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HomeMy WebLinkAboutReport/subsurface exploration/geotechnical review . .r 5 '�E�'�� ,e.'���j � r � � � 1�»' # ''�.°�+ � � A1IER1C�i� �E;���"d�� ��� � CONSULTANTS � ENGINEERING • ENVIRONMENTAL TESTING� INC. • MATOERALSICAL � • FORENSICS REPORT OF SUBSURFACE EXPLORATION AND GEOTECHNICAL REVIEW PROJECT: RF,PORTF,1) TO: PROPOSED RESIDEN"TIAL OAK HILL, INC. REDEVELOPMENT 14317 McGINTY ROAD WEST 2264 SHADYWOOD ROAD WAYZATA, MINNESOTA 5��91 ORONO. MINNESOTA ATTN: MR. TOM 7IFC'JLF_,R DAT�: PEBRUARY 1 l, 2008 AET JOB NO: 22-00173 INTRODUCTIO� This report presents the results of our substn�(�ace explc,ration ��r��ram and ����tcchnical rcvicw frn- this project. 7�he scope of services is outlined in �ur prop�sal dated .Iantiary ?9. ��0�. �ahich Oal< Flill, I��c. accepted on Februaiy 4, 2008. The authorized sc�pe includes the f��llowin�: • Drill and sample two Standard Penetration test (SPT) borings at the site, to a deptl� of 20 feet each. • Perform limited laboratoiy testing on selected recovered soil samplcs. this included moisttu-e conte�It testing of selected cohesive soil samples. • Prepai-e this geotechnical eilgineering report. Tl�e scope of our services is intended for geotechnical purposes only. This scope is n��� intendeci to explore for the presence or extent of chemical coutamiilation at the site. This document shall nol be reproduced,except in full,without written approval of American Engineering Testing,Inc. 1715 Lake Dr.W. Chanhassen, MN 55317 Phone 952-361-3781 •Toll Free 800-972-6364 •Fax 952-368-4218 •www.amengtest.com Offices throughout Florida,Minnesota,South Dakota&Wisconsin AN AFFIRMATIVE ACTION AND EQUAL OPPORTUNITY EMPLOYER , . AET#22-00173- Page 2 of 10 PROJECT INFORIVIATION Oak Hill, Inc. is proposing to redevelop an existing residential lot ]ocated at 2264 Shadywood Road in Orono, Minnesota. Currently, the site is occupied by a one-story, single family residence originally constructed in 1931. As part of the proposed redevelopment, the existing foundation will be incorporated in the proposed two-story, single family home. Oak Hill, Inc. proposes to remove the top 3 courses of the masonry block foundation wall, corefill the remainder of the wall solid, and construct the new foundation wall above. The proposed home will not have a basement level. An excavation and survey program performed by Oak Hill, Inc. indicated the foundation consists of 24" wide spread footings and that approximately '/z inch of differential settlement has occurred in the existing foundation. The foundation will also be expanded to include an attached garage with second-story living space located south of the existing home. The area of the planned addition is currently covered by grassy areas that abut the existing home. To improve the drainage around the new home, grade will be raised approximately 1' near the foundation and sloped away from the house. The proposed driveway will be located to the east of the new home, with access to Crystal Bay Road. As part of the proposed redevelopment, the City of Orono is requiring a geotechnical exploration program be performed at the site to evaluate the existing conditions and the proposed construction. The City is also requiring the existing basement to be filled prior to new construction. The presented project information represents our understanding of the proposed construction. This information is an integral part of our engineering review. It is important that you contact us if there are changes from those described so that we can evaluate whether modifications to our recommendations are appropriate. AET #22-00173- Page 3 of 10 SITE CONDITIONS Soi1s The log test borings and location diagram (Figure l) are included in the Appendix. The logs contain information concerning soil stratification, soil classification, geologic descriptions and relative moisture; the density or consistency are also noted, based on the Standard Penetration resistance (N-value, "blows per foot"). The boring logs only indicate the subsurface conditions at the sampled locations and variations often occur beyond the borings. Boring No. 1 was located in the footprint of the proposed garage addition. In this boring, we found about 5'/2 feet of fill; the fill consisted of a mixture of clayey sand, and sandy silt. Below the fill we found interbedded strata of naturally-occurring non-organic coarse alluvium and till to the boring termination depth of 21 feet. The granular soils consisted of silty sand and sand with silt and were of loose to medium dense consistency, with N-values ranging from 5 to 20. The cohesive soils consisted of sandy lean clay and clayey sand and were of a stiff to ve�y stiff consisiency, with N-values ranging from 13 to 20. Boring No. 2 was located off the northeast corner of the existing foundation. In this boring. we found approximately 10 feet of fill; the fill consisted of a mixture of sand, silty sand, clayey sand, and sandy silt. Trace roots were noted in the recovered samples. Below the fill, we found a layer of organic clay with sand to a depth of about ]2'/2 feet below grade. These organic soils were very soft to soft in consistency, with N-values ranging from weight of hammer to 4. Below the fill and organic soils, we found till to the boring termination depth of 31 feet. The cohesive soils consisted of clayey sand, sandy lean clay, and lean clay with sand and were of a soft to stiff consistency, with N-values ranging from 4 to ]0. AET #22-00173- Page 4 of 10 Water Level Measurements We encountered groundwater at a depth of about 4'/2 feet below grade at both borings, which corresponds