747.1 Bridge Surveys

EPG 747.1 Bridge Surveys is provided as supporting information and guidance for the preparation and submittal of bridge surveys. This section is to be used in conjunction with the Bridge Survey Checklist.

A proper procedure for, and a methodical approach to the analysis and computations for preparation of a bridge survey will result in a realistic recommendation for the proposed structure. A Bridge Survey consists of the [Survey Report along with applicable files and documents listed in EPG 747.1.2 Bridge Survey Submittals. Most documents for a Bridge Survey are submitted on standard sheets which are available in Word or MicroStation.

747.1.1 Purpose

Bridge surveys prepared and submitted to the Bridge Division by the district provide the basis for preliminary bridge layouts and ultimately for the preparation of bridge plans by the Bridge Division. Care exercised during the gathering and preparation of bridge survey data will be reflected throughout the life of the proposed bridge. The hydraulic design of the bridge waterway opening for a stream crossing is almost entirely based upon bridge survey data gathered in the field or from aerial photographs. Bridge surveys for grade separations should accurately describe geometrics, grades and other pertinent features of the proposed improvement. When new grade separation structures are to be incorporated with existing facilities or when existing structures are to be widened or rehabilitated, the bridge survey should reflect geometrics and grades of existing facilities as they exist. Seldom are existing geometrics and grades the same as shown on original design plans.

Bridge survey data should include all information regarding the bridge site which will have a bearing on the bridge layout and design.

Consulting engineering firms retained by the department to prepare bridge layouts should contact the Bridge Division for additional requirements beyond those listed in this article.

747.1.2 Bridge Survey Submittals

747.1.2.1 Bridge Survey Report

Applicable portions of this document are filled in completely by the district. Crossings with small drainage areas should be evaluated to determine if Bridge Division or the district is responsible for the design of the structure. See EPG 750.7.4.3 Summary of Responsibilities for more details.

Page 1. Describe the location of the road from features readily identified on maps such as towns or other state routes. Provide the anticipated means of handling traffic such as a temporary bridge, closing road to traffic, staged construction, etc. Provide data for existing bridge on or near alignment of proposed bridge. Complete the High Water Elevations at Proposed Bridge Site table using water elevations at survey centerline.

Page 2. Provide information on any improvements near the proposed bridge. Such improvements may include, but are not limited to, residences, businesses, other buildings and crop fields. The data for existing bridges need be completed only for bridges within 1000 ft. of the proposed bridge except where the data for structures beyond this distance will obviously be of value. The "Additional Remarks" space is used for general information relating to the crossing and is not restricted to remarks relating to existing bridges.

Information on Page 2 is used as part of the hydraulic analysis of the crossing by the Bridge Division and should be carefully completed by the district. If the crossing is over an organized drainage district ditch or encroaches on Drainage District levees, provide the corporate name of the Drainage District.

Page 3. Photographs depicting the site conditions at the time of survey shall be provided.

Page 4. General Instructions for Bridge Surveys.

747.1.2.2 Bridge Survey Sheets

The following Bridge Survey Sheets are submitted when applicable (each sheet is to be submitted as a dgn file and also as a PDF):

Plan Sheet(s)

Typical Section Sheet(s)

Profile Sheet(s)

Valley/Channel Section Sheet(s)

Cross Section Files/Sheet(s)

747.1.2.3 Preliminary Geotechnical Report

The preliminary geotechnical report provides critical information necessary for the proper layout of structures. The spill slope recommendation is needed to determine minimum structure length. The geological data provided is used to assess possible foundation types and subsurface problems thereby leading to a potentially more accurate preliminary cost estimate provided with the bridge memorandum.

747.1.2.4 GEO Files for Stream Crossings

GEO files contain geographic information that is imported into HEC-RAS to create the geometric portion of the hydraulic model. If survey data is provided for more than one stream, a GEO file is created for each stream. If additional sections or offset profiles are needed beyond what is available in the GEOPAK to HEC-RAS Converter spreadsheet, create multiple GEO files using the same streambed profile.

A GEOPAK to HEC-RAS Converter and tutorial videos are available in article 1.3 Bridge Survey on the CADD Support Services web page under GEOPAK Road – GEOPAK Support Material. The GEO file(s) and the GEOPAK to HEC-RAS Converter spreadsheet(s) are submitted with the Bridge Survey.

The following items are to be included in the GEO File(s) (stationing direction requirements for profiles and sections are based on the stationing directions required by HEC-RAS):

Centerline and Offset Profiles - Profile chains created for use in the GEOPAK to HEC-RAS Converter are created so that the stationing in the GEO file will run from left to right when looking downstream. Profile stationing for the GEO file starts at zero and may run the opposite direction of the roadway stationing.

Streambed Profile(s) – Stationing for streambed profiles should begin at zero at the downstream end and increase going upstream.

Valley Sections – Stationing for valley sections run from left to right looking downstream.

Typical Channel Sections - Stationing for channel sections run from left to right looking downstream.

Existing Bridges - Stationing for sections at existing bridges run from left to right looking downstream.

747.1.2.5 Additional Information

The following additional information is provided to aid the preliminary designer in the efficient and accurate layout of the structure:

.dgn Reference Files

.tin Files

GEOPAK Cross Section Files

Bridge Survey Checklist

Photos

747.1.2.6 Bridge Survey Submittal Process

747.1.2.6.1 Submitting the Bridge Survey

The completed bridge survey report including all applicable files and reports listed in EPG 747.1.2 Bridge Survey Submittals is submitted to the Bridge Division Bridge Survey Processor through ProjectWise. Once all the bridge survey documents are available in ProjectWise send an email to the Bridge Survey Processor indicating that the bridge survey is being submitted and providing a link to the bridge survey documents in ProjectWise.

