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Home My WebLink AboutSWP272714(1) W�A 4 � a � ��t4 taw 41 :< va sK. a f Earth Consultants Inc. Geotechnical Engineers.CwUbgisis&Environmental Scientists ' 4 a` MOM ZMAIWEM GEOTECHNICAL ENGINEERING STUDY PROPOSED RENTON CROWN APARTMENTS RENTON, WASHINGTON E-7186 y� ta� � March 21, 1996 PREPARED FOR RENTON CROWN LLC 1 '`---Ikaymond A. Coglas Staff Engineer S- ��WAS ' j4691 Robert S. Levinson, P. ' Principal 312'l�tk wims 03/07/9 iK ' Earth Consultants, Inc. 1805 - 136th Place Northeast, Suite 201 Bellevue, Washington 98005 ' (206) 643-3780 IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL ENGINEERING REPORT More construction problems are caused by site subsur- technical engineers who then render an opinion about face conditions than any other factor. As troublesome as overall subsurface conditions, their likely reaction to subsurface problems can be, their frequency and extent proposed construction activity, and appropriate founda- have been lessened considerably in recent years, due in tion design. Even under optimal circumstances actual ' large measure to programs and publications of ASFE/ conditions may differ from those inferred to exist, The Association of Engineering Firms Practicing in because no geotechnical engineer, no matter how the Geosciences. qualified,and no subsurface exploration program, no The following suggestions and observations are offered matter how comprehensive,can reveal what is hidden by ' to help you reduce the geotechnical-related delays, earth, rock and time. The actual interface between mate- cost-overruns and other costly headaches that can rials may be far more gradual or abrupt than a report occur during a construction project. indicates.Actual conditions in areas not sampled may ' differ from predictions. Nothing can be done to prevent the unanticipated, but steps can be taken to help minimize their A GEOTECHNICAL ENGINEERING impact. For this reason, most experienced owners retain their REPORT IS BASED ON A UNIQUE SET geotechnical consultants through the construction stage, to iden- tify variances,conduct additional tests which may be OF PROJECT-SPECIFIC FACTORS needed, and to recommend solutions to problems A geotechnical engineering report is based on a subsur- face exploration plan designed to incorporate a unique SUBSURFACE CONDITIONS set of project-specific factors. These typically include: the general nature of the structure involved, its size and CAN CHANGE configuration; the location of the structure on the site and its orientation; physical concomitants such as Subsurface conditions may be modified by constantly- access roads, parking lots, and underground utilities, changing natural forces. Because a geotechnical engi- and the level of additional risk which the client assumed neering report is based on conditions which existed at by virtue of limitations imposed upon the exploratory the time of subsurface exploration, construction decisions r program. To help avoid costly problems, consult the should not be based on a geotechnical engineering report whose geotechnical engineer to determine how any factors adequacy may have.been affected by time. Speak with the geo- which change subsequent to the date of the report may technical consultant to learn if additional tests are affect its recommendations. advisable before construction starts., Unless your consulting geotechnical engineer indicates Construction operations at or adjacent to the site and otherwise. your geotechnical engineering report should not natural events such as floods,earthquakes or ground- be used: water fluctuations may also affect subsurface conditions .When the nature of the proposed structure is and, thus, the continuing adequacy of a geotechnical changed, for example, if an office building will be report. The geotechnical engineer should be kept erected instead of a parking garage, or if a refriger- apprised of any such events,and should be consulted to e ated warehouse will be built instead of an unre- determine if additional tests are necessary frigerated one; .when the size or configuration of the proposed GEOTECHNICAL SERVICES ARE structure is altered; PERFORMED FOR SPECIFIC PURPOSES .when the location or orientation of the proposed AND PERSONS structure is modified; .when there is a change of ownership, or Geotechnical engineers' reports are prepared to meet ' •for application to an adjacent site. the specific needs of specific individuals. A report pre- Geotechnical engineers cannot accept responsibility for problems pared for a consulting civil engineer may not be ade- which may develop if they are not consulted after factors consid- quate for a construction contractor,or even some other ' ered in their report's development have changed. consulting civil engineer. Unless indicated otherwise, this report was prepared expressly for the client involved and expressly for purposes indicated by the client. Use MOST GEOTECHNICAL "FINDINGS" by any other persons for any purpose,or by the client ARE PROFESSIONAL ESTIMATES for a different purpose, may result in problems. No indi- vidual other than the client should apply this report for its Site exploration identifies actual subsurface conditions intended purpose without first conferring with the geotechnical only at those points where samples are taken, when engineer. No person should apply this report for any purpose they are taken. Data derived through sampling and sub- other than that originally contemplated without first conferring sequent laboratory testing are extrapolated by geo- with the geotechnical engineer. A GEOTECHNICAL ENGINEERING der the mistaken impression that simply disclaiming re- REPORT IS SUBJECT TO sponsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing MISINTERPRETATION the best available information to contractors helps pre- Costly problems can occur when other design profes- vent costly construction problems and the adversarial sionals develop their plans based on misinterpretations attitudes which aggravate them to disproportionate ' of a geotechnical engineering report. To help avoid scale. these problems, the geotechnical engineer should be READ RESPONSIBILITY retained to work with other appropriate design profes- , sionals to explain relevant geotechnical findings and to CLAUSES CLOSELY review the adequacy of their plans and specifications relative to geotechnical issues. Because geotechnical engineering is based extensively on judgment and opinion, it is far less exact than other ' design disciplines. This situation has resulted in wholly unwarranted claims being lodged against geotechnical BORING LOGS SHOULD NOT BE consultants. To help prevent this problem, geotechnical engineers have developed model clauses for use in writ- , SEPARATED FROM THE ten transmittals. These are not exculpatory clauses ENGINEERING REPORT designed to foist geotechnical engineers' liabilities onto someone else. Rather, they are definitive clauses which , Final boring logs are developed by geotechnical engi- identify where geotechnical engineers' responsibilities neers based upon their interpretation of field logs begin and end. Their use helps all parties involved