Sand Creek Road Bridges Crook County Wyoming

<figure id='attachment_8173' style='max-width:1280px' class='caption aligncenter'><img class="size-full wp-image-8173" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of completed Sand Creek Road Bridge." width="1280" height="960" /><figcaption class='caption-text'> Figure 1. Completed Sand Creek Road Bridge.</figcaption></figure>Location: Sand Creek Road and Interstate 90; Crook County, Wyoming Owner: Federal Highway Administration’s Central Federal Lands Highway Division delivered this project as part of the FLAP (Federal Lands Access Program) for Crook County. Year Constructed: 2016 National Bridge Inventory (NBI) Numbers: DWV, DWU, DWR and DWN (four GRS-IBS bridges – 1, 2, 5, and 6) Crossing Type: Roadway bridge over stream Superstructure Type: Precast Concrete Girders Span: 38 feet (Bridge 1), 46 feet (Bridge 2), and 65 feet (Bridges 5 and 6) Maximum Wall Height: 13.4 feet (Bridge 1) Maximum Wall Width (edge to edge): 47 feet (Bridge 5) Skew: 0 degrees (Bridges 1 and 2) and 30 degrees (Bridges 5 and 6) Facing Type: Segmental Retaining Wall Average Daily Traffic (when constructed): 242 Contract Type: Design-Bid-Build Unique Project Feature: Project features both GRS-IBS and micropile supported bridgesBackground: The pristine Sand Creek Road is located in northeastern Wyoming near the South Dakota border. Located in Crook County, Sand Creek Road stretches through the Black Hills National Forest and runs adjacent to Sand Creek. A major access route within the Black Hills National Forest, Sand Creek Road has direct connections to Interstate 90 (I-90) to the north and Moskee Road to the south. Sand Creek Road is one of the only roads connecting a network of private residences and is the only access point to the Sand Creek Wildlife Habitat and Access Management Area. Situated approximately three miles south of the town of Beulah, the Sand Creek Wildlife Habitat and Access Management Area is a 284-acre area that provides a habitat for white-tailed deer and public fishing access to Sand Creek.<figure id='attachment_8174' style='max-width:1153px' class='caption aligncenter'><img class="size-full wp-image-8174" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Sketches of the project location. To the left, project general location, to the right, Source: Open Street Map, ESRI, FHWA." width="1153" height="578" /><figcaption class='caption-text'> Figure 2. (a) Project Location and (b) Sand Creek Road bridges. Source: Open Street Map, ESRI, FHWA.</figcaption></figure>Given the meandering nature of Sand Creek, Sand Creek Road crosses the creek at multiple locations. Six bridges, numbered from north to south and shown in figures 2a and 2b, are located at these crossings and are the focus of this case history. The first bridge (Bridge 1) in the series is located at mile post (MP) 3.4 while the last bridge of the series (Bridge 6) is located at MP 5.6. Mile post 0.0 marks the intersection of Sand Creek Road and I-90.In 2014, Central Federal Lands Highway Division of FHWA (CFL) partnered with Cook County to replace the Sand Creek Road bridges. The six Sand Creek Road bridges were timber bridges; all six were approaching the end of their design life and needed to be replaced with new bridges of greater capacity. The project, referred to as the Sand Creek Road Bridges Project, also involved aggregate resurfacing of six miles of Sand Creek Road. These improvements were expected to make the roadway safer for users and increase capacity. Additionally, improved roadway access to the Black Hills National Forest would facilitate fire suppression activities and increase the chances of preserving local flora and fauna. As a result, the Sand Creek Road Bridges Project was selected to be part of the Federal Lands Access Program (FLAP). FLAP was established to improve transportation facilities, such as Sand Creek Road, that provide access to, are adjacent to, or are located within Federal Lands.Deployment: Four of the six bridges (Bridges 1, 2, 5, and 6), were constructed using Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS). Prefabricated, prestressed concrete girders (see figure 3) were selected as superstructures for the bridges. The GRS-IBS technology was chosen for these bridge sites because of competent bearing material available at relatively low depth with favorable scour and hydraulic conditions. Given these site conditions, GRS-IBS was decided to be the most cost-effective system for four of the six bridges. The rapid construction associated with GRS-IBS was another reason why the technology was the best fit for these bridges. Even though the sites of the remaining two bridges (Bridges 3 and 4) were also underlain by low-depth, competent, bearing soils, their design involved cast-in-place abutments on deep foundations (micropiles) due to great scour depths (5.5 and 8.7 feet respectively) and the need for the deep foundations to extend below estimated scour depths. At all bridge sites, riprap was placed on top of the native streambed.