747.1.2.6.2 ProjectWise

To submit the Bridge Survey, create a new folder named BR Survey under the appropriate job number in ProjectWise.

When there are multiple bridge structures in a Job number, create an additional folder for each location in the BR Survey folder. Use the route and feature crossed to designate the location (for example, B over Turkey Creek, 67 NB over 60, MSE Wall 67 over 60). Existing bridge numbers may be used for bridge replacement and rehabilitations.

Once the folders have been created, copy and paste the Bridge Survey documents into the appropriate folder(s). Be sure to include all reference files associated with the MicroStation .dgn files.

747.1.2.6.3 Creating a Link

To create a link, left click on the ProjectWise folder, left click in the address bar to highlight the contents, and then right click and select copy from the dropdown menu. Right or left click in the body of the email and click on the paste icon.

747.1.2.6.4 Revising Bridge Surveys

747.1.2.6.4.1 Naming Revised Documents

To prevent confusing revised documents with the original documents or previous revisions add the suffix "Rev" with the revision number to the file name (for example, 001_jobnumber_brplanRev1.dgn).

Subsequent revisions if required would be 001_jobnumber_brplanRev2.dgn, 001_jobnumber_brplanRev3.dgn, etc.

747.1.2.6.4.2 Submitting Revised Documents

To submit revised Bridge Survey documents, create a new folder named Revisions-“todays date” (yymmdd) (for example, Revisions-140811) in the appropriate BR Survey folder or location folder and, copy the revised documents into the folder. Be sure to include all reference files associated with the MicroStation .dgn files.

If additional revisions are required, create a new folder using the current date for each revision to prevent confusion.

E-mail the Bridge Survey Processor with a link to the appropriate folder and indicate that a revision to the bridge survey has been made.

747.1.2.6.5 Bridge Survey Submittal Timeline

Submit Bridge Surveys at least 12 months prior to the Plans Completion Date (PCD) for nonseismic bridges to allow adequate time for preliminary and structural design. See EPG 751.1.1.5 Routine New Bridge Design Schedule for additional details. Seismic bridges may require as much as 24 months for structural design; consult the Structural Liaison Engineer for an estimate of when Bridge Survey should be submitted.

747.1.3 Bridge Survey Sheet Data

747.1.3.1 Common Data (All Bridge Survey Sheets)

747.1.3.1.1 Title Block

Care should be taken to fill out the Title Block thoroughly and completely. For new construction, the new bridge number will not be known at time of Bridge Survey submittal.

The station to be used is the station along the project roadway at the intersection of the project roadway and the roadway below/above or the center of the stream below.

747.1.3.1.2 Other Information

Consistent uniform sheet numbering and naming practices allows for quick sheet identification thereby improving the efficiency of the work flow process.

To clarify how many bridge survey sheets there are and to differentiate them from the reference files, name Bridge Survey sheets using the following format:

001_Jobnumber_description.dgn

002_Jobnumber_description.dgn

003_Jobnumber_description.dgn

747.1.3.2 Plan Sheets

747.1.3.2.1 General Information for All Plan Sheets

The Plan Sheet is used to show a plan view of the proposed structure.

Guidance about the additional requirements for Stream Crossings, Grade Separations, Railroad Crossings and Retaining Walls is available.

The following items are included as general information for all Plan Sheets:

North Arrow - A north arrow shall be prominently placed on Plan Sheet.

Title - “PLAN” shall be placed at the top center of the sheet.

Scale - The preferred scale for plan sheets is 1 in. = 100 ft. Where the extent of the area is such that the entire area cannot be shown on one sheet at this scale, a scale of 1 in. = 200 ft. may be used, or additional sheets with match lines as required may be used. For further clarity, a larger scale may be used as long as all pertinent information fits on the Plan Sheet. A graphic scale shall be prominently displayed on Plan Sheet.

Stationing - Stationing shall be shown with stations increasing from left to right.

Details - Show location of existing and proposed roadways with stationing, labeling, bearings and dimensions. Center details on Plan Sheet as much as possible.

Horizontal Curve Data – If applicable, the horizontal curve data shall be given.

Structure Locations - Show location of existing bridge with general dimensions and stationing. Show location of proposed bridge.

Four Section Index - Provide small four section index map showing approximate course of streams and location of roads and bridges.

Bench Marks – See EPG 238.3.36.1.1 Benchmarks. Provide location, elevation and description of two permanent bench marks. These may be moved to the Typical Section Sheet if room is needed on the Plan Sheet.

State Plane Coordinate System – See EPG 238.1.4.2 Coordinate System. Provide the coordinate system (NAD83) used for the project. This may be moved to the Typical Section Sheet if room is needed on the Plan Sheet.

Vertical Datum – See EPG 238.1.4.3 Vertical Datum. Provide the survey datum used for the survey (for example, NAVD 88) and any datum shift information should be provided here as well (for example, NAVD 88 = NGVD 29 + 1.23’). This may be moved to the Typical Section Sheet if room is needed on the Plan Sheet.

Zone - Provide the zone (East, Central or West) for the project location. This may be moved to the Typical Section Sheet if room is needed on the Plan Sheet.

Projection Factor – See EPG 238.1.4.4 Projection Factor. Provide the projection factor for the project location. This may be moved to the Typical Section Sheet if room is needed on the Plan Sheet.

Existing and Proposed Incidental Features - Buildings, fences, drainage features, temporary bypasses and other improvements within the extents of the survey (see EPG 238.3.28, Man-made Features) should be shown on the Plan Sheet. Show all utilities (see EPG 238.3.29 Utilities) overhead and underground and note utilities to be placed on bridge, if any. Include location, size and flow line elevations of storm water drainage structures.

