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HomeMy WebLinkAboutKanu Drive Lot 1 - Revised Limited Geotechnical Engineering Investigation 2005.11.17€Krazan & A s s o c r A r E s, r N c. GEOTECHNICAL ENCTNEERING T BNVIRONMENTAL BNGINEBRING CONSTRUCTION TBSTTNC & INSPBCTION April26,2005 Revised November 17, 2005 Mr. Jon Fox 55 Cedar View Drive PortTownsend, WA 98368 RE: KA ProjectNo.092{5040 ' i irr' '-' REVISED Letnpp GnorpcrnncAl ENGINEERING luvnmrcIuoN LETTER REP0RT s0c7 6 t dl$trrP d L ,O5,ql House RemodeUAddition I Kanu Drive Port Townsen4 washington BUb a4 ' | 1 I I =I ::il DearMr. Fox: This letter report presents the result$ of our Revised Limited Geotechnical Engineering Investigation for the proposed single-family residenc€ addition at the referenced site. The scope of this study was outlined in our Proposal No. GO5-057WAW, dated April 5, 2005. Written authorization to proceed with this evaluation was given by you on April 6,2005. The fieldwork portion of the study was underaken on April 7,2005. Site Condltions The site is located at I Kanu Drive, in Port Townsend, Washington. The generat location of the property is shown on the attashed Vicinity Map (Figurc l). The subject property is cunently developed with a single family residerrce and associated driveways and landscaping. The majority of the site is generally level. An approximately 90 to 100 percart slope is prc$ent at the east edge of the property, extending downward to the southesst toward Puget Sound. The slope area is about 150 to 170 feet high. The house has a cunent horizontal setback of approximately 30 to 35 feet from the slope. The proposed addition is not planned to be located any near€r to the slope than the existing home. Proroed eonstnrction The project details are still preliminary at this time. We anticipate that the additions to the residence will include footing extension$ for new walls/rooms and minor excavations in the existing crawlspace. lYe anticipate that the structure loads for the additions wilt be founded on shallow, spread footings. Footing loads are expected to be light. Wo have not yet received a grading plan for the project. Preliminarily, we anticipate maximum cuts (in the basement area) on the order of approximately 2 to 4 feet and fill depths on thc order of approximately 2 feet or less. In the event that the structural or grading information detailed in this report is inconsistent with the final design, the geotechnical engineer should be notified so that we may update this writing as applicable. Ten Ofllces Servlng Tlre Wcstern Unlted Slates 19501 l44rh Arc. NE, #F-300: Woodinville, WA 980?2 o (425) 485-55t9; Frr,'( (42*t85-693? KANo.0%-05040 April26,?,005 PageNo.2 of ll Fleld Investigation A limited field investigation consisting of three exploratory hand auger borings, which were excavated approximately 4 feet below the existing site grade, was completed for shallow subsurface exploration. A Krazan & Associates geologist completed the hand auger borings. The holes were excavated by manually advancing a metal rod hand auger with a brrket type bit. The metal rods were pin connected and the hand auger was turned with aT-handle. The soils encountered, in the exploratory hand auger borings, were continuously examined and visually classified in accordance with the Unified Soil Classification System (USCS). Flgure 2 shows the approximate locations of the exploratory hand auger borings. Representative samples of the subsurface soils, encountered in the hand auger borings, were collected and sealed in plastic bags. These samples werc transported to our Woodinville Office for storage (30 days). Geoloslc Seltlnp The site lies within the central Puget Lowland. The lowland is part of a regional north-south trending trough that extends from southwestern British Columbia to near Eugene, Oregon. North of Olympia, Washington, this lowland is glacially carved, with a depositional and erosional history including at least four separate glacial advances/rctreats. The Puget l,owland is bounded to the west by the Olyrnpic Mounkins and to the east by the Cascade Range. The lowland is filled with glacial and nonglacial sediments consisting of interbedded gravel, sand, silt, till, and peat lenses. The United States Geological Survey (USGS), Geology of Washington, Northwest Quadrant, indicates that the property is underlain by Vashon Glacial Till. The Vashon Glacial Till is typically characterized by an unsorted, nonstratified mixturc of clay, silt" sand, gravel, cobbles and boulders in variable quantities. These materials are typically dense and relaiively impermeable. The