Geofoam Applications in the Design and Construction of Highway Embankments (2004)

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11-1 CHAPTER 11 CASE HISTORIES Contents Introduction.................................................................................................................................11-2 Hawaii: Highway H-3 (Likelike Highway) Emergency Escape Ramp for the Kaneohe Interchange, Island of Oahu........................................................................................................11-2 Indiana: State Route 109, Noble County ....................................................................................11-5 New York: State Route 23a, Town of Jewett, Greene County ...................................................11-7 Utah: I-15 Reconstruction.........................................................................................................11-10 Washington: State Route 516 - Lake Meridian Settlement Repair, King County ....................11-13 Wisconsin: Bayfield County Trunk Highway A.......................................................................11-15 Wyoming: Moorcraft Bridge, Crook County............................................................................11-16 Wyoming: Bridge Rehabilitation, N.F. Shoshone River ..........................................................11-18 Other Cases and State DOT Experiences..................................................................................11-19 Connecticut ...........................................................................................................................11-19 Illinois ...................................................................................................................................11-19 Maine.....................................................................................................................................11-20 Michigan ...............................................................................................................................11-20 City Of Issaquah, Washington ..............................................................................................11-20 Summary...................................................................................................................................11-21 References.................................................................................................................................11-22 Figures ......................................................................................................................................11-24 Tables ..................................................................................................................................................... 11-46 ______________________________________________________________________________________

11-2 INTRODUCTION The following case histories are presented to provide examples of cost-effective and successful EPS-block geofoam projects completed in the United States (U.S.). Although the focus of this report is limited to stand-alone embankments that have a transverse (cross-sectional) geometry such that the two sides are more or less of equal height (see Figure 3.4), several case histories involving hillside (side-hill) fills (see Figure 3.5) are also presented because these case histories provide useful cost or construction data that are applicable to traditional embankment geometries. In addition, in practice there is usually little or no separation made in the discussion of lightweight fills that utilize EPS-block geofoam. Chapter 12 presents an analysis of the cost data presented in these case histories and a comparison with other soft soil construction techniques. The summary at the end of this chapter summarizes the benefits of geofoam and the placement rates observed in these case histories. These placement rates are important because they can be compared with soil fill placement rates to estimate the decrease in construction time with the use of geofoam and facilitate bidding by contractors that are not familiar with geofoam placement. Finally, the case histories presented in this chapter are intentionally limited to the United States to reflect U.S. construction pricing and practices. Of course, there are many international geofoam case histories that are referred to throughout the report. In some cases the figures that have been reproduced use either all Système International d’Unités (SI) or all inch- pound (I-P) units. These figures have not been revised to show both sets of units. However, Appendix F presents factors that can be used to convert between SI and I-P units. HAWAII: HIGHWAY H-3 (LIKELIKE HIGHWAY) EMERGENCY ESCAPE RAMP FOR THE KANEOHE INTERCHANGE, ISLAND OF OAHU This case history involves the construction of a 12 to 21 m (39 to 69 ft) high vehicle emergency escape ramp for the Likelike Highway on the island of Oahu, Hawaii. Project information for this case history was obtained from (1). The purpose of the vehicle emergency escape ramp is to provide an escape route in the event that vehicles experience brake failure as

11-3 they descend from the tunnel exit at an elevation of about 213.4 m (700 ft) to an elevation of 39.6 m (130 ft) at the intersection with the Kahekili Highway. The downslope grade of the Likelike Highway is six percent. The lower elevation portions of the ramp are underlain by approximately 6.1 m (20 ft) of very soft organic silt with natural water contents ranging from 80 to 120 percent. Undrained shear strengths ranged from 9.6 to 19.2 kPa (200 to 400 lbs/ft2). The upper elevation portions of the site consist of soft to medium stiff clayey silt with natural water contents ranging from 60 to 80 percent and standard penetration values ranging from 2 to 8 blows per 0.30 metre (2 to 8 blows per foot). Undrained shear strengths obtained from unconsolidated undrained triaxial compression tests ranged from 38.3 to 105.3 kPa (800 to 2,200 lbs/ft2). The water level was at the ground surface. The original embankment was to be constructed of geotextile reinforced tunnel spoil material or select granular material. However, due to the presence of very soft organic silt in the lower portion of the ramp, this embankment design would have required time for consolidation to occur and to prevent a slope failure. Alternatives for construction of the ramp included relocation, concrete supported structure on deep foundations, in-situ stabilization of the existing soils, and lightweight fill. Lightweight fill was selected because the contractor could continue to construct the embankment thereby preventing delays to the project. The types of lightweight fills that the project team considered included volcanic cinder (unit weight of 11.8 kN/m3 or 75 lbf/ft3), lightweight concrete geofoam (unit weight of 3.9 to 4.7 kN/m3 or 25 to 30 lbf/ft3), and EPS-block geofoam (unit weight of 0.2 to 0.3 kN/m3 or 1.25 to 2 lbf/ft3). Although all three lightweight fill materials had similar costs, the volcanic cinder option was not used because it was heavier than EPS and lightweight concrete. The project team selected EPS based on discussions with suppliers of both products, availability of materials, and available construction methods. EPS-block geofoam with a minimum specified density of 20 kg/m3 (1.25 lbf/ft3 ) was utilized for only a portion of the embankment. The bottom of the embankment below the geofoam

11-4 consisted of 0.6 to 1.5 m (2 to 5 ft) of clean gravel which served as a stabilizing layer for construction activities and as a drainage blanket for surface water and water discharged by the vertical strip drains installed to accelerate consolidation of the foundation soils. An approximate 4.6 m (15 ft) layer of geotextile reinforced basalt tunnel spoil was placed above the stabilization layer between June and November 1993. A 0.3 m (1 ft) thick gravel drainage blanket layer was placed above the reinforced basalt rock and underlying the first layer of geofoam blocks. Figure 11.1 presents a design cross-section of the roadway embankment. Approximately 13,470 m3 (17,618 yd3) of EPS (6,450 blocks, each 700 by 1,200 by 2,400 mm or 28 by 47 by 94 in.) were placed from early December 1993 to mid February 1994. If it is assumed that EPS block placement started on December 1, 1993 and was completed on February 14, 1994, the number of work days is 54 days if weekends are not included and 76 days if weekend days are included. Based on this assumption, the production rate for EPS block placement can be estimated to be between 175 and 250 m3 (229 to 327 yd3) per day or 85 to 120 blocks per day. The placement of EPS fill was not greatly affected by rainy weather. At Sta. 9+55 the geofoam thickness was approximately 6.7 m (22 ft). A 410 g/m2 (12 oz/yd2) non-woven polypropylene geotextile overlying a 60 mil thick textured high density polyethylene geomembrane was placed after every three layers of geofoam blocks. The purpose of the geomembrane was to protect the EPS blocks from any potential damage from a petroleum spill and the purpose of the geotextile was to reduce EPS damage from construction operations including the placement of 2.1 to 2.7 m (6.9 to 8.9 ft) of select granular fill over the geofoam. Placement of the select granular fill was completed by March 1994. Construction of the entire embankment was completed within 14 months. Sixteen settlement gauges were installed as part of the embankment monitoring system following placement of the initial stabilization layer. Settlement measurements obtained during construction ranged from 305 to 1,650 mm (12 to 65 in.) for embankment heights ranging from 4.6 to 12.2 m (15 to 40 ft), respectively. Most of this settlement occurred during the placement of