rec- (assembled by site personnel)and laboratory evaluation ognize their individual responsibilities and take appro- of field samples. Only final boring logs customarily are priate action. Some of these definitive clauses are likely ' included in geotechnical engineering reports. These logs to appear in your geotechnical engineering report, and should not under any circumstances be redrawn for inclusion in you are encouraged to read them closely. Your geo- architectural or other design drawings, because drafters technical engineer will be pleased to give full and frank may commit errors or omissions in the transfer process. answers to your questions. ' Although photographic reproduction eliminates this problem, it does nothing to minimize the possibility of OTHER STEPS YOU CAN TAKE TO contractors misinterpreting the logs during bid prepara- tion. When this occurs, delays, disputes and unantici- REDUCE RISK pated costs are the all-too-frequent result. Your consulting geotechnical engineer will be pleased to To minimize the likelihood of boring log misinterpreta- discuss other techniques which can be employed to mit- ' tion, give contractors ready access to the complete geotechnical igate risk. In addition, ASFE has developed a variety of engineering report prepared or authorized for their use materials which may be beneficial. Contact ASFE for a Those who do not provide such access may proceed un- complimentary copy of its publications directory. Published by ' THE ASSOCIATION OF ENGINEERING FIRMS PRACTICING IN THE GEOSCIENCES 8811 Colesville Road/Suite G 106/Silver Spring, Maryland 20910/(301) 565-2733 0788/3M , Earth Consultants Inc. i Geotechnical Engineers.Geologists&Environmental Scientists March 21 , 1996 E-7186 Renton Crown LLC 704 Northeast Northlake Way Seattle, Washington 98105 ' Attention: Mr. Mark Lundberg Dear Mr. Lundberg: ' We are pleased to submit our report titled "Geotechnical Engineering Study, Proposed Renton Crown Apartments, Renton, Washington." This report presents the results of our field exploration, selective laboratory tests, engineering analyses, and review of the following geotechnical engineering studies previously performed at the subject site: ' 1 ) Shannon & Wilson, Inc., Boring and Test Pit Logs, dated August 1979 and June 1988. 2) Golder Associates Geotechnical Engineering Study 883-1538, dated November 1988. Based on the results of our study,it is our opinion the proposed development is geotechnically feasible. Medium to high plasticity silt was predominantly encountered at our test pit ' locations. Some shallow deposits of silty sand were also encountered at some of the test pit locations. With the exception of test pits T-P-8 through TP-11 , the medium to high plasticity silt encountered at our test pit locations was generally soft to depths of six to twelve feet ' below existing grades. The soft silt was encountered to depths of two to three feet below existing grades at test pits TP-8 through TP-1 1 . Below the upper deposits of soft silt, stiff, medium to high plasticity silt was encountered to the depths explored. ' Varying depths of fill were generally encountered at test pits TP-3, TP-7, and TP-8 through TP-1 1 . Fill depths generally ranged between approximately two feet to twelve feet with the ' deepest fill encountered at test pits TP-3 and TP-7. Slide debris was encountered at test pit locations TP-2, TP-4 and TP-5. This deposit was characterized by approximately six feet to ten feet of loose silty sand and silt, with isolated zones of moderate to heavy organics. In our opinion, the proposed buildings can be supported on conventional spread and continuous footings bearing on the native stiff silt, or on at least two feet of structural fill, ' provided the recommendations contained in this report are incorporated into the final design recommendations. 1805 - 136th Place N.E., Suite 201, Bellevue, Washington 98005 ' Bellevue (206)643-3780 Seattle(206)464.1584 FAX(206) 746.0860 Tacoma(206) 272-6608 Renton Crown LLC E-7186 March 21, 1996 Page 2 iWe appreciate this opportunity to have been of service to you. If you have any questions, or if we can be of further assistance, please call. Respectfully submitted, EARTH CONSULTANTS, INC. �r 1 Robert S. Levinson, P.E. Principal RAC/RSL/kml 1 1 1 1 1 i i 1 TABLE OF CONTENTS E-7186 ' PAGE INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ' SITE CONDITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Surface 2 Subsurface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ' Fill/Slide Debris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Native Silt . . . . . . . . . 3 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ' Laboratory Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 DISCUSSION AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 General . . . . . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Site Preparation and General Earthwork 4 Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Slab-on-Grade Floors . . . . . . . : : : : : : : : : : : : : : : : : : : : : : : : :' : : : : ; : : : : 7 Seismic Design Considerations 7 Excavations and Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Site Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Utility Support and Backfill 9 Pavement Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 LIMITATIONS 10 Additional Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 APPENDICES ' Appendix A Field Exploration Appendix B Laboratory Test Results ILLUSTRATIONS ' Plate 1 Vicinity Map Plate 2 Test Pit Location Plan Plate 3 Typical Footing Subdrain Detail Plate 4 Utility Trench Backfill Plate Al Legend ' Plates A2 through Al Test Pit Logs GEOTECHNICAL ENGINEERING STUDY PROPOSED RENTON CROWN APARTMENTS RENTON, WASHINGTON ' E-7186 INTRODUCTION ' General ' This report presents the results of the geotechnical engineering study completed by Earth Consultants, Inc. (ECI) for the proposed Renton Crown Apartments located along Renton Avenue South in Renton, Washington. The general location of the site is shown on the Vicinity Map, Plate 1 . The purpose of this study was to explore the subsurface conditions at the site, and based on the conditions encountered, develop geotechnical recommendations for the proposed site development. In developing these recommendations, we reviewed subsurface information at the site previously obtained by Golder Associates and Shannon & Wilson, Inc. At the time our study was performed, the building location, and our exploratory locations were approximately as shown on the Test Pit Location Plan, Plate 2. Project Description We understand it is planned to develop the site with approximately seven, two to three story, wood-framed apartment buildings with first-floor level parking garages at Buildings D, E and G only. The remainder of the site will consist of asphalt pavement areas and landscaping. We understand considerable regrading of the site will be required. It appears the most substantial cuts will be required primarily along the north and east portion of the site. We understand the existing 4H:1 V (Horizontal:Vertical) slope along the south side of the site will be regraded to an inclination of approximately 3H:1 