to approximately elevation 928. The cohesive fill soils on this site are estimated to have relatively low permeabilities, and an extended period of time, on the order of days or weeks, would be required for the groundwater to reach equilibrium levels in the borings. Thus, it is likely that groundwater may be shallower on this site than indicated by the 1eve1 of free water measured in the borehole during the relatively short period of time (approximately two hours per boring) in which we drilled. While on the site, we shot the elevation of tl�e ice at the shoreline of Lake Minnetonka, which abuts the northern portion of the property. The elevation of the ice was 928.7. This is slightly above the average water ]evel of the lake of 928.44 feet, but below the ordinary high water (OHW) elevation of 929.4 feet, according to the Minnesota Department of Natural Resources website. We believe groundwater elevation at the house will closely match the elevation of Lake Minnetonka due to the proximity of the lake. A discussion of the water level measurement methods is presented on the attached sheet entitled "Exploration/Classification Methods." Groundwater levels usually fluctuate. Fluctuations occur due to varying seasonal and yearly rainfall and snow melt, as wel] as other factors. RECOMMENDATIONS Based on our understanding of the performance of the original construction, existing foundation depths, and dimensions and loads associated with the planned new construction, it is our professional opinion that the existing foundation is suitable for support of the new constniction. It is also our opinion the subsurface soil conditions are suitable for support of typical spread footing foundations in the area of the new garage addition. As a result of the added loads from the new structure and fill soils that will be placed to infill the crawlspace area, some settlement will occur to the existing foundations and new grade supported slab. Oak Hill, Inc. will need to determine if the anticipated settlement is tolerable. AET #22-OO173- Page 5 of 10 Based on the soil conditions encountered at the boring locations and the proposed redevelopment plans, including filling of the existing basement, we have performed settlement estimates for the proposed redeveloped home. In our opinion, based on the existing conditions and proposed construction, differential settlements of 1'/2 to 2 inches may occur. These estimates are based on your Structural Engineer's estimate of required bearing pressure for the redeveloped home on the order of a maximum of 2,000 pounds per square foot (ps� and the City of Orono requiring that the existing basement be completely backfilled. If the basement is not backfilled, we estimate additional differential settlements of'/2 to 1 inch, based on the proposed consU-uction. To reduce the potential for harmful differential settlements, we recommend imposing a construction delay of at least 2 months following fill operations for the existing basement. This delay would allow primary consolidation of the existing fill and organic soils to occur and reduce the potential for long term differential settlements. During this time, the fill should be monitored with settlement plates to observe the consolidation of the underlying fill and organic soils. As an alternative, helical piles may be installed to reduce future settlement by underpinning the existing foundation. Based on the conditions found at the borings, we anticipate the garage addition will bear on undocumented fill or naturally-occurring non-organic soils, and we recommend that the spread foundations be designed for a maximum allowable soil bearing pressure of 2,000 pounds per square foot. lt is our judgment the recommended design bearing capacity should include a factor of safety of at least 3 against shear or base failure. We recommend the perimeter foundations for heated addition areas be placed such that the bottom is a minimum of 42" below exterior grade far frost protection. Interior foundations in heated areas can be placed directly below the floor slab. Exterior foundations (those noi bordering heated building areas) should be extended to a minimum of 60"below exterior grade. AET#22-00173- Page 6 of 10 Based on the proposed construction, this should limit total and differential settlements of the addition to ] inch and '/2 inch or less, respectively, provided that the bearing soils are not disturbed; wet or frozen at the time of construction. The specifications should include a note ihat the contractor must avoid disturbance or freezing of the bearing soils. Structure Backfillin� We recommend not using the clayey backfill in the basement or around the new foundation walls because clay can be difficult to compact in confined spaces. Rather, select soil such as Mn/DOT 3149.2B2 processed to have less than 12% passing the No. 200 sieve should be imported for the backfill. On-site cohesive soils could be used in the upper 1 feet of backfill and sloped away from the new home to direct run-off away from the foundation and to reduce surface water infiltration into the sand backfill. The backfill for the basement and around the newly constructed foundation walls should be placed in lifts, and mechanically compacted with manually operated equipment to at least 95% of the maximum Standard Proctor dry density (ASTM D 698). The fill should be placed in lifts thin enough to attain the specified compaction level throughout the entire lift thickness. This normally requires that fill be placed in loose lifts less than 8 inches thick. Large towed or self- propelled compaction equipment should not be used within 4 feet