Cuando un componente es seleccionado, el explorador de cuencas expande los sub-componentes de este elemento. Los resultados del modelo se encuentran en results. Explorador de Cuencas. Todos los datos pueden ser especificados por el editor de componentes.
En la Figura 3 se ve el editor de componentes cuando se tiene seleccionado la cuenca tenk 1. Figura 3. Editor de componentes. Figura 4. Mensajes de registro. Se pueden cargar mapas de fondo para ayudar a visualizar la forma de la cuenca. La cuenca Tenk se muestra en la Figura 5. Figura 5. Una nueva carpeta con este nombre es creado en el directorio de destino. En ella se guardaran todos los archivos creados en este proyecto.
Figura 6. Corporate Contributors:. United States. Federal Highway Administration. Office of Technology Applications ;. Resource Type:. Tech Report ;. Contracting Officer:. Krylowski, Tom ;. Corporate Publisher:. Federal Highway Administration ;. NTL Classification:. The manual provides guidelines and procedures for designing bridge deck drainage systems, inclusing illustrative examples. Should the design process indicate a drainage system is needed, utilization of the most hydraulically efficient and maintenance-free system is emphasized.
The manual also stresses the advantages of designing to minimize the complexity of bridge deck drainage systems. Integration of practical drainage details into overall structural design is presented. Other resources available to provide in-depth information, equations, and procedures to perform coastal scour include the First and Second volumes of HEC , Highways in the Coastal Environment, and HEC Sections 9.
Scour results from the erosive action of flowing water, which may remove and carry away material from the bed, banks of waterway, and from around coastal structures, such as piers and abutments. Different materials scour at different rates. Loose granular soils are rapidly eroded by flowing water, while cohesive or cemented soils are generally more scour-resistant.
Determining the magnitude of scour risk at structures in coastal waters is complex, as they are at the confluence of concurrent hydraulic forces e. Reviewing site conditions can lead to a better anticipation of the types of scour that may be present and should be evaluated. Once the types of existing structures or planned structures are known, the list of typical scour mechanisms can be reviewed for applicability.
Table lists common scour mechanisms. Examples of many of these mechanisms are also shown in Figure Roadway damage by bluff erosion and shoreline recession.
Clogging due to debris causing redirection of flow. C - Pavement damage due to waves and surge in an extreme event in Brazoria County after Hurricane Ike. Hydraulic analysis must consider the magnitude of design storms, characteristics and geometry of the tidal inlet, estuary, or bay, and the long-term effects due to placement of the bridge or other transportation asset. Structures located in coastal environments must also consider scour resulting from flow in two directions due to tidal fluctuations.
In addition, the analysis must consider the long-term effects of normal tidal cycles. This can be achieved by modeling and reviewing the time-dependent tidal flows, velocities, and depth on the following processes:. Geotechnical investigations are commonly used to evaluate scour mechanisms. Understanding the local soil and rock properties is important, as it provides a basis for describing common engineering properties of geomaterials and how different materials may behave under various conditions.
Geotechnical investigation can include surface samples, borings, and SEDflume testing. Surface samples and boring can be evaluated via Unified Soil Classification System USCS classifications, gradation, plasticity index, and hydrometer testing. Due to the dynamic nature of sediment transport in the coastal zone, most technical guidance is based on empirical equations, experience, and field observations.
The type of sediment located throughout the study area and suspended in the water column should be considered and equations based on available data used as appropriate. One area of focus that can vary the level of analysis needed or types of equations used is the type of soil to be evaluated, such as cohesive, non-cohesive, coarse, or erodible rock.
For non-cohesive material scour equations, it is important to know the D 50 and D 90 sediment diameters. For cohesive materials, when possible, it is important to know the erosion rate and critical velocity of sediment particles. These values can also be derived empirically if the D 50 and classification are known. Long-term sediment budgets are also important for understanding areas prone to scouring. The long-term sediment budget can be generally characterized by typical sediment movement within the littoral zone.
The littoral zone is the zone from the shoreline to just beyond the breaking wave zone. Littoral drift is the movement of beach material in the littoral zone by waves and currents. An aggrading or stable waterway may exist if the sediment supply to the project area from the littoral drift is large.
Such a situation may minimize the effect of contraction scour, and possibly local scour. Conversely, long-term degradation, contraction, and local scour can be exacerbated if the sediment from littoral drift is reduced. Important information for evaluating the effect of littoral drift includes historical information, future dredging, installation of jetties, etc. The Shoreline Change subsection provides a more in-depth discussion for long-term shoreline change and sediment budgets.
Other methods of determining the observed or potential scour mechanism include reviewing maintenance reports, reports from community engagement, and photos after storms. Understanding sediment budgets and geomorphic existing conditions provides a valuable tool for evaluating the potential for scour in tidal waterways. In most cases, this principle is not easy to quantify without direct measurements and hydraulic modeling.