V. At the time this report was written, specific structural design information was not available. However, based on our experience with similar projects, we would anticipate wall loads of approximately two kips per lineal foot, and floor loading of less than seventy (70) pounds per square foot. If any of the above design criteria are incorrect or change, we should be consulted to review ' the recommendations contained in this report. In any case, ECI should be retained to perform a general review of the final design. Earth Consultants, Inc. ' GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21 , 1996 Page 2 SITE CONDITIONS Surface ' The subject site is located along the west side of Rainier Avenue South, approximately in the vicinity of 119th Street South in Renton, Washington (see Plate 1 , Vicinity Map). The property is irregularly shaped and is approximately 7.5 acres in size. The east boundary of ' the property borders approximately 530 feet of Rainier Avenue South. An existing warehouse and office development is present along a portion of the north property boundary. No developments are immediately adjacent to the western and southern boundaries of the property. There are, however, residential developments along the top of the bluff that borders the west and northwesterly sides of the site. ' The predominant topographic features include a ravine and the previously mentioned bluff that generally trend north to south along the west side of the site. A small drainage course runs 1 to the north along the bottom of the ravine at the base of the bluff. The site generally slopes down to the north with a maximum elevation change of approximately ninety feet. It is evident that the site has experienced some disturbance in the form of benched cuts along the middle and lower east portions of the site. It appears some fill and slide debris have also been deposited primarily along the north and portions of the east sides of the site. An abandoned asphalt road runs along a portion of the north side of the site and accesses the upper bench trending east to west through the middle of the site. The site vegetation consists primarily of grasses with an abundance of blackberry and scotch broom. Deciduous trees are present along the west and northwestern portions of the site, along the ravine areas, and along the lower southeastern portions of the site. ' Subsurface The site was explored by excavating eleven test pits at the approximate locations shown on ' Plate 2. Please refer to the Test Pit Logs, Plates A2 through Al2, for a more detailed description of the conditions encountered at each location explored. The following is a generalized description of the subsurface conditions encountered. Fill/Slide Debris ' Fill and some slide debris was encountered primarily at test pit locations along the north and east portions of the site. The previously referenced Golder Associates Study indicates varying ' depths of fill are also located along the west side of the site. The fill ranged in depth between approximately two feet to twelve feet, and was encountered at Earth Consultants test pit locations TP-1 , TP-3, and TP-7 through TP-11 . The fill was wet, and was generally characterized as soft, medium to high plasticity silt and loose silty sand. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 3 It appears some slide debris ranging in depths between approximately six to ten feet is present ' at test pit locations TP-2, TP-4 and TP-5. It appears this deposit has resulted from periodic instability of the upslope regions of the site, primarily along the ravine located on the west side of the site. The slide debris was wet, and contained a significant amount of organic material. The soil conditions were generally characterized as loose silty sand and soft, medium to high plasticity silt. ' Native Silt Below the fill and slide debris, medium to high plasticity silt was encountered to the depths explored. The silt was stiff and generally fractured. Some mottling was observed along the upper portions of this deposit. Groundwater 1 Light groundwater seepage was encountered at varying depths in the majority of the test pits. These seepage zones generally occurred at the contact between the loose fill and slide debris, and the native silt. Groundwater levels and the magnitude of seepage, however, are not static; therefore, fluctuations can be expected depending on the season, amount of rainfall, surface water runoff, and other factors. Generally, the water level is higher and seepage rate is greater in the wetter winter months (typically October through May). Laboratory Testing ' Laboratory tests were conducted on several representative soil samples to verify or modify the field soil classification and to evaluate the general physical properties and engineering characteristics of the soil encountered. Moisture content tests were performed on all samples. ' The results of laboratory tests performed on specific samples are provided at the appropriate sample depth on the individual test pit logs. It is important to note that these test results may not accurately represent the overall in-situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results and their use in guiding our engineering judgement. ECI cannot be responsible for the interpretation of these data by others. ' In accordance with our Standard Fee Schedule and General Conditions, the soil samples for this project will be discarded after a period of fifteen days following completion of this report Iunless we are otherwise directed in writing. ' Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 4 rDISCUSSION AND RECOMMENDATIONS ' General Based on the results of our study, it is our opinion that the proposed development can be ' constructed generally as planned provided the recommendations contained in this report are incorporated into the final design. The critical geotechnical aspects of the planned development are primarily associated with foundation support and reducing post-construction differential settlements. Based on our understanding of the proposed site grading and building locations, it appears some of the buildings will be located in zones of cut/fill transition. The western two buildings on the north side of the site, and the southeast building appear to be at greatest risk for differential movement due to cut/fill transitions. Portions of the two northern buildings may be located in zones of existing fill ranging in depths between approximately four to six feet. 1 To help reduce post-construction differential settlements, portions of the buildings located in zones of existing fill, or on newly constructed fill, should be supported on at least two feet of structural fill. Additional removal of unsuitable fills may be required, depending upon the condition of the existing fill and final grades. Building slabs not supported on competent native soils should be supported on at least one foot of structural fill. The requirements for ' structural fill are defined in the "Site Preparation And Genera/ Earthwork" section of this report. ' This report has been prepared for specific application to this project only and in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area