poor sorting reflects the mixing of the materials as these sediments were overridden and incorporated by tlre glacial ice. Soil Proflle $nd Subsurface Condisons The subsurface conditions, observed within the exploratory hand auger borings, are described as follows: Exploratory Hand AugerBoring HA-l errcountered approximately 6 inches of loose, very darkyellowish brown, fine to medium sand with variable amounts of silt (topsoil). The topsoil is underlain by loose, grayish brown, silty, fine to medium grained sand with local organics (Undocumented Fitl) down to the termination depth of HA- I (approximately 4 feet below existing site grade). Exploratory Hand AugerBorings HA-2 and gA-3, below the approximately l0 inchas of topsoil, encountered I foot of loose, olive brown, fine grained sand (Undocumented fin). The sand is underlain by loose, grayislr brown, silty, fine to medium grained sand with local organics (Undocumented Fill) down to the termination depth of HA-2 and HA-3 (approximately 4 feet below existing site grades). For additional infornation about the soils encountered, please refer [o the attached logs of the exploratory hand auger borings. Krazan & Assoclales, Inc. Ten Offlces ServingTheWestem United States KA No.0E2-05040 April26,2@5 Page No. 3 of I I sry+rcs The hand auger borings were checked for the presence of groundwater during and immediately following the excavation operations. At the date and time of our investigation groundwater was not encountered in the exploratory hand auger borings. It should be recognized that water table elevations may fluctuate with time. The groundwater level will be dcpendent upon seasonal precipitation, irrigation, land use, and climatic conditions, as well as other factors. Therefore, water levels at the time of the field investigation may be different from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report. Groundwater flow may become heavier during construction, which takes place during the wet weather seaso& This may cause difficulties with the grading and excavation work. Certain remedial and/or de-watering measures may be required. Erosion Concern/Ilazard Erosion and sediment control (ESC) is used to minimize the transportation of sediment to wetlands, str€ams, lakes, drainage systems, and adjacent properties. Erosion and sediment control measures should be taken and these measures should be in generat accordance with local regulations. As a minimutn, the following basic rccommendations should be incorporated into the design of the erosion and sediment control features of the site: l) Phase the soil, foundation, utility, and other work, requiring excavation or tle disturbance of the site soils, to take place during the dry season (generally May through September). However, provided precautions are taken using Best Man4gement Practices @MP's), limited gading activities can be undertaken during the wet season (generally October through April). It should bo noted that this typically increases the overall cost of the project. 2) All site work should be completed and stabilized as quickly as possible. Additional perimeter erosion and sediment contml features may be required to reduce the possibility of sediment entering the surface water. This may include additional silt fences, silt fences with a higher Apparent Opening Size (AOS), construction of a bernr, or other filtration systems. Any runoff generated by dewatering discharge should be reated through construction of a sediment trap if there is sufficient space. If space is limited other filtration methods will need to be incorporated. Vegetation should be re-established in landscaped and slope areas prior to the onset of wet weather (typieally October through April). The owner should understand that the landscaped and slope arcas may require periodic maintenance. The owner should visually inspect the landscaped areas and slopes where vegetation has been rc+stablished after adverse rain events and at least once a week during prolonged rain events until vegetation has taken root. Once the vegetation has taken root" the owner should visually inspect the landscaped slopes at least bi-annually for any variations or undesirable conditions. If any vaiiations or undesirable conditions are observed a geotechnical engineer should be notified so that supplemental rccommendations can be made. Krazan & Assoclales, Ine Ten Offices Serving The Westem United Statcs 3) 4) s) KANo.0E2-05040 April26,2005 PageNo.4of ll General Based on the findings of this limited investigation, it is our opinion that the proposed house additions may be supported on a shallow