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Victor Jackson
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R-1 Conveyor Relocation Project Legend 0 500 1000 1500 ft.

mapping site and is for general reference only.

accurate, current, or otherwise reliable.

14 R-1 Conveyor Relocation Project Legend ft. This map is a user generated static output from an Internet mapping site and is for general reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. THIS MAP IS NOT TO BE USED FOR NAVIGATION. Map center: 45 38' 21.7" N, ' 15.8" W Scale: 1:5,000

16 September 9, 2009 W1031 CONSULTATION LTR WorleyParsons Westmar 200 Grand Boulevard, Suite 100 Vancouver, WA Attention: SUBJECT: Rachael Brake Geotechnical Engineering Services and Consultation Kinder Morgan Bulk Handling Facility Proposed R1 Slewing Conveyor Port of Vancouver, USA At your request, GRI is providing geotechnical engineering services and consultation for the proposed R1 slewing conveyor to be located on the south and west sides of the Kinder Morgan bulk storage building No at the Port of Vancouver, USA (Port). The purpose of the slewing conveyor is to replace the existing fixed conveyor over NW Harborside Drive to permit moving the conveyor out of the way so that high vertical loads, such as the Port s large mobile crane, can travel the roadway. Our engineering studies have relied on the existing subsurface information for the area, as provided in our August 27, 2008 (revised April 23, 2009), report to Westmar Consultants Corporation entitled, Geotechnical Investigation, Dry Bulk Material Handling Facility, Port of Vancouver, USA, and October 12, 2007, report by PBS Engineering + Environmental (PBS) for the Port entitled, Geotechnical Investigation Report, Proposed Kinder Morgan Water Treatment Facility, Vancouver, Washington, dated. This letter documents the work accomplished and provides our conclusions and recommendations concerning foundation design and construction. PROJECT DESCRIPTION The existing section of fixed conveyor that crosses the roadway will be replaced with a slewing conveyor that will have its pivot point supported on a new transfer tower constructed on the north side of the road. The opposite side of the slewing conveyor will be supported by a trolley with steel wheels that will operate on a 90 arced rail supported by a concrete grade beam. The conveyor will have a turning radius of ft and a height of about 30 ft on the north end and about 67 ft on the south end. The transfer tower will be supported with six columns on a common mat foundation measuring about 19 by 33 ft in plan dimension. The base of the mat foundation will be established about 6 ft below adjacent finished grades. Based on information provided to GRI by the project structural engineer, we understand the applied bearing pressure beneath the mat will be less than about 320 psf under normal operating conditions, and the maximum bearing pressure beneath the mat will be limited to about 1,600 psf under loading conditions that include wind and/or seismic forces. The grade beam under the trolley rail will be 2-6 wide and embedded 2-3 below adjacent finished grades. The dead and live loads on the wheels are estimated to be about 46 kips each under normal operating conditions, and the maximum bearing pressure beneath the grade beam will be limited to about 2,300 psf under loading conditions including wind and/or seismic forces. The new system will be designed to accommodate some foundation settlement. To our knowledge, large areal (storage) loads will not be placed in the immediate vicinity of the new foundation.