for the exclusive use of ' Renton Crown LCC and their representatives. No warranty, expressed or implied, is made. This report, in its entirety, should be included in the project contract documents for the information of the contractor. ' Site Preparation and General Earthwork The building and pavement areas should be stripped and cleared of all organic matter, and any other deleterious material. Based on the thickness of the root mat and topsoil encountered during our exploration, we estimate a stripping depth of approximately_ four to six inches. However, these depths may vary and will depend on conditions encountered during the stripping operation. In building areas where greater than two feet of fill is to be placed, and ' in paved areas with more than one foot of fill, the existing surface need not be stripped. However, long grasses should be cut and trees and shrubs should be removed prior to fill placement. Stripped materials should not be mixed with any materials to be used as structural fill. ' Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21 , 1996 Page 5 Once stripping operations are complete, excavations to building and pavement subgrades can begin. Pavement subgrades and the ground surface where structural fill is to be placed, should be proofrolled. All proofrolling should be performed under the observation of a representative of ECL Any areas that are found to be yielding or unstable should be repaired either by re-compacting the area, or overexcavating and replacing with structural fill. The use of a woven geotextile placed on the overexcavated surface may be useful in bridging over ' unstable areas. ' Existing utility pipes to be abandoned should be plugged or removed so that they do not provide a conduit for water and cause soil saturation and stability problems. ' Due to the fine-grained nature and in-situ moisture content of the soils encountered during our exploration, the use of on-site soils as structural fill may be difficult. Much of the existing fill encountered during our exploration was significantly above its optimum moisture content, 1 therefore, considerable moisture conditioning of these soils would be required. The moisture content of the competent native silt encountered during our exploration was generally at or slightly above its optimum moisture content. These soils will degrade quickly when exposed to wet weather conditions. The success of compacting these soils to the requirements of structural fill will depend on the moisture content of the soil at the time of construction. To help stabilize wet soils, the use of cement, or cement kiln dust may be considered. 1 Structural fill is defined as any compacted fill placed under buildings, roadways, slabs, pavements, or any other load-bearing areas. Structural fill under floor slabs and footings ' should be placed in horizontal lifts not exceeding twelve (12) inches in loose thickness and compacted to a minimum of 90 percent of its laboratory maximum dry density, except for the top twelve (12) inches which should be compacted to 95 percent. The maximum dry density should be determined in accordance with ASTM Test Designation D-1557-78 (Modified Proctor). The fill materials should be placed at or near the optimum moisture content. Fill under pavements and walks should also be placed in horizontal lifts and compacted to 90 ' percent of maximum density except for the top twelve (12) inches which should be compacted to 95 percent of maximum density. Earth Consultants, Inc. ' GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 6 Foundations Assuming compliance with the recommendations outlined in the "Site Preparation and Genera/ p Earthwork" section of this report, the proposed structure may be supported on a conventional spread and continuous footing foundation bearing on competent native soils or on a minimum of two feet of structural fill. As stated previously, it appears the western two buildings along the north side of the site will be partially located in zones of existing uncontrolled fill. To help resist differential movement at the cut/fill transitions, additional reinforcement in the foundation elements, ten feet on either side of the transition, should be considered. All ' footing overexcavations performed in the uncontrolled fill zones should be observed by a representative of ECI to determine if additional overexcavation is required. Structural fill placed in overexcavations should extend outward from the edge of the footing a distance equal to one-half the depth of the overexcavation. Footing excavations performed in competent native soils should also be observed by a representative of ECI prior to placement of foundation elements. Exterior foundations elements should be placed a minimum depth of eighteen (18) inches below final exterior grade. Interior spread foundations can be placed at a minimum depth of twelve (12) inches below the top of slab, except in unheated areas, where interior foundation elements should be founded at a minimum depth of eighteen (18) inches. With foundation support obtained as described, an allowable soil bearing capacity of two thousand five hundred (2,500) pounds per square foot (psf) can be used for foundations supported on competent native soils or structural fill. Continuous and individual spread footings should have minimum widths of eighteen (18) and twenty-four (24) inches, respectively. Loading of this magnitude would be provided with theoretical factor-of-safety in excess of three against actual shear failure. With structural loading as expected, total settlement in the range of one inch is anticipated with differential movement of about three-quarters of one inch. Most of the anticipated settlements should occur during construction as dead loads are applied. Horizontal loads can be resisted by friction between the base of the foundation and the supporting soil and by passive soil pressure acting on the face of the buried portion of the ' foundation. For the latter, the foundation must be poured "neat" against the competent native soils, or backfilled with structural fill. For frictional capacity, a coefficient of 0.35 can be used. For passive earth pressure, the available resistance can be computed using an tequivalent fluid pressure of three hundred (300) pcf. These lateral resistance values are allowable values, a factor-of-safety of 1 .5 has been included. As movement of the foundation element is required to mobilize full passive resistance, the passive resistance should be neglected if such movement is not acceptable. Earth Consultants, Inc. 1 GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 7 1 Slab-on-Grade Floors Slab-on-grade floors may be supported on competent or recom acted native soil, or on at least 9 Y PP P P one foot of structural fill. The slab should be provided with a minimum of four inches of free- draining sand or gravel. In areas where slab moisture is undesirable, a vapor barrier such as a 6-mil plastic membrane may be placed beneath the slab. Two inches of damp sand may be ' placed over the membrane for protection during construction and to aid in curing of the concrete. Seismic Design Considerations