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Home My WebLink AboutCA2016-12315 December 2016 David Klempin Historic Preservation 636 South Main Street Grapevine, Texas 76051 AFIlutur 7 tfll� A fts!t REO: HISTORIC PRESERVATION COMMISSION CERTIFICATE OF APPROPRIATENESS #CAI 6-123 608 SOUTH DOOLEY STREET GRAPEVINE, TEXAS 76051 This letter confirms on December 14, 20 16 the Historic Preservation Commission rovvP ro with condi"U"ons #CAI 6-123 for the property addressed as 60 8 South Dooley Street, legall descrCbed as Block 23, Lot 2, City of Grapevine, Texas. The foliot is Certi i ficate of Appropriateness.* wing was approved on this Re -plat Lot 2, Block 23 with 20,091 square feet into two lots- Lot A — 12,585 square feet in size at the Corner of East College Street and South D o*oley Street and Lot B — 7,505 square feet in size* Y 2. Relocate to Lot A the historic McPherson farmhouse, c. 1886 and garagei currently located at 901 Park Blvd, Grapevine, Texas; with the conditions the re -plat is approved by the Planning and Zoning Commission, a permit Is obtained from the building department and all exterior materials, windows, doors and door hardware, light fixtures and paint colors be approved under a separate Certificate of Appropriateness. An approved Certificate of Appropriateness is not an approved' Building Permit and a permit is not required. Contact the City of Grapevine's Building Department at 817-410- 3165 for fees and Information regarding permits. cc. Property Owne CA File I THIE'. CITY OF C310,YEVI.N"J" HISTORIC RR TION'r,,4 636 South,"N4. aij,-). Street"' em "exas m 7605 1 m Phone 817/4 10-3197 E, S ER VA fi Fax Number 817/41,0-3 E2,15 CERTIFICATE OF APPROPRIATENESS APPLICATION ..... 110� Date �dt�, ,��. meq) L Number �C � 1 � � ! Z 3 70,12 W Tenant Name/Occupancylu a Yes 0 No Block Lot )tog o Current o Historic 0 Approved 4011Approved with Conditions: Ic ka Office Use THIS IS NOT A BUILDING PERMIT. A SEPARATE BUILDING PERMIT MUST BE FILED AND APPROVED B E BUILDING DEPARMENFRE STARTING WORKI��::, DELIVERHISTORIC PRESERVATION DEPARTMENT 636 SOUTH MAIN STREET, GRAPEVINE, TEXAS City of Grapevine Historic Preservation Department — 636 South Main Street, Grapevine, Texas 76051 - (817) 410-3556 Tarrant Ap,praisal [district Real Estate 12/05/2016 Account Numben, 01091026 Georeference. .6-2,1 1.01 1 5.0 Property Location, 608 S DOOLEY ST, GRAPEVINE, 76051 Owner Informatiom- GRAPEVINE CITY OF PO BOX 95104 GRAPEVINE TX 76099-9704 3-PrInt.-Ownets Legal DescrIptiom, GRAPEVINE, CITY OF Block: 23 Lot: 2 Taxing jurlsdictions.e 011 CITY OF GRAPEVINE 220 TARRANT COUM 906 GRAPEVINE-COLLEYVILLE ISD 224 TARRANT COUNTY HOSPITAL 225 `ARRA NT COUNTY COLLEGE n �l rn r e, (p, (� � �!� �% 0" " ri [v :','z r d b a r� m ;,�,l t rl V rf"" n year A z ro ,,i, a i1,u,,, r I r c rJ 1", "! r i on, r, n C „:'i IL.,,,,,, Appraised Land 17MMMIM1171,1111 �� Deed Page: 0000000 Appraised Total Deed Volumv, 0000000 Instrument,,, D2053041,80 State Code,, C1 Vacant Land Residential $75,OD Garage Bays* 0 ............ - Central Air* N Pct lets, 0.00 CentralHeat, N TAD 2 U_6=10 Naap-* P0011 N MAPSCO.- TAR -028J $75-P Agent.& e S zett, yy . ....... . . . . . . . . . . . . . ........ a r� m ;,�,l t rl V rf"" n year A z ro ,,i, a i1,u,,, r I r c rJ 1", "! r i on, r, n C „:'i IL.,,,,,, Appraised Land 17MMMIM1171,1111 �� Deed Page: 0000000 Appraised Total Deed Volumv, 0000000 Instrument,,, D2053041,80 State Code,, C1 Vacant Land Residential $75,OD Garage Bays* 0 Year Built: Central Air* N Pct lets, 0.00 CentralHeat, N TAD 2 U_6=10 Naap-* P0011 N MAPSCO.- TAR -028J $75-P Agent.& 7 0 5 a 2026 Notice Sent, 0 Protest Deadline, EXeMAMOM PUBLIC PROPERTY 11.11 2 `i )'J , �j "S, 110 0 W In, S 1151 5 e ris 07 Deed Date: 09/27/2005 Deed Page: 0000000 Deed Volumv, 0000000 Instrument,,, D2053041,80 State Code,, C1 Vacant Land Residential Garage Bays* 0 Year Built: Central Air* N Pct lets, 0.00 CentralHeat, N TAD 2 U_6=10 Naap-* P0011 N MAPSCO.- TAR -028J Agent.& „ � :i �, : // / v :�� i. ,,' p oou pul pinpiilp il. ri%i ��,%i ,r, r, /,. .✓u�i�� r�' „l �� i !�j Legend #(;A 1`6mm 1 I I q. y Landmarked Pop rc is L___j Initial Selection r e Zoning City Limits 12/5/201,6 w I ,III. i G , I „ � :i �, : // / v :�� i. ,,' p oou pul pinpiilp il. ri%i ��,%i ,r, r, /,. .✓u�i�� r�' „l �� i !