of the walls since this eyuipment could damage the walls, and impart permanent lateral stresses against the wall which are not accounted for in the structural design. The backfill should not be loosely dumped, nor should it be compacted by "puddling"or flooding. Floor Slabs Any new fill placed to attain floor slab subgrade, including utility and foundation trench backfill, should be compacted to a minimum of 95% of the maximum Standard Proctor dry density (ASTM D 698). Due to the frost susceptible soils found near the surface in the boring locations, AET#22-00173- Page 7 of 10 we recommend that the garage floor slab be constructed independent to the rest of the structure (i.e. not tied into the foundation or walls). This reduces the potential for heave to the rest of the structure if the frost susceptible soils below the garage slab were to freeze and heave. You have indicated that the garage will be designed to be heated. For- additional recommendations pertaining to moisture and vapor protection of floor slabs, we refer you to the attached standard sheet entitled "Floor Slab MoistureNapor Protection." Dewaterin� The excavation must be properly dewatered so that the base soils can be observed and tested, and to allow footing installation under dry conditions. The level of groundwater drawdown should be achieved before the excavation reaches the planned elevation, and maintained at least 2 feet below the lowest anticipated subgrade or subcut elevation. However, the water table should not be lowered more than necessary to provide a dry excavation, to reduce the risk of settlement of adjacent structures and utilities. It is the responsibility of the designers of the dewatering system to assess the effects of lowering the groundwater on adjacent structures and utilities. CONSTRUCTION CONSIDERATIONS Runoff Water and Groundwater in Excavation Based on the conditions found in our boring, it is our opinion that groundwater will be a factor that should be considered in the design and construction of the lift station and construction dewatering will be required. To allow observation of the excavation bottom, and to reduce the potential for soil disturbance and facilitate lift station placement and filling operations, we recommendation that all free-standing water within the excavation be removed prior to proceeding with construction. AET#22-00173- Page 8 of l0 Potential Difficulties The soils that were encountered in our boring are susceptible to disturbance by construction traffic, especially when saturated or exposed to free groundwater. Disturbed soils should be carefully excavated and replaced with new compacted, engineered fill. Observation and Testi�� The recommendations in this report are based on the subsurface conditions found at our test boring location. Since soil conditions can vary, we recommend on-site observations by a Geotechnical Engineer or a Material Technician during construction to evaluate the soils. Soil density testing should be performed on all fill placed at the site to document that our recommendations, and the specifications for compaction and moisture have been satisfied. Where fill material type is important, laboratory sieve analyses should be performed to document that the fill meets the recommendation gradation criteria. SUBSURFACE EXPLORATION Our subsurface exploration program included drilling one standard penetration test (SPT) boring at this site on February 1, 2008. Oak Hill, Inc. staked the boring location in the field and our drill crew shot the ground surface elevation at the boring referenced to the top of the existing manhole located east and south of the lot on Crystal Bay Road. This benchmark had an elevation of 933.4 feet National Geodetic Vertical Datum (NGVD). Before we drilled, we contacted Gopher State One Call to locate public underground utilities on this site. We drilled the borings using 3 1/4 inch inside diameter hollow stem augers and mud rotary techniques. We backfilled the borehole with neat cement to comply with current Minnesota Department of Health regulations. [Refer to the sheet in the Appendix entitled "Exploration/Classification Methods" for detail regarding drilling and sampling of standard penetration borings, and methods used so classify soils and measure water levels.] AET#22-00173- Page 9 of 10 LIMITATIONS The data derived through this sampling and observation program have been used to develop our opinions about the subsurface conditions at your site. However, because no exploration program can reveal totally what is in the subsurface, conditions away from the boring and between samples and at other times, may differ from conditions described in this report. The exploration we conducted identified subsurface conditions only at those points where we took samples or observed groundwater conditions. Depending on the sampling methods and sampling fi-equency. every soil layer may not be observed, and some materials or layers which are present in the ground may not be noted on the boring logs. If conditions encountered during construction differ from those indicated by our boring, it may be necessary to alter our conclusions and recommendations, or to modify construction procedures, and the cost of construction may be affected. The extent and detail of information about the subsurface conditions is directly related to the scope of the exploration. It should be understood, therefore, that information can be obtained bv means of additional exploration. STANDARD OF CARE Our services for your project have been conducted to those standards considered normal for services of this type at this time and location. Other than this, no warranty, either express or implied, is intended. CLOSURE To protect you, AET, and the public, we authorize use of opinions and recommendations in this report only by you and your project team for this specific project. Contact us if other uses are intended. Even though this report is not intended to provide sufficient information to accurately AET#22-00173- Page I 0 of 10 determine yuantities and locations of particular materials. we recommend that your potential contactois be advised of the report availability. If you have questions about this report, ple�se contact �ne at (952) 36l-3781 or dvanheuveln%ri,amen�test.com. Report Prepar-ed bv: Report Reviewed by: American Engineering Testing, Inc. American Engineering Testing, I�c. �''�J`--� ''`_ JDerek S. Van Heuveln, P.E.