17 SITE DESCRIPTION General Much of the area surrounding the site is improved with buildings and other structures, pavements, roadways, and rail lines. The existing ground surface in the area is relatively flat and lies at about elevation 34 ft National Geodetic Vertical Datum (NGVD). The existing conveyor is supported on steel supports, some of which are supported on piles. Geology Our review of available geologic literature and our experience in the area indicates the site is mantled with sand fill underlain by alluvium deposited by the floodwaters of the Columbia River. The alluvial deposits consist of silt and fine- to medium-grained sand that is underlain by gravel. The gravel can be medium to very dense and cemented, and also contain interbedded layers of sand ranging up to tens of feet thick. SUBSURFACE CONDITIONS General The two previously referenced geotechnical reports indicate PBS boring B-1 is nearest to the new transfer tower. Subsurface conditions disclosed by the boring are similar to conditions encountered in GRI borings B-1 through B-4. The subsurface conditions disclosed by all the borings are consistent with our understanding of the local geology. A description of the soil and groundwater conditions at the site is provided below. Soils For the purpose of discussion, the materials and conditions described in the logs of the borings have been grouped into the following general categories. The terms used to describe the soils are defined in Table 1. Listed as occurring from the ground surface downward, the units are: 1. FILL 2. Interbedded Silty SAND to Clayey SILT 3. SAND 4. GRAVEL 1. FILL. The site is mantled with dredged sand fill that has been surfaced with pavement or crushed rock in most open areas. The sand is typically brown, fine to medium grained, contains a trace to some silt, and a trace of subangular to subrounded gravel. The fill extended to depths ranging from 11 to 12.5 ft in the GRI borings. The sand fill in PBS boring B-1 is interpreted to extend to a depth of 7.5 to 10 ft. Standard Penetration Test N-values ranging from about 3 to 27 blows/ft indicate the relative density of the fill is loose to dense. The moisture content of the fill ranges from about 5 to 25%. 2. Interbedded Silty SAND to Clayey SILT. Interbedded silty sand to clayey silt underlies the fill; the individual layers range from a fraction of an inch to several feet thick. This unit extended to depths of 25.5 to 37.5 ft in the borings. The soils are typically gray. N-values ranged from about 0 to 10 blows/ft and Torvane shear strength values ranged from about 0.40 to 0.60 tsf. The relative density of the sand phase is correspondingly considered to be loose while the relative consistency of the silt phase is considered soft to stiff. Natural moisture contents of the soils range from about 30 to 45%. 2

18 Consolidation testing indicates the silt is moderately preconsolidated. The test data also indicate the compressibility of the silt is relatively low for the range of stresses below the preconsolidation pressure and moderate in the range of stresses above the preconsolidation pressure. 3. SAND. Sand was encountered beneath the interbedded silty sand to clayey silt and extended to depths of 50 to 55 ft in the borings. The sand is primarily fine to medium grained and typically contains some silt, and may also contain a trace to some gravel and scattered cobbles in the deeper portions of the unit. N- values ranging from 13 to 34 blows/ft indicate the relative density of the sand ranges from medium dense to dense. The natural moisture content of the sand ranges from about 15 to 30%. 4. GRAVEL. The sand is underlain by gravel. The borings were terminated in this unit at depths of 56.5 to 71.5 ft. The gravel is sandy and contains a trace of silt and cobbles. Based on N-values ranging from 65 blows/ft to refusal (more than 50 blows for less than 6 in. of sampler penetration), the relative density of the gravel is very dense; however, it has been our experience that the Standard Penetration Test tends to overestimate the relative density of such coarsely graded granular materials. Groundwater Groundwater was measured in a GRI boring at depths of 24.4 ft (elevation +8.5 ft) and 26.9 ft (elevation +6 ft) on July 9 and 22, 2008, respectively. The groundwater level data indicate the groundwater level closely reflects the level of the Columbia River. It should be anticipated that the highest groundwater conditions will occur during flood stages of the river. However, perched groundwater conditions can occur near the ground surface locally, particularly during periods of intense or prolonged rainfall. CONCLUSIONS AND RECOMMENDATIONS General The site is mantled with a relatively competent sand fill. The thickness of the sand cap is estimated to be about 7.5 to 10 ft near the new transfer tower, which will be at the pivot end of the slewing conveyor. Although not encountered in the nearby borings, the sand cap is often known to locally contain layers of silt, and the original ground surface in the area may not have been completely stripped of organics prior to the fill placement. Interbedded silty sand to clayey silt underlies the sand cap to an estimated depth of about 38 ft near the transfer tower. Groundwater levels at the site will fluctuate with river levels. Groundwater resulting from the infiltration of rainwater may perch within the sand fill on top of the underlying less-permeable silt soils. The underlying silty sands to clayey silts are of low to moderate compressibility, and, in our opinion, the new transfer tower can be suitably supported on a mat foundation. Some future settlement at the site could occur as the result of a strong seismic event. Our conclusions and recommendations for design and construction of the new foundation are discussed below. Seismic Considerations A comprehensive discussion of seismic conditions at the site is provided in our April 2009 report for the planned bulk handling facility. In our opinion, our earlier conclusions and recommendations remain applicable for the design of this project, particularly with regard to the potential for liquefaction-induced soil strength loss and settlement. As discussed in the report, seismically induced liquefaction could result in about 1 in. of settlement at this site. In terms of other potential seismic hazards at the site, we anticipate 3