11-5 the granular stabilization layer, reinforced basalt rock, and gravel drainage blanket layer that were placed below the geofoam. These granular layers contributed to approximately 1.2 m (3.9 ft) of the 1.4 m (4.6 ft) of settlement that occurred at Sta. 9+55 during construction. The entire embankment height at Sta. 9+55 was 12.3 m (40 ft). The use of geofoam in the revised embankment design was successful because the embankment was completed ahead of the anticipated completion date and the use of geofoam significantly reduced ground settlement to tolerable levels and increased stability of the embankment (1). Figure 11.1. Trapezoidal embankment using geofoam and on-site material (1). INDIANA: STATE ROUTE 109, NOBLE COUNTY The Indiana Department of Transportation (DOT) reconstructed 335.3 m (1,100 ft) of Route 109 using EPS blocks with a density of 24 kg/m3 (1.5 lbf/ft3) (2). The roadway consists of two 3.7 m (12 ft) lanes with two 0.9 m (3 ft) shoulders for a total width of 9.1 m (30 ft). The foundation soil along the roadway consists of peat that extends to a maximum depth of 11.6 m (38 ft). Prior to reconstruction, continuous maintenance of the roadway had been required due to settlement of the embankment that was resulting in horizontal movement of the roadway and associated shear cracking of the pavement. In 1994, the side slopes were flattened but additional pavement cracking occurred and the Indiana DOT had to close the roadway to traffic. Remedial treatment procedures that the Indiana DOT considered included total removal and replacement of the peat with conventional fill material, soil modification, and partial removal and replacement with a lightweight fill material. The Indiana DOT decided to partially remove the peat to a maximum depth of 2.1 m (6.8 ft) and replace it and the embankment with EPS-block geofoam. The EPS embankment section consisted of a 102 mm (4 in.) maximum layer of sand, 380 to 1,520 mm (15 to 60 in.) layer of EPS blocks, 100 to 125 mm (4 to 5 in) thick reinforced concrete slab, 406 mm (16 in.) layer of No. 8 stone, and a 330 mm (13 in.) layer of an asphalt cement wearing surface. A 150 mm (6 in.) drain, wrapped in a geotextile, was placed at a depth

11-6 of 1.22 m (4 ft) below the pavement surface on both sides of the embankment. The pavement section design included sufficient dead weight to offset the hydrostatic uplift pressures from the 100 year flood. EPS block dimensions of 1.2 by 1.0 by 4.9 m (4 by 3.3 by 16 ft) were used. Figure 11.2 presents a design cross-section for the roadway embankment. Table 11.1 presents the construction schedule summary of the project. The total roadway reconstruction lasted 48 working days. The placement of the required 4,708 m3 (6,157 yd3) of EPS blocks was completed in only 11 days. This is a placement rate of about 428 m3 (560 yd3) per day. New Holland Model No. 553 skid-steer loaders were used to transport the EPS blocks to the edge of the fill and a dolly was then used to carry the blocks to the required location. Figure 11.2. Trapezoidal geofoam embankment detail (2). Table 11.1. Construction Schedule Summary for State Route 109, Noble County, Indiana (2). A cost comparison between the EPS embankment option that was used and the total removal and replacement of the peat is included in Table 11.2. As shown in Table 11.2, the estimated cost of the removal and replacement option would have been $339,617 (about 28 percent) more than the EPS embankment option. Additional benefits of using EPS over a total removal and replacement (TRR) option that are not included in the cost comparison include: a shorter construction time than that required for the TRR procedure, no dewatering which was probably necessary for the TRR procedure, less pavement maintenance than that required with the TRR procedure due to settlement that may have occurred within the proposed 11.6 m (38 ft) thick soil fill, no cost of sheet piles or additional right of way that would have been required for the TRR procedure, and completion before winter so no construction stoppages which might have occurred with the TRR option because EPS can be placed in most weather conditions. Neglecting these benefits results in a volumetric cost of the EPS ($86/m³ or $66/yd³) exceeding the cost of TRR ($12/m³ or $9/yd³) as shown in Table 11.2. However, it is clear that DOTS are recognizing

11-7 these tangible benefits, e.g., reduced construction time, because EPS was selected over TRR and the total cost is 28 percent less than the TRR option. Settlements measured forty-three months after pavement placement were between 0.05 and 0.09 m (0.18 and 0.29 ft). Pavement performance parameters were also measured. A Pavement Condition Rating of 94.5 indicated that the pavement was in the excellent range. The International Roughness Index of 89 also indicated that the pavement was in the excellent range. Rutting measured was approximately 1 mm (0.04 in.) which is minor. In summary, the closed roadway was able to open quicker, for less cost, and will probably remain open longer than a soil embankment because geofoam was used. Table 11.2. Cost Comparison Between EPS and Removal/ Replacement Alternatives for State Route 109, Noble County, Indiana (2). NEW YORK: STATE ROUTE 23A, TOWN OF JEWETT, GREENE COUNTY This case history involves the use of EPS-block geofoam to stabilize a roadway embankment on an unstable slope and is presented because cost information is available from (3,4). The site is located in a mountain valley and slopes downwards from north to south. Based on the results of two borings performed on both sides of the roadway, the subsurface soils at the centerline of the roadway consist of about 1.5 m (5 ft) of gravelly silt fill. The underlying native soils consist of approximately 4.3 m (14 ft) of layered clayey silt and silty clay overlying 10.7 m (35 ft) of clayey silt. The water table was located at a depth of 2.44 m (8 ft) in the clayey silt and silty clay or approximately 4.0 m (13 ft) below the pavement surface. Figure 11.3 presents a profile of the all soil embankment and subsurface soils A 91.4 m (300 ft) section of Route 23A became unstable after the roadway was reconstructed in 1966. These movements resulted in a continuous maintenance problem and traffic hazard. In 1979, horizontal drains were installed to lower the groundwater table. However, slope movements continued. Lateral movements measured over a period of 14 years after the drains were installed totaled 203.2 mm (8 in.). Inclinometer data indicated that the failure surface

