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HomeMy WebLinkAboutGeotechnical exploration oslund.and.assoc. 115 Washington Avenue North • Minneapolis, Minnesota 55401 Telephone: 612.359.9144 Fax: 612.359.9625 T r a n s m i t t a I To: Greg Gappa Date: March 9, 2001 City of Orono Job#: 1580.001 2750 Kelley Parkway Project: Minnetonka Center for the Arts Crystal Bay, MN 55323 From: Joe Favour, ASLA U.S. Mail: ❑ One Hour Courier: 0 Three Hour Courier: ❑ Overnight Delivery: ❑ Fax: ❑ Other: ❑ Fax Number: Number of Pages: Message: Attached, please find revised drawings (full size ��sets), a copy of the site's soil report, and a letter from our engineer about his conversation with Ismael Martinez of Bonestroo. We had a site meeting with the adjacent property owner to discuss options for the drainage through her site. After a subsequent conversation with Tom Kellogg, we revised our solution to provide overland drainage through the neighbor's property rather than a pipe. The neighbor(Nancy Roehr) prefers this solution. We have attempted to offset any erosion concerns with rock dams and rip-rap at the outlet. Please call me if you need additional information or have any questions. Thanks. ' .,��.,. ' �,,��, ��.,,,� ',, "�� ;_ � d, , - . � . ���,�,. Civil& Cons�� gineering,Inc. .�� March 6, 2001 ; Mr. Joe Favour Oslund and Associates 115 Washington Ave. North Minneapolis,MN 55401 Planning RE: Hydrology Analysis Minnetonka Center for the Arts Design Orono, MN MCCE Project No. 10081 Development Dear Mr. Favour, Construction I met with Mr. Ismael Martinez of Bonestroo, Rosene, Anderlik & Associates on this day to discuss the issues that were mentioned by Mr. Tom Kellogg in our meeting on Friday March 2, 2001. In my meeting with Mr. Martinez we discussed issues regarding CN values, the rainwater gardens, and several issues regarding the proposed pond and the overall water quality 2021 provided in by the proposed storm water management system. The issues regarding the xennepin Ave.E. pond were related to changing the bench in the pond to 10:1 from 20:1, providing some free Suite 355 board above the high water level, making a minor modification to the pond outlet structure Minneapolis to provide a skimmer. MN 55413 At this time it is my understanding that no additional design or redesign is required. By Phone: addressing the free board, bench profile, and outl�t structur� we s�iould meet the city's (612)676-0321 design criteria. It appears that additional conversations witn the city will be necessary regarding the water quality issue. It may be possible to address the water quality issue by Fax: enlargement of the rainwater gardens. This would have no impact on the flow quantity (612)676-1624 leaving the site. Visit our website at: If you have any questions regazding this letter please or if additional information is required www.masterengr.com please contact me. s OENEqq� `��, Sincerely, �A �� M�ster Civil & Construction Engineering, Inc. - y _ _ _ . r - �°F.,��w"� : _ Barry Morg , P.E.' � Project Manager GEOTECHNICAL EXPLORATION MINNETONKA CENTER FOR THE ARTS 2240 NORTH SHORE DRIVE WAYZATA, MINNESOTA GME PROJECT NO. 9256 � Copyright, 2001 - GME Conaultants, Inc. OMt CONSULTANTf,INC. GME CONSULTAIVT IN � S, C. CONSULTING ENGINEERS 14000 21 st Ave. No. / Minneapolis, MN 55447 Phone (763) 559-1859 / Fax (763) 559-0720 January 17, 2001 l�ir. Gary Gleason, P.E. M.A. Mortenson Company P.O. Box 710 Minneapolis, Minnesota 55440 Project No. 9256 RE: Geotechnical exploration for the Minnetonka Center for the Arts at 2240 North Shore Drive in Wayzata, Minnesota Dear Mr. Gleason: FolTowing the acceptance of our proposal of November 7, 2000, we have completed this. geotechnical exploration. In this report we present the results of our field and laboratory testing, and our recommendations for foundation and earthwork design and construction. We are submitting four copies of this report to you. We have enjoyed working with you on this phase of the development . If you have questions regarding this report, please contact us. Si cerely, G ONSU TANTS, INC. Wi iam C. Kwasn , P.E. Principal E esident WCK:ms W:\WCK\9256.dtr.ms WILLIAM C. KWASNY, P.E. THOMAS P. VENEMA, P.E. TAMMY A. LANDERS, P.E. GREGORY R. REUTER, P.E., P.G. BRYAN J. R�PP, P.E., P.G. WILLIAM E. BLOEMENOAL, P.E. MARK D. MILLSOP, P.G. TIMOTHY R McGLENNEN ERIN J. 0'BRIEN, P.E. An Equal Oppartunity Employer TABLE OF CONTENTS MINNETONKA CENTER FOR THE ARTS 2240 NORTH SHORE DRIVE WAYZATA, MINNESOTA GME PROJECT NO. 9256 SECTION PAGE ASFE Notes Regarding Geotechnical Exploration Reports INTRODUCTION 1 FIELD EXPLORATION 2 LABORATORY TESTING 3 SITE CONDITIONS 4 Topography/Surface Features 4 Soil Conditions 5 Groundwater Conditions 5 REVIEW AND RECOMMENDATIONS 6 Discussion 6 Site Preparation 7 Building Foundations 9 � Floor Slab Subgrade 11 Exterior Slabs and Patios 12 Pavement Subgrade 12 Stormwater Pond 14 CONSTRUCTION CONSIDERATIONS 15 Groundwater 15 Equipment Selection/Soil Disturbance 15 Winter Construction 16 Construction Safety 16 � Construction Testing 17 GENERAL QUALIFICATIONS 17 � STANDARD OF CARE 19 APPENDIX OME CONSULTANTf,INC. GME CONSULTANTS, INC. IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL ENGINEERING REPORT As the client of a consulting geotechnical engineer,you should know that site subsurface conditions cause more construction problems than any other factor. ASFE/The Association of Engineering Firms Practicing in the Geosciences offers the foliowing suggestions and observations to heip you manage your risks. A Geotechnical Engineering Report Is Based On A Unique Set Oi Project-Specific Factors Your geotechnical engineering report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors. These factors typically inciude: the general nature of the st�ucture involved, its size, and configuration; the location of the structure on the site; other improvements, such as access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the client.To help avoid costly problems,ask your geotechnical engineer to evaluate how factors that change subsequent to the date of the report may affect the reporYs recommendations. Unless your geotechnical engineer indicates otherwise, do not use your geotechnical engineering report: • when the nature of the proposed structure is changed,for example, if an office building will be erected instead of a parking garage, or a refrigerated warehouse will be built instead of an unrefrigerated one; • when the size, elevation, 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 adjacent site. � Geotechnical engineers cannot accept responsibility for problems that may occur if they are not consulted after factors considered in their report's development have changed. , Subsurface Condltlons Can Change A geotechnical engineering report based on conditions that existed at the time of subsurface exploration. Do not base construction decisions on a geotechnical engineering report whose adequacy may have been affected by time. Speak with your geotechnical consultant to learn if additional tests are advisable before construction starts. Note, too, that additional tests may be required when subsurface conditions are affected by construction operations at or adjacent to the site, or by natural events such as floods, earthquakes, or g�ound water fluctu- ations. Keep your geotechnical consultant apprised of any such events. Most Geotechntcal Flndings Are Professional Judgments Site exploration identifies actual subsurface conditions only at those points where samples are taken.The data were extrapolated by your geotechnical engineer who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations; you and your geotechnical engineer can work together to help minimize their impact. Retaining your geotechnical engineer to observe construction can be particularly bene- ficial in this respect. A Report's Recommendations Can Only Be Preliminary The construction recommendations included in your geotechnical engineer's report are preliminary, because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Because actual subsurface conditions can be discerned only during earthwork, you should retain your geotechnical engineer to observe actual conditions and to finalize recommendations.Only the geotechnical engineer who prepared the report is fully familiar with the background information needed to determine whether or not the report's recommendations are valid and whether or not the contractor is abiding by applicable recommendations. The geotechnical engineer