foundation systems bearing on properly compacted, structural fill, placed on medium dense native soils (at depth) or recompacted existing fill (if deemed suitable). All footing excavations should be inspected to evalsate the required depths of overcxcavation. Where undocumented fill is encountered, this material should be overexcavated down to medium dense native soils, or at least 2 feet. Overexcavated footings should extend an equal distance to the depth of overexcavation, beyond the footing edges. The overcxcavations should be bacKilled with structural fill. The structural fill should be compacted to at least 95 percent of the maximum dry density as determined by ASTM Test Method Dt557. We rccommend that the additions not be placed any closer t'() the slope than the eristing house, however, we feel that the existing setback of 30 to 35 feet is acceptable with the current slope configuration. Sile Prenaratlo4 Site clearing should be limited to the areas necessary for construction of the sdditions to the single family residence. Slope areas should be left naturally vegetaed to the grettest extent possible. Clearing should include removal of vegetation; tr€es and associated root systemsi wood; existing utilities; structures including foundations; rubbte; and rubbish. Site sFipping shoutd extend to a minimum depth of 4 to g inches (preliminary; based on our handauger boring locations), or until all organics in excess of3 percent by volume arc removed. These materials will not be suilable for use as structural fill. However, stripped topsoil may be stockpited and reused in landscape or non-structural areas. After stripping operations, the existing fill should be overexcavated at least 2 feet below the bottom of the proposed footing elevations, as well as 2 feet laterally in all directions from the proposed footing edges (evaluated by inspection). These soils should be replaced with a suitable structural fill. Recompaction of theexisting fill may be necessary depending on th€ conditions observed and their relative moisture contents. Structural fill material should be within t 2 percent of the optimum moisture conrent, and the soils should be compacted to a minimum of 95 percent of the maximum dry density based on ASTM Test Method Dl j57. During wet weather conditions, typically October through May, subgrade stability problems and grading difficulties may develop due to excess moislure, disturbance of sensitive soils and/or the presence of perched groundwater. Constnrction during the extended wet weather periods could create the need to ovsrexcavate these soils to a greater deph if they become disturbed and cannot be recompacted due to elevated moisture contents. The on site soils have variable silt contents and are considered moisture sensitive. If overexcavation is necessary, it should be confirmed through continuous monitoring and testing by a qualified geotechnical engineer or seniorgeologist. Soils that have become unstable may require dryiqg and recompaction. Selective dry,ng may be accomplished by scarifying or windrowing surficial material during extended periods of dry, warm weather(typically during the summer months). If the soils cannot be dried back to a workable moisture condition, remedial measwes may be required. General project site winterization should consist of the placement of aggregate base and the protection of exposed soits during the construction phase. It should b€ understood that Krazan & Acsociates, Inc. Ten Officcs Serving The Westem United Srates aff--_-.''_-.-' KA No.092-0504t) April26,2005 Page No. 5 of I I even if Best Management Practices @MP's) for wintertime soil protection are implemented and foltowed therc is a signifiiant chance that moisture disturbed soil mitigation wort will still be required. Any buried structurcs encouniered during construction should be properly rcmoved and bacldilled. Excavations, depressions, or soft and pliant areas extending below the planned finish subgrade lcvels should be cleaned to firm undisturbed soil, and bacKilled with structural fill. In general, any septic tanks, undergmund storage tanks, debris pits, cesspools, or similar structures should be completely removed. Concrete footings should be removed to an equivalent depth of at least 3 feet below proposed footing elevations or as recommended by the geotechnical engineer. The resulting excavations should be bacldilled with structural fill. A representative of our firm should be present during all site clearing and grading operations to test and observe earthwork construction. This testing and observation is an integral part of our