VIARNG JFHQ_Geotechnical Report_Bid Final 100 _050611.pdf

Virgin Islands Army National Guard Project Number: 520034 Estate Bethlehem, St. Croix Joint Force Headquarters [100%] Bid-Final Submission 06-May-2011

Prepared by Jacobs

APPENDIX C

Geotechnical Engineering Report

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LAW & ASSOCIATES, INC. e-mail: law-associates@law-associates.com Civil & Geotechnical Engineering, Materials Testing Telephone : (321) 235-9105 Land Surveying & Environmental Services Fax : (866) 267-1882

1480 O’Berry Hoover Road • Orlando • Florida • 32825

September 30, 2009

Jacobs Facilities, Inc.

1100 North Glebe Road, Suite 500 Arlington, Virginia 22201

Attention: Mr. Chuck Harris, P.E.

Subject: GEOTECHNICAL INVESTIGATION, PROPOSED JOINT FORCES

HEADQUARTERS, V.I. ARMY NATIONAL GUARD, ST CROIX, UNITED STATES

VIRGIN ISLANDS (LA09-01.4600)

Dear Mr. Harris:

Law & Associates, Inc. is pleased to submit this geotechnical engineering report for the proposed Joint Forces Headquarters at the VI Army National Guard Facility on St Croix, USVI.

The investigation indicates that the proposed buildings can be constructed on the site provided that adequate site preparation and foundation design is performed. Our evaluation of the subsurface conditions indicate that the buildings can be supported on a shallow foundation.

The attached report provides details on the subsurface conditions, evaluation of the site suitability and recommendations for foundation support design. Law & Associates, Inc should be retained to inspect the foundation installation to verify that it meets with the recommendations presented in this report.

We appreciate the opportunity to provide our services on this project and trust that the data and recommendations are clear and understandable. Should there be any questions on the report content or if we can be of further assistance, please call.

Very truly yours, LAW & ASSOCIATES, INC.

Donald S. Law, P.E., MBA President Florida Registration No. 45286

Attachments Location Plan - Sheet 1 Soil Profiles - Sheet 2

PROPOSED JOINT FORCES HEADQUARTERS

VI ARMY NATIONAL GUARD

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Introduction

Law & Associates, Inc conducted a geotechnical investigation for the proposed Joint Forces Headquarters

(JFHQ) at the Estate Bethlehem facilities of the Virgin Islands Army National Guard. This report presents the scope of work performed and the findings of the investigation. We also present our evaluation of the site conditions and suitability for the proposed development, together with recommendations for site preparation, foundation design and pavement support.

Site Description

The site is located near the center of the island of St Croix in Estate Bethlehem. It is off of Centerline Road on RT 707. The property is approximately 41 acres in area and is developed into several buildings. The buildings generally occupy the east area of the property. Along the west portion of the site there is approximately 17 acres of undeveloped land. This area is the designated site for the Regional Training Institute buildings.

Topography and Vegetation: This area of the property has a covering of tall grasses with scattered trees. The south area is more densely vegetated with shrubs and trees. There are small square buildings in the approximate center of this area. The ground surface within the proposed development area varies from approximately +114 feet to +96 feet. The grade slopes generally from the northwest corner of the property towards the south and east sides of the property. There is mound of soil in the north portion of the development area. The top of this mound is about +112 while the surrounding grade is between +105 and +108 feet. As a comparison, the ground surface elevation of the existing development on the east portion of the property ranges from +102 to +84 feet.

Regional Geology: The bedrock of the virgin islands was formed in the Cretaceous period between approximately 145 to 65 million years ago. This layer is comprised of the Caledonia formation, the Cane

Valley Formation and the Judith Fancy Formation. The Judith Fancy Formation is the youngest layer of this

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Land Surveying & Environmental Services zone. These rock formation are tuffaceous rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. There are some igneous rocks located in Windsor in the Northside range and

Recovery Hill in the East End Range.

The center of the Island of St Croix is considered a graben structure, which is the result of a block of land being downthrown producing a valley with a distinct scarp on each side. Graben structures are indicative of tensional forces and crustal stretching.

Above the rocks of the Cretaceous period is the Jealousy Formation which was deposited during the Eocene era (55 to 34 million years ago). The top of the Jealousy Formation slopes southeastward from about 100 feet above sea level on the northeast to 200 feet or more below sea level at the southern coast. The layer is approximately 1400 feet thick and is characterized by blue, green and gray clays.