— illiam K. Cody, P.E. Staff Engineer II Principal En�ineer/Vice President Minnesota I:icense No. 45922 Minnesota License No. 16136 �lttachments: Freezing Weather Effects on Building Construction Floor Slab Moisture/Vapar Protection Figtu-e l – Boring Location Diagram Log of�I�est Borings Minnesota Department of Natural Resources Lake Water Level Report Exploration/Classification Methods Boring Log Notes Unified Soil Classification System �.)5V;I�Ci: . �-�I 151���.__�-t}l;l�.. :l':t'Ll'!'i�`.�'�� 1 hereby certify that this plan,specification, or report was prepared by me or under my direct supervision and that I am a duly Licensed Professional Engineer under the laws of the State of Minnesota Print Name: Derek S.Van Heuveln Signature: I,( _ S. ��--.�_ Date: Z License#:45922 FREEZING WEATI-iER EFFECTS ON BUII,DING CONSTRUCTION GEI�TERAI. Because wacer expands upon freezing and soils contain water, sous which are allowed to freeze will heave and lose density. Upon thawing, these soils will not regain their original strength and densiry. The excent of heave and densiry/ svength toss depends on the soil rype and moisture condition. Heave is greater in sails with higher percentages of fines (silts/clays). High silt content soils are most susceptible, due to their high capillary rise po�ential wliich can create ice lenses. Fine grained soils generally heave about 1/4" [0 3!8" for each faot of frost penetration. T'his can transiate to 1" to 2" of totai fros[ heave. This total amount can he significandy greater if ice Iensing occurs. DESIGN CONSIDERATIONS Clayey and siity soils can be used as perimeter bacl�ill, although the effect of their poor drainage and frost properties should be considered. Basement areas will have special drainage and lateral load requirements which are not discussed here. Frost heave may be critical in doorway areas. Stoops or sidewalks adjacent to doorways could be designed as structural slabs supported on frost footings with void spaces below_ With this design, movements may then occur between tEie s�uctural slab and the adjacent on-grade slabs. IVon-frost susceprible sands (wit6 less than 12% passing a#200 sieve) can be used below snch areas. Depending on the function of surrounding areas, the sand layer may need a thicl�ess transirion away from the area where movement is critical_ With sand placement over slower draining soils, subsurface drainage would be needed for the sand layer. High densiry extruded insulation could be used within the sand to reduce frost penetration, thereby reducing the sand thickness needed. We caurion that insulation placed near the surface can increase the potential for ice glazing of the surface. T'he possible effects of adfreezing should be considered if clayey or silty soils are used as bacl�ill. Adfreezi.ng occurs when backfill adheres to rough surfaced foundation walls and Iifts the wall as it freezes and heaves. This o�currence is most common with masonry block walls, unheated or pooriy heated building situa�ions and ciay backfill. The potenrial is also increased where bacl�ill soils are poorly compacted and become saturated. The risk of adfreezing can be decreased by placing a Iow fricpon separating layer between the walt and backfill. Adfreezing can occur on exterior piers (such as deck, fence or other similar pi�r footings), even if a smooth surface is provided. This is more likely in poor drainage situations where soils become saturated. Additional foodng embedment and/or widened footings helow the frost zones (which includes tensiie reinforcement) can be used to resist uptift forces. Specific designs would require individual analysis. CONSTRUCTION CONSIDERATIONS Foundations>slabs and other improvements which may be affected by frost movements should be insulated from frosc penetrarion during freezing weather. If filling takes place during freezing weather, all frozen soils, snow and ice should be stripped from areas to be filled prior to new fill placemen[.The new fill should not be allowed to freeze during transit, placement or compaction. This should be considered in the project scheduling, bud�eting and quantiry estimating. It is usually beneficial to perform cold weather earthwork operations in small areas where grade can be attained quickly rather than working larger areas where a greater amount of frost stripping may be needed. If slab subgrade areas freeze, we recommend the subgrade be thawed prior to floor slab placement. The frost action may also require reworking and recompaction of the thawed subgrade. Q i REP015(2/�I} AMERICAN ENGINEERING 1'ESTIlVG, INC. FLOOR SLAB MOLSTURE/YAPOR PROTECTION Floor slab desien rela�ive to moisture/vapor pro�ec:ion should consider the rype and locacion of nuo elemenu, a granular layer and a vapor membrane(vapor retarder,wa[er resistant barrier or vapar barrier). In the following secuons, the pros and cons oi the possible opdons reeardine these eiements will be presented, such that you and your specifier can make an engineering decision based on the benefirs and cosu of the choices. GRANUI.AR LAYER In?