For the analysis of roadway structures located in tidal waterways, a three-level analysis approach, similar to the approach outlined in HEC , is recommended. Determining the appropriate level of analysis is dependent on-site conditions, level of approach, available data, and potential applicable scour mechanisms. Figure summarizes the guidance on level of approach as it pertains to scour estimation methods. Scour Methods and Corresponding Level of Analysis. There are several methods of infrastructure adaptation that can be incorporated during planning, designing, construction, operating, or maintaining infrastructure to mitigate for coastal scour.
HEC recommends a five-part approach: manage and maintain, increase redundancy, protect, accommodate, and relocate. Table summarizes each of the five steps in the recommended approach. If an existing transportation asset is identified as at risk to erosion, then protection might be the first option to immediately mitigate risk. All options can be reviewed and incorporated for proposed transportation assets.
For general scour conditions, such as local scour, contraction scour, stream instability, and overtopping flow, refer to Table 2. Since those measures are applicable for the above conditions and more well-known in riverine analysis, the remainder of this section will focus on examples of coastal protection and countermeasures.
Many different natural processes and forces impact roads near the coast. This section will focus on the most common erosion issues e. For roadways in coastal environments, highway overwashing is a very common occurrence due to nearshore locations and low elevations. There are several mechanisms that damage pavements subject to overwash including:. Coastal weir-flow and wave action will be discussed as they relate to impacts from these mechanisms later in this section.
Strategies for minimizing damage during the overwashing condition include:. Figure , below, shows the first three strategies in a roadway cross section view. One scour mechanism that damages pavements during overwashing is the coastal weir-flow damage mechanism.
During this mechanism, water overtops the roadway embankment. The embankment acts as a broad-crested weir to the incoming storm surge. Now we can begin to enter the cross section data station and elevation data, or XY coordinates. This data is entered from the left bank of the cross section to the right bank of the cross section the left side of the cross section will have lower numbers than the right side as though you were looking in the downstream direction, or in the direction of flow.
For this example, enter the numbers as shown in the following figure: Click the Apply Data button top center when finished to generate a cross section plot.
Next, enter the Downstream Reach Lengths left over bank, main channel, and right over bank , which is the length from this cross section to the next downstream cross section.
Next, enter the Main Channel Bank Stations. The 9 Main Channel Bank Stations delineate the left and right over bank areas flood plains from the main channel and will show up as red dots on the cross section plot. The Contraction and Expansion coefficients are used to compute the energy losses associated with the contraction and expansion of flow in a system. For most projects, 0. When you are finished entering the data as shown in the previous figure, click the Apply Data button.
A file containing a picture may also be linked to a particular cross section by clicking on the camera button: choosing the appropriate River, Reach, and River Station, and then by clicking on the Add Picture button to search for and add the corresponding picture file. There are other useful options for entering and editing data found by clicking the Options menu of the Cross Section Data window. We will use the Copy Current Cross Section option to create the next cross section.
Copying an existing cross section will simply copy all of the existing data exactly as it is, you must then modify the copied cross section data as needed e. The advantage of this option is that it allows you to interpolate a new cross section, or to copy an existing cross section which can be modified quickly using choices listed in the Options menu.
Select Copy Current Cross Section and enter the next river station which is 8. Click the Apply Data button when finished to generate the cross section plot. Next click on the Options menu and choose the Add a new Cross Section option. For this example, enter 7. Type in upstream boundary of Sample River, Lower Reach as the description. Next, enter the following cross section information as shown: 11 Click the Apply Data button when finished.
Repeat the previous procedure to add a cross section you may use the Copy Current Cross Section option at the end of the Lower Reach of Sample River and use the following river station, description, and cross section information as shown: 12 Since this is the downstream boundary of Sample River, the Downstream Reach Lengths are entered as zero or they may be left blank. If you choose the Copy Current Cross Section option, you may more easily duplicate the next cross section for this example by modifying the existing elevations.
This is done by clicking Options, Adjust Elevations, type The final step in this example is to enter the junction data. This is done by first going to the Geometric Data window and clicking on the Junction button: The Junction Data window will appear; enter the following information to indicate the lengths across each section of the junction: The Energy computation mode is already selected which means that the energy equation will be used to model the junction.
If the Momentum computation mode momentum 14 equation is used, the angle at which the tributary enters will have to be entered. Finally, save the geometric data by clicking File on the Geometric Data window, and then choose Save Geometry Data to update the geometric data saved previously see page 7.
The amount of flow through a system will depend on the type of study conducted. Determining which boundary conditions are required depends on the conditions of the system and the type of model being run. The options for running the model are steady and unsteady flow analysis, and within each of these are options for modeling a subcritical, supercritical, or mixed flow regime.
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