�j Legend #(;A 1`6mm 1 I I q. y Landmarked Pop rc is L___j Initial Selection r e Zoning City Limits 12/5/201,6 I10 E70: 0 )PIF AIIIIIII, "Now I I b, Tm 'VI ""0 % A rf v guxZ'Y 2.644 @ 99 RI m I A 2 3 4 5 6 2 , 114 1 opt lh'IVA Town% a of o pry 1) /IA aomf "P tio 4" , 00 "73 onefF Im" t",P1 Ald E Cab ROMA CANNON ST TR 2N 8 M0, IL 010) IIr 1111!0.711 f oft 'Ii 21" IS FIX qq,lgll 2 411101 ,ALI v"', `:::5% 1 Q60 YID f I t , 01101 CA 3A, CIO popm po% les, 0 4 0� 1 fro, 4 5 lly All, 6 AIIIII 7 n 2 3kVV p±I .56(6 fo �,,Wxo "N Y— 'j 7 & 9 10 8 13 12 j 2.44 . . . . . . . . . . . P P 3 Cab ROMA 2 1.325@ .964 Jai g" , M�VMF` Yr IIp o 10040, 'rR 2D2A 11115�1 M0, IL 010) IIr 1111!0.711 f oft 'Ii , eft, IOUlo, Vq YID f 2 1.325@ .964 Jai g" , M�VMF` Yr IIp o 10040, 'rR 2D2A 11115�1 IMSMIMEM \\\�� \\F \, \\ -IS z o0 15 30 60 Feet \\ \ \ \ \\ \\ Perimeter Measurements: \\901 Park Blvd Buildings P ILL KIM W ---f -., Attachment Photo and Maps Cio of Grapevinephoto - 2004 ,A101P,0 N', CERI""'IFICATE OF'APPRO. r-'R[/,kl ENESS", CITY Of GRAPEWNE R LEE EEA, 8 . D PURSUAN"r *,r c uggemp, r,)A,"rE al DE``,T-1'TM,EN0T OF" DEVELOI�',W,f NT SEFW1,r..ES CONTAu BUILDING WSPE-CTIOIC13 FOR PERW INFORMA11)(WI, Tarrant Coun_* Appraisal Dist?ict Map - 2004 Topographical depiction — 1981 Aerial photo — United States Geolo ,gical Survg — 1995 McPherson Farmhouse, c. 1886 CERTIFicxrE OF AP,PR(N3RlAT1l-:NESS", C" OF'(�RAFIEVINE REL E,..,,A,0S6 D PURSU T'" t23 DA-l'E DE A RITMIEN'T' OF' 1),FVELOPMENI'Si�,'-'�IRVI,CES CONT or BUILDING INSPECTIONS K I )R PERMIT INFORMAW)'N AgE y > 52 uj p 52M 5vS 2-,8 ;�. I I 03 97C 6 121 15! Zip uly k 0. 0 z c5 ra, co fis. Mn .0VA — M,9 — § 167 HT o -11 !j L�j L!j ---- [,-�T E- I rz E- I NNE fi Emil al R 111 PH; gi MH 11 �2 Jill 21 Iva mNM RN ...... . . ...... . ...... .w� l�lllll SII��IV13111VIII�II10@11 WHITWORTH E NG IN E ERIN DIAMOND JW INC PROPERTY OWNER: Structures built on ground supported concrete foundations depend not only on proper design and construction, but also on proper foundation environment maintenance performed by the occupant or owner of the property. A properly designed and constructed foundation may still experience distress if the surrounding soils are not being properly cared for. Active soils are any type of soil that, when exposed to certain conditions, will undergo shrinking and swelling. In areas such as Dallas/Fort Worth, where active soils are present, excessive moisture or too little moisture can affect the condition of the foundation. The objective of proper maintenance program is to maintain as near constant moisture content, as possible, for the soil under the foundation. The following is a list of items to be considered when planning proper foundation maintenance: 1. Drainage: ® Never allow water to pond near or against foundation slabs. ® Maintain positive drainage away from the foundation. The minimum slope shall be 5% for a distance of 10 feet from the edge of the foundation. (5% equals a 6 inch drop in 10 feet) ® Where a horizontal distance of 10 feet is not possible a berm or Swale shall be constructed which provides a minimum 2% slope conveying the water to an acceptable outfall. • The installation and maintenance of gutters and downspouts are highly recommended; they should be kept clear and discharge water away from the foundation. 2. Landscaping: ® There should be a minimum distance of 6 inches between the top of the slab and the ground. ® Landscape beds must also maintain the minimum positive slope of 5% away from the foundation. ® Where landscape beds are placed adjacent to the foundation, they should be equipped with a moisture barrier and/or area drains which convey water by means of buried pipe to an acceptable outfall. • Area drains must be checked periodically to ensure that they remain functional. ® Trees remove moisture from the ground in order to survive and should therefore be watered regularly. ® Trees should be placed at a distance no closer to the foundation than the full height of the mature tree. ® If existing tree removal is not an acceptable option, a root guard system should be constructed around the foundation in the area of the tree(s). Replace and compact any loose fill adjacent to the foundation with native soil. Water is conveyed quickly through sand or granular materials; these materials should not be used adjacent to the foundation unless accompanied by an appropriate drain system. 3. Seasonal Changes: ® Avoid excessive drying around the perimeter of the foundation - when soil pulls away from foundation, it is too dry. ® Excessive moisture is also a problem; therefore, avoid overwatering, even during dry seasons. 