�merican Concrece Instim[e(ACI}302.1-96,a"base materiai"is recommended, racher than the convenaoaal cleaner "sand custuon" material. The ma.nual mainrains [hat clean sand (eommo❑ "cushion" sand) is difficult to compact and maintain until concrete placement is comptete. ACI recommends a clean, fine�aded material(with at leas[ IO% to 30 0 of parcicles passing a/tI00 sieve)which is not contamina[ed with clay,silt or organic material. We refer you to ACI 302.1- 96 for addidonal deraiLs regarding the requiremenrs for the base material. In cases where potential staric wa[er Ieveis or si�ificant perched water sources appear near or abave rhe tloor slab, an underfloor drainage syscem may be needed wherein a drainale system is placed within a�hicker ciean sand or cravet layer. Such a system should be properly engineered depending on subgrade soil rypes and race/head of water inflow. vAPOR MEMBRANE The need for a vapor membrane depends on whecher the IIoor slab will have a vapor sensidve covering, wili have vapor sensiuve items stored on the slab, or if the space above the slab will be a humidity controlled area. If the project does no[ have this vapor sensiuviry or moisture conaol need,placement of a vapor membrane may noc be necessary. Your decision will chen relace to whether co use the ACI base material or a convendonal sand cushion layer_However, if any of the above sensiaviry issues apply, placeme� of a vapor membrane is recommended. Some floor covering syscems (adhesives and flooring materiaLs)require a vapar membrane ro maintain a specified maximum slab moisture conrent as a condiuon of their warcan[y. VApOR MED�RANE/GRAMILAR LAYER PL�+iCEMENT A number of issues should be considered when deciding whether to place the vapor membrane above or below the granuIar Iaye:.The benefirs of placing the slab on a�anular Iayer,with the vapor membrane placed beIow the oranular Iayer, include reducrion of the following: • Slab curling�"n�the curin�and drying process. • Time of bleeding, which allows for quicker finishing. • Vapor membrane puncturing. • Surface blistering or delaminauon caused by an extended bleeding period. • Craclang caused by plasuc or drying shrinkage. The benefics of placing the vapor membrane over the gramilar layer include the followine: • The moisture emission rate is achieved faster. • Eliminates a potential war.er reservoir within the gramilar layer above [he membrane. • Provides a "slip surface", thereby reducing slab restraint and the associaced random craclang. If a membrane is to be used in conjunetion with a;ranutaz layer,[he approach recommended depends on slab usage and the construcuon schedule.The vapor membrane shouid be placed above the granular layer when: • Vapor sensiave floar covezing systems are used or vapor sensiuve items will be direcdy placed on the slab. • The area will be bumidiry conrrolled,but the slab will be placed before the building is enciosed and sealed from rain. • Required by a floor covezing manufacturer's system warranry. The vapor membrane should be pIaced below the o anular layer when: • Used in humidiry controlled areas(wirhout vapor sensiave coverings/stored icems), with the roof inembrane in place, and the buiIciing enclosed co the poin[ where precipiTafion wiil not intrude into the slab area. Considerarion should be given to slight sloping of the membrane to ed�es where drainule or other disposal methods can alleviare potendal water sources, such as pipe or roof leaks, foundarion wall damp proofing failure, fue sgrinklez system acavarion, eu. There may be cases where membrane ptacement may have a deuimental effect on the subgrade suppon system (e.g., expansive soils). In these cases,your decision will need ro weigh the cost of subgrade opuons and rhe performance risks. O1REP013(2/Ol) AMERICAN ENGIlVEERING TESTING, INC. -(Pb n / / / t I � � �� 1V" � � "� a�{ uy. �/ ��///., f �� �i /lI anXH /� �\/�\ _/,eCfi p�� � �cYa �.�� � �. 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P/ 1 � `� � ' v r`� � LE•;GEND � I Z�, g� � ( I i �= APPROXIMA"I'E SOIL L30RING LOCA'I IONS ' ���`_ � _a4"� I I I I ♦ - BLNCHMARI<: 'I'OP RIM OF MANHOLE ` � ; , EL.EVn"I�IUN = 9;;.4 1�1=:E?f NGVU NO"fL: 13ASF.. MAP PKOVIL�F:D L3Y OAK FIILI., INC. PROJECT PROI'OS1�,D RL:SIDLN"I,IAI, REDEVCLOPMEN"I� AET JOI� NO. 2?64 Shadywood Road, Orono> MN ?2_Op 173 AMCR[CAN �UBJF,CT DATE ` [?NGINCI?121NC TCS'I'ING, INC. BORING LAYOUT February 1 1, 2008 SCALI: D1tAWN BY CHECKED BY None WKC DSV � AMERICAN � ENG�ERi1vG SUBSURFACE BORING LOG �� TESTING, INC. .�T.ios No� 22-00173 LOG OF BORiNG NO. j (p. ] O f j� Prto.i�cT: Proposed Residential Redeveloqment; Orono, MN D IPTH SURFACE ELEVATION: 932.3 GEOLOGY FIELD&LABORATORY TESTS N MC S�MPLE REC FEET MATERIAI.DESCRIPTION TYPE IN. �JC DEN LL PL o-ti2 FILL.mi�-ture of sand��silt and clave� sand.a FII.L � lirile gr�vel.trice roots.dark bro���n_frozen to 16" F� 33 2 � I j � � -� M SS 4 30 I i �' � ! 