service, as acceptance of earthwork construction is dependent upon compaction and stability of the material. Thc geooechnical engineer may reject any material that does not meet compaction and shbility requiremen[s. Further recomrnendations, contained in this report, are predicahd upon the assumption that earthwork construction will conform to the recommendations set forth in this section and in the structural Fill section. Temoorary Excavations The on site soils have low cohesion strengths, therefore the safe angles to which these materiats may be cut for temporary excavations is limited, as the soils may be prone to caving and slope failures in lemporary excavations deeper than 4 feet. Temporary excavations in the existing filt soils should be sloped no steeper than l/z H:lV (horizontal !o vertical) where room permits. Temporary excavations in medium dense glacial soils (if encountered at depth) strould be sloped no steeper than lH:lV (horizontal to vertical) where room permits. All temporary cuts should be in accordance with Washington Administrative Code (WAC) Part N, Excavation, Trcnching, and Shoring. The temporary slope cuts should be visually inspected daily by a qualified person during construction work activities and the results of the inspections should be included in daity reports. The conffactor is responsible for maintaining the stability of the temporary cut slopes and minimizing slope erosion during construction. The temporary cut slopes slrould be covered with visqueen to help minimize erosion during wet weather and the slopes should be closely monitored until the psrmanent retaining systems are complete. Materials should not be stored and equipment operated within l0 feet of the top of any remporary cut slope. A Krazan & Associates geologist or geotechnical engineer should observe, at least pariodically, the temporary cut slopes during the excavation work. The reasoning for this is that all soit conditions may not be fully delineated during the previous geotechnical exploratory work In the case of temporary slope cuts, the existing soil conditions may not be fulty revealed until the excavation work exposes the soil. Typically, as excavation work pKlgresses the maximum inclination of the temporary slope will rped to be reevaluated by the geotechnicat engineer so that supplemental recommendations can be made. Soil and groundwater conditions can be highly variable. Scheduling for soil work will need !o be adjustable, to deal with unanticipated conditions, so that the project can proceed smoothly and required deadlines can be nret. If any variations or undesirable conditions are encountered during construction Krazan & Associates should be notified so that supplemental recommendations can be made. Krazan & Assoclates, Inc. Ten Offices Serving The Westem United States KA No.@2-05040 April26,2005 PageNo.6of ll Struetural Fill Best Management Practices (BMP's) should be followed when considering the suitability of native or existing, undocumented filt material for use as $uuctural fill. The on site fill soils (silty soils) have relatively high fines (silt and clay) contents and are considered moisture sensitive. lt may not be possible to use these soils as structural fill. These soils may also have elevrted natural moisture contents, and may need to be dried back durrng dry, warm weather (typically during the summer months). Only the more sandy fill eoils are generally considered suitable for reuse as structural fill, provided the soil is relatively free of organic material and debris, and it is within * 2 percent of the optimum moisture content. If these soils are stockpiled for later use as structural fill, the stockpiles should be covered to help protect the soil from wet weather conditions. We recommend that a reFesontative of Krazan & Associates be on site during the excavation work to determine which soils are suitable for structural fill. It should not be taken for granted that the onslte solls may be used as the solc souroe for structural flll (especially during winter coretructlon activities). Durlng wet weather condltlons the solls with hlgher sltt and clay contents will be moisture sensitive, easily dlcturbed and most likely wlll not meet compacfion requirements. Furthermore, during the winter the on siSe soils typicrlty have elevated natural moisture contents, which will limit the use of these materlals rs structural fill without proper mltlgatlon metrsures. The contractor should use Best Management Practices to protect the soils durlng construcffon acdvltles and be familiar with wet weother and wintertime soll work. An allowanee