The Puget Lowland is classified as a Seismic Zone 3 by the Uniform Building Code (UBC). The largest earthquakes in the Puget Lowland are widespread and have been subcrustal events, ranging in depth from thirty (30) to fifty-five (55) miles. Such deep events have exhibited no surface faulting. Structures are subject to damage from earthquakes due to direct and indirect action. Direct action is represented by shaking. Indirect action is represented by foundation soil failures and is typified by ground failure or liquefaction. The UBC Earthquake regulations contain a static force procedure and a dynamic force procedure for design base shear calculations. Based on the encountered soil conditions, it is our opinion that a site coefficient of SZ = 1 .2 should be used for the static force procedure as outlined in Section 1628 of the 1994 UBC. For the dynamic force procedure outlined in ' section 1929 of the 1994 UBC, the curve for deep cohesionless or stiff clay soils (Soil Type 2) should be used for Figure 16-3, Normalized Response Spectra Shapes. Liquefaction is a phenomenon in which soils lose all shear strength for short periods of time during an earthquake. Groundshaking of sufficient duration results in the loss of grain to grain contact and rapid increase in pore water pressure, causing the soil to behave as a fluid. To have a potential for liquefaction, a soil must be cohesionless with a grain size distribution of a specified range (generally sands and silt); it must be loose to medium dense; it must be below the groundwater table; and it must be subject to sufficient magnitude and duration of groundshaking. The effects of liquefaction may be large total and/or differential settlement for structures founded in the liquefying soils. 1 Provided the recommendations in this report are followed, in our opinion, the potential for liquefaction on the site is low. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 8 Excavations and Slopes The followinginformation is provided solely as a service to our client. Under no circumstances P Y should this information be interpreted to mean that ECI is assuming responsibility for construction site safety or the Contractor's activities; such responsibility is not being implied and should not be inferred. rIn no case should excavation slopes be greater than the limits specified in local, state and Federal safety regulations. Based on the information obtained from our field exploration, the ' soils encountered would be classified by OSHA as Type C for the existing fill and upper soft portions of the native silt, and Type B for the competent native silt. As such, temporary cuts greater than four feet in height should be sloped at an inclination no steeper than 1 .51-1:1 V in the existing fill and upper soft portions of the native silt, and no greater than 1 H:1 V in the competent native silt. If slopes of these inclinations, or flatter, cannot be constructed, temporary shoring may be necessary. This shoring will help protect against slope or 1 excavation collapse, and will provide protection to workers in the excavation. If temporary shoring is required, we will be available to provide shoring design criteria, if requested. All permanent cut and fill slopes should be inclined no steeper than 2H:1 V. All cut slopes should be observed by ECI during excavation to verify that conditions are as anticipated. Supplementary recommendations can then be developed, if needed, to improve stability, including flattening of slopes or installation of surface or subsurface drains In any case, water should not be allowed to flow uncontrolled over the top of any slopes. ' All permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. 1 Site Drainage The site must be graded such that surface water is directed off the site. Water must not be ' allowed to stand in any area where buildings, slabs or pavements are to be constructed. During construction, loose surfaces should be sealed at night by compacting the surface to reduce the potential for moisture infiltration into the soils. Final site grades must allow for ' drainage away from the building foundations. The ground should be sloped at a gradient of three percent for a distance of at least ten feet away from the buildings, except in paved areas, which can be sloped at a gradient of two percent. Earth Consultants, Inc. ' GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21 , 1996 Page 9 Perimeter footing drains should be installed around portions of the proposed buildings where infiltrating water can damage interior finishes. Drains should also be placed around the perimeter of below grade foundation walls to help reduce hydrostatic pressures on the wall. The footing drain should be installed at or just below the invert of the footing, with a gradient ' sufficient to initiate flow. A typical detail is provided on Plate 3. Under no circumstances should roof downspout drain lines be connected to the footing drain system. All roof downspouts must be separately tightlined to discharge. Cleanouts should be installed at strategic locations to allow for periodic maintenance of the footing drain and downspout tightline systems. Utility Support and Backfill Based on the soil conditions encountered at the time of our exploration, the native soil should provide adequate support for utilities. If remedial measures are necessary to provide adequate utility support, the unsuitable soil can be overexcavated and replaced with a suitable ballast and pipe bedding material such pea gravel. Utility trench backfill is a primary concern in reducing the potential for settlement along utility alignments, particularly in pavement areas. It is important that each section of utility line be adequately supported in the bedding material. The material should be hand tamped to ensure support is provided around the pipe haunches. Fill should be carefully placed and hand tamped to about twelve (12) inches above the crown of the pipe before any heavy compaction equipment is brought into use. The remainder of the trench backfill should be placed in lifts having a loose thickness of less than twelve (12) inches. A typical trench backfill section and compaction requirements for load supporting and non-load supporting areas is presented on Plate 4. ' Pavement Areas The adequacy of site pavements is related in part to the condition of the underlying subgrade. ' To provide a properly prepared subgrade for pavements, the subgrade should be treated and prepared as described in the "Site Preparation and General Earthwork" section of this report. Native cut surfaces should be in a firm and unyielding condition when proofrolled and fill areas should meet the requirements of structural fill. In localized areas of soft, wet or unstable subgrade, a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. Earth Consultants, Inc. ' GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 10 The following pavement section for lightly-loaded areas can be used: • Two inches of asphalt concrete (AC) over four inches of crushed rock base (CRB) material, or • Two inches of AC over three inches of asphalt treated base (ATB) material. Heavier truck-traffic areas will require thicker