who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another party is retained to observe construction. Geotechnical Servlces Are Perfortned For Specific Purposes And Persons Consulting geotechnical engineers prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a coostruction contractor or even another civil engineer. Unless indicated otherwise,your geotechnical engineer prepared your report expressly for you and expressly for purposes you indicated. No other than you should apply this report for its intended purpose without first conferring with the geotechnical engineer. No party should apply this report for any purpose other than that originally contemplated without first conferring with the geotechnicaf engineer. GME CONSULTANTS,INC. Geoenvironmental Concems Are Not At Issue Your geotechnical engineering report is not likely to relate any findings,conclusions,or recommendations about the potential for hazardous materials existing at the site. The equipment, techniques, and personnel used to perform a geoenvironmental exploration differ substantially from those applied in geotechnical engineering. Contamination can create major risks. If you have no information about the potential for your site being contam- inated, you are advised to speak with your geotechnical consultant for information relating to geoenvironmental � issues. A Geotechnical Engineering Report Is Subject To Misi�terpretation Costly problems can occur when other design professionals develop their plans based on misinterpretations of a geotechnical engineering report. To help avoid misinterpretations, retain your geotechnical engineer to work with other project design professionals who are affected by the geotechnical report. Have your geotechnical engineer explain report implications to design professionals affected by them, and then review those design professionals'plans and specifications to see how they have incorporated geotechnical factors.Although certain other design professionals may be familiar with geotechnical concerns, none knows as much about them as a competent geotechnical engineer. _ Boring Logs Should Not Be Separated From The Report Geotechnical engineers develop final boring Iogs based upon their interpretation of the field logs(assembled by site personnel) and laboratory evaluation of field samples. Geotechnical engineers customarily include only final " boring logs in their reports. Final boring logs should not under any circumstances be redrawn for inclusion in architectural or other design drawings,because drafters may commit errors or omissions in the transfer process. � Although photographic reproduction eliminates this problem, it does nothing to minimize the possibility of contractors misinterpreting the logs during bid preparation. When this occurs, delays, disputes, and unantici- pated costs are the all-too-frequent result. � To minimize the likelihood of boring log misinterpretation, give contractors ready access to the complete geotechnical engineering report prepared or authorized for their use. (If access is provided only to the report prepared for you, you should advise contractors of the reporYs limitations, assuming that a contractor was not one of the specific persons for whom the report was prepared and that developing construction cost estimates was not one of the specific purposes for which it was prepared. In other words, while a contractor may gain important knowledge from a report prepared for another party, the contractor would be well-advised to discuss the report with your geotechnical engineer and to perform the additional or alternative work that the contractor believes may be needed to obtain the data specifically appropriate for construction cost estimating purposes.) � Some clients believe that it is unwise or unnecessary to give contractors access to their geotechnical engineer- ing reports because they hold 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. It also helps reduce the adversarial attitudes that can aggravate problems to disproportionate scale. Read Responsibllity Clauses Closely Because geotechnical engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines.This situation has resutted in wholly unwarranted claims being lodged against geotechnical engineers. To help prevent this problem, geotechnical engineers have developed a number of claus�s for use in their contracts, reports, and other documents. Responsibility clauses are not exculpatory clauses designed to ` transfer geotechnical engineers'liabilities to other parties. Instead,they are definitive clauses that identify where geotechnical engineers' responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your geotechnical engineering report.Read them closely. Your geotechnical engineer will be pleased to give full ��� and frank answers to any questions. Rely On The Geotechn(cal Engineer For Addlttonal Asslstance _. Most ASFE-member consulting geotechnical engineering firms are familiar with a variety of techniques and approaches that can be used to help reduce risks for all parties to a construction project, from design through construction. Speak with your geotechnical engineer not only about geotechnical issues, but others as well, to learn about approaches that may be of genuine benefit. You may also wish to obtain certain ASFE publications. ` Contact a member of ASFE for a complimentary directory of ASFE publications. l �45EETHE ASSOCIATION � RACT CINNG IN HE GEOSCIENCES § � 8811 COLESVILLE ROAD/SUITE G106/SILVER SPRING,MD 20910 TELEPHONE: (301)565-2733 FACSIMILE: (301)589-2017 '_. 6M6 CONSULTANTS,INC. f INTRODUCTION The existing facility for the Minnetonka Center for the Arts at 2240 North Shore Drive will be razed and a new building will be constructed to the north. The existing structure covers a footprint of about 17, 000 square feet and has a full basement; the demolition would require f�lling in the basement excavation. The new building will be a one and two-story structure with a footprint of about 25, 000 square feet, of steel frame and steel stud wall/brick veneer construction. Although the structural loads are not yet available, we estimate column loads in the range of 75 to 100 kips, and wall loads of 2 to 4 kips per lineal foot . The first floor slab of the new building will be cast on-grade; there will be no basement. The finished floor elevation will be 964 . 0 feet National Geodetic Vertical Datum (NGVD) . This will require the placement of as much as 3 to 4 feet of fill in the northern portion of the new building, as well as backfilling of the old basement excavation. We estimate that live floor loads in a building of this type wQuld probably not exceed 200 pounds per square foot . Extensive paved exterior courtyards, and paved parking and drive areas will be constructed to the south and west of the new building, after demolition of the existing building has been completed. The traffic pattern on the pavements would probably consist of numerous daily passes oMe coNsu�raNrs,iNc. M�. Gary Gleason, P.E. 2 January 17, 2001 GME ProjeCt No. 9256 of automobiles and light trucks (pick-ups and vans) , with occasional heavier vehicles such as waste collection trucks, delivery trucks . A riprap lined infiltration trench for stormwater disposal is planned in the southeast corner of the site . The purpo�es of this report are to describe the soil and groundwater conditions encountered in our subsurface exploration; to review and evaluate these conditions with respect to the proposed project; and to present r�commendations for methods of foundation and earthwork design and cons�ruction. FIELD EXPLORATION We drilled 12 borings for this project, as shown on the enclosed Soil Bqring Location Diagram. We suggested the number, depths, and locations o� the borings, based on the site plan for the new structure. We located the borings in the field by measuring from the existing building, using d�mensions scaled from the site plan. Our crew shot surface elevations at the borings in NGVD referenced to the f�rst floor of the existing building at the entrance on the south side. T�e elevation at this location is approximately 966 NGVD. Before we drilled, we contacted Gopher State One Call to locate public underground utilities. BM!CONWITANTl,INC. Mz. Gary Gleason, P.E. 3 January 17, 2001 GME Project No. 9256 We drilled the borings with a BK51HD rig, using hollow stem augers to advance the boreholes and sampling by the split barrel method (ASTM: D 1586) . Our crew kept field logs noting the methods of drilling and