for importing structural flll should be incorporated into the construction cost of the project (for wlntertime construction this may be as high as 100 percentimport). Imported structural fill material should consist of well-graded gravel or a sand and gravel mixture with a maximum grain size of. IYz inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). A wide variety of suiable structural fill materials may be used to backfill the overexcavated footing areas. These include 2 to 4 inch sized quarry spawls, l%-inch clean angular crushed rock, controlled density fill (CDF), lean mix concrete or structural concretf. All structural fill material should be submitted for approval to the geotechnical engineer at least 48 hours prior to delivery to the site. Fill soils should be placed in horizontal lifts not exceeding 8 inches loose thickness, moisture-conditioned as necessary, (moisture content of soil shatl not vary by morc than *2 percent of optimum moisture) and the material should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. The clean (free of fines) structural fill and concrete based materials will not need compaction, provided placement is in accordance with the gcotechnical engineer's recommendations. In place density tests should be performed on all structural fill (with fines) to venfy proper moisture content and adequate compaction. Additional lifts should not be placed if the prcvious lift did not meet the compaction requirements or if soil conditions are not considered stable. Groundwater Influence on StructuredConstruction Groundwater was not encountered in the exploratory hand auger borings during our field exploration work. If gfoundwater is encountered during the consuuction workn the groundwater is most likely perched. This perched gtoundwater develops where vertical infiltration of surface precipitation is impeded by a rclatively impermeable Krazan & Asrochtes, Inc. Ten Oftices Serving The t#estem United Ststes KA No.092-05OlO April26,2005 Page No.7 of I I soil layer, resulting in horizontal migration of the groundwater within overlying more permeable soils. If groundwater is encountered during construction, we should observe the conditions to determine if de-watering will be needed. Design of temporary dewatering sy$toms to rcmove groundwater should bc the responsibility of the contractor. If earthwork is performed during or soon aftcr periods of precipitatioru the subgrade soils may become saturated. These soils may "pump," and the materials may not respond to densification t€chniques. Typical remedial measure$ include: discing and aerating the soil during dry weather; mixing the soil with drier materials; removing and replacing the soil with an approved fill material. A qualified geotechnical engineering firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appncpriate rccommendations. Drainaee an*!,andscaolns The ground surface should slope away from building pads and pavement areas, toward appropriate drop inlets or other surface drainage devices. It is recommended that adjacent exterior grades be sloped a minimum of 2 percent for a minimum distance of 5 feet away from structures. Roof drains should be tightlined away from foundations and slope surfaces. Roof drains should not be connected to the footing drains, but may use the same oulfall piplng if connecrcd well away from the structure such that roof water will not backup into the footing drains. Subgrade soils in pavement areas should be sloped a minimum of I percent and drainage gradients should be maintained to carqy all surface water to collection facilities, and/or dispersion trsnches, away from slope surfaces. These grades should be maintained for the life of the project. The collection facilities and/or dispersion trsnches should be tightlined away from slopes that exceed 30 percent and disposed of where down slope properties, structure$ and slopes are notjeopardized. Specific rccommendations for and design of storm water disposal systems or septic disposal systems are beyond the scope of our sewices and should be prepared by other consultants that are familiar with design and discharge requirements. Infiltration systems should not be located on slopes that exceed 30 percent nor should systems be "stacked" or lined up with one another down the slope. Infiltration $ystems should not be located up slope of rcsidences or retaining slructures. Utititv Trench BsckfiIl Utility trenches should be excavated in accordance with Occupational Safety and Health Adminisration (OSHA) standards, by a contractor experienced in such work. The responsibitity for the safety of open