Boundaries - Show existing and proposed right of way and easements on Plan Sheet. Include labeled section, township and range lines when applicable.

Contour Lines – Contour lines shall be provided to the limits and intervals given in EPG 238.3.36.3.5 Extent of Contours and EPG 238.3.36.2 Grade Separation. Contours at 10 ft. intervals shall be shown using a heavier line.

Tie Station – The intersecting roadway stationing and skew angle for all streams, routes, railroad lines and retaining walls are to be clearly labeled where applicable.

747.1.3.2.2 Additional Information for Stream Crossings

For information required for all plan sheets see EPG 747.1.3.2.1 General Information for All Plan Sheets.

The plan sheet for stream crossing projects is used to show the alignment of the stream in reference to the alignment of the roadway. The information provided on this drawing is used in the hydraulic analysis for the project vicinity during flood events. The accuracy of the hydraulic analysis, the hydraulic performance of the new bridge structure during a flood event, and the determination of possible flooding effects on properties in the vicinity are all highly dependent upon the detail and accuracy provided in this drawing.

Roadway Design Frequency – The design flood frequency for the roadway design, see EPG 748.2 Roadway Design Criteria.

Plan Extents - The course of the stream plotted sufficiently to show the extent of the project vicinity affected during flood conditions – to the limits described in EPG 238.3.36.3.6 Streambed Profiles.

Contour Lines - Topographic contour lines in the project vicinity affected during flood conditions extending at least 1,000 ft. up and down the valley from the proposed crossing. Bridge Division evaluates all of the topographic elevation information in the project vicinity to aid in the development of the hydraulic analysis. Although the Valley Sections and the Channel Sections described below provide detail of the groundline information at certain locations, it is necessary for the hydraulic designer to be able to accurately develop additional valley sections based on the extent of the topographic contour lines provided on this plan sheet. As a result, the topographic contour lines should be provided far enough away from the stream to ensure that all portions of the valley that could be flooded are included.

Stream Meander - An accurate depiction of the meander of the stream, as obtained from a survey is shown. The accurate plan view representation of the stream layout is critical to the hydraulic analysis software used in the design. See EPG 238.3.36.3.4 Stream Meanders for additional information.

Flow Direction - The direction of stream flow.

Channel Changes - The location and alignment of past or proposed channel changes in the project vicinity. If a proposed channel change is to occur, the drawing should give reference to a typical proposed channel section that are shown on the Valley/Channel Section Sheets or the Cross Section Sheet(s).

Special Features - Location and description of any features above and below the crossing which could affect the course of the stream or the layout of the bridge.

Labeling - Name of the stream, stating whether it is a river, creek, drainage ditch, ravine, dry run, etc.

Valley Sections - Locations of surveyed Valley Sections, including stationing. The location of the valley sections should be located accurately on the plan sheet, including the distance upstream or downstream of the roadway centerline as measured along the centerline of the stream; as well as an orientation and skew of the section line to the stream. The section line should also be located in the plan view by offset distances and angles from tie points on the roadway. Stationing marks should be indicated on the section line, and confirmed with the cross section data to ensure that the centerline of the channel is located at the proper station. It is important that the orientation of the valley section when input into the hydraulic analysis software be “facing downstream”. Because of this need, the valley section should be surveyed so that the completed cross section will represent the viewer facing in the downstream direction, and so that when viewing the actual cross section shown on the associated Bridge Survey drawing, the “zero station” of the cross section will be shown to the left.

Channel Sections - Location of the typical Channel Sections, including stationing. These sections are intended to be accurate surveys of representative “typical” channel sections for the project vicinity; additional channel sections should also be provided to represent unusual or constrictive channel conditions. As noted for Valley Sections, the same orientation, stationing and descriptions of the section locations should be used.

Erosion - Identified areas of bank deterioration and erosion should be indicated on the plan sheet and supplemented with photographs, if possible. This will be of great help in preparation for further investigative field visits to the site.

747.1.3.2.3 Additional Information for Grade Separations

For information required for all plan sheets see EPG 747.1.3.2.1 General Information Required for all Plan Sheets.

Many of the criteria and principles pertaining to the layout of stream crossing bridges are also applicable to grade separation bridges.

Bridge length and substructure locations are usually controlled by horizontal and vertical geometrics. Vertical and Horizontal Clearance requirements are given in EPG 751.1.2.5 Bridge Width, Vertical and Horizontal Clearance.

For structures spanning freeway type facilities, two-span bridges with MSE walls in front of the end bents are commonly used if the required span length is not excessive.

Stationing - The stationing along the routes under the bridge are to be shown in enough detail to determine the direction of stationing and the location of stationing baseline (i.e., centerline roadway, median edge of pavement, centerline median, etc.).

Labeling - The under routes are to be clearly labeled with the name of the route and direction of traffic, (for example, Route 50, SBL, NBL, Ramp 1, North Outer Road, etc.).

Drainage Features - All roadway drainage features both existing and proposed are to be clearly identified and labeled.

Ramps - Information for all ramps shall include: tie station, location of stationing baseline, enough stationing to determine direction of stationing and horizontal alignment.

Outer Roads - Information for all outer roads shall include: tie station, location of stationing baseline, enough stationing to determine direction of stationing and horizontal alignment.

747.1.3.2.4 Additional Information for Railroad Crossings

For information required for all plan sheets see EPG 747.1.3.2.1 General Information for All Plan Sheets.

Information for Grade Separations in EPG 747.1.3.2.3 shall be provided in addition to the following data:

Stationing - The stationing along the railroad lines under the bridge is to be shown in enough detail to determine the direction of stationing.

Milepost - Railroad milepost at intersection shall be labeled.

Curve Data - If applicable, the horizontal curve data for all railroad lines shall be given.