The Kingshill Limestone lies on the Jealousy formation and was deposited between 23 to 5 million years ago in the Miocene era. This layer is about 600 feet thick and is comprised of porous, deep-water limestone and marl, calcareous clay, and some conglomerate. It is the most important aquifer on the island of St Croix.

Overlying the Kingshill Limestone in the southern and western parts of the central plain are unnamed post-Kingshill carbonate strata that consist of shallow-water calcareous sediments of limestones and minor dolomite of Pliocene age (5 to 2 million years ago) with some silt, sand, and gravel.

Alluvial material, including sandy to clayey river valley deposits, alluvial fan, debris flow, colluvial deposits, and beach terraces, overlies the Kingshill Limestone and unnamed post-Kingshill carbonate rocks. The alluvial material thickens southward to a maximum of about 80 feet, whereas silt- and clay-rich alluvial fan and debris flow deposits are usually less than 30 feet in thickness.

Proposed Development: The Joint Forces Headquarters (JFHQ) building has a foot print of approximately

38,000 square feet. It is located north of the proposed Regional Training Institute on the subject site. The

JFHQ will be a two-story block structure with the foundation comprised of perimeter wall footings and column

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Land Surveying & Environmental Services footings, as well as interior column footings. The anticipated maximum structural loads are reported as follows.

Column Loads 230 Kips

Wall Loads 15 Kips/LF

Floor Slab Live Load 100 psf

There will be paved parking areas associated with the building and a perimeter road around the entire development. An underground Cistern will be constructed near the southwest corner of the proposed building.

Purpose and Scope

The purpose of performing this investigation was to explore the subsurface soil and ground water table conditions beneath the proposed building and provide recommendations for foundation support. The geotechnical drilling of the site was performed by Caribbean Drilling Services under our supervision.

In order to accomplish this task, we drilled and sampled a total of nine (9) Standard Penetration Test (SPT) borings within the building footprint and the surrounding pavement areas. The borings were advanced to depths of 2 to 25 feet. The building SPT borings are identified as TB-1B through TB-9B. Six(6) Standard

Penetration Test (SPT) borings were performed within the roadway and parking areas. These were advanced to depths of 6 to 15 feet. The pavement SPT borings are identified as B-10S through B-15S. The approximate locations of the borings are identified on the Location Plan on Sheet 1. The soils encountered in the borings are presented in the form of Soil Profiles on Sheet 2.

Subsurface Exploration

Drilling Methods - The Standard Penetration Test borings were sampled in general accordance with the procedures of ASTM D-1586 using the open-hole rotary drilling method. Soil samples and corresponding SPT penetration resistance (N-values) were obtained throughout the profile using a split-barrel sampler driven by a 140-pound hammer, falling 30 inches.

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The soil samples recovered from the borings were visually examined in the field with representative samples sealed in airtight containers and transported to the Caribbean Drilling Services laboratory for further soil classification by a geotechnical engineer.

Laboratory Inspection and Testing

The soil samples were classified in accordance with the Unified Soil Classification System (USCS), ASTM

D-2288. The laboratory test results and the classification of the soils samples are indicated in the soil profiles in Sheet 2 attached to the report. The soil descriptions and the symbols used in the USCS system are shown on the Legend on Sheet 2.

The laboratory test included the determination of the natural moisture content in accordance with ASTM D-

2216. This method calculates moisture content by dry weight. The results are reported in the nearest 1%. The soil particle distribution was conducted in accordance with ASTM D-422 and the percent finer than the US

No 200 sieve was determined in accordance with ASTM D-1140. The Liquid and Plastic Limits were determined in accordance with ASTM D-4318.

Evaluation of Subsurface Conditions

USDA SCS Soil Survey - The soils in the vicinity of Estate Bethlehem were mapped by the USDA Soil

Conservation Service and published in the Natural Resources Conservation Service (NRCS) Reports. This survey reports that the soil types in the vicinity of the Virgin Islands Army National Guard Armory are comprised of Hogensborg Clay Loam 2 to 5 percent slopes (Hgb), Sion Clay Loam 0 to 2 percent slopes (SiA), Sion Clay Loam 2 to 5 percent slopes (SiB) and Glynn Gravel Loam (GyB). A brief description of these soils are presented below.