sampling, along with Standard Penetration values, preliminary soil classifications, and observed groundwater levels . Representative portions of the recovered samples were sealed in jars to reduce moisture loss, and submitted to our laboratory for examination, testing and f 'inal classification by a Geotechnical Engineer. We backfilled the boreholes with soil cuttings to comply with current Minnesota Department of Health r�gulations . , LP,BORATORY TESTING T$e laboratory testing program was initiated by a Geotechnical Engineer examining each of the recovered samples to determine the major and minor soil companents, while also noting the color, degree of saturation, and lenses or seams found in the samples . Selected samples were testec� for moisture content; the results of these tests are shown on the respective lpgs in the Appendix. The Engineer visually/manually classified each sample on the basis of texture and plasticity in accordance with the Unified Classification Soil System (USCS) . The capital letters and symbols in parentheses �ollowin,� the written soil descriptions on the boring logs are the BNIi CONlU�TANTf.INC. Mr. Gary Gleason, P.E. 4 January 17, 2001 GME Project No. 9256 estimated group symbols based on this system. A chart describing this classification system is included in the Appendix of this report . The Engineer grouped the soils by type into the strata shown on the boring logs . The stratification lines are approximate; in situ, the transition between soil types may be gradual or abrupt in the horizontal oz vertical directions . W� will retain the soil samples from this program for 30 days after the d�te of this report . If you wish to have the samples retained beyond this time, we ask that you please advise us; otherwise, the samples will b� discarded. SITE CONDITIONS Tppography/Surface Features At the time of our field exploration the site of the proposed addition was a landscaped area to the north of th� existing building. The ground surface was relatively level among our borings; we found about 3 to 4 feet of elevation difference, at a few feet below the existing slab. The site was snow covered at the time of our drilling. It appeared that the vegetation consisted of lawn, trees, and shrubs. , OME CONSYLTAMTS,INC. Mr. Gary Gleason, P.E. 5 January 17, 2001 GME Project No. 9256 . Soil Conditions The soil conditions we found in the borings are shown on the logs in the Appendix of this report . The conditions that we describe and discuss in this report are pertinent only at the boring locations and under the environment at the time of our field exploration. We encountered a topsoil layer consisting of dark brown to brown sandy silt with organic material and roots . ' The topsoil ranged from 1 to 2 feet thick. We encountered frost to a depth of 1 . 6 feet in the topsoil layer in �he underlying soils . Underlying the topsoil, we encountered granular soils ranging from silty sand with clay, to silty sand, to sandy silt and clayey silt . We also encounter�d occasional strata of silty clay with sand. The granular soils were loose to medium dense, with N-values ranging from 6 to 23 . T�e cohes�ve and semi-cohesive soils were generally stiff to very stiff . Gxoundwater Conditions � We did not encounter groundwater in our borings during or after completion of drilling. Based on the relatively permeable soils that we encountered, it is our opinion that these water level readings were representative of the groundwater conditions on the date of drilling. , OME CON8ULTANTS,INC. Mr. Gary Gleason, P.E. 6 January 17, 2001 GME Project No. 9256 The general grades around the site are at about elevation 965 . The normal water elevation of Lake Minnetonka, a few blocks to the east, is at about 929 .5 . It is our opinion that they hydrostatic groundwater table on this site, although it will fluctuate in elevation seasonally and annua�ly depending on local amounts of precipitation, evaporation, and infiltration, would not rise to such a level as to detrimentally affect the construction or performance of the proposed new building. REVIEW AND RECOMMENDATIONS Discussion Based on the conditions found in the borings, it is our opinion that the proposed x�ew building can be supported on conventional spread footing foundations, after site preparation, to include stripping of topsoil and all below-grade remnants of the razed building (including footings, foundation walls, floor slabs, and existing underground utilities) , and placement of compacted granular fill to form a building pad. Because of the sensitive nature of the high moisture sandy silt and clayey silt; we recommend placing a "mud mat" of 2 to 3 inches of lean eoncrete at the b�se of all footing excavations . This would help limit soil disturbance during fox�ming. 6Mt CONSULTANTS,INC. Mr. Gary Gleason, P.E. 7 January 17, 2001 GME Project No. 9256 Under the exterior patios, we recommend placement of a select non-frost susceptible (NFS) granular fill . Many of the soils encountered in our borings, although suitable for the support of foundations, are frost- susceptible and would seasonally freeze, expand, and heave the patio slabs or pavements . Placement of NFS backfill would mitigate this potential problem. Details of our recommendations are presented below. Site Preparation We recommend that all of the remnants of the existing building, including foundations, floor slabs, foundation walls, and underground utilities, be completely removed to expose the naturally-occurring underlying soils . In the main portion of the new building footprint, we recommend stripping the topsoil, and removing all tree stumps, major root systems, and other vegetation. The exposed soil at the base of the excavation and stripped areas should be compacted in-place with a heavy towed or self-propelled vibratory roller, applying a minimum of eight passes . � We recommend that only select granular soil be used as the backfill . This should be a material such as Mn/DOT 3149 .2B1, 2B2, 2C, or 2D. In addition, if the contractor wishes to propose another granular material for consideration, a sample should be sent to our laboratory for 6MB CONs11�TANTd,INC. Mr. Gary Gleason, P.E. 8 January 17, 2001 GME Project No. 9256 gradation testing and review by a Geotechnical Engineer to determine the suitability. We do recommend that fill material such as silty fine sand, uniformly graded fine sand, or clayey sand not be used as the fill . The granular fill should be placed in loose lifts about S to 10 inches thick. Each lift should be uniformly compacted to at least 95� of the maximum Modified Proctor dry density (ASTM: D 1557) . Under areas where the exterior patios, sidewalks, and entry slabs will be constructed, on the south and east sides of the building, we recommend that a special material be used as the subgrade soil, consisting of NFS sand. This should be a material such as Mn/DOT 3149 .2J, limited to no more than 4� passing the No. 200 sieve. The purpose of using NFS sand subgrade is to reduce the potential for the expansion that silty or clayey soils undergo when they freeze in the winter. This expansion can cause heaving of overlying slabs or pavements. Typically, this heaving is non-un�form, and can result in cracking and unevenness of the slabs . The NFS sand subgrade should be at least 3 feet thick under the exterior patios. It should be placed in loose lifts about 8 to 10 inches thick, and compacted to at least 95� of the maximum Modified Proctor dry density. OME CONSULTANT:,INC. Mr. Gary Gleason, P.E. 9 January 17, 2001 GME Project No. 9256 We recommend that an underdrain system be placed in all of the NFS sand subgrades, consisting of minimum 4 inch diameter continuous plastic pipe, slotted or perforated, and factory-wrapped in a geofabric sock. We recommend that these drain pipes be spaced no more than 20 feet on-center. They should be connected to one or more headers, and drained tp the stormwater pond located in the southeast corner of the site. The purpose of the drainage system is to remove water infiltrating into the free-draining NFS sand fill . In a11 footing excavations, we recommend that the contractor use a backhoe with a smooth edged bucket rather than a toothed bucket, to avoid tearing or ripping the bearing soiT . The sandy and clayey silt soils would be difficult to re-import . Each excavation base �areas should then be covered with a "mud mat" of 2 to 3 inches of lean concrete. The forms and reinforcing steel can be set on the "mud mat . " BuildinQ Foundations