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Home My WebLink About1985 Soil Investigation ReportSUBTERRANEAN ENBINEERINB CORPORATION eaV3 MIGMWAV NO GS NC PO box 3S371 mimneapolis. Minnesota 55.132 Job No. X-85057 April 18, 1985 Mr. Jeff D. Ulku 240 Russell Avenue South Minneapolis, Minnesota 55405 re: Soil Investigation Single Family Dwelling Lot 11, Block 1, Baldur Park 1416 Baldur Park Road Orono, Minnesota_ _ _ _ _ _ _ _ _ _ Wo were retained by Mr.Jeff Ulku to perform a soil investigation at this lot. The purposes of our work were to determine the soil and ground water conditions in the proposed building area, and to provide a report of our findings including recommendations for the foundation design and installation. PROCEDURE By agreement with the Client, a total of two (2) soil test holes were drilled at diagonally opposite comers of the proposed house location. The field work was performed on April 10, 1985 using a truck-mounted CME-45B drill unit. The test holes were advanced with 3?,"i.d. x 7"o.d. continuous flight, hollow stem augers which act as a temporary casing to prevent collapse of the sides of the hole. Standard penetration tests were performed in advance of the auger tip at 2 to 5 foot intervals of depth, in accordance with procedures designated in A.S.T.M. D—1586. Periodic observations for ground water levels in the boreholes were made while drilling and after completion. profoooionni OOiuCiona to your ooil onQinooring nooda <D- All soil samples obtained were brought to our laboratory for examination and classification. They will be retained for a period of at least 90 days from date of issue of this report, after which they will be discarded unless we are otherwise notified. Drawing No.l is a site plan showing the soil test hole loca tions in relation to the outline of the proposed building. Detailec soil descriptions together with a plot of the standard penetration test blows per foot are given on the Borehole Log, Drawing No.2. Following the regular written soil descriptions are capital letters in parentheses, which represent the appropriate group symbols of th« Unified Soil Classification System. A chart explaining this system is appended. All elevations in this report are to geodetic datum, and were obtained using the bench mark noted on the site plan. These eleva tions are approximate only. SITE AND GEOLOGY The site is located on a small peninsula extending into the North Arm of Lake Minnetonka, and is a lake shore lot. The propose building area is flat, and is only slightly higher than lake water level. This was formerly a swamp area, but was filled over to raisu it above lake level. An existing old wood cabin on this property, to be demolishe has sagged and settled. The underlying soils in this area, in order of their age fron youngest to oldest, are post-glacial organic swamp deposits, clayey and sandy, water modified glacial till related to the Des Moines ice lobe of the Wisconsin glaciation, and glacial outwash sand. According to information published by the State of Minnesota Geological Survey, the uppermost bedrock stratum under this area is believed to be Jordan sandstone or St. Lawrence dolomite, and probably occurs at considerable depth below ground surface. SUBTERRANEAN ENGINEERING CORP. MINNEAPOLIS. MINNESOTA <z> SOIL CONDITIONS Four basic soil types were encountered in our investiga tion. These are: fill; post-glacial organic soils; water-modifie| clayey and sandy glacial till; and glacial outwash sand and grave Fill In the proposed house pad area there is a 5% to 6* thick covering of fill. The fill consists mainly of clayey and silty fine to medium sand. This soil is mainly in a saturated and loose condition, since we believe that much of it was dumped unde water. In its present loose condition the fill is unsuitable for foundation or floor slab support. Post-Glacial Organic Soils Directly below the fill is a 15*s to 17^ foot thick layer of organic soil. The uppermost few feet of this deposit is peat, and the lower major portion is highly organic silt containing mollusk shell fragments. The peat and organic silt are weak and highly compressible. They are totally unsuitable for foundation support. Des Moines Sandy and Clavev Glacial Till Directly below the organic soils, at21^ to 23 foot depth below present fill surface, is a stratum of natural inorganic soil. It consists