1 » � � � M/� SS 6 3� � SIL.TY SAND,trace roots. fine grained. d�v-k ' .:COARSE gra�. a little grayish brown moist. loose.lense •-�:�ALLIJVI[.7M � of���aterbearing sand(SM) SII.Tl'SAND,a little gravel.fine to medium g grained,gray,wet loose,lanunations of sand ����'r� 6 w SS 12 (SM) � SANDY LEAN CLAY.a little gra��el.gray,a J •� TILL �o IitUe light gray,very stiff_laminations of silt and �g sand (CL) •-: COARSE ZO W SS ]4 1� SAND WITH SILT,a little gravel, mediwn to '•�•ALLUVILJM fine grained.brown��aterbearing.meditun �' '� �2 dense. lenses and laminations of silh�sand � TILL (SP-SM} " �3 SANDY LEAN CLAY.a little gravel.grayisl� I 3 M SS 16 20 bro���n to grayish brown and gray mottled. stiff �:� (CL) ts 14 M SS 16 22 16 17 18 CLAYEY SAND,a little gravel,gravish bro�vn. �9 stiff.lense of wet silt�sand(SC) 20 16 13 M SS ]8 21 END OF BORING I i � � I � i I DEPTH: DRILLING METHOD �t'ATER 1,EVF,L MEASUREMENTS NOTE: REFER TO 0-9'/z' 3.25" HSA DATE TIME SDEPTyD D�P�TH DE�P7'H FLr�U�IDLEVEL L�EVEL THE ATTACHED 9'/z'-19'/z' RD w/DM 2/1/08 10:10 6.0 4.5 �,9 q.g SHEETS FOR AN 2/1/08 10:15 0.0 0.0 �,9 {,3 EXPLANATION OF COMPLETED: 2/l/08 2/1/08 10:55 0.0 0.0 9.0 �.� TERMINOLOGYON DR: BR LG: TK Rig: 1C THIS LOG o�ioa AMERICAN � ENGINEERING SUBSURFACE BORING LOG �� TESTING, INC. �T�oB rro: 22-00173 LOG OF BORING NO 2 (p. 1 of 1) puo�ECT: Proposed Residential Redevelopment; Orono, MN DEPTH SURFACE ELEVATION: 933A FIELD&LABORATORI TESTS IN GEOLOGY N MC SAMPLE REC FEET MATERIAL DESCRIPTION TYPE IN. �1C DEN LL PL �0-#20 FILL.mostly sand�� silt.trace roots_black. FIl.1. F 5? 1 frozen 2 FILL,misiure of siln�s�u►d. clave� s�nd and ' FM1 SS 4 ?2 sand.a little gra��el.trace roots.dark bro�vn. ; bro��n and black_frozen to 16" �� N1 SS 6 a � 5 — 6 7 W SS 6 � FILL,mosd}�sand,a little gra��el.gra� 8 � W SS 4 9 �� ORGATIIC CLAY WITH SAND. tr�ce roots. SWAMP wl-I W SS 2�I 25 i 1 black,a little gray,verv sofi to soft.laminations DEPOSIT �2 of lean clay(OLJOH) � �3 LEAN CLAY WITH SAND.grn.soft_ lense of TILL a w SS 12 �3 clayey s�-u►d(CL) ]� SANDY LEAN CLAY.a little gra��el_grn•_soft �5 to finn(CL) 4 w SS 2� 24 16 17 18 � W SS ZO 22 19 20 21 � W SS 2U 23 22 23 SANDY LEAN CLAY.a little gra�el.gra��ish 2=� bro��r►.stiff(CL) z5 26 1O W SS ]8 21 27 28 29 CLAYEY SAND,a little gravel. gr��.finn(SC) 30 �1 R W SS 20 17 END OF BORING DEPTH: DRILLING METHOD WATER LEVEL MEASUREIvIENTS NOTE: REFER TO 0-9'/z' 3.25"HSA DATE TIME S DEPTLHD DEP"�I'H DE�P'TH FLUI�D LEnVEL LEAV�E L THE ATTACHED 9'/z'-29'/z' RD w/D1VI 2/1/08 12:10 6.0 4.5 5.1 q,q SHEETS FOR AN 2/1/08 12:18 0.0 0.0 5.] q.q EXPLqNAT[ON OF COMPLETED: 2/l/08 TERMINOLOGY ON DR: BR LG: TK Rig: 1C THIS LOG (X,104 Lake water level report: Minnesota DNR Page 1 of] . ��::' ( g:�v��. Y( , � �¢ +.t �? � Enter Keywords search . '� 1_� ._ .i. Site Map � Contact thc DNR � VVhat's New`? � Ne��sroom � T�.vents � S�asons > �9N DNR I lome > I.ak� I-�inder> Lake water level report Lake name: Minnetonka County: Hennepin Water Level Data Minnetonka - 276133A0 ,:_� Period of record: OS/30/l 906 to 11/06/2007 # of readings: ]8675 � y asu Highest recorded: 930.52 ft (09/07/2002) �. �E � , � ,; Lowest recorded: 921.78 fi (12/16/1937) � Recorded range: 8.74 fi � •'`" �; ; � � !, ( �;' � !� 1'� i� i t Average water level: 928.44 ft y `. �.,,{ �� ''�-' �i ,� ''� �+' �' Last reading: 928.55 ft (11/06/2007) W `-'"' `ti�,'I �'-� OF-IVV elevation: 929.4 ft Datum: 1929 (ft) f��f 194+u 1599 2p00 2901 2002 2003 2004 2005 2P06 20p7 Download lake level data as: [dBase) [ASCI[] Last ]0 years of data, click to enlarge. (If you have trouble try right clicking on the appropriate link and choosing the "Save ... As" option.) Benchmarks No benchmark information available. ,�-2008 Minnesota Deparrn7errt of Nalural Resout-ces. C'opl�ri,�Tht:'l�'otice.������ � ����4 Web site policies: :�ce.•e.s.sihilil3�. Li��kirr„ Pri�-crrti� http://www.dnr.state.mn.us/lakefind/showlevel.html?id=27013300 2/11/2008 • EXPLORATTON/CLASSIFICATION METHODS SAivfPLING METHODS Split-Spoon Samples (SS} - Calibrated to N�Values Standard peneuaaon(split-spoon)samples were collected in general accordance with ASTM:D 1586 with one primary modificacion_ The ASTM tesc method consists of driving a 2" O.D. spiit-barrel sampler in[o the in-situ soil with a 140-pound hammer dropped from a height of 30". The sampler 'rs driven a to�al of 18" into the soil. Afcer an ini[ial set of 6", the number of hammer blows co drive the sampler the final 12" is known as the scandard penetration resiscance or N-vaIue. Our method uses a modified hammer wei�ht. which is determined by measuring the syscem ener;y using a Pile Driving Analyzer (PDA) and an instrumented rod. In the past, standard pene[ra�ion N-value tests were performed usine a rope and cathead for the Iift and drop sys[em. The ener�y cransf�erred to the spli�-spoon sampler was rypically lirni[ed to about 60% ot it's poten[ial enerey due to the friction inheren�in this system. This convened energy then provides what is known as an N�blow count. Most of todays drill rigs incorporate an automatic hammer lift and drop system, which has higher energy efficiency and subseq�encly results in tower N-values than the traditional N� values. By using the PDA euergy measurement equipment, we are able to determine actual energy eenerated by the drop hammer. With the various hammer systems available, we have found highly variabte energies ranging from 55% to over 100%. Tt�erefore, the intent of AET's hammer calibrations is to vary the hammer weieht such that hammer energies lie within about 60% to 65% of the theore[ical ener;y of a 140-pound weight falling 30". The current ASTM procedure acknowledees the wide variation in N-values,sta[ing that N-values of 100%or more have been observed. Althoueh we have noc yet decemuned the scatistical measurement uncertainry of our calibrated method to date, we can sca�e that the accuracy devia[ion of the N-values using this method are significandy hetter than the standard ASTM Method. Disturbed Samples (DS)lSpin-up Samples (Sin Sample rypes described as "DS" or "SU" on the boring logs are disturbed samples, which are taken from the flights of the