sections depending upon site usage, pavement life and site traffic. As a general rule, the following sections can be considered for truck- trafficked areas: • Three inches of AC over six inches of CRB, or • Three inches of AC over four inches of ATB. These pavement thicknesses may be modified based on anticipated traffic loads and frequency. Asphalt concrete (AC), asphalt treated base (ATB), and crushed rock base (CRB) materials should conform to WSDOT specifications. All rock base should be compacted to at least 95 percent of the ASTM D-1557-78 laboratory test standard. LIMITATIONS Our recommendations and conclusions are based on the site materials observed, selective laboratory testing and engineering analyses, the design information provided to us by you, and our experience and engineering judgement. The conclusions and recommendations are professional opinions derived in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area. No warranty is expressed or implied. The recommendations submitted in this report are based upon the data obtained from the test pits. Soil and groundwater conditions between test pits may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, ECI should be requested to reevaluate the recommendations of this report and to modify or verify them in writing prior to proceeding with the construction. Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Renton Crown LLC E-7186 March 21, 1996 Page 11 Additional Services As the engineer of record, ECI should be retained to perform a general review of the final 9 P design and specifications to verify that the earthwork and foundation recommendations have ' been properly interpreted and implemented in the design and in the construction specifications. ECI should also be retained to provide geotechnical services during construction. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. We do not accept responsibility for the performance of the foundation or earthwork unless we are retained to review the construction drawings and specifications, and to provide construction observation and testing services. 1 1 Earth Consultants, Inc. ' APPENDIX A FIELD EXPLORATION E-7186 Our field exploration was performed on March 15 1996. Subsurface conditions h p p at the site were explored by excavating eleven test pits to a maximum depth of sixteen (16) feet below the existing grade. The test pits were excavated by Five Ball Construction Inc. Approximate test pit locations were determined by pacing from existing landmarks. The test pit locations should be considered accurate only to the degree implied by the method used. These approximate locations are shown on the Test Pit Location Plan, Plate 2. The field exploration was continuously monitored by an engineer from our firm who classified the soils encountered, maintained a log of each test pit, obtained representative samples, measured groundwater levels, and observed pertinent site features. All samples were visually classified in accordance with the Unified Soil Classification System which is presented on Plate Al , Legend. tLogs of the test pits are presented on Plates A2 through Al2. The final logs represent our interpretations of the field logs and the results of the laboratory examination and tests of field samples. The stratification lines on the logs represent the approximate boundaries between soil types. In actuality, the transitions may be more gradual. Earth Consultants, Inc. 1 84j}I - h0 ST N 411 AVALON �!f N 38TH ST Q c• < 1 W SE ee M 37TH ST Ala��t.o SE 877 KENNYDALE 36TH S > e E 36TH = BEACH PARK h 8 7TH �°. 35TH ST, < ti/ ST 34TH < ST D W < sF _ W Z SOUTH POINT 33RD PL z t iv NE 33RD N 33RD ST £` > CT :.> COLEMAN ` POINT N 31ST ST N 31ST ST N 3OTH a ST CREEK ; RK N 29TH m N 287 PL ItNE 28TH ST --- --- N 28TH ST , z NE NE 27TH' _LADE ` ti . 2TTH z CT N.. 26TH Sr `�`w . W Z _ .... +KENN 24TN ST E w N Ll 1 SHI NGTON _ NERD ST m z< �EN' 1 -r {L� 'NE 20TH w z > Sr Z r= HE IM ST BOAT LAU NCHNE 14TH 3 - S e,NEhORIAt � �, c N� S 112TH ST �BEAGI`PARK', NE "12TH 1 2 AV N N S .113 S S 1 o m� ST RENTON 115 ST Lp AIRPORT m SQ 115 fl PL BOAT LAUNCH NE 10TH - - 1 6 a ST BOEING •� Z NE 10TH sr S Film ST s RENTON . , •11 NE 9TH <> S 117TH PL m PLANT S Y 118TH > g zt- NE n NE,-'.BkYN Q I STMAWR z NE RTH z 1 !' PARK F S 1197H T E _ WE S Ir120TH ST9 > �< p > 7 ST A w < N TH ST Nf S ' 121ST D c m S ;S �' 122ND I STI I TH Ns N H y 6TH vt. 1 7= S S' s 123RD ST t ! NW 1TH ST ? 'r" 2J5 M PARK -Zy} ST 4 6MM CT Reference: King County/Map 626 By Thomas Brothers Maps Dated 1993 Vicinity Map Earth Consultants Inc. Renton Crown Apartments Geaechnical Engimners.Geologists&Environmental Scientists Renton, Washington ' Proj. No. 7186 1 Drwn. GLS Date 3/15/96 Checked RAC Date Mar.'96 Plate 1 1 0 ° 0 Slope To Drain o ° 6 inch min. :o o ° 18 inch min. .O.o• � _o ,' •e. C' ,e.�.s.' •.O- s� .o 00 roc • I� O 4 inch min. Diameter Perforated Pipe Wrapped in Drainage _ . o ° e Fabric :. i ee. 2 inch min. 2 inch min. / 4 inch max. 12 inch min. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING LEGEND ' Surface seal; native soil or other low permeability material. Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the WSDOT Specifications. ' O brain pipe; perforated or slotted rigid PVC pipe laid with perforations or slots facing down;tight jointed;with a positive gradient. Do not use flexible corrugated plastic pipe. Do not tie building downspout drains into footing lines. Wrap with Mirafi 140 Filter Fabric or equivalent. Earth Consultants Inc. TYPICAL FOOTING SUBDRAIN DETAIL ceo+�� M �&FwArmmmial�„fis,s Renton Crown Apartments Renton, Washington ' Proj. No. 7186 FDrwn. GLS Date Mar.'96 Checked RAC Date 3/15/96 Plate 3 ' Non-Load Supporting Floor Slab or Areas Roadway Areas - ° ° ° Varies ° 95 0 ° 0 0 0 0 85 104 95 1 Foot Minimum ' Backfill 80. 90 Varies o. .:.o_Q .• oo PIPE o '0'' •: 0 °.°A;; oo;0..°°a.a°� "0.0'50 o�aoo: doo ' •.o'D�e. Oo. b•e°.oe••.0•'•. O oo'• O•..COQ .•O'O.• Bedding °'� o• .°.0'°' °°oo••od4° °. Varies 70- 'oo•. pdo 0.00 p•o,Ova .0.p Ooo oOOpOo�Q u O6 .00°9'00, .0'Qo-o o OQ..oQ LEGEND: Asphalt or Concrete Pavement or Concrete Floor Slab . o ° °,° .I Base Material or Base Rock ' Backfill; Compacted On-Site Soil or Imported Select Fill Material as Described in the Site Preparation of the General Earthwork Section of the Attached Report Text. ' 95 Minimum Percentage of Maximum Laboratory Dry Density as O Determined by ASTM Test Method D 1557-78 (Modified Proctor), Unless Otherwise Specified in the Attached Report Text. Bedding Material; Material Type Depends on Type of Pipe and Laying Conditions. Bedding Should Conform to the Manufacturers Recommendations for the Type of Pipe Selected. TYPICAL UTILITY TRENCH FILL Earth Consultants Inc. Renton Crown Apartments G("rchnical Fsglnef r.Ge01o9LUs&FnOrmn ilal Soo isls Renton, Washington ' Proj. No. 7186 FDrwn. GLS Date Mar.'96 Checked RAC Date 3/15/96 Plate 4 ¢ aa LLIzc — x ¢ r� rrG- m APPENDIX A Field Exploration 1 i 1 Earth Consultants, Inc. MAJOR DIVISIONS GRAPH LETTER TYPICAL DESCRIPTION SYMBOL SYMBOL O GW Well-Graded Gravels, Gravel-Sand Anddvel Clean Gravels Q o Q o Q o gW Mixtures, Little Or No Fines Gravelly (little or no fines) M M Coarse Soils