mainly of grey, layered or interbedded clayey and silty fine sand, fine sandy silt, sandy' clay, with random lenses of fine to coarse sand throughout. The clayey and silty component of this soil has slight plasticity and is stiff in consistency. The sandy component is saturated, non-plastic, and loose to medium dense. This soil stratum would be suitable to support light build ing loads. Glacial Outwash Sand Commencing below the 33' depth in Test Hole 1 is a stratum of clean,well graded sand and gravel. This soil layer is medium dense, and is a competent load-bearing stratum. (& SUBTERRANEAN ENGINEERING CORP. MINNEAPOLIS. MINNESOTA o GROUND WATER CONDITIONS Free ground water was observed in both boreholes. The final measured water levels were at 1* depth below ground surface, corresponding to elevation 929.8 to 929.6 feet. The lake water elevation at the time was 929.8 feet. The ground water table at this site will fluctuate very slightly as the Lake Minnetonka water elevation varies. We were informed that the 100-year design flood elevation of Lake Minneton is 931.5 feet. The low water level is 928.6 feet. DEVELOPMENT PLANS It is proposed to build a single family dwelling having an attached wood deck and porch at the rear or northerly side, closes to the lake. There will also be a separate, detached, two-car garage at the southerly end of the property close to Baldur Park Road. It is likely that the house will not have a basement. Structural loads on the foundations of such buildings are relatively light. However these buildings are sensitive to settle ment. ANALYSIS AND RECOMMENDATIONS The ground surface elevation at this property is presently very low, only about 1' above lake water level. Thus it is certaii that fill will have to be imported to raise the grades sufficient!; to permit the construction. The addition of any new fill will create compression and settlement of the thick buried peat and organic silt layer. Furthermore the peat and organic silt extend much too deep to permit excavation. It is recommended that the house structure at this site should be supported upon a deep foundation system which extends down through the fill and peat, and achieves its load-bearing capacity by a combination of skin friction and point bearing in the underlying inorganic sandy and clayey soils. s SUBTERRANEAN ENGINEERING CORP. MINNEAPOLIS. MINNESOTA o Class B timber piles treated with creosote would be suitabr for this site. Our estimated lengths for nominal 25-ton gross capacity piles are 45 to 50 feet. The piles should be driven to an actual gross load-bearing capacity of at least 28 tons each, with a hammer having a rated energy of at least 15,000 foot-pounds per blow. A pile-driving formula may be used as a guide only, but a minimum embedment of at least 20 feet into the underlying sand is required, notwithstand ing the observed pile-driving bla^ counts. No pile on the projec should be less than 42 feet long, measured from cut-off to pile tip. To allow for downdrag or negative skin friction effects on the piles, caused by continuing settlement and consolidation of thi peat and organic silt, it is recommended that the actual net worki ig load on each pile should be limited to 16 tons. The bottoms of the grade beams spanning the piles should be at least 3h' below outside finished grade for frost protection purposes. As an added precaution we recommend that at least 4” of styrofoam insulating batts be placed below the bases’ of the gra beams, to act as a cushion and additional preventative against frost action. The house lowest floor slab should also be a structural floor, supported on piles. There is a definite tendency for the yard area to settle away from buildings which are supported on piles, causing problems at entry points into the structure, garage aprons, etc. Therefore it would be advisable to place any required fill as early as possible and to delay the actual house construction as much as possible, in order to allow the situation to stabilize. The use of driven piling is not mandatoiry for the detached garage structure. This could be supported upon a heavily reinfor ced, thickened edge concrete slab having internal stiffener ribs in both directions. Some settlement of the garage would still be likely to occur, but it should not restrict the utility of this structure. SUBTERRANEAN ENGINEERING CORP. MINNEAPOLIS. MINNESOTA —O' In any pavement areas on this lot it is recommended that a minimum 30" thickness of clean, well graded sand and gravel fill should be provided and thoroughly surface compacted, prior to installation of the conventional base course and bituminous wearing surface. GENERAL The soil conditions have been established at our test hole locations only. There are likely to be variations in conditions between and around the borings, and interpolation or extrapolation of the results is not warranted. During construction all fill plac ment, grading, compaction, pile-driving and foundation installation should be monitored and tested by a qualified Soil Engineer. We would be pleased to provide the necessary field observation and testing services. In the event that any changes in the nature, design or loca tion of the building are planned, the conclusions and recommenda tions contained in this report shall not be considered valid unless the changes are reviewed and the conclusions modified or verified in writing. This report has been prepared for the exclusive use of Mr. Jeff D. Ulku and his agents for specific application to a single family dwelling at Lot 11, Block 1, Baldur Park, Orono, Minnesota in accordance with generally accepted soil and foundation engineer ing practices. No other warranty, expressed or implied, is made. SUBTERRANEAN ENGINEERING CORP. Mervyn Mindess Registered Professional Engineer MM/pg Distribution:4 cc Mr. Jeff Ulku 1 cc File 1 i SUBTERRANEAN I ENGINEERING CORP. ' MINNEAPOLIS. MINNESOTA GENERAL NOTES DESCRIPTIVE TERMINOLOGY DENSITY TERM Very loose loose Medium Dense Dense Very Dense N VAIUE 0-4 5-10 11-30 31-50 Over 50 CONSISTENCY TERM Soft Stiff Tough Very Tough Hard N VALUE 0-4 5-8 9-15 16-30 Over 30 APPROX UNCONFINED COMPRESSION STRENGTH 0 1200 2000 4000 Over 1200 psf 2000 psf 4000 psf 8000 psf 8000 psf RELATIVE PROPORTIONS TERM Trace A Little Some With RANGE 0 - 5®/o 6 - 15®/o 16 - 30®/o 31 - S0«/o MATERlAi CLASSIFICATION TERM Boulder Cobble Med Course Grovel Fine Gravel Sond Silt and Clay SIZE Over 8 inches 8 —4 inches 4-3/8 inches 3/8 in-N® 10 sieve N® 10 sieve-N® 200 sieve Finer than 200 sieve MOISTURE DESCRIPTION Dry Humid Damp Moist Wsl Soluroltd DEGREE OF SATURATION % 0 1-25 25-50 50-75 75-99 100 WATER LEVEL SYMBOL -▼ Water levels shofvn on the boring logs are the levels measured in the borings at the time end under the conditions indicated. In sand, the indicated levels can bo considered reliable ground water levels. In clay soil, it ts not possible to determine the ground water level within the normal scope of a test boring investigation, except where lenses or layers of more pervious waterbearing soil are present and then a long period of tinro may be necessary to reach equilibrium. Therefore, the position of the water level syrr^ol for cohesive or mixed texture soils may not indicate the true level of the ground water table. The available water level information is given at the bottom of the log sheet. SUBTERRANEAN ENGINEERING CORP. CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES ASTM Dttignation: O 2487 - 66T AND D 2488 - 66T Jntlitd Soil Ctottification Svfttm Mijor divMont Group f^mboli Typical namai Laboratory cla«iftcafion crittria s '3 I s J! 6 II 1 i s •5 I I I ! I =1 ■h *P !< 'vII I W#ll*graded gravali, graval^sand mlxturat, littia or no fines Poorly pradad gravels, gravel- undmixturesJinte or no fines Silty gravels, gravel-sand-silt mixtures Dayey gravels, grevel-sand-clay mixtures ! l ,1 s^ I □ Well-graded sands, gravelly sands, little or no fines Poorly graded sands, gravelly sands, little or no fines I ‘3 t *3 I! IIli 3 ■o I I 10 M t eL-o| - 5511 o. y Silty unds, sand-tilt mixtures Clayey turas ends, und-clay mix- rrfijI SI si llllll il>iSsllr^” Dho —greater than 4; ^c* betvwen 1 and 3 Not meeting all gradation requirements for GW Atterberg limits below **A*' line or P.l. less than 4 Abov, “A" liiw with P.l. batwMn 4 and 7 ara bor- dbr/ine cases requiring uu of dual symbolsAtterberg limits above **A** line with P.l. greater than 7 Oio (Dm)^ greater than 6; batwun 1 and 3 Not muting all gradation raqulramonts for SW Atterberg limits below **A” line or P.l. lets than 4 Limits plotting In hatched zone with P.l. bttwun 4 and 7 ara bordteU’m euu requiring uu of dual sytn- bols.Atterberg limits above **A*' line with P.l. gruter than 7 O II s ll y»2 Inorganic silts and very fine sands, rock flour, silty or clay- ay fine unds or clayey silts with slight plasticity 60 Inorganic clays of low to me dium plasticity, gravelly days, undy clays, silty clays, lean days Organic silts and organic silty clays of low plasticity It MM Inorganic silts, micaceous or diatomacaoue fine sandy or silty soils, elastic tilts Inorgsnic days of high plas ticity, fat clays Organic clays of medium to high plasticity, organic silts 10 7 4 0 1 1 1 1 1 For claaification of fina-grai soils and fine fraction of coa __grained soila. Atterberg Llmlte plotting hatched aru ara bordarlina dr fications requiring uu of c symbols. 