11-8 was about 11 to 12.2 m (36 to 40 ft) below the roadway surface which corresponds to the clayey silt layer. Figures 11.4 and 11.5 present a plan and profile view of the scarp, respectively. Consequently, in 1994, the New York State DOT (NYSDOT) evaluated the following remedial measures: soil removal and replacement with EPS blocks (weight reduction) and installing drainage, placement of a berm at the toe of the slope, use of a shear key, relocation of the roadway uphill away from the failure zone, lowering the grade and installing stone columns, and soil nailing. The NYSDOT selected the weight reduction and drainage option because it considered the other alternatives impractical due to limitations imposed by the site and its environment and/or considered the other alternatives too costly. Figure 11.3. Profile of all soil embankment and subsurface soils (3). Figure 11.4. Plan view of scarp (3). Figure 11.5. Profile of failure surface (3). Figure 11.6 presents a cross-section of the EPS-block geofoam embankment. Sheeting was required to support the excavation during soil removal and replacement due to the depth of soil removal required and the need to maintain one lane of traffic opened at all times adjacent to the excavation. The EPS-block geofoam fill system was designed against hydrostatic uplift because Schoharie Creek is located on the south side of the slope. Based on the 100-year flood, the depth of geofoam that could be used was limited to 4.6 m (15 ft). A subsurface drainage system was placed below the geofoam to lower the groundwater table and to maintain a positive drainage path. The drainage system consisted of a 0.61 m (2 ft) thick layer of graded crushed stone with a network of 152.4 mm (6 in.) diameter perforated polyethylene drainage pipes embedded in the stone. Both the stone and pipes are exposed on the embankment-slope face. The crushed stone also provided a working platform and a level surface for the placement of the geofoam blocks. Figure 11.6. Profile of EPS-block geofoam embankment (3).

11-9 The EPS blocks were placed in mid-November 1995 and all construction was completed in January 1996. The blocks, which had dimensions of 0.61 by 1.22 by 2.44 m (2 by 4 by 8 ft), were delivered to the site on flatbed trailers. About 76.5 m3 (100 yd3) of blocks arrived per truckload. Blocks were unloaded by two laborers and carried and placed by four persons. The average placement rate was 1 hr to unload and place a trailer load of 40 blocks. This is a placement rate of 76.5 m3 (100 yd3) per hour or about 382.5 m³ (500 yd³) per day. Two metal barbed inter-block connector plates were placed on each block. One plate was placed in the center and the second plate was placed near an edge to approximate a 1.22 m (4 ft) grid pattern. A 101.6 mm (4 in.) thick reinforced concrete slab was placed over the geofoam. A minimum of 0.61 m (2 ft) of subbase material consisting of graded crushed-stone subbase was placed over the concrete cap. This minimum thickness of subbase material was based on the Norwegian experience to minimize potential problems of differential pavement icing. A supplemental measure utilized by the NYSDOT to minimize differential icing included the use of a subbase material with 25 to 60 percent passing the 6.35 mm (1/4-in.) sieve to provide a high heat-sink capacity. The pavement consisted of 228.6 mm (9 in.) of asphalt concrete. The quantity of EPS fill that was initially estimated was 3,115.7 m3 (4,075 yd3). The bid price for the EPS block was $85.01 per m3 ($65 per yd3). However, only 2,817.6 m3 (3,685 yd3) of geofoam was used because the sheeting was driven 0.61 m (2 ft) off-line toward the excavation. In order to compensate for the reduced amount of soil removed, additional soil fill was placed along the toe of the slope. The removal of 2,817.6 m3 (3,685 yd3) of soil and replacement with geofoam resulted in a net reduction of driving weight of about 5,352.5 Mg (5,900 tons) and an increase in factor of safety of 1.0 to over 1.5. No significant movements have been recorded in slope inclinometers between the end of construction and December 1998. Piezometers installed within the crushed stone drainage blanket below the geofoam have indicated no pore pressure buildup since installation in November 1995. The NYSDOT is obtaining readings twice a year during wet periods of the year to monitor pore

11-10 pressure buildup that may indicate that the drainage blanket is clogged and thus serve as an early warning of rising water table which may cause uplift of the geofoam. No differential icing during the winter nor pavement deterioration, due to slight temperature increases that have been recorded by thermistors in the subbase during the summers, have been observed between the end of construction and December 1998. UTAH: I-15 RECONSTRUCTION The design-build contractor utilized various soil improvement techniques as part of the I-15 reconstruction in Salt Lake County, Utah. These techniques included prefabricated vertical drains (PVD), lime-cement columns (LCC), EPS-block geofoam, embankment surcharging, geotextile reinforced slopes, and mechanically stabilized earth (MSE) walls (5). The I-15 construction, includes a total of 27 km (17 mi) of highway reconstruction and 142 rebuilt or new bridge structures at a cost of $1.59 billion and was scheduled to be completed by July 15, 2001 (6). The project involves replacing the existing six- lane highway with a 12-lane highway. The use of a design-build contractor has allowed the use of these soil improvement techniques, which had not been used by the Utah DOT (6). The subsurface soils along the I-15 construction consist of soft clays with low undrained shear strength and high compressibility (7). Settlements of up to 1.5 m (5 ft) were estimated in certain embankment sections with the use of conventional borrow material (7). Staged construction using MSE walls are being utilized in areas of large settlement. However, geofoam is being used as an alternative to MSE walls in certain locations to minimize settlement damage to buried utility lines that underlie the proposed embankment (5). Where geofoam is used, settlement of less than a few centimeters (1 in.) is expected (5). The benefits of using geofoam in utility corridors include the cost and time savings associated with utility replacement and service interruption if damage occurs due to settlement and cost of not having to relocate the utility (5). The secondary use of geofoam has been as an alternative to granular backfill for MSE walls that are 10 to 14 m (33 to 46 ft) high due to stability concerns, scheduling problems, and/or