Hogensborg Clay Loam (HgB): The Hogensborg component makes up 85 percent of the map unit. This component is on terraces and on coastal plains, alluvial fans on coastal plains. The parent material is clay sediments. The depth to a root restrictive layer is greater than 60 inches. The natural drainage class is well

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Land Surveying & Environmental Services drained. Water movement in the most restrictive layer is low. Available water to a depth of 60 inches is high.

Shrink-swell potential is very high. The soil is not flooded. It is not ponded. There is no zone of water saturation within 72 inches. Organic matter content in the surface horizon is about 5 percent. It is in

Hydrologic Soil Group D.

Sion Clay Loam (SiA, SiB): This soil makes up 85 percent of the map unit. This component is on valley floors on coastal plains. The parent material is alcaline marine deposits. The depth to a root restrictive layer is greater than 60 inches. The natural drainage class is well drained. Water movement in the most restrictive layer is moderately high. Available water to a depth of 60 inches is high. Shrink-swell potential is low. There is no zone of water saturation within 72 inches. Organic matter content in the surface horizon is about 4 percent.

The soil does not meet Hydric criteria. It is in Hydrologic Soil Group B.

Glynn Gravelly Loam (GyB): The Glynn gravelly loam makes up 85 percent of the map unit. This component is on alluvial fans on uplands, terraces on uplands. The parent material is made up of stratified alluvial sediments weathered from volcanic residuum. The depth to a root restrictive layer is greater than 60 inches.

The natural drainage class is well drained. Water movement in the most restrictive layer is moderately high.

Available water to a depth of 60 inches is moderate. Shrink-swell potential is moderate. The soil is not flooded. It is not ponded. There is no zone of water saturation within 72 inches. Organic matter content in the surface horizon is about 4 percent. It is in Hydrologic Soil Group C.

Soil Stratigraphy - The general stratigraphy in the area of the borings performed for this study is comprised of brown silty sand, bluish-gray gravel (Strata 2) and bluish gray rock (Strata 8) in the upper 15 feet below the ground surface. Below this surface material we encountered light brown to light gray silty clay (Strata 5) and light brown and orange, mottled, silty clay (Strata 6) to the termination depth in most borings. Penetration through the upper rocky material was not achieved in some areas.

A more detailed description of the soils encountered is presented on Sheet 2. Please note that although the boring logs indicate distinct strata breaks, the actual transition between the soil layers may be gradual.

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The SPT below counts (N-values) were recorded during drilling. These values are presented adjacent to the soil profiles on Sheet 2. With the exception of the near surface soils, the materials encountered are in a medium dense to very dense condition. The N-values recorded during drilling ranged from 7 blows per foot

(bpf) to more than 50 blows per penetration of 3 inches.

Groundwater Conditions - The ground water table was not encountered in the boreholes at the time of the drilling operation. The stabilized water levels were measured again after more than 24 hours and the water level was not encountered in the boreholes. The water table elevation is influenced by on-site soils, nearby drainage features, tidal fluctuations, relief points, site improvements, etc. The groundwater table will typically attain its highest level near the end of the rainy season. Based upon the soil types encountered, the antecedent rainfall and the measured water levels, we anticipate that the normal seasonal high water table (SHWT) will be greater than 10 feet below existing grade. However, based upon the presence of silty to clayey fine sands near the surface, we anticipate that water runoff will remain perched on these soils for some time after rainfall events.

Engineering Evaluations and Recommendations

General Discussion

Based upon the findings of the investigation, we believe that the site can be made suitable for the support of the proposed buildings and pavement areas. With the exception of the near surface topsoil, no organic soils were encountered within the depth of the borings performed. The soils within the depth of the proposed foundations are comprised of silt, clay and gravel and rock. It will be difficult to work with and achieve compaction in the silt clay soils since they tend to retain moisture in excess of the soils optimum moisture.

Also, due to the nature of the soils encountered, the excavation for the buildings foundation will be in gravelly silt and hard rock. More than typical foundation soil preparation is anticipated for this project in order to make the site suitable for the support of the buildings. Recommendations for foundation design and foundation-related site preparation are presented in the following subsections.