trenches should be borne by the contractor. Trrffic and vibration adjacent to trcnch walls should bs minimized; cyclic wetting and drying of excavation side slopes should be avoided. Depending upon th€ location and depth of sonrc utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation. Both silty and sandy soil conditions were encountered at shallow depths at this site. These soils are relatively cohesionless and can save in trench watl excavations along joint fractures. Shoring or sloping back trench sidewalls may bercquiredwithin these soils. Krazsn & Assoclalesr Inc Ten Offises Servlng The Western Unihd States KA No.092-05040 April26,2005 Page No. 8 of I I All utility trench bactfill should consist of imported structural fill or suitable on-site material. Utility trench bacKill placed in or adjacent !o buildings and exterior slabs should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. The upper 5 feet of utility trench bacKill placed in pavement areas should be compacted to at least 95 percent of the maximum dry density based on ASIM Test Method D1557. Below 5 feet, utility trench bacKill in prvernent areas should be compacted to at least 90 percent of the maximum dry density based on ASTM Test Method D1557. Pipe bedding should be in accordance with the pipe manufacturet's recommendations. The contractor is responsible for rcmoving all water-sensitive soils from the trenches regardless of the bacldill location and compaction requirements. The contractror should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction. Floor Slabs an{Exterlor tr'latwork If slab on grade structures arc prcposed and reducing floor dampness is desire4 such as in areas covered with moisture sensitive floor coverings, we recommend that concrete slab-on-grade floors be underlain by a water vapor retarder system. The water vapor rctarder systcm should be installed in accordance with ASTM Specification El&-94 and Standard Specifications 81745-97. According to ASTM Guidelines, the water vapor retarder should consist of a vapor retarder sfieeting underlain by a minimum of 4-inches of compacted clean (less lhan 5 percent passing the U.S. Standard No. 200 Sieve), open-graded coarse rock of %-inch maximum size. The vapor retarder sheeting should be protected from puncture damage. The exterior floors should be placed separately in order to act independently of the walls and foundation system. All fills required to bring the building pads !o grade should be structural fill. Moisture within the structurt may be derived from water vapors, which were transformed from the moisture within the soils. This moisture vapor c&n travel through the vapor membrane and penetrate the slab-on-grade. This moisture vapor penetration can rffect floor coverings and produce mold and mildew in ths structure. To minimize moisture vapor inlrusion, it is reconmended that a vapor reterder be installed in accordance rvith ASTM guidelines. It is recommended that the utility trenches within the structure be compacted, as specified in our report, to minimize the transmission of rmisture through the utility trench backfill. Special attention to the immediate drainage and inigation around the building is recommended. Positive drainage should be established away frorn the structure and should be maintained throughout the life of the structure. Ponding of water should not be allowed adjacent to the structure. Over-iuigation within landscaped areas adjacent to the structure should not be performed. In addition, ventilation of the structure (i.e. ventilation fans) is recommended to reduce the accumulation of interior moisture. Foundations The proposed additions to the existing single family residense may be supponed on shallow foundation $ystems bearing on properly compacted, structural fill, placed on recompacted existing fill soils or suitable native soils- Continuous wall or column footings rnay be dasiped for a net allowable bearing pressure of 1,500 pounds per square foot (psf) dead plus live load, if the footings bear directly on structural fill, placed on the suitable underlying soils, Krazan & Assoclnhr, Inc. Ten Offices Serving The Western United States KANo.0E2-05040 April26 2O05 Page No. 9 of lt A l/3 increase in the above value may be used for shorl duration, wind and seismic loads. Structurat fill placed on bearing subgrade should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D155? (unless otherwise, approved by the geotechnical engineer). Footing excavations should be inspected to veri$ drar the foundations will bear on suitable material. Exterior footings should have a minimum depth of 18 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. Interior footings should have a minimum deph of 12 inches below pad subgrade (soil grade) or adjacent exterior grads, whichever is lower. Footings should have a minimum width of 12 inches regardless of load. If constructed as recommended, the total settlement is not expected to exceed I inch. Differential settlement, along a 20-foot exterior wall footing, or between adjoining column footings, shoutd be less than % inch, producing an angular distortion of 0.