4. Swimming pools, pipe systems, and sprinkler lines: ® Routinely check for leaks. All property owners should conduct a yearly survey of their foundation and perform any maintenance necessary to improve drainage and prevent the ponding of water adjacent to these structures. This is especially important during the first ten (10) years after construction because this is usually the time when the most severe adjustment between the new foundation and its supporting soil occurs. Sri Z 51, Pc Rus ll J. Whitworth, P.E. Owner's Signature ,' : 817-236-6106 M : 817-236-6184 V : plans@rjwe.com u 'W1/HIITWORTH 11�' 11 �I N ESIM Ilii 1114 C DIAMOND JW INC'. Report No. ST17-0079 February 22, 2017 Geotechnical Investigation of Site -Specific Subsoil 608 South Dooley Street Lot 2; Block 23 City of Grapevine Grapevine, Texas Prepared for: City of Grapevine 636 South Main Street Grapevine, Texas Prepared by: Whitworth Engineering 4200 N. Main St. #150 Fort Worth, TX 76106 February 22, 2017 City of Grapevine Attn: David Klempin 636 South Main Street Grapevine, Texas Re: Geotechnical Investigation @ 608 South Dooley Street, Grapevine, Texas Dear Mr. David Klempin, Per your request, Whitworth Engineering has conducted a geotechnical investigation for the pad site at the above -referenced property. This investigation included an analysis of published information about the subsurface conditions in the area and a subsurface exploration of one (1) test boring. The information collected during this investigation was then used to determine some of the engineering properties of the supporting subsoil. The conclusions of this investigation are included herein. We appreciate the opportunity to provide this service to you and look forward to assisting you with any of your other construction requirements. Whitworth Engineering has a design team that can assist you with the foundation design and the inspections & testing of construction activities. If you have any questions or comments pertaining to this report, or if we can be of further assistance, please contact our office at 817-236-6106. Sincerely, Alan Golightly, P.E. The seal appearing on this document was authorized by Alan Golightly, P.E. 81471 Whitworth Engineering F-3973 ST17-0079 Page 2 of 14 port Number Builder 17-0079 City of Grapevine South Dooley Street hvision of Grapevine Coun )evine Tarrant Geology USDA Mountains 11810 JiN O Design Summary Formation Eagle Ford Formation Classification Navo-Urban Land Legal Description Lot 2; Block 23 GPS North 32.93526 Classification FAT CLAY (CH) Depth(ft) 18 #200 89 tum 50 LL 57 PI 37 Shrink/Swell Potential High Recommend Piers Yes (see section 4.2) GPS East -97.07372 Lab Results Allowable Soil Bearing(psf) 1740 Em Center(ft) 8.0 Em Edge(ft) 4.1 Yin Center(in) .93 average Yin Edge(m) 1.22 average PVR in 2.3 Pier Skin Friction (psfl 800 ST17-0079 Page 3 of 14 Table of Contents 1.0 EXECUTIVE SUMMARY..................................................................................................................................5 1.1 PROJECT DESCRIPTION.....................................................................................................................................5 1.2 LABORATORY STANDARDS................................................................................................................................5 1.3 SCOPE OF SERVICES..........................................................................................................................................6 2.0 INVESTIGATION OF PUBLISHED INFORMATION...................................................................................7 2.1 USDA..............................................................................................................................................................7 2.2 GAT.................................................................................................................................................................8 2.3 TWDB.............................................................................................................................................................8 3.0 SUBSURFACE EXPLORATION......................................................................................................................8 3.1 SITE CONDITIONS.............................................................................................................................................8 3.2 SOIL CONDITIONS............................................................................................................................................8 