GP Poorly-Graded Gravels,Gravel- • � gp Sand Mixtures, Little Or No Fines Grained �, Soils More Than GM Silty Gravels,Gravel-Sand- 50% Coarse Gravels With gm Silt Mixtures Fraction Fines(appreciable Retained On amount of fines) GC Clayey Gravels, Gravel-Sand- No. 4 Sieve gC Clay Mixtures Sand o 00 'p SW Well-Graded Sands, Gravelly And Clean Sand C o ' o C SW Sands, Little Or No Fines Sandy (little or no fines) q ;; q;.;.:� More Than a::> >% ' SP Poorly-Graded Sands, Gravelly 50% Material c:;;A<:::o;::;: s;<: Sp Sands, Little Or No Fines ' Larger Than More Than No. 200 Sieve 50% Coarse SM Silty Sands Sand Silt Mixtures Size Sands With Sm Fraction F ines(appreciable SevePassing No.4 amount of fines) ' SC Sc Clayey Sands, Sand-Clay Mixtures ' ML Inorganic Silts&Very Fine Sands,Rock Flour,Silty- ml Clayey Fine Sands;Clayey Silts w/ Slight Plasticity Fine Silts Liquid Limit CL Inorganic Clays Of Low To Medium Plasticity, ' Grained And Soils Clays Less Than 50 / Cl Gravelly Clays, Sandy Clays, Silty Clays, Lean I I I I I QL Organic Silts And Organic I I I I I OI Silty Clays Of Low Plasticity I '1 More Than MH Inorganic Silts, Micaceous Or Diatomaceous Fire mh Sand Or Silty Soils 50% Material Silts Smaller Than And Liquid Limit Cll norganic Clays Of High No.200 Sieve Clays Greater Than 50 Ch Plasticity, Fat Clays Size OH Organic Clays Of Medium To High Oh Plasticity, Organic Silts Peat, Humus, Swamp Soils Highly Organic Soils Pt With High Organic Contents Topsoil y y Humus And Duff Layer Fill Highly Variable Constituents The discussion in the text of this report is necessary for a proper understanding of the nature ' of the material presented in the attached logs. DUAL SYMBOLS are used to indicate borderline soil classification. C TORVANE READING,tsf I 2"O.D. SPLIT SPOON SAMPLER qu PENETROMETER READING,tsf W MOISTURE,%dry weight 24'I.D. RING OR SHELBY TUBE SAMPLER P SAMPLER PUSHED * SAMPLE NOT RECOVERED i WATER OBSERVATION WELL pcf DRY DENSITY, lbs.per cubic ft. LL LIQUID LIMIT, % a DEPTH OF ENCOUNTERED GROUNDWATER PI PLASTIC INDEX DURING EXCAVATION t SUBSEQUENT GROUNDWATER LEVEL W/DATE Earth Consultants Inc. LEGEND \I I (iuv,i Iuw, 11-94-7rs,Oh A)61,,Is& SCNa11tsis FProiNO.7186 I Date Mar. '96 1 Plate Al Test Pit Log Project Name: __F�hW of Renton Crow7Artments Job No. ed by: Date: Test Pit No.: 7186 CP 3 15 96 TP-1 ' Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 75' Notes: ° o r N a Surface Conditions: Depth of Topsoil &Sod 4-6": blackberry, duff w r } a O N O N N ML FILL Brown medium to high plasticity SILT, soft,wet ' 1 2 ' 38.2 3 4 5 ML Native, increasing stiffness, blocky structure 1 39.3 6 7 8 9 34.6 10 11 ' 12 13 -becomes grad, medium plasticity, silt, medium stiff, moist, light 32.6 seepage at 13 14 ' 15 Test pit terminated at 15.0 feet below existing grade. Groundwater seepage encountered at 13.0 feet during excavation. cD a N Test Pit Log CO Earth Consultants Inc. Renton Crown Apartments r- Renton,Washington J F Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A2 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown Apartments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 1 RAC 3 15 96 TP-2 1 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 65' Notes: ' INu o + ! N o Surface Conditions: Depth of Topsoil &Sod 4-6": blackberry, duff I U z � N A N N SM FILL SLIDE DEBRIS: Blacl to brown silty fine to medium SAND, loose, wet (moderate organics, branches, stump fragments) 1 2 ' 20.6 3 -becomes brown, some interbedded silt 4 17.9 5 Q -light seepage at 5.5' 6 ML Gray SILT, stiff, moist 29.3 7 8 9 Test pit terminated at 9.0 feet below existing grade. Groundwater seepage encountered at 5.5 feet during excavation. `D a N Test Pit Log Earth Consultants Inc. Renton Crown Apartments CCO1CC EQO"MCeOi°�` """SdCndWS Renton,Washington J F Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A3 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. a cannot accept responsibility for the use or Interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown Apartments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-3 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 60' Notes: o t ! N o Surface Conditions: Depth of Topsoil &Sod 4-6": blackberry, duff w r 0. .13 } a . L N O N N SM FILL- Brown to black silty fine to medium SAND, loose,wet 1 2 ML FILL: Becomes predominantlySILT, loose,wet 26.0 -organics (stum fragments) 3 -interbedded gray silt 4 5 6 7 8 -brown silty sand lens, some organics 30.7 9 10 11 ' 12 NIL Gray medium high plasticity SILT, stiff, moist, slightly mottled -light seepage at 12' 32.2 13 14 Test pit terminated at 14.0 feet below existing grade. Groundwater seepage encountered at 12.0 feet during excavation. `a a N N Test Pit Log Earth Consultants Inc. Renton Crown Apartments N "t `4vie Enom 'Ceoi°�&Ewu"W`e"`wSdffw°" Renton,Washington J a Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A4 1 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. a cannot accept responsibility for the use or interpretation by others of information presented on this log. 1 Test Pit Log Project Name: Sheet of Renton Crown Apartments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TPA Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 60' Notes: o r o N o Surface Conditions: Depth of Topsoil &Sod 4-6": blackberry, duff m A ? U M � ? M N N N SM FILL SLIDE DEBRIS: Brown to gray silty fine to medium SAND, loose, wet, interbedded—saridy SILT 1 ' 2 ML FILL/SLIDE DEBRIS: Becomes predominantly SILT 30.2 3 4 -some organics (roots, branches) 5 -1'to 2' silty sand lens 6 41.6 7 -becomes gray,wet, mottled 8 9 17 26.1 10 NIL Brown medium to high plasticity SILT, stiff, moist, light seepage at 10' 11 12 Test pit terminated at 12.0 feet below existing grade. Groundwater seepage encountered at 10.0 feet during excavation. o N iTest Pit Log a3 Earth Consultants Inc. Renton Crown Apartments r- "t `e010Chrkal Ero`ms.Ce &awt°`sr""soffwms Renton, Washington J F Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A5 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or Interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown A rtments 1 1 by: D Job No. Logged ate: Test Pit No.: 7186 RAC 3 15 96 TP-rJ Excavation Contactor. Ground Surface Elevation: Fiveball Construction t 65' Notes: c s ! N o Surface Conditions: Depth of Topsoil &sod 4-6": blackberry, duff w L + a U M N N N SM FILL/SLIDE DEBRIS: Brown to gray silty fine to medium SAND, loose, wet, some interbedded silt 1 2 ML FILL SLIDE DEBRIS: Becomes predominantly SILT, mottled -some Interb d si ty sand 1 3 41.1 4 ' S 6 -light seepage at 7' ML Brown to gray medium to high plasticity SILT, stiff, moist 34.0 a 9 Test pit terminated at 9.0 feet below existing grade. Groundwater seepage encountered at 7.0 feet during excavation. o N Test Pit Log cc Earth Consultants Inc. Renton Crown Apartments r, "t `eoio Er*Vaeem Ce°`°m°'°t°'""w&F W SdCrW°" Renton,Washington J F Proj.No. 7186 I Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A6 Subsurface conditions depicted represent our observations at the time and location of this expPloratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or Interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown A rtments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-6 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 80' Notes: U � L N o Surface Conditions: Depth of Topsoil &Sod 4f": scotch broom, grass W C i"CL a %j M 7 A L A 75 SM FILL Brown silty fine to medium SAND, loose, moist, interbedded silt 1 2 ML FILL Becomes predominantly SILT with silty sand lenses P Y 41.1 3 4 5 6 ML Brown to gray medium to high plasticity SILT, stiff, moist 38.9 a 9 10 -seepage at 10' -increasingly stiff 11 ' 12 13 34.4 14 15 16 Test pit terminated at 16.0 feet below existing grade. Groundwater seepage encountered at 10.0 feet during excavation. L o N Test Pit Log CO Earth Consultants Inc. Renton Crown Apartments Renton,Washington J F Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A7 Subsurface conditions d%cted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown Apartments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-7 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 50' Notes: o t ! N o Surface Conditions: Depth of Topsoil &Sod 4-6": blackberry, duff w 'C + a U D M " a ' � i � a O V) N N SM FILL Brown silty fine to medium SAND, loose, moist, some interbedded silt 1 2 ML FILL' Becomes predominantly SILT gray to brown, mottled loose,wet p Y � 9 Y 26.8 ' 3 4 ' 5 6 8 -organics (stump fragments, branches) s ML Brown to gray medium to high plasticity SILT, medium stiff, moist, light seepage at 8.5' 10 11 Test pit terminated at 11.0 feet below existing grade. Groundwater seepage encountered at 8.5 feet during excavation. tD a N N Test Pit Log W Earth Consultants Inc. Renton Crown Apartments ` ` "Horan` `Bmtow&rM Renton,Washington J a,- Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A8 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations, a cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown A rtments 1 1 Job No, logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-8 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 45' Notes: t ° o r ! N o Surface Conditions: Depth of Topsoil &Sod 4-6": grass w r Jo } ' a U M M ? ILA 7 ] � N � N N ML FILL Grat to brown SILT and sandy SILT, loose, wet 1 27.7 2 s ML Brown to gray medium to high plasticity SILT and sandy SILT, stiff, moist, light seepage at 2.5' 27.1 4 5 6 Test pit terminated at 6.0 feet below existing grade. ,Groundwater seepage encountered at 2.5 feet during excavation. i I N N Test Pit Log CO Earth Consultants Inc. Renton Crown Apartments GcooDaw Enorre'`'`�`RwVavr&rAWsuer'°" Renton,Washington J F Proj.No. 7186 1 Dwn. GLS I Date Mar.'96 Checked SDD Date 3/22/96 Plate A9 Subsurface conditions depicted represent our observations at the time and location of this expPlorstory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown A rtments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-9 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 45' Notes: W r o } i ti o Surface Conditions: Depth of Topsoil &Sod 4-6": grass a U (%) ° 7 ° L` i 0 a ML FILL Gray SILT and sandy SILT, loose,wet 1 2 37.8 3 ML Gray to brown medium to high plasticity SILT, stiff, moist, some 23.0 interbedded sandy silt 4 5 Test pit terminated at 5.0 feet below existing grade. No groundwater seepage encountered during drilling. o- N Test Pit Log CO Earth Consultants Inc. Renton Crown Apartments r- `'`°wa"cw Enonee Geoio� awwaimmsmSCdC71 mm Renton,Washington J Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate A10 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. a cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown A rtments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-10 Excavation Contactor: Ground Surface Elevation: Fiveball Construction t 45' Notes: L + ! H Q Surface Conditions: Depth of Topsoil &Sod 4-6": grass W . a a o H ° y v, SM FILL Brown to gray silty fine to medium SAND, loose, wet, some Interbedded silt 1 11.5 ML Brown to gray medium to high plasticity SILT, stiff, moist, some 2 interbedded sandy silt 3 4 Test pit terminated at 4.0 feet below existing grade. No groundwater 1 seepage encountered during excavation. o N Test Pit Log LD CO Earth Consultants Inc. Renton Crown Apartments r, "t ``°'° Er4*'O=Ccoio� ewVavnffMSoff"'m Renton,Washington J F Proj.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate Al Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of Renton Crown Apartments 1 1 Job No. Logged by: Date: Test Pit No.: 7186 RAC 3 15 96 TP-11 Excavation Contactor: Ground Surface Elevation: Fiveball Construction f 45' Notes: ° - - - o L • N a Surface Conditions: Depth of Topsoil &Sod 4$": grass ' O N N N ML FILL/SUDE DEBRIS: Gray SILT and sandy SILT, loose, wet, some interbedded silty sand t 2 NIL Brown to gray medium to high plasticity SILT, stiff, moist 9 Y 9 3 4 Test pit terminated at 4.0 feet below existing grade. Groundwater seepage encountered at 2.0 feet during excavation. N N Test Pit Log Earth Consultants Inc. Renton Crown Apartments le r- "t GeoWchn"Er**-ccmceo&o »&mwu"vr&rtwsdmideft Renton, Washington J a. Prof.No. 7186 Dwn. GLS Date Mar.'96 Checked SDD Date 3/22/96 Plate Al Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of information presented on this log. � a. a. mzm m IMAM M M M M M M r r M M r ' M� f APPENDIX B Laboratory Test Results 1 t 1 ' Earth Consultants, Inc. 100 80 x 60 w 0 z �_ CH U �- 40 �A-Line U) - -- Q J — a. C 20 � & 0 CL-ML OL 0 20 40 60 80 100 LIQUID LIMIT Natural ' Key Boring/ Depth Soil Classification USCS L.L. P.L. PI. Water Test Pit (ft) Content ' • TP-6 14 Gray SILT ML 49 30 19 34.4 Atterberg Limits Test Data litEarth Consultants Inc. Renton Crown Apartments Ge"t hnwalFnglrw rs,Geobgists&EnvironmentalSOeVisfs Renton, Washington Proj. No. 7186 Date mar. '96 Plate B1 1 DISTRIBUTION E-7186 4 Copies Renton Crown LLC 1 c/o Mark Lundberg 704 Northeast Northlake Way Seattle, Washington 98105 1 1 1 1 M 1 1 _ 1 1 1 1 i 1 Earth Consultants, Inc. 1 110 100 90 6o 70 60 50 120 r � r G7P-4 1 _ 40 j TP- 4 rP-113 -TP-7 r '-, 1 - i 7P-112 TP- -i- P-3 gel r P-4 - , -• TP-8 ' TP-5 Approximate Scale r TP-toe -e -o-7P- o- 11 0 50 100 200ft. - TP-1 40 TP-6_ 1 -o- TP-10�- 8 2 LEGEND -o 17P-109 TP-1 rP-110 _o�TP GB- TP-1 -:- Approximate Location of Tp-g m ECI Test Pit, Proj. No. 7P- E-7186, Mar. 1996 -o- 130 -107 ' rP-103 r -o _ _ 0_ GrP-1 -o- Approximate Location of 7p- 0-0 �-105 7P-10M°- G Test Pit by Golder Assoc., TP-115 !- Aug. 11, 1988 - - TP-11 t� G� 1 S'; ' _ 7P-101 -o- Approximate Location of GrP-10_ -o- -o- rP- Test Pit by Shannon & Wilson, -�8-1 TP-101 GB-1 June 23, 1988 sa GB-1-o- Approximate Location of Boring by Golder Assoc., 130 ' � Aug. 19, 1988 —O— 70 120 GTP-2 r 110 -- '� P-1 -0- Approximate Location of 110 120 130 130 120 110 Im 9n so Boring by Shannon & Wilson, Aug. 10, 1979 ' Proposed Building 9 1 Boring and Test Pit Location Plan Earth Consultants Inc. Renton Crown Apartments Ce"echn"FsghleM.G ologiSLS 6 Fnvirorvrkmlal$Cien1i5LS Renton, Washington Proj No. 7186 Drwn. GLS Date Mar.'96 Checked RAC Date 3/15/96 Plate 2 1 v � � b �#• � t'�`{'•"4R nF +�' d.� %.erg.r. '�` o1't'4+t. .. � r p�.%.am. r -tee _ «' ••',. "��{;r � � �CS� �`x.'® 3+ *.ec., n 5 �9 �,-gig.b a .� ' ar a ��< ,� � yv -,�,• ,�� .z, a, � '�«�. 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