<figure id='attachment_8175' style='max-width:1280px' class='caption aligncenter'><img class="size-full wp-image-8175" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of Prefabricated prestressed concrete girder supported by GRS abutments." width="1280" height="960" /><figcaption class='caption-text'> Figure 3. Prefabricated prestressed concrete girder supported by GRS abutments.</figcaption></figure>The new bridges were designed for a 50-year flood event with two feet of freeboard. Hydraulic analyses were performed using HEC-RAS. As the bridges are located in a seismic zone 1 according to ASSHTO LRFD Bridge Design Specifications, the peak ground acceleration (PGA) was determined to be 0.04g and was used for the design of the bridges. All bridges were designed to have two lanes with widths ranging from 28 to 32 feet and spans between 38 and 65 feet.Project Challenges and Solutions: The Sand Creek Road Bridges Project provides a good example of site conditions that are favorable for GRS-IBS as well as conditions with greater scour depths where shallow foundations are inadequate and deep foundations are necessary. The challenges discussed below pertain only to the project’s four GRS-IBS bridges. Though labeled as “challenges and solutions,” the discussion below highlights the versatility of GRS-IBS technology.Contractor’s first GRS-IBS project Prior to the bidding process, the Sand Creek Road Bridges Project contractor staff had some knowledge of the GRS-IBS concept but had never constructeda GRS-IBS bridge. The contractor did, however, have experience with a project involving similar elements (e.g., segmental retaining wall projects). During the bidding process, contractor staff used the education materials (e.g., manuals, webinars and videos) developed by Federal Highway Administration (FHWA) to become more familiar with the technology. Contractor staff found these materials to be very useful in submitting the winning bid package. During the construction phase, contractor staff benefited from high quality project plans and support documents prepared by seasoned CFL engineers. This collaboration, composed of the quick study contractor staff and the experienced CFL engineers, was a good fit for the project.Remote location The contractor had an office in Wyoming and was able to staff the project with mostly in-state residents. When it was necessary to hire craftsmen, the contractor focused the search on the local community, who proved to be competent and hardworking. Despite the remote site location, the contractor could procure all necessary materials from a few locations, including Spearfish and Rapid City in South Dakota. Typically, the resources, equipment, and craftsmen necessary for GRS-IBS construction are fairly common which makes their procurement straight forward. The familiarity of the contractor with the area also aided the construction process and working in a remote location presented its own benefits to the contractor. For example, reduced management of traffic when compared to working in a densely populated area was one of the benefits of working in the remote, rural area.Dewatering GRS-IBS abutments had to be constructed using dewatering. The materials within the abutment footprints consisted of gravels and cobbles in a sandy soil matrix and had high permeability. Controlling water infiltration into excavation under such conditions proved very difficult and several techniques were attempted before developing a successful dewatering system. At Bridge 6, sand bags with impervious fabric were used to prevent the water from flowing into the area excavated for the reinforced soil foundation (RSF). This method was successful in diverting water from Sand Creek but failed to prevent water from infiltrating the soil. At Bridges 2 and 5, culverts were initially used to divert the water (see figure 4), but the same problem persisted as at the Bridge 5 site. In the end, the soil infiltration issue was resolved by using several pumps in addition to the previously mentioned techniques to dewater the excavated area. Working efficiently to find a timely solution to this challenging dewatering problem helped the project team to avoid further delays.