After the site has been prepared as described above, the building may be supported on conventional spread footing foundations. We recommend that the bottom of exterior footings for the heated building bear at least 4 feet below final outside grade for protection from frost penetration. The bottom of interior footings should typically bear about 18 to 24 -� OME CONdULTANTS,INC. Mr. Gary Gleason, P.E. 10 January 17, 2001 , GME Project No. 9256 ' inches below finished floor elevation, provided that these footings would not be subjected to winter conditions during construction. At these depths of embedment, we anticipate that the footings would bear on compacted granular fill placed over a densified non-organic soil subgrade, or on the naturally-occurring soils having a minimum N-value of 6 blows per foot . We recommend that these footings be proportioned for a maximum allowable design bearing pressure of 2, 500 pounds per square foot to proportion the footing sizes . This refers to the pressure that may be transmitted to the bearing stratum in excess of the pressure from the surrounding depth of overburden. The factor of safety with respect to - soil bearing capacity for. this design would exceed 3 . We recommend that continuous wall footings have a minimum width of 2 feet and that isolated column footings have a minimum width . of 3 feet, to avoid excessively narrow footings, regardless of the contact pressure. With this design, we estimate that maximum building settlement would be about 1 inch, with differential settlement approximately half this amount, provided that the bearing soils are not soft, wet, disturbed,� or frozen at the time of construction. OME CONfULTANTf,INC. Mr. Gary Gleason, P.E. 11 January 17, 2001 GME Projeet No. 9256 Floor Slab Subgrade We recommend that backfill around the new foundations and in underslab utility trenches be select imported granular soil . This material should be placed in loose lifts about 6 inches thick, and compacted with manually-operated vibratory plate compactors to at least 95� . We recommend that large towed or self-propelled vibratory compactors not be used within 4 feet of new foundation walls, to avoid damaging these walls . Based on a subgrade prepared with fill placed during mass grading, and with compacted fill placed in foundation and utility trenches as described above, the floor slab may be cast on-grade. We recommend that the Structural Engineer use a modulus of subgrade reaction of 175 pounds per cubic inch to design the floor slab thickness and reinforcement . Because of the silty and semi-cohesive nature of some of the subsoils encountered in our borings, we recommend that a vapor barrier be placed � under the floor slab. The purpose of a vapor barrier is to reduce �the potential for the upward migration of water vapor from the soil into and through the concrete slab. Water vapor migrating upward through the slab can damage floor. coverings such as tile, carpeting, or wood. One method for installing a vapor barrier is given in Part 2, Section 302, of the Manual of Concrete Practice of the American Concrete Institute. However, OM!CONSULTAMTS.INC. Mr. Gary Gleason, P.E. 12 January 17, 2001 GME Project No. 9256 we also recommend that you contact the manufacturers of the specified floor coverings to determine how they wish to have the vapor barrier installed, since their preferred method may vary from the ACI . The floor slab have construction joints and control joints at spacings recommend by the Portland Cement Association and the American Concrete Institute, to reduce the potential for excessive curling and cracking. The slab should be cast independent of the foundation walls and footings of the building, to allow for relative movement between the structural members . Exterior Slabs and Patios In a previous section of this report, we presented our recommendations for constructing a subgrade of NFS sand for exterior patios and slabs . We recommend that these slabs be designed using a modulus of subgrade reaction of 150 pounds per cubic inch. The slabs should not be �attached to the building by mechanical connections or reinforcing steel . Pavement Subgrade The borings in the areas that will be paved indicate variable soil conditions, including silty sand, sandy silt, and clayey silt below the . OME CONSULTANTs,INC. Mr. Gary Gleason, P.E. 13 January 17, 2001 GME Project No. 9256 topsoil . Prior to placement of fill needed to grade the site, we recommend that all the surficial topsoil and vegetation be stripped. We recommend that the pavement section include a minimum of 1 foot of select free-draining sand to form a subbase . This will help extend the pavement life. Preparation of the subgrade and placement of the sand subbase should be carried our as described under the Site Preparation section of this report . Based on a subgrade as described above, we recommend the following pavement section. RECOMMENDED PAVEMENT THICKNESSE3 Light-Duty Heavy-Duty (automobiles/light (entry/service Pavement Component trucks) drives) Subbase, fr'ee-draining sand 12 inches 12 inches Granular base course, . Mn/DOT 6 inches 10 inches Class 5 100� crushed rock or 100� recycled concrete Binder course 1 .5 inches 2 inches Tack Coat, Mn/DOT 2357 Yes Yes Wear course 1 . 5 inches 2 inches We estimate that these pavement sections would have a useful life of 10 to 15 years. However, this does not mean that the pavements would last this period of time without maintenance. Within one to three� years after construction, typical shrinkage cracks will develop due to thermal expansion and contraction of the pavement, and due to the loss of volatile tiME CONSULTANTS,INC. Mr. Gary Gleason, P.E. 14 January 17, 2001 GME Project No. 9256 compounds from the bituminous cement . These cracks should be cleaned and sealed wit� a hot flexible material on an annual basis. Within three to five years after construction, distressed areas may develop at entry drive and areas where service trucks are parked or slowly turn. Such areas should be cut out and repaired expeditiously in order to extend the pavement life. Periodically during the course of the pavement life, a seal coat of hot bituminous and rock chips should be applied. The determination of when to apply a seal coat should be made by the Civil Engineer responsible for the facility maintenance. Stoz�rwater Pond We drilled boring P-3 in the area of the stormwater pond. In this boring, we encountered sandy silt with clay to a depth of 6 feet, underlain by silty sand to 10 feet. In our opinion, these soils have relatively low to moderate permeability, which we estimate would only permit very limited infiltration of collected stormwater. We recommend using this pond as a colZector pond, to allow sedimentation of suspended solids in the water. However, it is our opinion that it may be necessary to dispose of this pond by outflow, rather than by infiltration, based on the soil conditions in the area where the pond is proposed. 9ME CONSULTANT�,INC. Mr. Gary Gleason, P.E. 15 January 17, 2001 GME Project No. 9256 CONSTRUCTION CONSIDERATIONS Groundwater Based on the conditions found in our borings, it is our opinion that the hydrostatic groundwater table would not be encountered during excavation or construction for this project based on the proposed depths. Water which enters excavations from surface runoff, precipitation,. or perched groundwater seepage should be promptly pumped out . It should not be allowed to stand ponded over the foundations, floor slab, or pavement bearing/subgrade soils, since standing water would soften and disturb - these soils. � The contractor should not be allowed to place concrete or fill into standing water or over soils softened in an attempt to displace these materials . This technique can result in trapping the softened soils under the building, causing excessive post-construction settlement, even if the softened zone is only a few inches thick. Equipment Selection/Soil Disturbance The soil types at this site can be easily disturbed by construction equipment, especially when the soils are saturated or during freeze/thaw conditions. It is the earthwork contractor' s responsibility to choose •M!CONfULTANTl,INC. Mr. Gary Gleason, P.E. 16 January 17, 2001 GME Project No. 9256 equipment and work procedures which will not disturb the subgrade soils . The contractor should also route construction traffic away from foundation soils, and areas of pavements and slabs, to reduce soil disturbance. If the equipment the contractor