4.0 DESIGN ANALYSIS...........................................................................................................................................9 4.1 POTENTIAL SOIL MOVEMENT............................................................................................................................9 4.2 SOIL BEARING CAPACITY................................................................................................................................10 5.0 DESIGN RECOMMENDATIONS...................................................................................................................10 5.1 BUILDING FOUNDATION................................................................................................................................10 5.2 DRILLED PIERS...............................................................................................................................................12 5.3 SITE PREPARATION AND MAINTENANCE.........................................................................................................12 5.4 INSPECTIONS AND TESTING............................................................................................................................13 6.0 REPORT QUALIFICATIONS AND LIMITATIONS....................................................................................13 ST17-0079 Page 4 of 14 1.0 Executive Summary 1.1 Project Description The purpose of this report is to evaluate the engineering properties of the site-specific subgrade soil for the residential property located at 608 South Dooley Street in Grapevine, Texas. This property is recorded as Lot 2; Block 23 of the City of Grapevine subdivision, per the plat records as listed for Tarrant County, Texas. A map illustrating the location of the property is included below as Figure 1.1: Property Location Map. FIGURE 1.1: Property Location Map In s, 1.2 Laboratory Standards Whitworth Engineering has prepared this Geotechnical Investigation in general accordance with the 2005 Standards as prepared by the American Society of Testing and Materials (ASTM). Per these standards, many of the testing procedures have a referenced guideline. There are three (3) main types of standards used: guides, test methods, and practices. Provided below is a summary of the ASTM standard guidelines used to prepare this Investigation. ST17-0079 Page 5 of 14 1.2 Laboratory Standards Whitworth Engineering has prepared this Geotechnical Investigation in general accordance with the 2005 Standards as prepared by the American Society of Testing and Materials (ASTM). Per these standards, many of the testing procedures have a referenced guideline. There are three (3) main types of standards used: guides, test methods, and practices. Provided below is a summary of the ASTM standard guidelines used to prepare this Investigation. ST17-0079 Page 5 of 14 TABLE 1.2: Referenced ASTM Standards Used ASTM# Description Type D420 Site Characterization for Engineering Design and Construction Guide D421 Dry Preparation of Soil Samples for PSA and Soil Constants Practice D422 Particle -Size Analysis (PSA) for Soils Test D1140 Amount of Material in Soil Finer than #200 sieve Test D1452 Soil Investigation and Sampling by Auger Borings Practice D1587 Thin -Walled Tube Sampling of Soils Practice D2216 Lab. Determination of Moisture Content by Mass Test D2217 Wet Preparation of Soil Samples for PSA and Soil Constants Practice D2487 Classification of Soils for Engineering Purposes Practice D2488 Description and Identification of Soils (visual -Manual Procedure) Practice D3740 Minimum Requirements for Soil Testing Agencies Practice D4220 Preserving and Transporting Soil Samples Practice D4318 Atterberg Limits of Soils Test D4753 Evaluating, Selecting and Specifying Balances for Soil Testing Guide D6026 Using Significant Digits in Geotechnical Data Practice D6951 Standard Test Method for use of the Dynamic Cone Penetrometer Test 1.3 Scope of Services On February 16, 2017 Whitworth Engineering directed a site inspection of the subject property and one (1) test boring was advanced down to 18 feet below the existing ground because a significant bedrock layer was encountered. The location of the boring was based on the location of the residential structure and the limits of the property. The boring location is provided in Appendix A of this report. The subject boring was sampled in five (5) foot intervals, unless there was a detectable change in soil layers. Upon collection the samples were