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Earthwork Considerations

Clearing and Grubbing - The construction area should be cleared and grubbed to remove all existing vegetation, topsoil, buildings, construction debris, and other unsuitable materials buried under the ground surface. These operations should be completed to a minimum distance of 5.0 feet beyond the limits of the construction area. The depth of grubbing and stripping should be determined in the field based on visual observations and proper judgement. The spoil generated during these operations should be removed from the site and disposed of as directed by the owner.

Site Grading - The final grading plan of the site should allow for a minimum vertical separation of 18 inches between the estimated SHWT and the bottom of the floor slabs of the proposed structures and base layers of any pavement. This separation is recommended between these features and any clay layers that is encountered near the surface and cannot be adequately compacted. This may require local excavations and/or filling with suitable compacted fill while controlling both surface water and groundwater, as needed, to perform site grading in dry conditions. During construction, the area should be graded to direct surface runoff away from the structures and temporary excavations.

Excavation - Temporary side slopes of excavations above the water table may stand near vertical for short periods. Side slopes of excavations to 10 feet should be laid back at 2 Horizontal to 1 Vertical or flatter. Side walls of excavation deeper than 10 feet should be protected by a method designed by a registered engineer.

The contractor should follow all recent OSHA safety requirements for excavation.

Excavation of rock layers near the surface may be accomplished by using hydraulic jack hammers. Blasting may be used, only if approved by the local authorities and by experienced contractors.

Suitable Fill - Suitable fill required for site grading and backfilling should be comprised of clean, non-plastic sands containing less than 15 percent passing the U.S. No. 200 Sieve. The fill should be free of topsoil, roots, organic material, rocks larger than 2 inches, debris, trash or other objectionable material that may be

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Land Surveying & Environmental Services compressible, degradable or which cannot be compacted properly. On-site material that contains rock pieces larger than 2 inches in nominal diameter should be crushed to 2 inches or less before using as structural fill.

Fill Placement and Compaction - The fill should be placed in relatively level lifts, dried or wetted as needed, and then compacted to a minimum density of 95 percent of the Modified Proctor Maximum dry density (ASTM

D-1557) unless otherwise specified. The lifts should not exceed 12 inches in loose thickness if compaction is performed by a heavy vibratory roller and 6 inches if an approved hand-operated compaction plate is used.

Sheep-foot rollers may be required on the soils that contain more than 15 percent fines. Vibratory rollers should not be used in a vibratory mode within 75 feet of any existing structures without vibration monitoring.

Where the final subgrade level is in the dense rock, no compaction is required.

Foundation Support

Foundation Loading Conditions - The structural data provided suggests that the maximum column loads are expected to be 230 kips. The wall loads will be on the order of 10 kips per linear foot with a maximum load fo 15 kips per linear foot. These loads are considered moderately heavy. If the foundation soils are prepared as recommended, the proposed buildings may be supported on a shallow foundation designed to support the factored building loads.

Subgrade improvement - The soil in the vicinity of TB-1, TB-2, TB-3 along the south footing of the proposed building is comprised of a dense rock layer near the surface. Penetration of this layer was not achieved using the conventional drilling methods. Based upon the borings performed in the other areas of the site, the rock is anticipated to be approximately 6 to 10 feet thick. The footings for the JFHQ will be embedded in this material. Excavation of the rock may be accomplished as recommended above.

We recommend that the subgrade soils below the proposed foundation in the areas away from the rock layer, be compacted and tested to a minimum density of 95 percent of the Modified Proctor Maximum dry density

(ASTM D-1557) for a minimum depth of 3.0 feet below the foundation elements. This operation should extend to a minimum margin of 3.0 feet beyond the footing width. Because of the silty to clayey conditions

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Land Surveying & Environmental Services encountered in the borings, we anticipate that it will be difficult to achieve compaction in the existing foundation soils. We believe that it will be necessary to over-excavated the foundation soils to a minimum depth of 3 feet and replaced with suitable material in order to achieve uniform compaction. It is the intent of this recommendation that there be a minimum of 3.0 feet of compacted and tested soil beneath all foundation elements.

Net Allowable Bearing Pressure - Provided that the foundation soils are prepared as recommended, the structure can be supported on a shallow foundation comprised of column and wall footings designed using a net allowable bearing pressure of 3000 pounds per square foot or less. The wall and column footings should have a minimum width of 36 inches, regardless of the net bearing pressure. Each footing should have a minimum embedment depth of 30 inches as measured from the bottom of the footing to the lowest adjacent finished grade.