auger. Because the auger dismrbs the samples, possible soil layering and contact depths should be considered approxunate_ Sampling Limitations Untess actually observed in a sample, contacts between soil layers are estimated based on the spacing of samples and the action of drilling tools.Cobbles, boulders, and other large objects generally cannot be recovered from test borings, and they may be presenc in the ground even if they are not noted on the baring (ogs. CLASSIFICATION 1VfETAODS Soil ciassifica[ions s6own on the boring logs are based on the Unified Soil Classification (USC) system. The USC system is described in ASTM:D2487 and D2488. Where laboratory classificaaon tests (sieve analysis or Atterberg Limits} have been performed, accurate classifica[ions per ASTM:D2487 are possibie. Otherwise, soil classifications shawn on the boring logs are visual-manuai judgments. Charts are attached which provide information on the USC system, the descaptive ter.ninology, and the symbols used on the boring Iogs. ' The boring logs inciude descriptions of apparent geology.The geologic depositional origin of each soil layer is interpreted primarily by ohservatian of the soil samples, which can be 1'united. Ohservations of the surrounding topography,vegetation,and deveiopment can somecunes aid this judgment. WATER LEVEL MEASUREMENTS The ground water level measurements are shown a[the bottom of the boring logs.The foilowing informadon appears under "Wa[er Level Measuremencs" on the logs: • Date and Tune of ineasurement � S2TT1Pled Dep[h: lowest depth of soif sampling ac rhe time of ineasurement • C3SiIIg Depth: dep[h co bottom of casing or hollow-stem auger at nme of ineasuremenc • C3ve-iI1 DePih: dep[h a[which measuring npe scops in t6e borehole • Watei I.2ve1: dep�h in che borehole where free waeer is encaun�ered • Drilling Fluid Level: same az Waier L.evei,except that rhe liguid in the barehole is driltiag fluid The true location of the water table at the boring locations may be different than the water levels measured in the boreholes. This is possible because there are several factors that can affect the water level measurements in the borehole. Some of these factors include: permeability of each saii tayer in profile, presence of perched water, amount of tune between water Ievel readinas, presence of dritling fluid, weather condi[ions, and use of borehole casing. v SAMPLE STORAGE Unless notified to do otherwise, we routinely retain representative samples of the soils recovered from the borings for a period of 30 days. OIREPOSIC(9/03) AMERICAN ENGINEERING TESTING, INC. BORING LOG NOTES DRILLING AND SAMPLING SYMBOLS TEST SYMBOLS Svmbol Definition Symboi Definition CONS: Une-dimensionaI consoiidation test B,H,N: Size of flush joint casing DEN: Dry densiry, pcf CA: Crew Assistant (initials} DST: Direct shear test CAS: Pipe casing, number indicates nominal diameter in E: Pressuremeter Modulus, csf inches HYD: Hydrometer analysis CC: Crew Chief(initials) LL: Liquid Limit, % COT. Clean-out tube LP: Pressuremeter Liruit Pressure, tsf DC: Drive casing; number indicates diameter in inches OC: Organic Content, % DM: Drilling mud or bentonite slurry PERM: Coe�cient of permeability (K) test; F- Fieid; DR: Driller (initials) L- Laboratory DS: Disturbed sample from auger flights PL: Plastic Limit, � FA: Flight auger; number indicates outside diameter in qp: Pocket Penetrometer suength, tsf(�proximate) inches q�: Static cone bearing pressure, tsf HA: Hand auger; number indicates outside diameter q,,: Unconfined compressive strength, psf HSA: Hollow stem auger;number indicates inside diameter R: Electrical Resistiviry, ohin-cros in inches RQD: Rock QuaIity Designation of Rock Core, in percent LG: Field logger(initials) (aggregate leng[h of core pieces 4" or more in length MC: Column used [o describe moisture condition of as a percent of total core run) samples and for the ground water level symhols SA: Sieve analysis N (BPF): Standard pene�ation resistance (I�value) in blows per TRX: Triaxial compression test foot (see notes) VSR: Vane shear strength, remoulded (field), psf NQ- NQ wireline core barrel VSU: Vane shear strengih, undisturbed (field), psf PQ: PQ wireline core barrei WC: Water content, as percent of dry weight RD: Rotary drilling with fluid and roller or drag bit %-2d0: Percent of material finer than#20Q sieve REC: In split-spoon (see notes) and thin-walled tube sampling,the recovered leng[�(in inches)of sample. STANDARU PENETRATION TFST NOTES In rock coring, the length of core recovered (Calibrated Hammer Weight) (expressed as percent of the total core run). Zero � The standard penetration test consists of driving a split-spoon indicates no sarriple recovered. sampler with a drop hammer(calibrated weighc varies to provide REV: Revert drilling fluid N�values)and counting the number of blows applied in each of SS: Standard split-spoon sampler (steel; 13/e" is inside three 6" increments of peneuation. If the sampler is driven less diameter; 2" outside diameter); unless indicated than 18" (usuaIly in highly resistant material}, permitted in otherwise ASTM:DI586, the bIaws for each complete 6" increment and SU Spin-up sample from hollow stem auger for each partial increment is on the boring log. For partial TW: Thin-walled tube; number indicates inside diameter increments, the number of blows is shown to the nearest O.I' in inches below the slash. WASH: Sample of ma[erial obtained by screening returni.ng rotary drilling fluid or by which has collected inside The length of sample recovered, as shown on the "REC" the borehole after"falling" through drilling fluid column, may be greater than the distance indicated in che N WH: Sampler advanced by staac weight of driIl rod and cotumn.The disparity is because the N-value is recorded below hammer the initial 6" set (unless partial penetration defined in WR: Sampler advanced by static weight of drill rod ASTM:D2586 is encouutered) whereas the length of sample 94rnm: 94 millimeter wiretine core barrel recovered is for the entire sampler drive (which may even �- Water level direcily measured in boring extend more than 18"}. 