11-11 geometry constraints (5). A typical MSE wall requires about 6 months of construction and observation time before the rigid pavement can be placed (5). This time includes foundation preparation, prefabricated vertical drain installation, wall construction, and surcharging. A vertical "geofoam wall" system with an exterior tilt-up panel facing can be constructed in 1 month. This time includes minor foundation preparation, geofoam placement, tilt-up panel wall placement, and a reinforced concrete slab placement on top of the geofoam. Approximately 100,000 m3 (130,795 yd3) of EPS-block geofoam will be used as part of the I-15 reconstruction (8). Figures 11.7 through 11.9 present typical construction details for the geofoam walls. Because the I-15 project is a design-build project, a cost breakdown was not reported to the Utah DOT. However, based on discussions with the contractor, the Utah DOT provided the following approximate cost information (9). The cost of EPS block is about $65 per m3 ($50 per yd3) and $75 per m3 ($57 per yd3) for a system without and with a facia wall, respectively. Thus, the facia wall system can be estimated at $10 per m3 ($7 per yd3). The reinforced concrete slab being utilized above the EPS blocks is about $55 per m2 ($5 per ft2) for a typical 150 mm (6 in.) slab. Placement rates ranged from approximately 200 blocks per day for one crew for one shift to 350 blocks per day for two shifts (9). This corresponds to a placement rate of 470 m³ (615 yd³) for one shift and 940 m³ (1,230 yd³) for two shifts per day based on a block size of 0.8 m × 1.2 m × 4.9 m (2.6 ft × 4 ft × 16 ft). A crew is defined as four laborers and a foreman. Various soil improvement techniques in addition to the use of EPS-block geofoam were utilized as part of the I-15 reconstruction. Cost information on these alternate methods is presented in Chapter 12. In (9), it is reported that the cost of the tilt-up-panel-facia wall is approximately $200 per m2 ($19 per yd2). The cost for non-geofoam MSE walls are about $335 per m2 ($31 per ft2) of wall face (10). This includes a cost for the prefabricated vertical drains of about $35 per m2 ($3 per ft2) of wall face. The cost of the prefabricated vertical drains is based on an average width of embankment treatment of 16 m per m (52.5 ft per 3.3 ft) of wall, prefabricated vertical drain

11-12 installation depth of 25 m (82 ft), rectangular drain spacing of 2 m (6.6 ft) or 4.5 drains per lineal m of wall (1.4 drains per ft), a typical 8 m (26 ft) high MSE wall, and a cost of $2.50 per lineal m ($0.76 per lineal ft) of drain installed. Figure 11.7. Construction detail for a vertical EPS wall (11). Figure 11.8. Detail for traffic barrier and load distribution slab (12). Figure 11.9 Detail for precast concrete wall panels for a vertical EPS wall (13) Lime-cement columns (LCCs) were utilized to support an MSE wall Number SS-01. LCCs were utilized because of concerns about a potential slope failure into an adjacent commercial property due to the extreme height of the fill, accelerated construction schedule, and the close proximity of the Utah DOT right-of-way to the face of the wall (5). Wall heights ranged from 10 to 12.5 m (32 to 41 ft). A surcharge of 3 m (9.8 ft) was placed above the top of the finished wall to pre-compress the soils beneath the tips of the columns so the differential settlement criteria established for the roadway could be satisfied (14). Columns of about 22 m (72 ft) in length and 600 to 800 mm (24 to 32 in.) in diameter were used. The wall face is supported by LCC panels that consist of overlapping 800 mm (32in.) columns spaced at 2 m (6.6 ft) center- to-center spacings. These panels extend 2 m (6.6 ft) in front and 2 m (6.6 ft) behind the wall (14). The fill behind the walls are supported on 600 mm (24 in.) individual columns placed in a rectangular spacing of between 1 m (3.3 ft) and 1.2 m (3.9 ft). As the I-15 project progressed, the contractor decided not to utilize LCC because of concerns about adequate installation production rates (5). The reported cost of the LCC support system is $30 per m ($9 per ft) and that on average this would suggest a cost of $60 per m3 ($46 per yd3) (15). It is indicated in (14) that LCC costs ranged from $45 to $65 per m3 ($34 to 50 per yd3) of column. The cost of LCC depends on the spacing of the columns needed for stabilization. The LCC process did not result in spoils being brought up to the ground surface so no costs associated with spoil disposal were incurred. Settlement on the order of 100 mm (3.9 in.), which is about one-tenth of the normal settlement

11-13 experienced for MSE walls placed on untreated soil, has been reported for the LLC support system (5). WASHINGTON: STATE ROUTE 516 - LAKE MERIDIAN SETTLEMENT REPAIR, KING COUNTY This project utilized a vertical EPS-block embankment with a treated wood face to reconstruct a portion of an embankment that was experiencing settlement problems. Project information was obtained from the Washington State DOT (WSDOT). In 1993, the WSDOT performed a widening program of SR 516 from 132nd Ave. SE to 160th Ave. SE. The project is located approximately 40 miles southeast of the city of Seattle. The initial design consisted of raising the north shoulder by about 305 to 457 mm (12 to 18 in.) and placing 457 to 914 mm (18 to 36 in.) of new fill on the existing slope. In order to accommodate the eastbound (north side of the embankment) traffic during bridge construction on the westbound side (south side of the embankment), the WSDOT widened the existing north shoulder by about 0.6 to 1.2 m (2 to 4 ft) with quarry spalls. This shoulder widening changed the existing embankment slopes from an existing 1.5H:1V to 2H:1V. Movement was observed in the westbound lane soon after placement of the new rip-rap fill on the existing slope. The WSDOT estimated that settlement on the order of 76 to 102 mm (3 to 4 in.) occurred from the time the rip-rap was placed in April 1993 to mid June 1993 when a monitoring program was initiated. Vertical and horizontal movements of 33 mm and 25 mm (1.3 and 1 in.), respectively, were measured between June and September 1993. The geotechnical report dated November 12, 1993 (16) indicates that the movements were likely caused by embankment settlement and lateral displacement into the underlying and adjacent peat and possibly from vibrations induced by pile driving and traffic. The WSDOT considered five alternatives for stabilizing the embankment. These options included continued monitoring, removing some of the rip-rap and constructing a reinforced fill embankment, retaining the fill embankment with sheet piles or soldier piles along the north edge of the slope,

11-14 constructing a structural boardwalk for the sidewalk, and constructing a half bridge on the north side of the roadway. The monitoring approach was selected in the anticipation that movements would decrease to acceptable levels with time. A concrete sidewalk was constructed along the north side of the embankment. However, up to 0.10 m (0.33 ft) of vertical and 0.11 m (0.36 ft) of lateral movement was measured from July 1994 to February 1995 in the sidewalls. A memorandum dated May 3, 1995 (17) indicates that vertical and lateral displacements of 0.21 m (0.68 ft) and 0.25 m (0.82 ft), respectively, had occurred between Sta. 152+00 to 153+50 and vertical and lateral displacements of 30 mm (0.1 ft) and 46 mm (0.15 ft) had occurred in the remainder of the sidewalk between Sta. 149+50 and 154+00. There was concern that the sidewalk would become unsafe and if future movements occurred at the same rate, the roadway pavement and the underlying water lines would become distressed. The WSDOT decided to replace a portion of the earth embankment with EPS blocks. Figure 11.10 shows the typical elevation and plan view of the EPS block repairs. Block sizes of 0.76 by 1.22 by 2.44 m (2.5 by 4 by 8 ft) were utilized. Two types of EPS embankment sections were used. Repairs from Sta. 152+00 to 154+00 consist of the first layer of EPS blocks extending 1.83 m (6 ft) horizontally from the facing system and Sta. 149+50 to 152+00 consist of the first layer of EPS blocks extending 1.22 m (4 ft) horizontally from the facing system. The second layer of EPS in both sections extends 2.44 m (8 ft) horizontally from the wall face. A 510 mm (2 in.) layer of sand was placed below the EPS blocks as a leveling layer in all locations. A 0.15 m (6 in.) concrete cap was placed on top of the EPS. A minimum of 2 timber fasteners per block was specified between blocks. The facing system for the vertical wall consists of 92 by 92 mm (4 by 4 in.) treated wood posts spaced at 1.8 m (6 ft) center-to-center and extending 0.76m (2.5 ft) below the proposed subgrade level. Treated wood lagging (40 by 143 mm or 2 by 6 in.) was placed horizontally between the vertical posts. Figure 11.11 presents a photograph of the treated wood facing system.