Labeling - The location of required cross sections shall be shown and clearly labeled as to identify the direction of stationing. See EPG 747.1.3.6 Cross Section Sheet(s).

747.1.3.2.5 Additional Information for Retaining Walls

For information required for all plan sheets see EPG 747.1.3.2.1 General Information for All Plan Sheets.

Location - The retaining wall shall be shown at the proposed location. The baseline for the wall shall be clearly labeled.

Tie Points and Offset Dimensions - Station and offset dimension ties are to be given at the ends of the wall and any breakpoints (change in direction/alignment) in the wall. Offset dimensions are to be shown to the critical wall location; front face of the wall if the under route offset is critical and fill face of wall if the over route offset is critical.

Alignment - Provide proposed horizontal alignment of the wall. Provide horizontal curve data if the wall is not parallel to the centerline roadway.

747.1.3.3 Typical Section Sheet

747.1.3.3.1 Typical Sections (Roadways, Ramps, Bypasses)

Typical sections provide a multitude of valuable information necessary for the proper layout of structures. Typical sections, for existing and proposed roadways, should be provided for the main line route, all under routes, all ramps and outer roads in the near vicinity of the proposed structure that may affect or be affected by the construction of the structure.

Scale - Typical sections should be placed on the sheet using a scale that allows easy legibility and arranged in such a manner to provide distinction between the sections.

Labeling - The title under each section should include the name of the roadway, ramp, etc. and the station limits for which the section is valid.

Profile Grade - The location of the profile grade shall be clearly identified.

Cross Slope - The cross slope and/or superelevation of each lane and shoulder shall be shown with an arrow indicating the direction of slope. Inclination of side slope(s) shall also be shown.

Dimensioning - Dimensions shall be provided for all lane widths, shoulder widths, multi-use paths/sidewalks, median widths, side slopes and ditch widths.

Clear Zone - The clear zone shall be shown by dimensioning from the edge of travelway and clearly labeled as such.

Guardrail, Barrier Curb and Fence - The locations of any guardrail, barrier curb and/or fence either existing or proposed shall be shown along with dimension to edge of travelway, roadway or shoulder.

747.1.3.3.2 Design Traffic (Construction Year and Design Year)

Traffic information is typically provided for the route on which the structure is to be built. It is generally not necessary to provide traffic data for ramps and outer roads.

Traffic Counts - Design year traffic and construction year traffic in the form of ADT and AADT with the percentage of traffic attributed to trucks and the design speed shall be placed on the sheet near the section to which the data pertains.

Traffic Handling - If provision is to be made for handling traffic in the immediate vicinity of the structure that will affect the structure in any way, a recommendation for the location of a bypass, and/or staging of construction are included.

747.1.3.3.3 Other Information

The typical section sheet can serve as a location for several other pieces of information.

Survey Points - Survey control points, reference points, benchmarks, and survey datum can be placed at any convenient location on the typical section sheet.

Shape File - The superelevation transition data table (i.e., shape file) should be shown if applicable.

747.1.3.4 Profile Sheet

747.1.3.4.1 General Information for All Profile Sheets

Guidance about the additional requirements for Stream Crossings, Grade Separations, Railroad Crossings and Retaining Walls is available.

The three lines of ground profiles plus the proposed profile grade provide critical information used in the layout of structures. The profiles aid in determining the length of structure, allowable substructure location, span lengths, superstructure type, superstructure depth, verification of the proposed profile grade and may be used as valley sections for hydraulic analysis. This information is used in conjunction with the freeboard or minimum vertical clearance requirements.

Profiles – See EPG 238.3.36.1.3 Centerline and Offset Profiles. Three existing ground profiles are to be shown parallel to the roadway. One profile is taken at the centerline of the roadway and the other two beyond the outer extents of the shoulders on either side. For stream crossings, especially bridge replacements over streams, the left and right profiles should be taken outside of any existing roadway fill, roadway ditches and/or drainage tributaries. Generally these are 30 ft. left and right of the centerline.

Profile Key - A profile key is shown indicating the line style and color designation for each of the profile lines.

Scale - The scale of the profile sheet in the vicinity of the structure shall be 1”=10’. For stream crossings, the portions of the profile in the valley not occupied by the structure may be to a smaller scale.

Proposed Vertical Profile - The proposed vertical profile grade line is shown with the vertical curve data and the V.P.C., V.P.I. and V.P.T. labeled. The thruway profile is shown for a distance of at least 500 ft. either side of the proposed structure.

Grades - Grades to the limits of the profiles, both proposed and Existing, are included on the report for the thruway and the crossroad. Superstructure depth requirements are used along with the Minimum Vertical Clearances Table to establish the relation of the grades at the intersection where minimum clearances control. For vertical clearance requirements see EPG 751.1.2.5 Vertical and Horizontal Clearance. Refer to EPG 131.1.7 Deficient Vertical Clearances on Interstates for information about coordinating minimum vertical clearance for grade separation structures with the Defense Department.

Placement and Labeling - The profiles shall be aligned on the profile sheet such that even stationing and elevations are in line with the gridlines of the sheet. Gridlines shall be labeled every 10 ft. in elevation and 50 ft. in stationing.

Bridge Widening Profiles - In the case of widening an existing structure, field shots shall be taken every 10 ft. along the gutter lines and centerline of the structure and reported on a profile sheet with the station and elevation of each location labeled.

747.1.3.4.2 Contracted Profile

A contracted profile provides a greater overview of the profile.

Scale - The scale for the contracted profile shall be 1”=100’ horizontal and 1”=10’ vertical.

Profiles - The contracted profile shall include the centerline groundline profile and the proposed profile grade line listed in EPG 747.1.3.4.1.

747.1.3.4.3 Additional Information for Stream Crossings

For information required for all profile sheets, see EPG 747.1.3.4.1 General Information for All Profile Sheets.