logged, placed in labeled bags and transported to the lab. Particle Size Analysis (ASTMD422) A Particle Size Analysis (PSA) test was conducted on selected soil samples from the boring. This test was used to determine the size and distribution of the soil particles in a given sample. The subject analysis was made utilizing an H452 Hydrometer to determine the percent of soil particles finer than two (2) microns (}gym) and by washing the tested sample through a #200 sieve. Atterherg Limits (ASTM D4318) The Atterberg Limits are a set of tests that are used to determine how a soils volume will vary with a change in the moisture content. The Liquid Limit (LL) is the moisture content at which the soil will flow as a heavy viscous fluid, and the Plastic Limit (PL) is the moisture content at which the soil begins to lose its plasticity and becomes brittle. The difference between LL and PL is referred to as the Plasticity Index (PI) of a soil and is often used to classify potential soil fill material. ST17-0079 Page 6 of 14 Soil Classification (ASTMD2487) Once the aforementioned tests have been reported, the soil can be classified per the Unified Soil Classification System (USCS). The USCS classifies soils using alphabetic sequences of between 24 letters; these are typically reported in all caps. The most common soils in the DFW area are Clays (C), Silts (M), and Sands (S) respectively. Fine grained soils, more than 50% finer than a #200 sieve, such as clays and silts are classified as Lean (L) or Fat (H) based on their Atterberg Liquid Limit. Potential Vertical Rise The Potential Vertical Rise (PVR) of a soil is used to determine the "potential ability of a soil material to swell at a given density, moisture and loading condition, when exposed to capillary or surface water, and thereby increase elevation of its upper surface, along with anything resting on it" (from Tex 124-E pg 3). The PVR unless otherwise stated in this report is calculated to a depth of 10 feet. The PVR potential below 10 feet is typically very small due to the surcharge of the soil above it. We consider this reasonable as the calculation is based on the dry condition which is more conservative. Furthermore, the calculation does not take into account the loading from the structure to be built which will also reduce the swelling potential. The PVR values are determined using TX DOT, TX 124 design spreadsheet. Dynamic Cone Penetration (ASTM D6951) The Dynamic Cone Penetration Test of a soil is used to determine the load bearing capacity of materials encountered in foundation exploration work. By determining the number of blows required to drive a conical point 6 inches, one can correlate the Point Bearing capacity for various soil types. The point bearing capacity given for the Dynamic Cone Penetrometer test is based on ASTM D6951 CBR values and CBR bearing capacity values developed by the Portland cement association. 2.0 Investigation of Published Information 2.1 USDA The United States Department of Agriculture (USDA) has published general soils information for the approximate area of the subject property. Per this information, the area soil appears to be classified as Navo-Urban land complex (CL -ML). The soil in this complex is deep, and gently sloping. It is on broad ridges and slopes above drainageways. The complex is 50 to 70 percent Navo soil, 15 to 40 percent Urban land, and less than 25 percent closely similar soils. Typically, the surface layer of the Navo soil is brown clay loam about 12 inches thick. The upper part of the subsoil, from 12 to 28 inches, is brown clay. From a depth of 28 to 66 inches, it is yellowish brown clay, grading to light olive brown clay. The lower part of the subsoil to a depth of 72 inches is light yellowish brown clay. Brownish, reddish, and yellowish mottles occur throughout. Reaction ranges from neutral to moderately alkaline. The Urban land part of the complex is covered by dwellings, small businesses, apartments, and schools and adjoining streets, driveways, sidewalks, and patios. The Navo soil is ST17-0079 Page 7 of 14 moderately suited to most urban uses. Shrinking and swelling with changes in moisture, corrosivity to uncoated steel, and permeability are the main limitations. 2.2 GAT According to the Geologic Atlas of Texas, Dallas Sheet, the subject property is located in the Eagle Ford Formation and consists of shale, sandstone, and limestone. This formation is approximately 200-300 feet thick. 