Uplift Resistance - Uplift resistance for the footings will be provided by the dead loads applied on the footings and by soil backfill placed above the footings. Soil resistance may be calculated as the weight of soil backfill above the footing plus the shearing resistance along the vertical face of the soil prism. Alternatively, it may be calculated as the weight of the soil prism defined by a diagonal line drawn from the top of the footing to the ground surface at an angle of 30 degrees to the vertical. Additional uplift resistance, if needed, can be realized by increasing the footing weight, the embedment depth or by anchoring the footings. A minimum factor of safety of 1.5 should be used against uplift.

Seismic Considerations - Since the Island of St Croix is subjected to occasional earthquake forces, the building should be designed to account for lateral earthquake forces. Liquefaction of the subgrade soils is a concern for buildings foundations in earthquake zones. However, liquefaction is a concern when the foundation soils are predominantly loose, saturated sand deposits. The groundwater table at the subject site is deeper than 40 feet as measured in the borings performed on the site. Also, the soils are in a medium dense to very dense conditions and has a relatively high percent of silts and clays. As a result, we anticipate that the liquefaction potential is low to nil.

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The site class was evaluated using the Standard Penetration Test N-Values and the site class definitions of the

International Building Code (IBC) and the National Earthquake Hazard Reduction Program (NEHRP). Based upon the consistency of the soil profile and the combination of rock and stiff soil, we estimate that the site can be categorized as Site Class C.

Foundation Settlement - Provided that the subgrade soils are prepared as recommended and with the foundation designed and constructed as recommended, we anticipate the total foundation settlements will be one inch or less, given the loading conditions detailed earlier. The differential settlements that occur between adjacent unequally loaded foundations are not expected to exceed one half inch. These settlement estimates are based upon foundation loads not exceeding 200 kips. Should loads exceed this number, we should be notified so that we can re-evaluate the settlement estimates. We anticipate that the majority of the settlement will occur as the building loads are applied.

Slabs-on-grade - The soils beneath the slab-on-grade should be compacted as recommend above fo r a minimum depth of 12 inches. Where the silty to clayey soils are difficult to compact at the slab subgrade level, this material should be replaced with suitable compacted soils as recommended earlier in this report. We recommend the use of a vapor barrier beneath the floor slabs to minimize moisture entry through the slabs.

A plastic or vinyl membrane (minimum 6 mils thickness) may be used for this purpose. The membrane should be protected from damage during construction and concrete placement.

The floor slab should be designed with steel mesh or fiber-reinforced concrete to minimize temperature cracking. Proper curing methods should be initiated immediately after placement of the concrete to minimize cracking due to hydration. The floor-slab may be designed with adequate joints or saw-cuts to control cracking.

Elevator Pits and Cisterns: The elevator pits and cisterns for the proposed buildings will likely be embedded in the gravelly soils encountered. Depending upon the location and invert elevation of these features, the excavation may encounter the very dense rock. Appropriate, approved construction methods should be used to excavate the rock.

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The walls of the elevator pits should be waterproofed using industry standards and methods. The elevator pits should also be designed to resist uplift. We recommend that the base slab of the pit be extended beyond the perimeter walls to assist in uplift resistance. The uplift resistance can be calculated as described earlier in this report.

Lateral Earth Pressures : Any wall that is used to support backfilled soils should be designed to support the lateral loads. For the design of rigid walls that are not free to rotate, we recommend that the "at rest" earth pressure be calculated using an equivalent fluid pressure of 60 pounds per cubic foot (pcf) above the water table and 30 pcf below the water table. Where retaining walls are free to rotate at the top, the "active" earth pressure should be calculated using an equivalent fluid pressure of 40 pcf above the water table and 20 pcf below the water table. In each of these designs, hydrostatic forces must be considered. If a uniform surcharge is applied to the top of the walls, this will produce an additional lateral pressure along the wall equal to about

1/3 the vertical contact pressure.

Lateral Resistance : Lateral forces applied to footings may be resisted by the passive pressure mobilized on the buried face of the footing and by friction along the base of the footings. The passive pressure produced by compacted granular backfill can be taken as that equivalent to the pressure exerted by a fluid weighing 350 pcf above the water table and 180 pcf below the water table.

