2022 Grichards talk contribs created page Flotation (Created page with " __NOTOC__ Category:Global Stability of a Dam ---- "This mode of failure occurs when the net uplift force (gross uplift on the base minus the weight of surcharge water above the structure) exceeds the summation of forces due to the weight of the structure, the weight of water contained in the structure, and other surcharge loads." <ref name="EM2100">Stability Analysis...")
17:41, 14 December 2022 Grichards talk contribs moved page Best Practices Resources to Best Practices Resources Catalog without leaving a redirect
17:37, 14 December 2022 Grichards talk contribs moved page Contribute to Contribute To This Site without leaving a redirect
17:29, 14 December 2022 Grichards talk contribs deleted page Trainings (content was: "{| class="wikitable sortable" style="width: 100%; background-color: #fff;" |- ! Author !! Title !! Date |- | ASDSO || On-Demand Webinar: HEC-RAS 2D Modeling || 2017 |}", and the only contributor was "Camrenbt" (talk))
04:59, 14 December 2022 Grichards talk contribs created page Photogrammetry (Created page with " __NOTOC__ Category:Geotechnical Exploration ---- {{Picture  |image= Lake_Rotokawau.jpg  |link=  |caption= Aerial Photograph }}  "Photogrammetry is generally defined as the art and science of making accurate...")
04:47, 14 December 2022 Grichards talk contribs moved page Photogrammetry to Aerial Photography without leaving a redirect
22:28, 13 December 2022 Grichards talk contribs created page Breach Scenarios (Created page with "__NOTOC__ Category:Dam Breach Inundation Analysis ----  “Typically, several hydrologic and non-hydrologic (fair weather) events are evaluated as part of an event-based dam safety analysis. For hydrologic failure events, an extreme flood event ranging from the 50-year event for low-hazard dams up to the PMF for high-hazard dams is selected based on the potential for los...")
21:39, 13 December 2022 Grichards talk contribs created page Piano Key Spillways (Created page with "__NOTOC__ Category:Spillway Control Structures ---- “A piano key (PK) weir is a recently developed alternative to traditional labyrinth weir designs that was developed specifically for smaller control structure footprint applications. Two main differences of PK weir designs, relative to traditional trapezoidal labyrinth weir designs are: (1) the PK weir has a simple rectangular crest layout (in plan view), essentially creating a labyrinth weir with α = 0 (rectangu...")
21:35, 13 December 2022 Grichards talk contribs created page Labyrinth Spillways (Created page with "__NOTOC__ Category:Spillway Control Structures ---- “The flow capacity of a weir is largely governed by the weir length and crest shape. A labyrinth weir is a linear weir folded in plan-view; these structures offer several advantages when compared to linear weir structures. Labyrinth weirs provide an increase in crest length for a given channel width, thereby increasing flow capacity for a given upstream head. As a result of the increased flow capacity, these weirs...")
21:28, 13 December 2022 Grichards talk contribs created page Earth-Cut/Vegetated Spillways (Created page with "__NOTOC__ Category:Spillway Control Structures ---- “Vegetated auxiliary spillways typically have trapezoidal cross-sections and a grass cover to protect them from damaging erosion. They adapt well to sites capable of sustaining vigorous grass growth by normal maintenance without irrigation." <ref name="TR60">Technical Release 210-60: Earth Dams and Reservoirs, NRCS, 2019</ref> "Designs may use earth auxiliar...")
21:19, 13 December 2022 Grichards talk contribs created page Ogee-Crested Weirs (Created page with "__NOTOC__ Category:Spillway Control Structures ---- “An additional type of weir is the ogee. The downstream section of an ogee crest is parabolic shaped to mimic the underneath side of the nappe jet passing over a sharp-crested weir. Ogee weirs are commonly found in large hydraulic structures where passing the design flow at minimum head is important. For more information on ogee crests, see U.S. Department of Interior Bureau of Reclamation, [[Design of Small Dams]...")