Water elevations are shown on the plot of the three line ground profile.

High Water Elevation - The extreme high water elevation at the immediate site of the stream crossing as ascertained per EPG 238.3.36.3.10 Extreme High Water Elevation.

Ordinary High Water Elevation - The ordinary high water elevation at the immediate site of the stream crossing as ascertained per EPG 238.3.36.3.11 Ordinary High Water Elevation.

Low Water Elevation - The low water elevation at the immediate site of the stream crossing as ascertained per EPG 238.3.36.3.12 Low Water Elevation.

747.1.3.4.4 Additional Information for Grade Separations

For information required for all profile sheets, see EPG 747.1.3.4.1 General Information for All Profile Sheets.

Over-Route Vertical Profile - All profile lines should show the proposed roadway(s) under the structure including pavement, ditches and spill slopes.

New Under-Route Vertical Profile - If the roadway under the proposed structure is also new (to be constructed with the structure or in the future) then a vertical profile of the under route shall be provided for a distance of at least 100 ft. on either side of the proposed structure.

Existing Under-Route Vertical Profile - If the roadway under the proposed structure is existing, then the profile of the existing road shall be provided in the form of field shots every 10 ft. along the edges of shoulder, edges of pavement, and centerline of roadway for a distance of at least 100 ft. on either side of the structure. Cross sections may be provided in lieu of the profile sheet, see EPG 747.1.3.6.2 Additional Information for Grade Separations for details.

747.1.3.4.5 Additional Information for Railroad Crossings

For information required for all profile sheets, see EPG 747.1.3.4.1 General Information for All Profile Sheets.

Information for Grade Separations in EPG 747.1.3.4.4 shall be provided, when applicable, in addition to the following data:

Over-Route Vertical Profile - All profile lines should show the rails under the structure along with any ditches and spill slopes.

Rail Survey - Field shots of the rails shall be provided on 25 ft. increments extending for at least 500 ft. on either side of the structure. These field shots may be provided in the form of a rail profile sheet, cross sections of the rails or in tabular form.

747.1.3.4.6 Additional Information for Retaining Walls

For information required for all profile sheets, see EPG 747.1.3.4.1 General Information for All Profile Sheets.

Location - When a retaining wall is to be used under a proposed bridge, a vertical line showing the proposed placement of the face of the wall at the bridge centerline is to be shown on the profile.

Wall Elevation - The existing and proposed ground line along the face of the wall shall be shown displaying a developed elevation of the proposed wall.

747.1.3.5 Valley/Channel Section Sheets

General Information for all Valley/Channel Section Sheets

The preparers of the Bridge Survey drawings and report are referred to EPG 238.3.36.3 Stream Crossings for more supportive information and general requirements, and to EPG 238.3.36.3.7 Valley Sections and EPG 238.3.36.3.8 Typical Channel Sections for detailed critical information regarding this information. The following items in particular should be identified in the Bridge Survey drawings that provide the surveyed valley and channel cross sections:

Scale - Valley and Channel cross sections should be drawn to the following scales: Horizontal scale: 1” = 100’ Vertical scale: 1” = 10’.

Valley section under nearby existing structure(s) - When there is an existing nearby stream-crossing structure, a surveyed cross section should be provided underneath the structure to provide an accurate representation of the constriction size to the stream created by that structure. See EPG 238.3.36.3.9 Existing Bridges.

Extreme High Water Elevation - The extreme high water elevation(s) as ascertained per EPG 238.3.36.3.10 Extreme High Water Elevation should be provided on all valley sections. If actual high water elevations were not obtained for each valley section, the high water elevation from the survey centerline is shown at each valley section; however this elevation is adjusted to account for slope of the stream and the distance to each valley section. The adjustment is made by adding or subtracting, as appropriate, the local streambed slope multiplied by the distance along the streambed profile between the valley section and the survey centerline.

Distance Upstream or Downstream - The location of the Valley or Channel Section must be identified in reference to the proposed stream crossing. The distance to the Valley or Channel section should be provided along the line that approximates the path of the deepest part of the stream so that there will be an accurate distance either upstream or downstream of the centerline of the proposed stream-crossing structure. For example, if the Valley Section 1 is located 400 ft. upstream of the centerline of the stream crossing structure, the drawing cross section should indicate both the section name “Upstream Valley Section 1” and “(located 400’ upstream)”. Additionally, the section should be plotted on the drawing so that it is viewed in the downstream direction. The preparers of the Bridge survey drawings should also check the bottom of channel elevation of each of the Valley and Channel sections in comparison to the bottom of channel elevation shown at the corresponding location on the Streambed Profile to ensure that the bottom of channel elevations are in agreement.

Streambed Profile - The streambed profile shall show the bottom of channel elevation. For details on stationing and profile length, see EPG 238.3.36.3.6 Streambed Profiles.

As noted in the above EPG 747.1.3.5 Valley/Channel Section Sheets, Distance Upstream or Downstream, the bottom of streambed profile elevations should be checked at the surveyed Valley and Channel section locations to ensure matching elevation.

747.1.3.6 Cross Section Sheet(s)

747.1.3.6.1 General Information for all Cross Section Sheets

Additional requirements for Grade Separations, Railroad Crossings and Retaining Walls are available.

Cross Section File - A GEOPAK cross section file is to be provided whenever cross sections are required.

Scale - The scale of the cross sections shall be 1”=10’.

Legend - The legend of each cross section shall include the station at which the cross section is taken and a base elevation line.

Sheets File - A cross section sheets file corresponding to the GEOPAK cross section file shall also be submitted.

Ground lines - All cross sections are to include both existing and proposed ground lines.