11-15 The wood facing was placed before the EPS blocks and the EPS blocks were subsequently placed against the wood facing. Pea gravel meeting the gradation requirements of AASHTO No. 8 coarse aggregate was used to backfill the void between the wall of the cut and the EPS blocks. The lowest bid price for the 410.6 m3 (537 yd3) of EPS blocks was $105.94 per m3 ($81 per yd3). Although some lateral and vertical movement occurred during the February 28, 2001 Nisqually earthquake, the EPS embankment did not sustain any damage. Figures 11.12 and 11.13 present photographs of the embankment during construction and after the completion of construction, respectively. Figure 11.10. Details of EPS-block vertical-faced fill used for the S.R. 516 repair in King County, Washington (Washington State Department of Transportation). Figure 11.11. Photograph of treated wood facing system (Washington State Department of Transportation). Figure 11.12. Photograph of geofoam used to support a sidewalk on top of an earthen embankment (Washington State Dept. of Transportation). Figure 11.13. Photograph of completed EPS-block geofoam fill (Washington State Department of Transportation). WISCONSIN: BAYFIELD COUNTY TRUNK HIGHWAY A This case history involves the use of EPS-block geofoam as a hillside fill to repair a slow- moving landslide that had persisted for over 20 years (18). The Bayfield County Trunk Highway A in northern Wisconsin was 45 m (148 ft) wide and had a slope of approximately 14 degrees in the landslide area. The height of the embankment was 5 m (16 ft). The glaciolacustrine soils below the embankment consist of very soft, highly plastic clays and silts. The failure surface identified by an inclinometer is 6.1 m (20 ft) below grade and sliding was occurring in the soft, highly plastic clays and silts. The roadway was frequently patched due to the occurrence of tension and lateral shear cracks that developed within the asphalt pavement.

11-16 In addition to the lightweight fill alternative, excavation of the soils within the slide mass and replacement with granular fill was also considered. However, the total excavation alternative was not selected because it would require excavation below the groundwater level and temporarily closing the highway. Soil from the head of the slide was removed and replaced with EPS-block geofoam. The geofoam had a density of 24 kg/m3 (1.5 lbf/ft3) and dimensions of 0.81 by 1.22 by 2.44 m (2.7 by 4 by 8 ft). Three layers of EPS blocks were used. A drainage blanket consisting of 0.3 m (1 ft) of free-draining sand conforming to Wisconsin Department of Transportation Section 209, Grade 1 and a system of 200 mm (8 in.) diameter slotted plastic pipe was placed below the EPS blocks. The drain pipes were placed parallel to the road at the back of the excavation as well as transverse to the road at 15 m (50 ft) intervals. The transverse pipes extended from the parallel pipe at the back of the excavation to the embankment face. An impermeable membrane was placed on top of the geofoam as protection against petroleum spills. The top of the geofoam was kept at a depth of 1.5 m (4.9 ft) below the final pavement surface to minimize the potential for differential icing conditions. The fill placed over the EPS blocks and the sides of the embankment consists of free-draining sand. The installed cost of the EPS block was $61.50 per m3 ($47.00 per yd3). EPS-block geofoam was also used to remediate two other landslides along Bayfield County Trunk Highway A but cost information is not available for these applications. WYOMING: MOORCRAFT BRIDGE, CROOK COUNTY EPS-block geofoam was used as fill for both approaches for the Moorcraft bridge located along I-90 in Crook County, Wyoming in the summer of 1993. Project information was supplied by the Wyoming DOT and also obtained from (19). Two layers of EPS blocks with a density of 24 kg/m3 (1.5 lbf/ft3) were placed overlying a thin layer of 25 to 50 mm (1 to 2 in.) of crushed rock and pea gravel on the east and west abutments, respectively (19). Figure 11.14 presents a photograph of the EPS-block geofoam blocks used. The bottom EPS layer extended 10.4 m (34 ft) horizontally from the abutment and the upper EPS layer extended 10.7 m (35 ft)

11-17 from the abutment, about 3 m (10 ft) beyond the approach slab. A polyethylene geomembrane was placed on top of the geofoam to protect against petroleum spills. A 305 mm (12 in.) layer of sand was placed between the concrete approach slab and the geomembrane. The approach slab extended 7.6 m (25 ft) from the abutment and had a thickness of 3 m (1 ft) and a width of 12.5 m (41 ft). An asphalt cement pavement was placed on top of the concrete slab. Rings of barbed wire 100 mm (4 in.) in diameter were used as inter-block fasteners because the timber fasteners did not arrive on time (19). Figure 11.14. Photograph of EPS-block geofoam used for the Moorcraft bridge approach (Wyoming Department of Transportation). The main objective of the project was to reduce the differential settlement occurring at the abutment/embankment interface which had to be annually leveled. The initial project design consisted of a MSE wall approach fill. The approach design was subsequently changed to EPS block geofoam for the purpose of providing a full scale instrumental field test to obtain technical data on the use of EPS as bridge approach fill and facilitate future use by the DOT (19). The Wyoming DOT estimated the cost for the MSE wall approach fill design to be $58,696 while the cost of the EPS block approach fill option was $79,732, or $21,036 (28 percent) more than the original MSE wall option. This cost includes $37,000 for material and labor for the EPS blocks, geomembrane, sand base, as well as labor to drill holes in the abutment for monitoring instrumentation. Because this was one of the first EPS-block bridge approach projects in Wyoming, the higher cost of the EPS-block alternative could be attributed to the lack of familiarity by local contractors and probably did not consider the full benefits of the ease and speed of EPS-block placement and the possible placement of EPS blocks in adverse weather conditions. A cost comparison between the EPS-block and MSE systems is included in Table 11.3. A total of 377 m3 (493 yd3) of EPS blocks were utilized of which 65 m3 (85 yd3) were donated by the supplier. MSE walls had been utilized by the Wyoming DOT for over five years. The estimated volumetric costs for the EPS and MSE walls are $17.30 and $9.60 per m³ of wall.