<figure id='attachment_8176' style='max-width:377px' class='caption aligncenter'><img class="size-full wp-image-8176" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Photograph of dewatering area of excavation using culverts and pumps." width="377" height="283" /><figcaption class='caption-text'> Figure 4. Dewatering area of excavation using culverts and pumps.</figcaption></figure>Segmental Retaining Wall Construction As the contractor did not specialize in Segmental Retaining Wall (SRW) construction, the contractor considered subcontracting this work. After soliciting and carefully evaluating SRW construction bids, the contractor concluded that it would indeed be quicker and more cost effective to subcontract this work. The winning subcontractor constructed the SRW using proprietary block, completing the wall on schedule and below budget. Upon conclusion of the Sand Creek Bridges Project, it was clear that hiring a subcontractor to complete the SRW work was the right decision.Conclusion: The Sand Creek Road Bridges Project was the first project in the state of Wyoming to use GRS-IBS technology. Considering the challenging dewatering conditions, the project was considered a success and proved to be a great way to introduce the state of Wyoming to GRS-IBS technology. To promote the GRS-IBS method and educate transportation officials and engineers about its advantages, FHWA held a showcase for the project. The event featured the four GRS-IBS bridges at various stages of construction (the bridges were constructed simultaneously) and was pronounced a major success by attendees, who were impressed with the versatility of the technology and its cost-saving potential. Based on the final project cost estimates, the costs of the GRS-IBS bridges were 14 to 19 percent less than the costs of micropile-supported bridges.FHWA’s Office of Federal Lands Highway (FLH) is divided into three regions (Eastern, Central and Western) and has completed several GRS-IBS projects as of this writing. In addition to the Sand Creek Road Bridges Project, FLH has successfully delivered the following GRS-IBS crossings: Province Lands Road over Province Lands Bike Trail in Provincetown, Massachusetts; Daniel K. Inouye Highway Underpass in Hawaii, Hawaii; Unpaved Trail over East Fork Kaweah River in Sequoia National Park, California; and, Toadstool Road over Sand Creek in Oglala National Grassland, Nebraska.Project Contact: Khamis Y. Haramy Lead Geotechnical Engineer Federal Highway Administration, Central Federal Lands Khamis.HARAMY@dot.gov (720) 963-3521Project Technical Paper: A technical paper has not been published for this project.REFERENCES“Federal Lands Access Program (FLAP)”, U.S. Department of Transportation Federal Highway Administration. Office of Federal Lands Highway. Retrieved from: <a href="https://flh.fhwa.dot.gov/programs/flap/">https://flh.fhwa.dot.gov/progr…;. Accessed May 22, 2017.“Plans of Proposed WY FLAP 129 (1). Sand Creek Road, Black Hills National Forest, Crook County” (construction drawings, U.S. Department of Transportation, 2013).“Sand Creek Access Area”, Wyoming Game and Fish Department. Retrieved from: <a href="https://wgfd.wyo.gov/accessto/access/sandcreek.asp">https://wgfd.wyo.go…;. Accessed May 22, 2017.“Sand Creek Bridge Project”, Crook County, WY. Retrieved from: <a href="http://www.crookcounty.wy.gov/departments/road_and_bridge/sand_creek_br…;. Accessed May 2, 2017.“WY FLAP 129(1), Sand Creek Road - Federal Project”, Government Tribe. Retrieved: <a href="https://govtribe.com/project/wy-flap-1291-sand-creek-road-1">https://go…;. Accessed May 2, 2017.Daniel Alzamora, phone conversation with the author of this document, May 16, 2017.Dominic Monarco, “Final Geotechnical Report”. WY 129 (1). Sand Creek Bridges. Central Federal Lands, January, 2015Khamis Haramy, email correspondence with the author of this document, May 22, 2017 and May 31, 2017.Ryan Owen, “Sand Creek Bridges Design Plans” (presentation, Wisconsin Department of Transportation).Veronica Ghelardi, “Hydraulics Report”. WY 129 (1). Sand Creek Bridges. Central Federal Lands, October 2014.

Title

Technology

Mechanically Stabilized Earth Wall System