747.1.3.6.2 Additional Information for Grade Separations

For information required for all Cross Section Sheets, see EPG 747.1.3.6.1 General Information for all Cross Section Sheets.

Profile Sheet Substitution - In the place of the existing roadway profile sheet (EPG 747.1.3.4.4 Additional Information for Grade Separations), a cross section file containing cross sections taken every 10 ft. extending at least 100 ft. on either side of the structure may be submitted for the under route. The elevation of pavement centerline, pavement edges and shoulder edges shall be shown.

Drainage - Drainage features shall be shown.

747.1.3.6.3 Additional Information for Railroad Crossings

For information required for all Cross Section Sheets, see EPG 747.1.3.6.1 General Information for all Cross Section Sheets.

Information for Grade Crossings in EPG 747.1.3.6.2 shall be provided in addition to the following:

Cross Sections - Three cross sections are taken perpendicular to the tracks. One cross section is taken just before the structure, one at the centerline intersection with the structure, and one just after the structure. These cross sections are required by the railroad company to provide the perspective of a train passing through the crossing. The railroad railbed, rails, ditches and elevation of rails shall be shown. Cross sections shall extend at least 12 ft. on either side of the centerline of the exterior tracks. See EPG 751.1.2.5 Bridge Width, Vertical and Horizontal Clearance. See EPG 751.5.2.1 Pavements and Railroads for adjustments to section width for curved tracks.

Rail Survey Profile Substitution - In lieu of the rail survey profiles, cross-sections may be obtained at intervals not exceeding 25 ft. along the railroad and for a distance of at least 500 ft. each side of the structure. Cross-sections are to include rails, rail elevations, railbed, railroad drainage features, ditches and existing and proposed ground lines.

747.1.3.6.4 Additional Information for Retaining Walls

For information required for all Cross Section Sheets, see EPG 747.1.3.6.1 General Information for all Cross Section Sheets.

Location - Cross sections shall be taken at 10 ft. intervals perpendicular to the face of the wall starting approximately 25 ft. before the beginning of the wall and continuing for approximately 25 ft. beyond the end of the wall. The cross sections shall include wall location and the existing and proposed ground lines.

747.1.4 Aerial Imagery Overlay Procedure

747.1.4.1 Purpose

This procedure is a quick and comprehensive design tool that can be made part of the Bridge Survey submittal package at the consensual agreement of those involved with incorporating and utilizing it on a project-by-project basis. Therefore, use of this procedure is not required but should be considered as subject to core team discussion prior to submittal of surveys to determine level of interest on the part of both the district Design divisions and Bridge Division. It is important that any imagery attached to a MicroStation file have the capability of being preferentially turned off at the discretion of the designer(s).

This procedure can provide a more complete representation of the land use around a bridge that is not included in the typical survey information. It can also be used to generate a more accurate hydraulic model. As a time savings tool, the procedure and options provided can reduce guesswork and lengthy preliminary layout and design investigations while visually enhancing unusual terrestrial features combined with complex roadway geometry through the utilization of photogrammetric data.

747.1.4.2 Guidance

The economical design of a stream-crossing bridge that satisfies flooding design requirements relies on the extent of the information provided in the Bridge Survey Report drawings that identify the unique nature of the stream, the stream valley and the natural and manmade features that exist within the portion of that valley that is affected by potential flooding.

As a result, an aerial view that shows details of ground cover, structures and public and private improvements for the entire extents of the plat sheet coverage is a very valuable tool that can accurately tie data used for the hydraulic design of the bridge to the specific locations of the physical features that exist in the field near the project.

For situations where accurate and extensive topographic information upstream and downstream of the bridge (as described in EPG 747.1.4.3 Additional Information for Stream Crossings and EPG 750.3.2.2 Data Collection) may not be readily available, an aerial view layer in the MicroStation Bridge Survey plan drawing that is of the same scale as the roadway drawing can be used to support design assumptions, and to better identify the best locations for additional survey data or field investigation, when needed.

For any bridge project, the ability of the designer to use MicroStation’s measuring tools with combined aerial photography and roadway and bridge design geometry supports production of effective and economical design.

Latest mapping should be used with filename and date recorded on/with the image for future reference and historical purposes, or at least noted in the correspondence.

747.1.4.3 Instructions for Importing Aerial Imagery into MicroStation

CADD Support Services has provided valuable information on many different procedures related to attaching imagery to a MicroStation file or converting MicroStation geometry to a format that can be viewed inside Google Earth. As technology improves, CADD Support Services will continue to update this information along with any other CADD related items on the CADD wiki site to have the most up-to-date processes for our MoDOT users. Listed below are some links to the CADD Support wiki site that contain documentation or videos on these procedures.

Option 1, Using Web Map Server Imagery

Geographic Coordinate System & Google Earth Tools

Utilizing Web Map Server Imagery

CADD Support has provided links to available web map servers that contain aerial and quad imagery that can be utilized inside a MicroStation file. The web map server links are tied to a server with the Missouri Spatial Data Information Service (MSDIS). The aerial imagery is at 2 ft. pixel resolution. (Quality of aerial imagery depends on pixel resolution which may be different for different areas of the state. Availability of imagery is dependent upon MSDIS and some areas may not be available or updated yet.) Once the web map imagery has been attached, an image may be created from the web map imagery for the limits of the project.

To use this procedure correctly, a geographic coordinate system will need to be applied to the MicroStation file first so the imagery will lay in correctly with the MicroStation data.

Option 2, Using Imagery and USGS Quads with MicroStation

Photogrammetry has provided for MoDOT users aerial and quad imagery that can imported into the MicroStation file. This imagery normally comes from the Missouri Spatial Data Information Service (MSDIS). The imagery will have a little better resolution (at 2 ft. pixel resolution) than the Web Map Server imagery. Keep in mind though that this is 2008 imagery vs. the 2012 imagery from the web map server.