11-18 Table 11.3. Cost Comparison Between EPS and MSE Approaches for the Moorcraft Bridge Structure. WYOMING: BRIDGE REHABILITATION, N.F. SHOSHONE RIVER This project involved the rehabilitation of approaches to a bridge over the N.F. Shoshone River in Wyoming. Project information was provided by the Wyoming DOT (Wyoming DOT Project No. 031-1[68]) . The actual date of construction was estimated to be between 1997 and 1999. Two types of bridge approach fills were used below the approach slabs. One approach fill consists of EPS block geofoam and the other consists of an MSE wall (20). The bridge abutments are skewed approximately 55 degrees from the centerline of the bridge roadway. Both approach slabs have a surface area of 88 m2 (947 ft2) and a corresponding width of 6.24 m (20 ft) as measured normal to the abutment or 55 degrees from the roadway centerline. Both approach slabs consist of a 255 mm (10 in.) thick concrete slab and an overlying 50 mm (2 in.) thick bituminous pavement layer. The depth of the EPS block approach fill system is 3 m (9.8 ft) at the centerline of the bridge roadway and includes 50 mm (2 in.) of sand below the EPS blocks, 2.7 m (9 ft) of EPS blocks and 205 mm (8 in.) of sand at the top of the blocks. The fill extends 2.5 m (8 ft) horizontally from the abutment and then slopes at 1(H):1(V). The density of EPS blocks used is 24 kg/m3 (1.5 lbf/ft3). The depth of the MSE wall approach system is 2.65 m (8.7 ft) at the centerline of the bridge roadway. The fill extends 3 m (9.8 ft) horizontally from the abutment then slopes at 1.8(H): 1(V) for a horizontal distance of 3.24 m (10.6 ft) as measured from the bottom of the fill and 1(H):1(V) for the remaining horizontal distance of 750 mm (30 in.). Figures 11.15 and 11.16 present details of the EPS-block geofoam bridge approach. Figure 11.15. Detail for geofoam backfill behind the bridge abutment (23). Figure 11.16. Detail of bridge approach pavement system over geofoam (24). Table 11.4 provides a summary of the bridge approach costs for the EPS and MSE alternatives. The estimated volumetric costs for the EPS and MSE walls are $202 and $100 per

11-19 m³ ($154 and $76 per yd3) of wall. Although the cost of using an EPS approach fill is $9,330 (32 percent) higher than the MSE wall, the EPS block approach fill system was used on one side because of its speed of construction and because of its lightweight properties (21). The higher cost of the EPS approach alternative may have been due to unfamiliarity of the EPS construction procedure by local contractors (22). OTHER CASES AND STATE DOT EXPERIENCES Connecticut The Connecticut DOT recently awarded a contract to construct an embankment that involves placing expanded-shale aggregate over EPS-block geofoam. The cost of the EPS-block geofoam will be $98.09 per m3 ($75 per yd3) and the cost of the expanded shale aggregate will be $13.08 per m3 ($10 per yd3) . These unit prices include placement. Table 11.4. Cost Comparison Between EPS and FRS Approaches for the N.F. Shoshone Bridge Structure. Illinois Based on information obtained from the Illinois DOT several problems occurred during construction on an embankment that utilized EPS-block geofoam as lightweight fill. The embankment is a four-lane state roadway (143rd Street) in Orland Park, Illinois. The embankment consists of about 1.22 m (4 ft) of geofoam in the inner lanes (part of the roadway that was reconstructed) and 1.52 m (5 ft) of geofoam in the outer lanes (new widened area). The project began in 1999 and was to be completed in 2000. A total of approximately 15,291 m3 (20,000 yd3) of EPS blocks were to be used in the embankment. The placement rate for the first phase of the project was approximately 313 m3 per day (410 yd3 per day). The first problem encountered involved the initial shipment of EPS blocks not meeting the specified density of 24 kg/m3 (1.5 lbf/ft3). The second problem involved hydrostatic uplift of part of the geofoam embankment during a heavy rainfall. A crack developed in the concrete cap, which was already in-place when uplift occurred, along the 1.22 to 1.52 m (4 to 5 ft) geofoam thickness transition line. Pumping

11-20 costs associated with providing temporary dewatering during construction to minimize the potential for uplift re-occurring was greater than anticipated. Figure 11.17 presents a cross-section of the EPS-block geofoam roadway and Figures 11.18 and 11.19 present details of the storm drain pipe and guardrail used with the EPS-block geofoam roadway embankment. Figure 11.17. Cross-section through geofoam embankment containing a storm drain and guardrail (25). Figure 11.18. Detail of storm drain pipe in geofoam embankment (26). Figure 11.19. Detail for guardrail on top of geofoam embankment (27). Maine Based on a personal communication with the Maine DOT in 1999, the cost provided by a manufacturer for only geofoam blocks that were proposed for an embankment project was $57.21 per m3 ($43.74 per yd3) (28). This unit cost is a freight-on-board (FOB) site unit price and does not include placement. Michigan Table 11.5 below is a summary of the bids obtained from the Michigan DOT in 1999 for two embankment projects. No further project information was supplied. These projects involve the use of EPS-block geofoam for both bridge approaches and embankments. This data indicates a volumetric cost for the EPS embankment of $220 per m³ ($168 per yd³) in Project 1 and $1,160 per m³ ($887 per yd³) in Project 2. This large difference in volumetric cost in the same state illustrates the importance of obtaining site specific cost estimates. Table 11.5. Unit Bid Prices for EPS Projects in Michigan. City of Issaquah, Washington Approximately, 1,835 m3 (2,400 yd3) of EPS-block geofoam was used for an approach fill on a bridge replacement project in 1995. The city of Issaquah is approximately 15 miles southeast of the city of Seattle. EPS was used instead of a surcharge procedure with prefabricated vertical drains because the use of EPS was cost competitive and the bridge approaches could be

11-21 constructed within one construction season as opposed two construction seasons for the surcharge option. The cost of the EPS block was $59 per m3 ($45 per yd3) and $72 per m3 ($55 per yd3) installed. Thus, the EPS installation cost was about $13 per m3 ($10 per yd3). Figures 11.20 through 11.22 provide photographs showing the placement of the EPS-blocks, concrete separation layer, and utilities. Although the bridge approach embankments settled approximately 50 mm (2 in.) because of liquefaction of the foundation soils, the bridge approaches did not experience damage due to any shifting of the blocks during the February 28, 2001 Nisqually earthquake. Nearby roadways that did not include EPS experienced more damage. Figure 11.20. Placement of EPS blocks (City of Issaquah, WA). Figure 11.21. Placement of concrete separation layer over the EPS blocks (City of Issaquah, WA). Figure 11.22 Placement of utilities on top of sand base overlying the EPS blocks (City of Issaquah, WA) SUMMARY This chapter of the report presents case histories of geofoam usage in transportation applications that can be utilized to assess whether or not the proposed use is similar to prior uses. These case histories illustrate the many intangible or non-quantifiable benefits of geofoam that result in DOTs selecting geofoam over less costly and more traditional techniques. Some of these benefits include reduced placement time which is illustrated in Table 11.6 that presents observed geofoam placement rates, placement in adverse weather conditions, decreased maintenance costs because of smaller differential settlements, reduced lateral stress on bridge approach abutments, use of a vertical embankment which reduces right-of-way requirements, negligible impact on underlying utility corridors, excellent seismic behavior, elimination of surcharging and/or staged construction, excellent durability.