1 nad »ru-y / 1 In ■il- fuel CH / / Eq uatlon PI-0.; of A-lii 3(LL na: •20) / a* /f OH an dMH CL / / ......:L-Mi5 MLai dOL Put and othsr highly organic soils 30 40 50 60 70 Liquid Limit PIsMicHy Chart 180 subterranean engineering ino. IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL ENGINEERING REPORT More construction problems are caused by site subsurface conditians than any other factor As troublesome as sub surface problems can be. their frequency and extent have been lessened considerably in recent years thanks to the Association of Soil and Foundation Engineers lASFE) When ASFE was founded in 1969, subsurface problems were frequently being resolved through lawsuits In fact, the situation had grown to such alarming proportions that consulting geotechnical engineers had the worst profc'S- sional liability record of all design professionals By 1980. ASFE-mcmfw consultiiia sari iinJ fflunJalion enmnn fiaJ Ihc (vsl prolfsuonal lutfiiliiy morj This dramatic turn-about can be attributed directly to client acceptance of problem-solving programs and materials developed by ASFE for its mem bers' application Tiiij aufftancf uus yaniftf htaiisf diriils PfndveJ Itif ASFE arrmu/i ta K' in llinr I'un fvsl iiiI.toIs Disputes benefit only those who earn their living from others' disagreements The following suggestions and observations ate offered to help you reduce the geotechnical-related delays, cost-over runs and other costly headaches that can occur during a construction project A GEOTECHNICAL ENGINEERING REPORT IS BASED ON A UNIQUE SET OF PROiEcr-sPECinc factors A geotechnical engineering report is based on a subsurface exploration plan designeef to incorperate a unique set of project'Specific factors These typical y include the general nature of the structure imolved. its s.ze and configuration, the location of the structure on the site and its orientation, physical concomitants such as access roads, parking lots, and underground utilities and the level of additional risk which the client assumeii by virtue of limitations imposed upon the exploratory program To help avoid costly prob lems consult the geotechnical engineer to determine how any factors which change subsequent to the date of his report may affect his recommendations Unless your consulting geotechnical engineer indicates otherwise imur cmrnuvmifi ravri sliou/J fviisnf • When the nature of the proposed structure is changed, for example if an office building will be erected instead of a parking garage or if a refriger ated warehouse will be built instead of an unrefrig- crated one. • when the size or configuration of the proposed structure IS altered. • when the location or orientation of the proposed structure is modified. • when there is a change of ownership, or • for application to an adiacenl site A arnffidiHiarl cuiriiifrr lamun iicfcrr for problems u ’hicfi niau ifo'oVr if fu ’ «<^f consul/rd after factors considered im fiis reports dirtiopmenl naveduutgeti MOST GEOTECHNICAL "RNDINGS" ARE PROFESSIONAL ESTIMATES Site cxploriiiion identifies actual subsurface conditions only at those points where samples are liiken* when they are taken Data derived through sampling and subsequent iaboratory testing ate extrapolated by the geotechnical engineer who then renders an opinion about overall sub- t-urlace conditioris. their likely reaction to proposed con- Mfudion activity and appropriate foundation design Even under optimal circumstances actual conditions may differ from iJ.ose op.n^^d to exist, because no geotechnical en gineer no mairef how qualified, and no subsurface cxplo- futior. t>rogram no matter how comprehensive, can reveal whiii iS hidden by earth, rexk and lime For example the a^Uja! irUerfacc between materials