selects causes rutting or pumping, it is the earthwork contractor's responsibility to switch to other types of equipment or methods. The responsibility to properly select construction equipment to avoid disturbing soils on the site lies solely with the contractor. A note to this effect should be included in the project specifications. Winter Construction Only unfrozen backfill shou�d be used, and contractors may charge extra for importing unfrozen soil or keeping backfill from freezing. Placement of fill and/or foundation concrete must not be permitted on frozen soil, nor should bearing soils under footings or slabs be allowed to freeze after concrete is placed, because excessive post-construction settlement could occur as the frozen soils thaw. ' Construction Safetv All excavations must comply with the requirements of OSHA 29 CFR, Part 1926, Subpart P, "Excavations and Trenches. " This document states that OM�CONSYLTANTB,INC. Mr. Gary Gleason, P.E. 17 January 17, 2001 GME Project No. 9256 excavation safety is the sole responsibility of the contractor. Reference to this OSHA requirement should be included in the job specifications . The responsibility to provide safe working conditions on the site, for earthwork, building construction, or any associated operations, is not borne in any manner by GME Consultants, Inc. Construction Testing � We recommend that the Owner, or the designers acting as the Owner' s � representative, retain the testing services for this project, in accordance with the Uniform Building Code. This should include � observation and testing of subgrade soils during site preparation, and laboratory Proctor tests, and gradation tests and field density tests of compacted fill and backfill. The building materials should be constructed in accordance with UBC requirements or "Special Inspections." We welcome the opportunity to provide the observation and testing services for this project . � QENERAL QUALIFICATIONS This report has been prepared based on the soil and groundwater conditions found in our borings and on the design data available from OM�CONSULTANTt,INC. Mr. Gary Gleason, P.E. 18 January 17, 2001 GME Project No. 9256 M.A. Mortenson Company. This report is intended solely for this project at the specific locations discussed. If there are any changes in size, scope, elevations, structural loads, use, or nature of the building from those outlined in the Introduction of this report, or if our understanding of the project is incomplete or incorrect, it is necessary that you contact us so we can review our recommendations to determine if they are applicable. If we are not given the opportunity to review any changes in the design, then the recommendations presented in this report shall not be considered valid. We determined the soil and groundwater conditions at 13 (or 12???) locations on this site. The subsurface conditions that we describe and discuss. in this report are pertinent only at the boring locations and under the environment at the time of our field exploration. We encountered variations in the subsurface conditions, and it is likely that additional variations exist that cannot be determined from our borings or from our site reconnaissance. These variations would not become apparent until construction excavation is started. No warranty, express or implied, is presented in� this report with respect to the soil and groundwater conditions on this site. 8Mt CONSULTANTs,INC. Mr. Gary Gleason, P.E. 19 January 17, 2001 GME Project No. 9256 STANDARD OF CARE The recommendations contained in this report represent our professional opinions. The soil testing and geotechnical engineering services performed for this project have been conducted in a manner consistent with that level of skill and care ordinarily exercised by other members of the profession currently practicing in this area, under similar budgetary and time constraints. No other warranty, express or implied, is made. Prepared by: i iam C. K , P.E. rincipa ngin er/President • � Reviewed by: Thomas P. Venema, P.E. Principal Engineer/Vice President WCK:ms w:\wck\9256 dtr.ms.doc I hereb certify that his plan, speciflcatio�, or report as re are by me or under my direct • supe i i a at 1 am a duly Registered - Prof i ineer under the laws ot the Sta f i ta � illi m C.Kwasn Date: ��/� d� Reg.No.11427 9MB CONSULTANTs,INC. GENERAL NOTES DRILLING &SAMPLING SYMBOLS: SL : SS with Liner SS : Sptit Spoon—1�e" I.D.,2"O.D., unless OS : Osterberg Sampler—3"Shelby Tube otherwise noted HS : Hollow Stem Auger ST : Shelby Tube—2"O.D., unless otherwise noted WS : Wash Sample PA : Power Auger FT : Fish Trail DB : Diamond Bit—NX: BX:AX RB : Rock Bit AS : Auger Sample BS : Bulk Sample JS : Jar Sample PM : Pressuremeter test—in situ VS : Vane Shear Standard"N"Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2 inch OD split spoon, except where noted. WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WCI : Wet Cave In DCI : Dry Cave In WS : While Sampiing WD : While Drilling BCR: Before Casing Remvoal ACR: After Casing Removai AB : After Boring Water levels indicated on the boring logs are the levels measured in the boring at the times indicated. In previous soils, the indicated elevations are considered reliable ground water levels. In impervious soils,the accurate determination of ground water elevations is not possible in even several days observation,and additional evidence of ground water elevations must be sought. GRADATION DESCRIPTION &TERMINOLOGY Coarse Grained or Granular Soils have more than 50%of their dry weight retained on a#200 sieve;they are described as: boulders,cobbles,gravel or sand.Fine Grained Soils have less than 50%of their dry weight retained on a#200 sieve;they are described as:clays or clayey silts if they are cohesive,and silts if they are non-cohesive. In addition to gradation,granular soils are defined on the basis of their relative In-place denslty and fine grained soils on the basi� of their strength or consistency,and their plasticity. MaJor Descrfptive Term(s) Component (Of Components Also Percent of Of Sample Size Range Present in Sample) Dry Welght Boulders Over 8 in. (200mm) Trace 1 —9 Cobbles 8 in.to 3 in. Little 10—19 (200mm to 75mm) Gravel 3 in.to#4 sieve Some 20—34 (75mm to 2mm) Sand #4 to#200 sieve And 38—50 (2mm to.074mm) Silt Passing#200 sieve (0.074mm to 0.005mm) Clay Smaller than 0.005mm CONSISTENCY OF COHESIVE SOILS: RELATIVE DENSITY OF GRANULAR SOILS: Unconiined Comp. Strength',Qu, tsf Consistencv N—Blows/ft. Relative Density <0.25 Very Soft 0—3 Very Loose 0.25—0.49 Soft 4—9 Loose 0.50—0.99 Medium (Firm) 10—29 Medium Dense 1.00— 1.99 Stiff 30—49 Dense 2.00—3.99 Very Stiff 50—80 Very Dense 4.00—8.00 Hard 80+ Extremely Dense >8.00 Very Hard , GME CONSULTANTB,INC. ' �_ . . . . . . POND I � ; PROPOSED • PARKING AREA • P�4 � P-3 � B-1 ' I EXISTING ' BUILDING IB-4 P-2 I : „�,B-2 � . I �-3 I . . � . o I PROPOS D I � PARKING AREA = ' B-5 , N . � � IPROPOSED -6 P-� I z � BUILDING � I I • B-7 . • B-8 . I I I L . . . . . . . . PROPERTY UNE . . . J APPROXIMATE SCALE _ �� FEET 80� 9256.DWG GME CONSULTANTS, INC. SOIL .BORING LOCATION DIAGRAM Geotechn�cal•Materia�•Ernironmental MINNETONKA CENTER FOR THE ARTS �4000 2�stAvenue N. WAYZATA, MINNESOTA Minneapoiis,Minnesota.55447 n63�559'�859 VJL WCK JAN 01 GME Project No. 9256 LOG OF BORING B-1 PROJECT SITE 2240 North Shore Drive Minnetonka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayto� Design, Ltd. � op c� �u --0-- 7 2 3 4 S mJ � DESCRIPTION OF MATERIAL � WATER � � w � c~n � CONTENT% � z' �, � � � �' �, m --�-- � a � W ~ � J � STANDARO PENETRATION(BLOWSlF00'n Q � Q � SURFACE ELEVATION a w > —� � 7 d' 3 v� i 961.5 v� � z �o zo 3o no so Dark brown to brown SANDY SILT WITH 1AS ORGANICS-(ML-0L)(Topsoil)-Frost 2i �,g encountered to 1.6 feet Brown fine to medium SILTY SAND WITH CLAY, trace gravel-medium dense-damp- 2SS (SC-SM) 15 r4, <<�, 4.0 � � Brown fine SILTY SAND-medium dense- 3SS � damp-(SM-ML) 18 6.0 � Gray brown fine SILTY SAND, trace clayey siit � 4SS seams-medium dense-damp-(SM) Zo . . � I 9.0 Brown SANDY SILT, trace sand seams- I ' 5SS medium dense-(ML) 18 I I I I i I sss ,s 'i 15.0 End of boring at 15 feet Holiow stem auger used full depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwaternotencountered �iN�CONSULTANTS.INC. BORINGCOMPLETED 1/3/01 W.L. while driliing or after HSA ,�Z°`,'�'„�" �nta1 RIG BK51HD DRILLER TA W,�, remova nn�,MN5S447 �WN KMB APPROVE�►CK �e,s>as�..,e� �oe�e 9256 SHEET 1 of 1 The stratiflcation lines represent approximate bounda�ies . between soll a;tnsltu the transition ma be radual. LOG OF BORING B-2 PROJECT SITE ?240 NortMShore Drive Minnetonka Center for the Arts Wayzata, innesota CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. � ap c� � � Z --0-- a s � w � DESCRIPTION OF MATERIAL � WATER � _ '� ��" W � CONTENT% Z W � U I- m --�-- u- � } � � � J j STANDARD PENETRATION(BLOWSIFOO� � � Q � SURFACE ELEVATION a w > —�— � �d' 3 v� � 961.3 m � z �o so ao 4o so Brown CLAYEY SILT,trace organics-(ML) 1AS (Topsoil)-Frost encountered to 1.6 feet 2A Gray brown fine SILTY SAND-loose to 2SS medium dense-damp-(SM) 9 \ \ 3SS 15 � 6.0 Brown SANDY SILT-medium dense- � 4SS (SM-ML) 15 � I � I 9.0 I Gray brown fine SILTY SAND, trace clayey silt � � 5SS seams-medlum dense-damp-(SM) �� ]� ��� I I I I I I I sss zo 15.0 End of boring at 15 feet Hoilow stem auger used fuil depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encountered GME CONSULTANTS,INC. BORING COMPLETED 1/3/01 W,�, while drilling or after HSA ,�z'd,"�„�' � R�G BK51 HD ����R TA W,�, remova �"""�� �Rnwr� KMB �'PRo��WCK �e,�a�,� ,roe�e 9256 sHeEr 1 Of 1 The stratification lines represent approximate boundaries � between soil s;insitu the transition ma be radual. LOC OF BORING B-3 PROJECT SITE 2240 North Shore Drive Minnetonka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. � cp c� � ^ --0-- t z 3 a s mJ � DESCRIPTION OF MATERIAL WATER � W � . �i � CONTENT% W Z Wa � (� � y m --�-- a � W �.Q.. . g J J STANDARD PENETRATION(BLOWSIFOO� W � � Q � SURFACE ELEVATION a w > -�— 7d' � �' 961.8 �n � z �o so ao ao so Brown SANDY SILT,trace clay, organics- 1AS (ML)(Topsoil)-Frost encountered to 1.6 feet 2.0 Brown CLAYEY SILT WITH SAND-stiff- ZSS (ML) 8 2� 4.0 � Brown SANDY SILT-loose-(ML) 3SS 6 � �� 6.0 � Brown CLAYEY SILT,trace sand-stiff-(ML) � 4SS 8 3j 9.0 Gray brown fine SILTY SAND-medium 1 " 5SS dense-damp-(SM) 14 � I I I I 13.0 � Brown and�ray brown SANDY SILT WITH 6SS CLAY-medium dense-(ML) ' �s � � 15.0 End of boring at 15 feet Hollow stem auger used fuli depth Borehole backfllled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 . W.L. Groundwater not encountered GN�CONSULTANT3�INC. BORING COMPLETED 1/3/01 W.�, while drilling or after HSA �,�Z°�;q,�� E"V1f0""1°"� RIG BK51HD DRILLER TA W,�, remova M��"��� �w�,ww KMB APPROVEDWCK �s,�ssa.,e5s �oe� 9256 sH�r 1 of 1 The stratification lines represent app�oximate boundaries between soil types;insitu the transftion may be raduaL LOG OF BORING B-4 PROJECT SITE 2240 NOI'th ShOf@ DriV@ Minnetonka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. W QP(� W ^ —'O-- � � 7 2 3 4 5 m J � DESCRIPTION OF MATERIAL WATER � ? tu � � c~n � CONTENT°� W Z W � U � m --�-- � � � � � � � J � STANDARD PENETRATION(BLOWSIFOO� � Z � � SURFACE ELEVATION a w > —�� ` a i 962.6 cn � z ,o zo ao ,w ao Brown SANDY SILT WITH CI.aY, trace 1AS organics-(ML) (Topsoil)-Frost encountered +� to 1.6 feet 2.0 Brown fine SILTY SAND, trace silty clay 2SS seams-loose-damp-(SM) � � 2� 4.0 � Brown fine SILTY SAND WITH CLAY- 3SS medium dense-damp-(SM-SC) �o 6.0 Brown SILTY CLAY WITH SAND-stiff-(CL) � 4SS 11 1 \ 9A 1 Brown CLAYEY SILT,trace sand-very stiff- \ ' 5SS (ML) �8 I I I I 6SS 21 � 15.0 End of boring at 15 feet Hollow stem auger used full depth Botehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encountered �n+�cot�su�ra�rrs,�Nc. BORING COMPLETED 1/3/01 W.L. while drilling orafter HSA ��'�,",�;`� ��a1 RIG BK51HD �R�LLER TA W.�, remova �"""�147 oRawrv KMB APPROVEDWCK �,z�s�-,e� �os� 9256 SHEET 1 of 1 The stratiflcation lines represent approximate boundaries between soil ea;insitu the trans�ion ma be radual. LOG OF BORING B-5 PROJECT SITE 2240 Nort�i_Shore Drive Minnetonka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. � av a� � ^ --0—- � 1 2 3 4 5 m J Z DESCRIPTION OF MATERIAL � WATER � � W, �q yW � CONTENT°� LL 2 W J V � F- � m --�-- � a � W � � � j STANDARD PENETRATION(BLOWSIFOO� W � Z Q � SURFACE ELEVATION a w > —�� o y Q � y � 961.6 v� � f �o so ao <o so Brown CLAYEY SILT WITH SAND, trace 1AS organics-(ML)(Topsoii)-Frost encountered z� to 1.6 feet 2.0 Brown SANDY SILT-medium dense-(ML) 2SS 13 ��� I I 3SS 13 � I I I 4SS 15 � I I I � I 5SS 16 �Z ' 1 1 1 1 13.0 Brow+n fine SILTY SAND,trace s91t seams- 6SS medium dense-damp-(SM) 22 15A End of boring at 15 feet Hollow stem auger used full depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwate�not encountered GME CONSULTANTS,INC. BORING COMPLETED 1/3/01 W.L. while drilling orafter HSA ,�2'a,'�M� ErnMa� RIG BK51HD DRILLER TA W,�, remova ������ �w►wN KMB APPROVEDWCK �os� 9256 SHEET 1 of 1 The stratification lines represent approximate boundaries � between soil es;insitu the transition ma be radual. LOG OF BORING B-6 PROJECT s�� 2240 NOrth Shore Drive Minnetonka Center for the Arts VNayzata, Minnesota CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. � na c� � ^ --0-- 7 2 3 4 S m J Z DESCRIPTION OF MATERIAL WATER � � � 4= �W � CONTENT°r6 W Z W V I— m --�-- �� � a} � ia- � � � STAND�ARD PENETRATION(BLOWS/FOO� F- Q � � 3 � SURFACE ELEVATION � a w > —�– 965.3 v� � z ,o zo ao eo so Brown fine SILTY SAND-(SM)-Frost 1AS encountered to 1.6 feet 2.0 Brown SANDY SILT-medium dense-(ML) 2SS �a ' 4.0 � Brown fine SILTY SAND-medium dense- � 3SS damp-(SM) 12 6.0 Brown CLAYEY SILT with sandy silt seams- � 4SS very stiff-(ML) 16 � 2� 1 \ 9.0 Gray brown fine SILTY SAND-medium \ ' 5ss dense-damp=(SM) 23 � � I I I 13.0 , I Brown SANDY SILT-medium dense-(ML) � . 6SS .. 21 . 15.0 End of boring at 15 feet Hollow stem auger used fuli depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encountered GME CONSULTANTS,INC. BORING COMPLETED 1/3/01 Ci�otedx�cN M�arhb Ernkam�ntal W.L. while driliing orafter HSA �,��p�nA�� RIG BK51HD DRILLER TA W.L. remova Mr,�.,,aa��ss�a� DRAWN KMB nPPaove�lNCK �e,�sss-,�e �oB� 9256 SHEET 1 of 1 The stratification lines represent approximate boundaries between soil s;insitu the transition ma be raduaL LOG OF BORING B-7 PROJECT SITE �40 NOPthMShore Drive Minnetonka Center for the Arts ayzata, innesota CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. � ap c«� - � ^ --0-- 1 2 3 4 S � ? J � DESCRIPTION OF MATERIAL � WATER W W � CONTENT°r6 2 W � V F- m --�—- � a �- W �a,,, U ? � STANDARD PENETRATION(BLOWS/FOO� Q � � 3 � SURFACE ELEVA T I ON � a w > —�- 961.5 cn � z �o � � ,a � Brown flne to medium SILTY CLAYEY SAND, 1AS trace gravel-(SC-SM)-Frost encountered to , 1.6 feet 2.0 Brown fine to medium SILTY SAND-loose- 2SS damp-(SM) 8 4A Brown fine SILTY SAND-medium dense- � � 3SS damp-(SM-ML) 13 � 6.0 Brown fine SILTY SAND with clayey silt � 4SS seams-medium dense-damp-(SM) 14 � I I 9.0 Brown SANDY SILT,trace clay-medium I � 5SS dense-(ML) 15 ,�I�, 2� �� I I I I 13.0 � Gray brown fine to medium SAND WITH .�. � . . 6SS SILT, trace gravel-medium dense-damp- �� � (SP-SM) 15.0 End of boring at 15 feet Hollow stem auger used full depth Borehole backfilled with cuttings WATER LEVEI OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encountered OME CON3ULTANT3,iNc. BORING COMPLETED 1/3/01 W.L. while drilling or after HSA ,��,,,�° �"��"°� RIG BK51 HD DRILLER TA W.L. ��'tOVB (e12��e��aa� DRAWN KMB APPROVE�INCK �oB�e 9256 SHEET 1 of 1 The stra�flcation lines represent approximate boundaries between soii ty es;insitu the transition ma be radual. ' LOG OF BORING B-8 PROJECT SITE 2240 North Shore D�ive Minnetonka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT-ENGINEER : M.A. Mortenson Company James Dayton Design, Ltd. �j aa c�1 � ---0-- 1 2 3 4 S mJ Z DESCRIPTION OF MATERIAL � � WA-�R W = j � y W � CONTENT°� � 2 W J V I- � � --�-- � a � W � � ,.�j � STANDARD PENETRATION(BLOWSIFOO'n o � � ~ � SURFACE ELEVATION a w > —�— d� � y � 965.6 v� � z to so ao ao so Brown CLAYEY SILT WITH SAND, t�ace 1AS organics-(CL-ML)(Topsoil)-Frost encountered to 1.6 feet 2.0 Brown fine SILTY SAND, trace clay-medium 2SS dense-damp-(SM) �� 4.0 \ Gray brown fine SAND WITH SILT-medium � 3SS dense-damp-(SP-SM) �� � 6.0 Gray brown fine SILTY SAND, trace clayey silt � 4SS seams-medium dense-damp-(SM) 1e I� I . I i 5SS 18 I I I I 13A � Gray brown fine to med9�m SAND WITH � 6SS SILT, trace gravel-medium dense-damp- 1e (SP-SM) . 15A End of bo�ing at 15 feet Hotlow stem auger used full depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 . V11.�. GrOU�dWBt@��Ot efICOU�t@f@d ���NSULTANTS,INC. BORING COMPIETED 1/3/01 W.L. while drilling or after HSA ,�z°�'�` �""''°""°"`� RIG BK51HD DRILLER TA w,�, remova ����� DRAWN KMB APPROVE�1/CK �os� 8256 SHEET 1 of 1 The stratification lines represent approximate boundaries � between soil pes;insltu the transftion ma be radual. . . . . _ .. _ ,. .