11-22 Table 11.6. Summary of Placement Rates of EPS-Block Geofoam in Embankment and Slope Repair Projects. REFERENCES 1. Mimura, C. S., and Kimura, S. A., “A Lightweight Solution.” Geosynthetics '95 Conference (1995: Nashville, Tenn.) Conference Proceedings, Nashville, Tenn., Vol. I (1995) pp. 39-51. 2. Zaheer, M. A., “Experimental Feature Study The Use of Expanded Polystyrene (EPS) in Pavement Rehabilitation S.R. 109 in Noble County, Indiana.” Indiana Department of Transportation Materials and Tests Division, Indianapolis (1999) 17 pp. 3. Jutkofsky, W. S., “Geofoam Stabilization of an Embankment Slope, A Case Study of Route 23A in the Town of Jewett, Greene County.” Geotechnical Engineering Bureau, New York State Department of Transportation, Albany (1998) 42 pp. 4. Jutkofsky, W. S., Sung, J. T., and Negussey, D., “Stabilization of an Embankment Slope with Geofoam.” Transportation Research Record 1736, Transportation Research Board, Washington, D.C. (2000) pp. 94-102. 5. Bartlett, S. F., “Research Initiatives for Monitoring Long Term Performance of I-15 Embankments, Salt Lake City, Utah.” Proceedings of the 34th Symposium on Engineering Geology and Geotechnical Engineering, Utah State University, Logan, Utah, (1999) pp. 54-67. 6. Warne, T. R., and Downs, D. G., “All Eyes on I-15.” Civil Engineering, Vol. 69, No. 10 (October 1999) pp. 42-47. 7. Gunalan, K. N., Lee, T. S., and Sakhai, S., “Stage 1 Geotechnical Studies for Interstate 15 Reconstruction Project, Salt Lake County, Utah.” Proceedings: Fourth International Conference on Case Histories in Geotechnical Engineering, St. Louis, Missouri, (March 9-12, 1998) pp. 458-468. 8. Negussey, D., “Putting Polystyrene to Work.” Civil Engineering, Vol. 68, No. 3 (March 1998) pp. 65-67. 9. Bartlett, S., Negussey, D., Kimble, M., and Sheeley, M., “Use of Geofoam as Super- Lightweight Fill for I-15 Reconstruction (Paper Pre-Print).” Transportation Research Record 1736, Transportation Research Board, Washington, D.C. (2000) . 10. Bartlett, S. F., Personal Communication,7 October 1999. 11. “Typical Section Geofoam (EPS) Wall.” I-15 Corridor Reconstruction, Elev.-Geofoam Wall (8 m - 11 m), Corridor Standard Plan, Utah Dept. of Transportation (1998) pp. CS- 77. 12. “Load Distribution Slab Restraint Section.” I-15 Corridor Reconstruction, Elev.- Geofoam Wall (8 m - 11 m), Corridor Standard Plan, Utah Dept. of Transportation (1998) pp. CS-80. 13. “Precast Wall Panel.” I-15 Corridor Reconstruction, Elev.-Geofoam Wall (8 m - 11 m), Corridor Standard Plan, Utah Dept. of Transportation (1998) pp. CS-44. 14. Esrig, M. I., and Kenna, P. E. M., “Lime Cement Column Ground Stabilization for I 15 in Salt Lake City.” Proceedings of the 34th Symposium on Engineering Geology and Geotechnical Engineering, Utah State University, Logan, Utah, (April 28-30, 1999) pp. 29-52. 15. Elias, V., Welsh, J., Warren, J., and Lukas, R., “Ground Improvement Technical Summaries.” Publication No. FHWA-SA-98-086, 2 Vols, U.S. Department of Tranportation, Federal Highway Administration, Washington, D.C. (1999) .

11-23 16. “Report Supplemental Geotechnical Engineering Services Area G-SR 516 Roadway Improvements King County, Washington, For Washington State Department of Transportation.” GeoEngineers, Inc., Redmond, WA (1993) 23 pp. 17. Allen, T. M., and Jenkins, D. V., Memorandum to R.Q. Anderson and T. Hamstra , SR- 516, C.S. 1738, OL-2297, Lake Meridian Embankment Settlement Repair, Expanded Polystyrene (EPS) Fill,3 May 1993. 18. Reuter, G., and Rutz, J., “A lightweight solution for landslide stabilization.” Geotechnical Fabrics Report, Vol. 18, No. 7 (September 2000) pp. 42-43. 19. Preber, T., and Bang, S., “Field Application and Instrumentation of Expanded Polystyrene Blocks as Bridge Backfill.” Proceedings of the 1995 Annual Symposium on Engineering Geology & Geotechnical Engineering (No. 31), Logan, Utah, (1995) pp. 84- 102. 20. Price, J. T., and Sherman, W. F., “Geotextiles Eliminate Approach Slab Settlement.” Public Works, (January 1986) pp. 58-59. 21. Hager, G. M., Personal Communication,8 November 1999. 22. Fulton, K., Personal Communication, 27 August 1999. 23. “Section A-A (Abut No. 1).” Approach Slab No. 1 Details, Bridge Rehabilitation Bridge Over N.F. Shoshone River US 14,16,20 (P-31), KP 51.50 (MP 32.01), Wyoming Dept. of Transportation (1997) pp. Sheet 9. 24. “Section B-B, C-C, D-D.” Approach Slab No. 1 Details, Bridge Rehabilitation Bridge Over N.F. Shoshone River US 14,16,20 (P-31), KP 51.50 (MP 32.01), Wyoming Dept. of Transportation (1997) pp. Sheet 10. 25. “Sta. 77+00 to 81+00.” 143rd Street Expanded Polystyrene Foam Typical Sections and Details, Illinois Dept. of Transportation (1998) pp. Sheet 25B. 26. “EPS Layout Beneath Storm Sewer.” 143rd Street Expanded Polystyrene Foam Typical Sections and Details, Illinois Dept. of Transportation (1998) pp. Sheet 25D. 27. “SPB Guardrail Type A. Special.” 143rd Street Expanded Polystyrene Foam Typical Sections and Details, Illinois Dept. of Transportation (1998) pp. Sheet 25D. 28. Breskin, K., Personal Communication,30 November 1999.