Option 3, MicroStation Geometry to Google Earth

Geographic Coordinate System & Google Earth Tools

MicroStation has the capability to convert the geometry inside the file into a file format (KML) that can be viewed inside Google Earth. Once the KML has been created, it can be viewed over Google Earth imagery. The KML file also has the ability to turn on/off levels and references files that were in the MicroStation file when the KML file was created.

As with Option 1, a geographic coordinate system will need to be applied to the MicroStation file first before this can be done correctly.

How To Videos

For Options 1 and 3, there are also some online videos on these procedures that may be helpful.

Custom Geographic Coordinate System

Exporting MicroStation Geometry to Google Earth (KML)

Attaching Web Map Server and Creating Job Image

747.1.5 Other Miscellaneous Structures

Elevations and geometric data sufficient to develop plans for the proposed structure, including sign attachments and special footings such as for high mast tower lights, should be provided. Any subsurface investigation required will be coordinated by the Bridge Division. Right of way and/or permanent easement limits expected to affect the location or dimensions of the structure should be provided.

Guidelines for the Design of Miscellaneous Foundations

Examples of miscellaneous foundations, other than bridges, requiring geotechnical surveys and specific design are sign trusses, high mast lighting, etc. The district should submit the following information to the Bridge Division Bridge Survey Processor (Bridge Survey Processor@modot.mo.gov) when a foundation design is required. Providing this information as outlined below, and in a timely manner, will allow the Bridge Division to produce cost efficient designs and details for structural foundations.

Foundation designs for tubular span supported highway signs will be designed as shown in the standard plans. Foundation designs for box trusses (i.e., aluminum, butterfly and cantilever, and structural steel) will be determined by the Bridge Division relative to cost-effectiveness.

The Bridge Division personnel will be available to serve as a liaison between the district and involved functional units.

Time Frame Required. The Bridge Division will need 22 weeks to design any miscellaneous structure foundations and it is essential that all required information be submitted no later than 22 weeks prior to the due date. Within this 22 week timeframe, the Soils and Geology Section will need 10-12 weeks to perform the following:

• Put the geotechnical survey into the drilling schedule.
• Allow time for inclement weather conditions.
• Drill and sample the foundation materials.
• Perform strength and classification tests on the soil and rock encountered in the drilling operations.
• Interpret the geotechnical data and report findings and recommendations for the foundation design.

District Request. Unless a drilled shaft foundation is specifically requested by the district to be the only option considered, the Bridge Division will choose the most cost-efficient foundation (spread footing or drilled shaft foundation). Value engineering proposals, after award of the project, for the foundation design will not be considered and will be stated as such in the Bridge special provisions.

Layout. The district is to provide stationing and offsets for foundation locations to the Bridge Division so that the miscellaneous foundation layouts can be sent to the Construction and Materials Division with other structure layouts from the Bridge Division. This procedure allows for surveying, utility marking and dispatching of drilling equipment and personnel in the most efficient manner.

Geotechnical Report to the Bridge Division. The Construction and Materials Division will provide geotechnical parameters for design of the foundations to the Bridge Division Bridge Survey Processor (Bridge Survey Processor@modot.mo.gov), with a copy to the district.

Location and Sign Information Layout. The district will provide detailed information about each structure. The information typically shown on the data sheet and the cross section for each structure in a set of roadway plans is necessary for the proposed foundation design computations. The quantity for footing and pedestal concrete, normally shown on the D-32, D-33 and D-34 truss data sheets, is not required with this submittal.

747.1.6 Additional Information for Retaining Walls

747.1.6.1 Cast-in-place Retaining Walls

When the use of retaining walls along the shoulder line of a roadway is required, either in cut or fill sections, the same type of wall through the entire structure length is preferable rather than incorporating an "L" type at each end when height permits. In fill sections, a concrete safety barrier curb shall be provided and shall be tied into a concrete shoulder as a roadway item. In cut sections, a type B concrete traffic barrier shall be provided as a roadway item and placed against the retaining wall at the shoulder line. Provisions shall be made to attach standard bridge anchor section (thrie beam) to eliminate point obstacles where retaining walls end in cut or fill sections.

747.1.6.1.1 “L” Type Retaining Walls

The "L" type takes its name from being shaped like the letter "L." The footing of the wall may be placed under the proposed fill or as part of a paved shoulder and may or may not have a concrete safety barrier curb for traffic safety. Walls greater than 5 ft. in height are to be identified by a bridge number, which can be acquired from the Structural Resource Manager in the Bridge Division.

747.1.6.1.2 “Cantilever” Type Retaining Walls

This is a conventional reinforced concrete type wall supported by a spread footing or pile footing. "Cantilever" type walls greater than 5 ft. in height are to be identified by a bridge number which can be acquired from the structural resource manager in the Bridge Division.

747.1.6.2 Mechanically Stabilized Earth (MSE) Wall Systems

Description. Mechanically stabilized earth wall systems consist of a reinforced soil mass placed behind facing units. Types of MSE walls include small block and large block (panel). Information concerning the types, appropriate uses and design of MSE walls can be found in EPG 751.24 LFD Retaining Walls. Contractors are responsible for performing the design of MSE walls. Only the wall systems shown in the bridge prequalified products listing will be available for use by the contractor. The bridge prequalified products listing is available through the Bridge Division or on MoDOT’s website.

When NOT to Use MSE Walls. You must have adequate room behind the wall for the reinforcing straps (need horizontal clearance behind the wall of approximately 0.7 times the height). You also can NOT use MSE walls in locations where the underlying soil cannot support the weight of the fill and the wall (rare occurrence). This is determined by the District Geologist/Geotechnical Director.