A coefficient of friction of 0.42 may be used for calculating the frictional resistance along the base of cast-in-place concrete footings. Additional lateral resistance may be realized by designing the retaining wall footings with a "key" at the base and mobilizing the passive resistance along the vertical face of the key.

The values presented presume that the footings are surrounded by well-compacted, suitable soil with a moist unit weight of approximately 115 pcf and that the footings can withstand small movements on the order of 1/4 inch. A factor of safety of at least 1.5 is also recommended in the design.

Pavement Support

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General Requirements: The pavement area should be cleared, grubbed, graded as needed and the subgrade compacted as recommended below, prior to pavement construction. A minimum separation of 18 inches should be maintained between the bottom of the base layer and the wet season water level or perched water levels. If this separation is not provided, we recommend the use of underdrains to protect the pavement from groundwater-related damage.

In order to promote proper drainage for the pavement section, we recommend that the clayey soil encountered in the upper profile be removed and replaced. Further recommendations for suitable pavement materials are presented in the following subsections of this report.

The pavement may be designed in accordance with the Department of the Army Corps of Engineers Methods.

For the purpose of design, we assume that the traffic composition will be Category III. This includes small trucks and a few heavy trucks. We anticipate that the Average Daily Traffic (ADT) will be less than 1000.

As a result, the road may be classified as Class E, two-lane road. A Design Index of 2 may be used for this classification.

Pavement Subgrade: The pavement subgrade material should be comprised of granular material with a maximum of 15 percent passing the US no 200 sieve. This material should have a maximum liquid limit of

35 and Plasticity Index less than 12. The California Bearing Ratio (CBR) of the subgrade shall not be less than

20. The subgrade material should be compacted to a minimum of 98 percent of the soils maximum modified proctor value as determined by ASTM D-1557. The depth of compaction should be achieved to a minimum of 12 inches below the subgrade level.

Borings TB-12S and TB-15S in the proposed pavement is comprised of hard rock at the surface. Depending upon the final grades, there may be the need to over-excavate the rock and replace it with suitable pavement subgrade soils. The surface soils in TB-10S and TB-14S is a silty clay. This material is not recommended for pavement subgrade and should be removed to a minimum of 2 feet below the pavement sub-base. The replacement material should be as recommended earlier in this report.

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Sub-base Course: The subbase material in the flexible pavement section shall have a minimum strength equivalent to a California Bearing Ratio (CBR) of 30. The material shall have a maximum of 15 percent passing the US No 200 sieve, a liquid limit of not more that 25 and Plasticity of 5 or less. We recommend a minimum thickness of 6 inches, compacted to a minimum of 98 percent of the maximum modified proctor value. The compacted material shall be firm and unyielding.

Base Course: A limerock base course is recommended for the pavement. The base material should be compacted to a 100 percent of the maximum modified proctor value and should have a minimum California

Bearing Ratio (CBR) of 80. The minimum thickness of the limerock base should be 6 inches. Alternative materials may be used provided that it meets the specifications for base course and that the thickness, strength and compaction are considered in the pavement design.

Surface Course: We recommend a Hot Mix Asphalt for the wearing surface of the pavement. The mix design selected for the HMA should be stable, weather-resistant, wear-resistant, waterproof and non slippery. We recommend a minimum thickness of 2 inches of compacted pavement. The surface smoothness shall have a maximum deviation of 1/4 inch.

Underdrains: Where the clayey soils will prevent proper drainage of the pavement subgrade, underdrains may be used to control the water. Underdrains may also be required in landscaped medians where heavy irrigation is anticipated. The underdrains will collect and direct water away from the base course, thus minimizing damage to the pavement.

Limitations

This report was prepared in accordance with commonly accepted geotechnical engineering practices for the exclusive use of our client only for the subject project. No other warranty, expressed or implied, is made. The analyses and recommendations presented herein were based on the results of our subsurface exploration, available information about the subject site and the proposed site improvements. In addition, the exploration does not address deep geological activity. If significant changes in the final site grades, changes in building

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Land Surveying & Environmental Services locations, or foundation loads other than those described herein, or if subsurface conditions different from those encountered in the borings become evident prior to, or during, site preparation or construction, Law &

Associates, Inc. should be immediately notified so that we may review and, if necessary, modify our analyses and recommendations.

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