FIGURE 11.1 PROJ 24-11m.doc 11-24

FIGURE 11.2 PROJ 24-11m.doc 11-25

FIGURE 11.3 PROJ 24-11m.doc 11-26

FIGURE 11.4 PROJ 24-11m.doc 11-27

FIGURE 11.5 PROJ 24-11m.doc 11-28

FIGURE 11.6 PROJ 24-11m.doc 11-29

FIGURE 11.7 PROJ 24-11m.doc 11-30

FIGURE 11.8 PROJ 24-11m.doc 11-31

FIGURE 11.9 PROJ 24-11m.doc 11-32

FIGURE 11.10 PROJ 24-11m.doc (a) Elevation view. (b) Plan view 11-33

FIGURE 11.11 PROJ 24-11m.doc 11-34

FIGURE 11.12 PROJ 24-11m.doc 11-35

FIGURE 11.13 PROJ 24-11m.doc 11-36

FIGURE 11.14 PROJ 24-11m.doc 11-37

FIGURE 11.15 PROJ 24-11m.doc 11-38

FIGURE 11.16 PROJ 24-11m.doc 11-39

FIGURE 11.17 PROJ 24-11m.doc 11-40

FIGURE 11.18 PROJ 24-11m.doc 11-41

FIGURE 11.19 PROJ 24-11m.doc 11-42

FIGURE 11.20 PROJ 24-11m.doc 11-43

FIGURE 11.21 PROJ 24-11m.doc 11-44

FIGURE 11.22 PROJ 24-11m.doc 11-45

TABLE 11.1 PROJ 24-11m.doc Activities Dates Excavation 10/11/95 to 10/26/95 EPS Placement 10/11/95 to 10/26/95 Concrete Slab Placement 10/23/95 to 10/27/95 No. 8 Aggregate Placement 11/2/95 to 11/8/95 Asphalt Base, Binder & Surface 11/22/95 to 11/29/95 Road Opened to Traffic 12/15/95 11-46

TABLE 11.2 PROJ 24-11m.doc Items EPS Embankment (Plan) Total Removal & Replacement (Option) Quantity Unit Unit Cost in U.S. Dollars Cost in U.S. Dollars Quantity Unit Unit Cost in U.S. Dollars Cost in U.S. Dollars Common Excavation 2,318.9 (3,033) m³ (yd³) $5.23 ($4.00) $12,132 2,318.9 (3,033) m³ (yd³) $5.23 ($4.00) $12,132 Peat Excavation 7,703.7 (10,076) m³ (yd³) $5.23 ($4.00) $40,304 77,256.7 (101,048) m³ (yd³) $5.23 ($4.00) $404,192 Borrow Fill 0 0 $0 $0 81,119.3 (106,100*) m³ (yd³) $6.54 ($5.00) $530,500 Concrete Slab 3,066.1 (3,667) m2 (yd2) $40.66 ($34.00) $124,678 0 0 $0 $0 EPS Block 4,708 (6,157) m³ (yd3) $86.58 ($66.20) $407,593 0 0 $0 $0 Compacted Crushed Aggregate No. 8 Stone 1,360.8 (1,500) Mg (ton) $16.53 ($15.00) $22,500 0 0 $0 $0 Total Cost $607,207 $946,824 Notes: -The unit cost of peat excavation does not include cost for wet excavation, excavation using dredge line, peat disposal, etc. However, if this cost is added to the peat excavation then the cost of total removal and replacement option will be higher. -* To estimate the fill volume, 5% is added to the volume of cut. - Borrow fill is sand fill. 11-47

TABLE 11.3 PROJ 24-11m.doc ITEM UNIT UNIT COST QUANTITIES for MSE Wall QUANTITIES for EPS Wall MSE COST EPS COST Misc.Force Account Work - - - - $15,000 $37,000 Dry Excavation m³ (yd³) 15.70 (12.00) 1,192.7 (1,560) 1,529.1 (2,000) $18,720 $24,000 Bridge Approach Backfill m³ (yd³) 20.93 (16.00) 856.3 (1,120) 642.2 (840) $17,920 $13,440 Bridge Approach Fill Reinforcing Fabric m2 (yd2) 1.67 (1.40) 4,214.1 (5,040) 3,160.6 (3,780) $7,056 $5,292 TOTAL $58,696 $79,732 11-48

TABLE 11.4 PROJ 24-11m.doc EPS Block Approach Costs MSE Approach Costs Item Quantity Unit Cost Cost Quantity Unit Cost Cost Dry Excavation 210 m³ (275 yd3) $18.00 ($13.76) $3,780 230 m³ (300 yd3) $18.00 ($13.76) $4,140 Bridge Approach Backfill Material 20 m³ (26 yd3) $30.00 ($22.94) $600 210 m³ (275 yd3) $30.00 ($22.94) $6,300 Geotextile for Foundation Separation 110 m² (132 yd2) $6.75 ($5.64) $742 0 0 $0 Geotextile for MSE 0 0 $0 850 m³ (1112 yd3) $1.75 ($1.34) $1,487 Expanded Polystyrene Blocks 146 m³ (191 yd3) $104.00 ($79.52) $15,184 0 0 $0 HDPE Geomembrane 200 m² (239 yd2) $4.50 ($3.76) $900 0 0 $0 Reinforced Concrete Approach Slab 88 m² (105 yd2) $96.00 ($80.27) $8,448 88 m² (105 yd2) $96.00 ($80.27) $8,448 Underdrain Pipe (Perforated) 150 mm 6 m (20 ft) $34.50 ($10.52) $207 4.5 m (15 ft) $34.50 ($10.52) $155 Underdrain Pipe (Non- Perforated) 150 mm 15 m (49 ft) $31.00 ($9.45) $465 15 m (49 ft) $31.00 ($9.45) $465 Total Cost = $30,326 Total Cost = $20,995 11-49

TABLE 11.5 PROJ 24-11m.doc Project Quantity of EPS m3(yd3) Bid A Unit Price $/m3($/yd3) Bid A Total Bid $ Bid B Unit Price $/m3($/yd3) Bid B Total Price $ 1 1,052 (1,376) 52.50 (40.14) 1,960,244 43.00 (32.88) 2,202,666 2 4,919 (6,434) 58.50 (44.73) 5,696,731 50.00 (38.23) 5,970,269 11-50

TABLE 11.6 PROJ 24-11m.doc Project Application Placement Rate of EPS-Block Geofoam per Day Hawaii Embankment 175 – 250 m³ (229 – 327 yd³) Indiana Embankment 428 m³ (560 yd³) New York Slope Repair 382 – 383 m³ (500 yd³) Utah I-15 Embankment 470 m³ (615 yd³) Illinois Embankment 313 m³ (410 yd³) 11-51