21:16, 13 December 2022 Grichards talk contribs created page Sharp-Crested Weirs (Created page with "__NOTOC__ Category:Spillway Control Structures ---- “A weir is a notch of regular form through which water flows. The structure containing the notch is also called a weir. The edge over which the water flows is the crest. The two basic types of weirs are sharp-crested weirs and broad-crested weirs. The sharp-crested weir is used to measure the channel or stream flow. In a sharp-crested weir, the flow springs clear of the crest."<ref name="NRCS650">National Engine...")
21:07, 13 December 2022 Grichards talk contribs created page Broad-Crested Weirs (Created page with "__NOTOC__ Category:Spillway Control Structures ---- “These types of control structures are associated with staged releases and suited for auxiliary and emergency spillways. A fuseplug control structure may include one or multiple bays containing the fuseplug embankments. The zoned embankments will be placed to a specified height and include a pilot channel through each embankment crest set to a specified elevation associated with a given fl...")
03:24, 13 December 2022 Grichards talk contribs created page Precipitation Spatial Distribution (Created page with " __NOTOC__ Category:Rainfall Runoff Modeling ----  For large watersheds, it is appropriate to consider spatial variations in precipitation depths of the design storm. "Various methods of areally distributing PMP have been developed over the years. Caution should be used in the application of these methods, and their...")
03:17, 13 December 2022 Grichards talk contribs created page Precipitation Temporal Distribution (Created page with " __NOTOC__ Category:Rainfall Runoff Modeling ----  When using precipitation depth estimates for hydrologic modeling, it is necessary to define the "temporal distribution of the rainfall, which is how the precipitation is distributed over time throughout a storm of a particular duration. For example, a 24-hour rainfa...")
03:09, 13 December 2022 Grichards talk contribs created page Precipitation Depth (Created page with " __NOTOC__ Category:Rainfall Runoff Modeling ----  "In watershed studies, it is often necessary to know the average depth of rainfall over an area.”<ref name="NEH210-640">National Engineering Handbook: Chapter 4 - Storm Rainfall Depth and Distribution | National Engineering Handbook: Chapter 4 - Storm Rainfall D...")
02:57, 13 December 2022 Grichards talk contribs deleted page Precipitation Estimates (content was: " __NOTOC__ Category:Rainfall Runoff Modeling ----  “In areas of relatively uniform terrain and little spatial variability or precipitation, classical textbook procedures, such as Thiessen polygons or the isohyetal method, can be used and are generally adequate. These procedures are simple methods of developing spatia...")
00:13, 13 December 2022 Grichards talk contribs created page Water Availability (Created page with "__NOTOC__ Category:Low Flow Conditions ---- “The determination of storage-yield relationships for a reservoir project is one of the basic hydrologic analyses for reservoirs. The basic objective can be to determine the reservoir yield given a storage allocation, or find the storage required to obtain a desired yield. The determination follows a traditional engineering approach:<ref name="EM 1110-2-1420" /> #"Determine the study objectives. This includes the proj...")
00:13, 13 December 2022 Grichards talk contribs created page Flow Regulation (Created page with "__NOTOC__ Category:Low Flow Conditions ---- “Reservoirs may improve water quality by merely <noautolinks>permitting</noautolinks> the management of flow. This management may include maintenance of minimum flows, blending selective releases from one or more reservoirs to maintain a given stream quality, and the exclusion of a flow from a system by diversion.<ref name="EM 1110-2-1420">Hydrologic Engineering Requirements for Reservoirs (EM 1110-2-1420) | EM 1110...")
22:00, 9 December 2022 Grichards talk contribs deleted page Hazard Potential (content was: "__NOTOC__ Category:Environmental ----  “To assist in the evaluation of hazard potential, areas delineated on inundation maps should be classified in accordance with the degree of occupancy and hazard potential. The potential for loss of life is affected by many factors, including but not limited to the capacity and number of exit roads to higher ground and available transport...")
21:46, 9 December 2022 Grichards talk contribs deleted page Regulatory Compliance (content was: "__NOTOC__ Category:Emergency Management ----  [Paragraph here] ==Examples== {{Website Icon}} ==Best Practices Resources== {{Document Icon}} ==Trainings== {{Video Icon}} <!-- For information on notation for in text citations visit https://www.mediawiki.org/wiki/Help:Cite Or simply enclose the citation as shown <ref> citation </ref> in the location of the in text mention. Cita...")