@2. Most settlement is expected to occur during construction, as the loads are applied. However, additional post-construction settlement may occur if the foundatisn soils arc flooded or saturated or if a strong seismic event results in liquefaction of the underlying soils. It should be noted that the risk of liquefaction is considered low, given the composition and density of the native, on site soils. Seasonal rainfall, water run-off, and the normal practice of watering trees and landscaping areas around the proposed structur€, should not be pennitted to flood and/or saturate fmtings. To prcvent the buildup of water within the footing areas, continuous footing drains (with cleanouts) should be provided at the bases of the footings. The footing drains should consist of a minimum 4-inch diameter perforated pipe, stoped to drain, with perforations placed down and enveloped by l-inch sized washed rock in all directions and filter fabric to pr€vent the migration of fines. Resistance to lateral footing displacement can be computed using an atlowable friction factor of 0.30 acting between the basss of foundations and the supporting subgrade. Lateral rpsistance for footings can alternatively be developed using an allowable equivrlent fluid passive pressure of ?.4A pounds per cubic foot (pcQ acting against the appropriate vertical footing faces. The allowable ftiction factor and allowable equivalent fluid passive prcssure values include a factor of safety of 1.5. The frictional and passive rpsistance of the soil may be combined without reduction in determining the total lateral resistance. A l/3 incrcase in the above values may be used for short duration, wind and seismic loads. Testins and Insnectlon A rcpresentative of Krazan & Associates, Inc. should be present at the site during the earthwork activities to confirm that actual subsurface conditions are consistent with the exploratory fieldwork. This activity is an integral part of our services es acceptance of earthwork construction is dependent upon comprction testing and stability of the material. This representative can also veri$ that the intent of these r,commendations is incorporated into the project desrgn and construction. Krazan & Associates, Inc. will not be responsible for grades or staking, since this is the responsibility of the Prime Contractor. Krazan & Associsl€s, Inc Ten Offices Serving The Westem United States KANo.0!D45040 April25,2005 Page No. l0 of I I LilIIITATIONS Geotechnical engineering is one of the newest divisions of Civil Engineering. This branch of Civil Engineering is constantly improving as new technologies and under$tanding of earth scierces improves. Although your site was analyzed using the most apprcpriate curent techniques and methods, undoubtedly there will be suhtantial future improvements in this branch of engineering. In addition to improvements in the field of geotechnical engineering, physical changes in the sits either due to excavration or fill placement, new aggncy rcgulations or possible changes in the proposed structure after the time of completion of the soils report may require the soils report to be professionally reviewed. In tight of this, the Owner should be aware that there is a practical limit lo the usefulness of this report without critical review. Although the tirne limit for this rcview is strictly arbitrary, it is suggested that two years be considered a reasonable time for the usefulness of this report. Foundation and earthwork construction is charccterized by the presence of a calculated risk that soil and groundwater conditions have ben fully revealed by the original foundation investigntion. This risk is derived from the practical necessity of basing interpretations and design conclusions on limited sampling of the earth. The recommendations made in this report are based on the assumption that soil conditions do not vary significantly from those disclosed during our field investigation. If any yariations or undesirable conditions are encountered during construction, the geotechnical engineer should be notified so that supplemental