�.�_r LOG OF BORING P-1 PROJECT SITE 2240 North Shore Drive Minnetonka Center for the Arts Wayzata, Minnesota CUENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. � aP c�m � ^ --p-- 1 2 3 4 S m J � DESCRIPTION OF MATERIAL WATER � � � yW � CONTENT q6 � Z W � (� F- m --�-- a �n � a � w la– g � � STANDARD PENETRATION(BLOWSIFoo'n � Q � � SURFACE ELEVATION a w > —�— �' 964.9 v� � z �o zo ao ,eo so Brown SILTY CLAY, trace sand, organics- 1AS (CL-ML) (Topsoil)-Frost encountered to 1.6 z feet 2.0 Brown CLAYEY SILT WITH SAND-very stiff- 2SS (ML) 22 z� 4.0 � Brown SILTY CLAY WITH SAND-very stiff- 3SS (CL-ML) � � 6.0 Brown SANDY SILT WITH CLAY, trace sand � 4SS seams-medium dense-(ML) 17 � 2� 8.0 Brown fine SILTY SAND, trace silt seams- 5SS medium dense-damp-(SM) 23 � 10.0 End of boring at 10 feet Hoilow stem auge�used full depth Borehole backfilled with cuttings ' WATER LEVEL OBSERVATIONS BORING STARTED 1/3/O 1 W.L. Groundwater not encountered �ME coNsu�Tan�rs,iNc. BORING COMPLETED 1/3/01 W,�, while drilling or after HSA ,�z"�',,,�' � RIG BK51 HD DRILLER TA W.L. �remova ����� DRAWN KMB APPROVEDWCK �oe� 9256 SHEET 1 of 1 The stratfication lines represent approximate boundaries between soil types;Insitu the transition may be raduaL LOG QF BORING P-2 PROJECT SITE 2240 North Shore Drive Minneto�ka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT-ENGINEER M.A. Mo�tenson Company James Dayton Design, Ltd. � �can w --0-- � 1 2 3 F. 6 m J � DESCRIPTION OF MATERIAL � � WATER w � �''� � W � CONTENT°�6 LL Z W � CJ H y W --�-- T � � � � � J J STANDARD PENETRATION(BLOWSIFOO� F a � � � w z a SURFACE ELEVATION a w > —�— e � a 3 m i 964.5 v� � z ,o so ao eo so Dark brown CLAYEY SILT WITH ORGANICS 1AS -(ML-OL)(Topsoil)-Frost encountered to 1.6 feet 2.0 Brown CLAYEY SILT WITH SAND-firm- 2SS (ML) 6 � '� O I I 3SS 7 � �� 6.0 � Brown fine SILTY SAND, dark brown sandy 4SS silt seam-medium dense-damp-(SM) 12 8.0 Dark brown fine SILTY SAND-medium dense I 5SS -damp-(SM) 12 10.0 End of boring at 10 feet Holtow stem auger used full depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encounte�ed GME CON3ULTANTS,INC. BORING COMPLETED 1/3/01 1�/,�, while drilling or after HSA ,��Z"�',",�;'��°�'� RIG BK51 HD DRILLER TA W.L. remova M�,�� �w�wN �g APPROVEDWCK ro,z>sss.,ess �oe� 9256 SHEET 1 of 1 The stratification lines represent approximate bounda�ies beiween soil s;insitu the transition ma be raduaL LOG OF BORING P-3 PROJECT SITE 2240 North Shore Drive Minnetonka Center for the Arts Wayzata, Minnesota CLIENT ARCHITECT ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. av c� � --0-- 1 2 3 4 5 mJ � DESCRIPTION OF MATERIAL � WATER �j � W? � WN � CONTENT% � 2 W W V F- m --�-- W a J a � � � STANDARD PENETRATION(BIOWS/FOO'n OJ. � � ~ O � � 3 � SURFACE ELEVATION a w > —�— i 960.9 v� � z ,o zo ao eo so Brown CLAYEY SILT WITH SAND, trace 1AS arganics-(ML)(Topsoil)-Frost encountered z� to 1.6 feet 2.0 Brown SANDY SILT WITH CLAY-loose- 2SS (ML) � � 2� I I 3SS 7 � � 6.0 � Brown fine SILTY SAND, trace clayey silt � 4SS seams-medium dense to loose-damp- �o (SM) I I 5SS 9 10A End of boring at 10 feet Hollow stem auger used full depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encountered GME CON3ULTANT3,iNc. BORING COMPLETED 1/3/O1 W.L. while drilling or after HSA ,�'�a �""�°""'"�' RIG BK51 HD DRILLER TA w,�, remova ����� DRAWN KMB APPROVEDWCK �a��ssa�e�e �oe s 9256 sHeer 1 of 1 The stratiflcation lines represent approximate boundaries between soil es;insitu the transition may be radual. � LOG OF BORING P-4 PROJECT SITE 22 40 No� Shore Drive Minnetonka Center for the Arts Wayzata, Minnesota ; CLIENT ARCHITECT-ENGINEER M.A. Mortenson Company James Dayton Design, Ltd. �j QD Os� W '� ——�—— u' 1 2 3 4 S W J CW7 DESCRIPTION OF MATERIAL WATER m F � � vW� ,� CONTENT°k W Z W � V F— m --�-- � uJ' � � � � � j STAN�4RD PENETRATION(BLOWS/F00'� Q � a 3 � SURFACE ELEVATION � 960.1 a � z �0 20 �— 40 ,o Brown fine to medium SILTY SAND, trace clay 1AS -(SM)-Frost encounte�ed 401.6 feet 2. Brown SILTY SANDY CLAY, trace gravel- 2ss firm-(CL) s � o 4.0 I Brown CLAYEY SILT WITH.SAND, trace sand 3SS seams-firm#o stiff-(CL-ML) � � I . � I 4SS g 2j I 5SS 10 O ?� 10.0 � End of boring at 10 feet Hollow stem auger used full depth Borehole backfilled with cuttings WATER LEVEL OBSERVATIONS BORING STARTED 1/3/01 W.L. Groundwater not encountered GME CONSULTANTS,INC. BORING COMPLETED 1/3/01 W.L. while drilling o�after HSA ,�„�,� E""''°"""�"' RIG BK51 HD DRILLER TA W.L. remova �7z""���"�� oRnwN KMB APPROVEDWCK � JOB� 9256 sHEEr 1 of 1 The stratfication lines represent approximate boundaries beiween soil s;insitu the transition ma be raduai. CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES (ASTM: D 2487 and 2488) Major divfsions Group Typical names Laboratory classlfication criteria symbols ^m Well-graded gravels,gravel-sand �so ��30�2 m a+ GW C„=—greater than 4;C�= between 1 and 3 d S miztures,Iittle or no flnes a �� c � �io ��oX�so V M � O � C �» N N O� � a� � U z GP Poorly graded gravels, gravel- d � �, m � � � Not meeting all gradatlon requlrements for GW � o ,� sand mixtures,Ilttle or no fines o V N W ��� � N y q � O tv N �r Z N 3� J C! C7�i0 C - d �H N y C y �� d a GM Silty gravels, gravel-sand-silt � ��m a Atterberg Ifmits below "A" 00 � � w �� mixtures 'N 3r�o T Iine or P.I.less than 4 Above "A" Iine wlth P.i. N ` � 0 0 1O �a � u �N ��m '" between 4 and 7 are 6order- 2 � a A� � o y � � �o d Z llne cases requiring use ,°n= � a GC Clayey gravels,gravel-sand-clay h A Atterberg limits below "A" of dual symbols � m �Q mixtures �;L Ilne or P.I.greater than 7 c P� rn°1 a_ E m �� � N �!� � � �so (�30)2 ,� Well-graded sands, gravelly d g o�! y d SW ��� C�=—greater tha�6;C� between 1 and 3 A a� sands,little or no fl�es A V � c � 0 9� �to �toX�so `o od '� c cy �y C 10 N jp `y �p O 9 C t CI d d C` . W d V: SP Poorly graded sands, gravelty �o ; ; ; Y �•;� v a, o • Not meeting all gradatfon requirements for SW m sands,little or no fines � rn= c � d o�* m m o� a+ N V �, y C� y U . � C O Z �U � V y . A a C y L.t C d � a,�6_1 a.N- c�,t y � c'm'^ � Atterber Iimlts below "A" � y d o SM Silty sands,sand-silt mixtures �' o a � m �' 9 c� S �� d ��«�N line or P.I.less than 4 Limits plotting in hatched a, E r d ; � . �� d a, �� zone with P.I. between 4 m O �h 3�� d a�, ���� and 7 are borderllne cases a `o °1 d'o requfring use of dual sym- ya SC Clayey sands, sand-clay mix- �� '" Atterberg limits below "A" bols. ¢ tures Nne or P.I.greater than 7 Inorganic silts and very fine ML sands, rock flour, silty or clay- � ey fine sands or clayey silts � with slight plasticity 60 — W� Inorganfc clays o( low to me- For classification ol fine-gralned � � soils and fine fractlon of coarse- y d dium plasUcity, gravelly clays, �-- C� 50 9rained soils. e, '�'— sandy clays, silfy clays, lean � _ E Atterberg limits plotting In clays hatched area are borderline classi- g y P flcatfons requiring use of dual "' v 40 symbols d Organic silts and organic ailty k Z OL y Equation ot A-Iine: � clays of low plasticity � PI=0.73(LL-20) t � `—" � �30 $� Inorganic silts, mtcaceous or A e c y MH diatomaceous }ine sandy or a p;��c �� � slity soils,elastic silts 20 ° OH and MH �Z A d h r LL10 �d CL E o � ` CH Inorganic clays of high plas- �� ;� w °1 tieity,fat clays L ='E �-------- � m m= CL-ML �,� ML and OL t v 4------- ; � o � Organlc clays of inedium to 0 � � OH higli plasticity,organ(c silts 0 10 20 30 40 50 60 70 80 90 100 Llquid Limit ��_ Pt Peat and other highly organic PlastiCity Chaft = Q�: soll 0 SPECIAL NOTES ON PLACEMENT OF COMPACTED FILL SOIL GENERAL The placement of compacted fill for support of foundations, floor slabs, paveme�ts, or earth structures should be carried out by an experienced excavator with the proper equipment. The excavator must be prepared to adapt his procedures,equipment,and materials to the type of project,to weather conditions,and the structural requirements of the architect and engineer. Methods and materials used in summer may not be applicable in winter; fill used in dry excavations may not be suitable in wet excavations or during periods of precipitation; proposed fill soil may require wetting or drying for proper placement and compaction.Conditions may also vary during the course of a project or in different areas of the site. These needs should be addressed in the project drawings and specifications. EXCAVATION/BACKFILL BELOW THE WATER TABLE It is common to have to excavate and replace unsuitable soils below the