0: Estimated water level based solely on sample appearance O1REP052C(O1/OS) AMERICAN ENGINEERING TESTII�tG, INC. UNIFIED SOIL CLASSIFICATION SYSTEM AMERICAN � ASTM Desigrr�ations: D 2487,D2488 ENGINEERING TESTING, INC. �� Soil Classificanon Notes Cncena Cor Assien�ne Group Symbols and Group Nama Usmg Labora[ory Tesa" Group Group Name "Based on the marerial patsine the 3-in Svmbol (75-mm) sieve. Coarse-Gra�ned Gravels More Clean Gcavels Cu�1 and 1<Cc<3 GW Well graded gravel' eif field sample contained cobbla or Soils NSore than�0%coarse Less than 5% boulders,or both, add"wich cobblcs or than 50% fcac:ior, reea«ed fines� Cu�4 andlor 1>Cv3` GP Poorlv gr�..dc.+�ve! poulders,ar b;,tt;"[o grcup�ame. re[ained on on No.4 sieve �Gmvels wi[h�[o[?%ftnes require dual No.Z00 sieve Gravels with Fina classify as ML or MH GM Silry gravel` ���5: Fines more � GW-GM we[I-graded grave!wi�h silt than i_/o fines Fina dassifi•u CL or C� GC Clayey gavel GW-GC well-graded grdvel with ct�y GP-GM poorly�rraciicd etavcl with silt Sands 50%or Clean Sands Cu?6 and 1<Cc<3 SW well_eraded sand GP-GC poorly graded eavd wrth clay more of coarse Less than 5% °Sands wiih 5 to 12°/a fines reqoire dual frattion passu fines° Cu<b ar 1>Cv3 SP Poorfy-gracied sand symbols: No.4 sieve SW-SM well-graded sand with sift Sands with Fines clazsify as ML or MH SM Silry sand 5W-SC well-graded sand with c[ay Fines more SP-SM poorly graded sand with silt than 12%fines° Fina classi as CL or CH SC Cfavev sand SP-SC poorfy graded sand wi[h clay Fine-Gramed Silts and Clays inorganic PI>7 and plou on or above CL I.ean cla Soils SO%or Liquid limit lus "A"fine� (D���: more pazses than 50 PI<4 or lou below ML Sil ECu=D6olDu,, Cc= the No.200 "A"line� � sievt Dioz D�, � organic Liouid limit—oven dned��S OL Organ�c cla Liquidlimit—notdried o Flfsoilcontains>IS%san�add"with (see Platticity Organic silt� sand"to group name. Chart below) �[f fines classify az CL-ML,use dual Silts and Clays inorganic PI plou on or above"A"line CH Fat cla s�mbol GC-Glv�or SGSNL Liquid limit 50 If fines arc organic,add"wirh organic or more P!ploa below"A"tine MH Elasuc sil fina"to group name. �Ifsoil contains>IS%gravel,add`�vith organic ��puid limit--oven dried�p 75 OH Organic da gravel"to group name. Liquid limit—not dned Q jlf Atterberg(imiu plot is hatched are� Organic silt�'`i soils is a CL-ML silty clay. Highly oroanic Primarily organic matter, dart: PT Pea �'If soil conrains I S to?9�o plus No.200 soil in color,and or�anic in odor add"with sand"or "wich gravel". wh�chevcr is predommant s�vE uu�rs�s m �[f soil contains>30%plus No.200, .�,m..a�n,_,...�...�_� predominanUy sand,add "sandy/'[o �a h.�,v m.,..s.�.o.d. �r o�n + a w x n m +.o�o � group name. 'm' '' '' ; � � I i� s � �v,�-F-�,,, 1 "�tf soil contains>30%plus No-200, :1,i ; - MovailR.amLL�HS af"' f2dORLI12f1I� V �� � i I i I �� � o,,,R.n��-� ��' � P Y� el,add "gravefly" � �i I ' j I � � j '� � � '� to group name_ �a} ' : i+ ;o,'„y,;,, ; , � �� � � v:v u eA=; I , �. I �Pb4 and plo[s on or above"A"line. a �i �� ' I`� { i I I �`� � b °�R�aD�u,� G °Pf<4 or plocv below"A"line. � j ; � i , ( I � . I F PPI plocc on or abovc"A"line. � � l i I � i p.:zs.�I � � m �' I QPI plors betow"A"[ine. , �, � Fiber Content dacripuon shown below. I` I : I I I C; OH�M n � ' � ( � m U«RQt'a.n �, ;' � i I I I i I ! ,� : - ML�OL . n •, •, °o ,o ro a m m so m �u eo 00 ,ro no �°A�'���'"'"""�5 uano u�.sr a.0 G�0.•YnIDS•m G. IdY i .i6 o-•d�•,s Plazucity Char[ ADDITIOPtAL 1'ERMINOLOGY NOTES USED BY AET FOR SOIL IDENTIF1CA7701Y AND DESCRIPTION Gram Size Gravel Percen[aees Consistenct�of Plastic Soils Relative Densitv of Non-Plastic Soils Tertn Particle Size Term Percent Tertn N-Value.BPF erm N-Velue.BPF Boulders Over IZ" A Little Gravel 3%-14% Very 5oft las than 2 Very Loose p_y Cobbles 3"to 12' Witfi G�avel IS%-29% Soft 2-4 Loose 5-1D Gravel {t4 sieve to 3" Gcavelly 30%•50% Firm 5-8 Medium Dense f 1-30 Sand �200 to#4 sieve Saff 9-l5 Drnce 31-50 Fines(silt&clay) Pass�200 sieve Very Stiff 16-30 Very Dense Greater than 50 Hard Greater than 30 MoismrdFrost Condnion Laverine No�es I Fiber Con�en[of Peaz OreanidRooa Descnu[ion(if no lab rests) (MC Column) Laminations: Layers less than Fiber Content Soits are dacribed as nrronic,if soif is not peat �(uryj. i�th�uc of muistwe,�i-m�ty,dry w 'l," �.�c��a: ";e�^; (`.rises!e•r:•••�••� a.^.d s jedped •r F�av? suffic�en! organic fines iouch. differing ma�eria! �+ ~� conrcnc to influence the soi!propertia. li hdi� M(Moist): Damp,although frer water noc or color. Fibric Pcat Grearer than 67% orranic used for bordedine c�sa. v�sible. Soil may still have a high Hemic Peat: 33—67% �vater con¢nt(over'optimum"). Lenses: Pockea or layers Sapnc Pear. Less than 33% With roots: Judged to have sut�cient quantiry w(weV Free wa[er visibfe in[ended w greaur than Y:" af roots to influence the soil �Naterbearing): describe non-pluUc soils. [hick of difFuing propertiu. Wazerbearing usually rela[cs[o ma[erial or color. Trace roo[s: Small roo[s presrn4 bu[no[judged sands and sand with silt �o be in sufficient m F(Frozen): Soil iroun �� significanU}•affm soil proper[ies. OlCLS021(2/04) ANIERICAN ENGINEERING TESI'ING,INC.