rruiy be far more gradu-il or abrupt than the report indicates, and actual corKiiiior.' in areas not sampled may differ from predic- tionc Notbina am fv i/imc ft» rairiif thr ummlinptrd. furl srfr»s am fV rar*»‘ii I.') fir/r wmh»ii:r rfin» imrart For this reason, mnst aiWMmf ivnrr5 reran: IfinrcrivrerfmiMf mnsufmiif throuah the ion*itfiuuon Mte to identify variances conduct additional te4s which ma; be needeci and to recommend solutions ic pre filems ern ountered on site SUBSURFACE CONDITIONS CAN CHANGE Sijl'surface conditions may he modified by constantly* char.g.mg natural fi^^ces Because a geotechnical engineer ing report is based on c mditlons which existed at the time ol subsurface exploration. cnHsmicrian JeasraMS sf:nuM luif be on a anritUmal enamctwhi repiyrt wfioseadeifuactj may have (mt a/!o(ted h time Speak with the geotechnical consultant to ICiirn if additional tests are advisable before construc tion starts Construction operations at or adjacent to the site and natural events such as floods earthquakes or groundwater fluctuations may also affect subsurface conditions and. thus the continuing adequacy of a geotechnical report The geotechnical engineer should be kept apprised of any such ev’cnts. and should be consulted to determine if additional tests are necessary A GEOTECHNICAL ENGINEERING REPORT IS SUBIECTTO MISINTERPRETATION Costly problems can occur when other design profession als develop their plans based on misinterpretations of a geotechnical engineering report To help avoid these prob lems. the geotechnical engineer should be retained to work with other appropriate design professionals to explain relevant geotechnical findings and to review the adequacy of their plans and specifications relative to geotechnical issues BORING LOGS SHOULD NOT BE SEPARATED FROM THE ENGINEERING REPORT Final boring logs are developed by the geotechnical en gineer based upon his interpretation of field logs (assem bled by site personnel! and laboratory evaluation of field samples Only final boring logs customarily are includea in geotechnical engineering reports Thes^logs s>ipuU ner uitJtr any rirrumsfaitcrs be redrawn for inclusion in architectural or other design drawings, because drafters may commit errors or omissions in the transfer process Although photo graphic reproduction eliminates this problem, it does nothing to minimize the possibility of contraaors misin- terpretating the logs during bid preparation When this occurs, delays, disputes and unanticipated costs are the all-too-frequent result To minimize the likelihood of boring log misinterpretation, ^rvr contraitors ready to the complete engineering report Those who do not provide such access may proceed under the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability Providing the best available information to contractors helps prevent costly construction problems and the adversarial attitudes which aggravate them to disproportionate scale READ RESPONSIBIUT/ CLAUSES CLOSELY Because geotechnical engineering is based extensively on iudgement and opinion it Is far less exact than other design disciplines This situation has resulted in wholly unwarranted claims being lodged against geotechnical consultants To help prevent this problem, geotechnical engineers have developed model clauses for use in written transmirrals These are nol exculpatory clauses designed to foist the gcciet hnical engineers liabilities onto someone else Kdther they are definitive clauses which identify where the geottxhnical engineer s responsibilities begin and emi Their use fielps all parties involved recognize their individual responsibiliticniand take appropriate action Some of these definitive clause^* are likely to appear in your geotechnical engineering report, and you are encouraged to read them closely Your geotechnical engineer will be pleased to give full and frank answers to your questions OTHER STEPS YOU CAN TAKE TO REDUCE RISK Your consulting geotechnical engineer will be pleased to discuss other techniques which can be employed to miti gate risk In addition, the Association of Soil and Founda tion Engineers has developed a variety of materials which may be beneficial Contact ASFE for a complimentary copy of Its publications directory PuWisftrd by ASSOCIATION OF SOI AND FOUNDATION ENGINEERS 881 1 Colesville Road/Suite 225 Silver Spring. Maryland 20910 301/565-2733