recommendations can be made. The conclusions of this report are based on the information provided regarding the proposed construction. If the proposed construction is relocated or redesigned, the conclusions in this report rnay not be valid. The geotechnical engineer should be notified of any changes so that the recommendations can be reviewed and reevaluated. This report is a limited geotechnical engineering investigation with the purpose of evaluating thc soil conditions in terms of foundation design. The scope of our services did not include any environmental sitE assessment for the presence or absence of hazardous and/or toxic materials in the soil, groundwater or almosphere, or the presence of wetlands. Any statements, or absence of statements, in this report or on any hand auger boring log, regarding odors, unusual or suspicious items, or conditions observed are strictly for descriptive purposes and are not intended to convey engineering judgment regarding potential hazardous and/or toxic assessments. The geotechnical information presented herein is based upon professional interpretation utilizing standard engineering practices and a degrce of conservatism deemed proper for this project. It is oot warranted that such information and interpretation cannot be superseded by future geotechnical developments. We emphasize that this report is valid for this project as outlined abovg and should not be used forany other site. Krazen & Associates, Inc Ten Offices Serving The Westem United Stateg KANo.092-05040 April26,2005 PageNo ll of ll We hope that this report provides the information required at this tirne. If you have any questions, or if we may be of further assistance, please do not hesitate to contact our office at (425) 485-5519. Respectfully submitted, KRAZAN & NSOCIATES, INC. nej Phil Haberman, L.G. Engineering Geologist PlVslc Attartmen*: Figurcs (5) L. Caraway, P.E. Geotechnical Division Manager .t. \."rl ,1 r! 2513 Krazrn & Associales, Ins. Ten Offices Serving The\trestem Unihd States {otc: Figure generated from TOPO USAO. KRAZAN & ASSOCIATES 19501 144$ Avenue Northeast #F-300 WoodinvlllgWA 980?2 425-485-3519 FIGURD 1- VICINITY MAP Locallon: Port Townsend,Wacbington Job No. :092-04040 Cllent Mr. Jon Fox Date:4-29-05 I,rl e Flgure ?1 Konu Drive Fox fb Sctr I ASSOC|AIIS,Ikazan!$n rFr gS m r t I I I I I I I I I I I + r HA-A -1 Exlstlng SFR HA-1 HA.3+ t--J Drlvewoy LEGENI} Hord Augtr HA-tLcotlon '+ ___r t--- Kqnu Dnlve t.ftiTT]i l:itilclr-?:I'Fl '...'--.€* 'l .) ProJecB Fox Proporty Clienfi Jon Fox Location: Port Townserd, WA Defih toWater Proiect No: ogzooolo Flgure No: A-t Logged By: CM AtGompletion: Log of Hand Boring HA.1 Surface Elevatlon: Daturn: lnltlal: Not Errcountered SUBSURFACE PROFILE SAMPTE I- DynamicCone Penetromet€r tBlovrs/l.75") 20 40 60 80ttlt WaterContent (%) wt:lro0t6 EE tt Descriplion g E3 rt)EE6a {to-F 8. t-- rt,a.E16(r, 'vl oJ €B10z@ 0- 5- t0- 15- stlw9AND$M) Loose, riory fine grained sand, dark yelloryieh brown, moi6l. Soms organics. - Color changes lo olive brown at 1 foot. - Burnt vrood at 2.67 teel. - l'on oxids sblnlng at 3 feel - Burnt wood at 3.5 fe€|. il t I i l l I I I I b-1 s-2 Grab s-it |jleD s-4 ctlab End of Borchole r!l Ir!lrit._.i__L___ Ddll Method: Hand Augor Ddller: CM Krazan rnd Agsoclateg 19501 l44th Ave. NE #F-300 Woodinville, Waahlngton 98472 Drlll Date: TApril 05 $amplo Mclhod: Grab Sheek I ofl ff'r'_-' ,,^)) Prolect Fox Properly Gllen* Jon Fox Location : Port Townsend, WA Depth to Water Project No: $245040 Flgure No: A"2 Logged By: cM At Completlon: Log of Hand Boring HA-z Surface Elevatlon: Datum: lnitial : Not Enoourderod SUBSURFACE PROFILE SAMPLE I- DymmicCono Ponolromotsr (Blowsr1.75) 20 WsterContent (w W-cd|Dcl -olt E v) Desoiplion o.o E5z rDa Eoa 8.F 0!g Q'E.E(! at ir, O- *Eztt 0- 5- 10- 15- End of Borehole s-1 gftlb I I ! I I s€Grab I II Drltl i,lethod: Hand Augor Driller: CM Krazan and Aesoclates t950t l44th Ave. NE #F.300 Woodlnville, Washlngton 98072 Drlll Dab; 7 April 05 9ample Method;Grab Shset 1 oft Profecft Fox Properly Gllent: Jon Fox Loeatlon: Port Townserd, WA Depth to Water Project No3 og2-0504o Figure No: A*g Logged By: cM AtGompletion: Log of Hand Boring HAA Surface Elevatlon: Datum: lnltlal: Nol Encounlersd SUBSURFACE PROFILE SAMPLE I- DynamhCone Penetromeler (Blowsr1.7Y) Wat6rConlgnt (o'/ol W.c.aoo E ErD Oescrlpllon o,oEt3oaE(to otCL F g F.oaEG'o ir't:o- FE2g 1 1 End of Boreholo t I II s-1 Girab s-2 Grab : i I ,J. I Drlll Date:7Apd e5 $ample Mel[odl Grab Shseft I oft Krazan and Assoclatog 19501 l44th Ave. NE #F-300 Woodlnvllle, Washlngton 98072 Drl[ Method: Hand Auger Drlllen CM