19 the risk of earthquake-induced fault displacement, ground rupture, and lateral spread is low, and the risk of tsunamis or seiches at the site is absent. Foundations and Settlements The existing ground surface at the site was created by placing dredged fill on the Columbia River floodplain. This placement of fill has resulted in settlement due to the consolidation of the underlying alluvial soils beneath the weight of the sand cap. The total settlement that has occurred since the fill was placed has both a short-term and long-term component. The short-term component is associated with primary consolidation, which occurs as excess porewater pressures in the underlying compressible soils produced beneath the weight of the newly placed fill dissipate over time. Primary consolidation tends to occur relatively rapidly, and is complete due to fill placement. However, the underlying soils continue to compress over time due to secondary compression, which has a rate that tends to be linear with the logarithm of elapsed time since the fill was placed. Since the fill has been in place for several decades, we estimate that future settlement due to secondary compression will be small and probably less than 1 in. Adjacent areas will undergo similar settlement so that differential settlement and angular distortion will be small. The sand cap that mantles the site is significantly less compressible than the underlying alluvial soils, and the settlement of the new mat foundation will depend in part on the thickness of the sand. In the area of the new transfer tower, the sand cap is estimated to be between 7.5 and 10 ft thick. We understand the mat foundation that will support the tower will have a footprint of about 19 by 33 ft with the bottom of footing embedded 6 ft below surrounding finished grades. The corresponding normally applied bearing pressure for the mat will be about 320 psf and we estimate the resulting primary settlement will be less than 1 in. The grade beam that will support the trolley rail will be 2-6 wide and 2-3 deep. In our opinion, deformations of the grade beam under load can be best estimated using an assumed modulus of subgrade reaction of 225 pci for a beam on an elastic foundation. Minor differential settlement could occur due to non-uniform foundation loading conditions or variations in the underlying subsurface profile and will also depend on the overall bending stiffness of the mat or grade beam. However, we anticipate that differential settlement due to these variations will likely be limited to less than about half of the total estimated settlement. As discussed in our April 2009 report, we previously recommended that the allowable bearing pressure for shallow foundations be limited to 2,500 psf. We understand the maximum bearing pressures beneath the mat and the trolley rail grade beam for the total of all loads, dead, live, and wind or seismic, will be about 1,600 and 2,300 psf, respectively, both of which are less than the recommended maximium allowable bearing pressure. Following excavation to footing level, the subgrade should be examined by the geotechnical engineer. Any identified soft, loose, or otherwise unsuitable material should be overexcavated and replaced with granular structural fill. Following evaluation of the mat subgrade, we recommend placement of a 6-in.- thick layer of 3 /4- or 1-in.-minus crushed rock compacted as structural fill. Horizontal forces may be resisted by friction developed beneath the base of the mat and the underlying subgrade. An ultimate value of 0.35 may be assumed for the coefficient of friction beneath the foundation. If additional lateral resistance is required, a passive earth pressure against the sides of the embedded 4