water table for site correction. As a general rule of prudent construction technique,we recommend that excavation/backfill below the water table not be permitted, uniess the excavation is dewatered. Numerous problems can develop when this procedure is attempted without dewatering. — Inability of the equipment operators and soil technicians to �bserve that all unsuitable soii/materials have been removed from the base of the excavation. — Inability to observe and measure that proper lateral oversizing is provided. — Inability to prevent or correct sloughing of excavation sidewalls, which can result in unsuitable soils trapped within the select backfill. — Inability of the contractor to adequately and uniformly compact the backfill. — Possibility of disturbance of the suitable soils at the base of the excavation: The dewatering methods, normally chosen at the contractor's option, should fo�low prudent construction practice. Excavations in clay can often be dewatered with sump pits and pumps; this technique would�not be applicable for excavation extending into permeable granular soil, especially fo�depths significantly below the water table. Dewater- ing granular soils should normally be done with well points or wells. When dewatering is needed, we strongly recommend that the procedures be discussed at pre-bid or pre-construction meetings. The dewatering technique chosen by the contractor should be reviewed by the architect and engineer before construction starts;it should not be left until excavation is under way. The selection of proper backfill materials is important when working in dewatered excavations. Even with dewatering, ihe base is usually wet and the contractor must be careful not to disturb the base.We recommend that the first lifts of backfill be a clean medium to course grain sand with less than 5°/a passing the#200 sieve.The use of silty sand,clayey sand, or cohesiye/semi-cohesive soils is not recommended for such situations.The excavator should be required to submit samples of the proposed material(s)he plans to use as backfill betore the fill is hauled to the site,so that it can be tested for suitability. � WINTER EARTHWORK CONSTRUCTION Winter earthwork presents its own range of problems which must be overcome;the situation may be complicated by the need for dewatering discussed above. During freezing conditions,the fill used must not be frozen when delivered to the site. It also must not be allowed to freeze during or after compaction. Since the ability to work the soil while keeping it from freezing depends in part on the soil type, the specifications should require the contractor to submit a sample of his proposed fill before construc- tion starts,for laboratory testing. If the soil engineer and structural engineer determine that it is not suitable,it should be rejected. In general, silty sand, clayey sand, and cohesive/semi-cohesive soils should not be used as fill under freezing conditions.All frozen soil of any type should be rejected for use as compacted fill. . It is important that compacted fitl be protected from freezing after it is placed.The excavator should be required to submit a plan for protecting the soil. The plan should include details on the type and amount of material (straw, blankets,extra loose fill,topsoil,etc.)proposed for use as frost protection.The need to protect the soil from freezing is ongoing throughout construction and applies both before and after concrete is placed, until backfilling for final frost protection is completed. Foundations placed on frozen soil can experience heaving and significant settlement, rota- tion, or other movement as the soil thaws. Such movement can also occur if the soil is allowed to freeze after the concrete is placed and then allowed to thaw.The higher the percentage of fines(clay and silt,P-200 material)in the fill, the more critical is the need for protection from freezing. GME CONSULTANTS,INC.- MOISTURE CONTROL OF FILL The contractor should be required to adjust the moisture content of the soil to within a narrow range near the optimum moisture content(as deflned by the applicable Proctor or AASHTO Test). In general,fill should be placed within about 2%of optimum.The need for moisture control is more critical as the percentage of fines increases.Naturally-occurring clayey sand or cohesive/semi-cohesive soil are often much wetter than the optimum. Placing and attempting to compact such soils to the specified density may be difficult,or not possible.Even if compacted to the specified density, � excessively wet soils may not be suitable as fioor slab or pavement subgrades due to pumping under applied load.This is especially true when wet cohesive/semi-cohesive soil is used as backfiil in utility trenches under streets.Excessively wet soil in thick fill sections may cause post-construction settlement beyond that estimated for fill placed at or near (±2%) the optimum moisture content. An exception to this would be low permeability soil placed as a pond liner or for a dam. Such soil should usualiy be placed at 2%to 4%above the opti,mum moisture content, to provide for a lower insitu permeability.Also, shrinking/ swelling soiis(expansive clay)should be placed at about 2%to 4%above optimum moisture to reduce the possibility of soil expansion. Clayey silt, silt, or very sifty fine sand should be placed excessively dry. Such soils can undergo post-construction consolidation upon being wetted,even if the specified density had been achieved.This is caused by the collapse of flocculant soil particle arrangement,and can result in settlement of buildings or slabs constructed over the soiL Proper control of fill soil moisture is the responsibility of the excavator. The excavator should evaluate the need for wetting or drying the soils,based either on the data in the soil report,or his own site testing. If the excavator is bringing in off-site fill,it is also his responsibility to evaluate the moisture content of the soil,and the need for wetting or drying. We recommend that this matter be addressed in the project specifications. CONSTRUCTION ON COMPACTED SOIL After the select fill has been placed, compacted,and tested, it must be maintained and protected in order to properly support structures. The suitability of compacted fill soil can be greatly diminished if it is altowed to freeze, become saturated while unconfined(such as in footing excavations or at the surface of slab/placement subgrade),or disturbed by construction equipment. The responsibility for protecting the soil,or for correcting any disturbance,should be clearly defined in the specifica- tions. Soils which become wet and soft after compaction testing do not necessarily reflect inaccurate field density tests. Especially with non-expansive cohesive/semi-cohesive soils, saturation when unconfined can severely reduce the shear sirength while the density remains adequate.The reduced shear strength can cause footings,floor slabs,or pavements to settle or fail under load. We strongly recommend that all pavement subgrade be test rolled (MN/DOT Specification 2111) immediately before paving to determine if the subgrade has not been protected and soft spots have developed. FLOOR SLAB SUBGRADE AND UTILITY TRENCHES This facet of constructfon presents special problems,especially if the slab subgrade is allowed to freeze.When the soil thaws, it undergoes a period of temporarily lower shear strength. Floor slabs should not be cast over soil in such a weakened or frozen condition (reference pertinent PCA and ACI publications). To do so can result in cracked and failing slabs. The time period to heat and thaw a building may place the construction schedule and/or costs in jeopardy.We strongly recommend that this matter be reviewed in pre-bid and pre-construction meetings. Backfilling of utility trenches in the floor slab subgrade can be difficult. If the soil is wet,compaction to the specified density may be dtfficult, or not possible. The narrowly cut trenches may preclude the use of proper compaction equipment. With the use of small equipment in confined areas, the contractor must place the soil In thin lifts (4 to 6 , inches), with the soil at the proper moisture content.This work is typically carried out by contractors other than the mass grading or earthwork contractor.We strongly recommend that the responsibility to carry out the compaction be clearly detailed in the applicable section of the specifications, and reviewed with the appropriate contractor and subcontractor. GME CONSULTANTS,INC. -