Plans Developed by the District

Plans for MSE walls will be developed by the district unless they go under a bridge, in which case the Bridge Division will develop the plans.

The following table provides an overview of MSE wall design procedure:

Minimum Embedment - Minimum embedment is defined as the distance between the finished ground line and the top of the leveling pad. It is based on this table (FHWA Demo. #82):

The absolute minimum embedment is 2 ft. When the soundings are returned from the Geotechnical Director, they will include a minimum embedment necessary for global stability.

747.2 Bridge Rehabilitation and Widening

Bridge rehabilitation may include widening, redecking, superstructure replacement, repairs or other work necessary to restore an existing bridge to serviceable condition. When bridge rehabilitation of any type is proposed, consideration should be given to total structure rehabilitation.

747.2.1 Bridge Rehabilitation and Widening Submittals

747.2.1.1 Bridge Rehabilitation Checklist

For each structure that is to be rehabilitated a Structural Rehabilitation Checklist is completed along with descriptions and photographs of deteriorated members. Seldom are existing elevations and dimensions the same as shown on original structure plans. Thorough descriptions with photographs will aid the Bridge Division in recommending repairs and in estimating repair costs.

747.2.1.2 Additional Information for Bridge Superstructure Widening

The following information is to be provided when the bridge superstructure is to be widened:

Deck Elevations. Deck elevations at 10 ft. intervals at the centerline and gutterlines. The centerline elevations may be omitted if high traffic volumes are present and would represent a hazard to survey personnel.

Beam Seat Elevations. Substructure bearing beam elevations at each end of each substructure unit.

747.2.1.3 Additional Information for Bridge Substructure Widening

In addition to the Rehabilitation Checklist a complete Bridge Survey will also need to be submitted.

747.2.2 Bridge Rehabilitation Submittal Process

Structural Rehabilitation Checklists and associated documents are submitted as described in EPG 747.1.2.6 Bridge Survey Submittal Process.

747.2.3 Bridge Rehabilitation Submittal Timeline

Submit Structural Rehabilitation Checklist(s) at least 10 months prior to the Plan Completion Date (PCD) to allow time for applicable tests and structural checks. If more than 10 checklists are submitted for one project, the Structural Rehabilitation Checklist should be submitted at least 12 months prior to the PCD. When the rehabilitation of a bridge includes widening of the substructure, the submittal timeline will be as described in EPG 747.1.2.6.5, Bridge Survey Submittal Timeline.

747.3 Additional Correspondence, Reports and Permits

747.3.1 Bridge Memorandum

Upon receipt of the bridge survey or bridge rehabilitation checklist, the Bridge Division will review the data and make an in-depth analysis of the proposed crossing. The analysis may include hydraulic design of the waterway opening for stream crossings, geometric layout for grade separations, economic analysis of structure types and span lengths, and investigation of any special features evident from the data. If applicable a tentative bridge layout will be prepared.

A bridge memorandum will be prepared covering the details of the proposed bridge or bridge repairs.

The bridge memorandum is the instrument which coordinates bridge plan and roadway plan preparation. An electronic copy of the bridge memorandum is sent to the district for review and signature. If, during the design process, revision to the bridge memorandum by either the district or the Bridge Division becomes necessary, all parties to the memorandum are to be notified immediately. The proposed revisions must be agreed to by all parties that signed the original bridge memorandum. The process for establishing the agreement on the Bridge Memorandum is shown in EPG 751.1.2.18.5 Bridge/District Agreement Process.

747.3.2 Layout for Soundings

The purpose of the soundings (borings) is to define subsurface conditions at the project site. This information will be used to determine type of foundation (driven piles, pile cap footing, spread footings, drilled shafts), preliminary estimate of pile lengths and engineering design properties.

Upon receipt of the Layout for Soundings, the district design personnel assists in coordinating the survey staking of the boring locations for the geotechnical section.

747.3.3 Design Layout Sheet

Once the signed bridge memorandum and final sounding report is submitted to the Bridge Division the Design Layout sheet is created. An electronic copy of the Design Layout sheet is sent to the district along with plan and profile sheets reflecting the proposed structure.

The district will receive foundation details, quantities and a cost estimate from the Bridge Division to incorporate into the final project design.

747.3.4 Bridge Permits or Approvals by Other Agencies

Organized Drainage District. Written agreement documenting drainage district approval of the proposed structure layout is to be obtained by the district.

Railroads. Written approval from the railroad of proposed structure layout and of the final design plans is obtained by the Multimodal Operations Division with the cooperation of the Bridge Division.

U.S. Corps of Engineers Sec. 404 Permit. Application is initiated by the district, submitted to and further pursued by the Design Division with the cooperation of the Bridge Division.

U.S. Coast Guard Bridge Permit. When required, application is prepared and submitted by the Bridge Division.

Utility Relocations or Permits. Agreements are obtained by the district with cooperation, if necessary, of the Design Division and the Bridge Division.

FHWA Bridge Approvals. When FHWA preliminary bridge layout approval or bridge plan approval is required, written approval is obtained by the Bridge Division.

Flood Plain Development Permit. Bridge Division will prepare and submit the application to the State Emergency Management Agency.

FHWA, Missouri State Historic Preservation Officer (SHPO), Advisory Council on Historic Preservation (ACHP). Disposition of historically significant bridges to be replaced must be determined. Preservation of the historic bridge in place (rehabilitated or for alternative uses such as pedestrian walkway) must be considered.

Adverse effects to historically significant bridges from proposed rehabilitations also must be determined.

Determining the historical significance and the disposition of such bridges will be coordinated by Design Division Historical Preservation Staff.

The Request for Environmental Services (RES) should indicate existing bridges that will be affected by the project. Historical Preservation Staff will coordinate with the Transportation Project Manager to complete the evaluation.