20 foundation can be computed using an equivalent fluid with a unit weight of 250 pcf. This design passive earth pressure would be effective only if compacted granular structural fill is used for the backfill; the dredged sand fill at the site would be suitable for this purpose. The footing backfill and any other structural fill should be compacted to a minimum of 95% of the maximum dry density at a moisture content within about 3% of optimum as determined by ASTM D Any overturning forces acting on the footings would be best resisted by the weight of the footing and the weight of any backfill placed over the footing. The weight of any backfill placed over a footing as structural fill may be assumed to be about 125 pcf. We further recommend the foundation dimensions be proportioned so that the resultant of all forces acting on the mat lie within the middle third of the footing length and width to avoid uplift at the edges of the foundation. It is unlikely that groundwater will be encountered in the excavation; however, minor seepage could occur due to perched water. All temporary excavation sidewalls should be sloped no steeper than 1H:1V. Design Review and Construction Services We welcome the opportunity to review and discuss construction plans and specifications for this project as they are being developed. In addition, GRI should be retained to review all geotechnical-related portions of the plans and specifications to evaluate whether they are in conformance with the recommendations provided in this letter. Additionally, to observe compliance with the intent of our recommendations, design concepts, and the plans and specifications, we are of the opinion that all construction operations dealing with earthwork and foundations should be observed by a GRI representative. Our constructionphase services will allow for timely design changes if site conditions are encountered that are different from those described in this letter. If we do not have the opportunity to confirm our interpretations, assumptions, and analyses during construction, we cannot be responsible for the application of our recommendations to subsurface conditions that are different from those described in this letter. LIMITATIONS The scope of our consultation is limited to the specific project and location described herein, and our description of the project represents our understanding of the significant aspects of the project relevant to foundation design and construction. In the event that any changes in the design and/or location of the proposed improvements as outlined in this letter are planned, we should be given the opportunity to review the changes and to modify or reaffirm the conclusions and recommendations of this letter in writing. The conclusions and recommendations submitted in this letter are based on the existing geotechnical information for the site and from the other sources of information as discussed in this letter. In the performance of subsurface investigations, specific information is obtained at specific locations at specific times. However, it is acknowledged that variations in soil conditions may exist between or beyond exploration locations, and this letter does not reflect these variations. The nature and extent of variation may not become evident until construction. If, during construction, subsurface conditions different from those encountered in the borings are observed or encountered, we should be advised at once so that we can observe and review these conditions and reconsider our recommendations where necessary. If you have any questions regarding this letter, please contact the undersigned at your convenience. 5

21 Submitted by GRI, Renews 5/2011 Dwight J. Hardin, PE Matthew S. Shanahan, PE Philip L. Wurst, PE Principal Project Engineer Senior Engineer This document has been submitted electronically. 6

22 Table 1 GUIDELINES FOR CLASSIFICATION OF SOIL Description of Relative Density for Granular Soil Relative Density Standard Penetration Resistance (N-values) blows per foot very loose 0-4 Loose 4-10 medium dense Dense very dense Over 50 Description of Consistency for Fine-Grained (Cohesive) Soils Standard Penetration Torvane Resistance (N-values) Undrained Shear Consistency blows per foot Strength, tsf very soft 2 Less than Soft medium stiff Stiff very stiff Hard over 30 over 2.0 Sandy silt materials that exhibit general properties of granular soils are given relative density description. Grain-Size Classification Modifier for Subclassification Boulders Percentage of in. Other Material Adjective In Total Sample Cobbles 3-12 in. Clean 0-2 Gravel Trace /4-3 /4 in. (fine) 3 /4-3 in. (coarse) Some Sand Sandy, silty, No No. 40 sieve (fine) Clayey, etc. No No. 10 sieve (medium) No No. 4 sieve (coarse) Silt/Clay - pass No. 200 sieve

ATTACHMENT A PRELIMINARY GEOTECHNICAL SUMMARY

ATTACHMENT A PRELIMINARY GEOTECHNICAL SUMMARY Kevin M. Martin, P.E. KMM Geotechnical Consultants, LLC 7 Marshall Road Hampstead, NH 0384 603-489-6 (p)/ 603-489-8 (f)/78-78-4084(m) kevinmartinpe@aol.com