2.3 TWDB Information published by the Texas Water Development Board (TWDB) suggests that the subject property is located over the Twin Mountains formation of the Trinity Aquifer. Well records for the general area of the property indicate groundwater from this formation at approximately 1810 feet below the existing ground. However, this is only applicable to usable groundwater. Undetermined quantities of groundwater can become trapped between soil layers or at fractures in the bedrock. This type of groundwater formation will vary in depth and change with climatic conditions. 3.0 Subsurface Exploration 3.1 Site Conditions The subject property is a single family residential lot and the pad site was identified by estimating the likely location. The approximate location of the subject boring is illustrated on the Boring Location Plan provided in Appendix A. The subject lot is grassy with a few trees around the pad site as illustrated in the Site Photos provided below. The subject property has a gentle slope to the east. 3.2 Soil Conditions The information provided by the Boring Log suggests that the profile of the site soils consists of 2-3 soil strata consisting of LEAN CLAYS and FAT CLAYS. ST17-0079 Page 8 of 14 The design material is a moist, stiff, yellowish brown and gray FAT CLAY (CH) that is present at the surface and extends to 18 feet below ground. This material is fine grained with 89% of the soil particles finer than a #200 sieve and 50% finer than 2 }gym. With a LL of 57 and a PI of 37 this soil has a HIGH potential for moisture, induced volume change. For additional soils information, please refer to the Boring Logs in Appendix A. Trapped groundwater was not present in the boring. Typically, groundwater levels are seasonal and fluctuate with weather conditions. If groundwater is encountered during the construction of the proposed foundation, it should be reported to the engineer immediately. 4.0 Design Analysis 4.1 Potential Soil Movement To determine the shrink/swell potential of the foundation soil, the soil properties determined from the laboratory tests were used as input values for VOLFLO 1.5 software as developed by Geostructural Tool Kit, Inc. This software uses the unsaturated soil mechanics theory to determine the Edge Moisture (em) variation distance and the Differential Soil Movement (ym), that are used in the design of post, tensioned concrete slabs. These parameters are then evaluated for a center lift condition and an edge lift condition. If designing a PTSOG foundation, the PTI 3 Edition Manual including Addendum #1 should be used to design the foundation from these soil movement parameters. These parameters are further defined below. Values: ➢ Edge Moisture (em), feet - The distance from which moisture is expected to migrate through the soil as measured in feet. ➢ Differential Vertical Movement (ym), inches - The estimated distance that the soil surface will move from its as -built condition as measured in inches. Both the equilibrium condition and the extreme conditions are shown below. The equilibrium condition assumes that the soil moisture content in the active zone is at or near equilibrium at the time of construction. The extreme condition is reflective of a suction change from unusually moist or dry soils to an unusually dry or moist soil. If this condition is anticipated, it is recommended to use the extreme differential vertical movement (ym) values for design. Conditions: ➢ Center Lift (C) - The situation that occurs when the soil under the center section of the foundation swells up, with dryer edge moisture conditions. ➢ Edge Lift (E) - The situation that occurs when the soil around the edge of the foundation swells up, with dryer center of slab moisture conditions. ST17-0079 Page 9 of 14 The values that were determined using the critical site-specific values are provided below in Table 4.1: PTI Design Parameters. Table 4.1: PTI Desien Parameters The Potential Vertical Rise PVR (from TEX 124-E) for the first 10 feet of this soil was determined to be 2.3 inches. Please see Section 1.3 for a description of this calculation. 4.2 Soil Bearing Capacity The allowable bearing capacity of the site soil was determined from Dynamic Cone Penetrometer readings taken in the field. Using these values, provided in the Boring Logs in Appendix A, the allowable bearing capacity that should be used for the subsurface soil in the first 5 feet is 1740 PSF. Due to the potential for organic material decay within the soil (it was located in a wooded area), we recommend using piers to avoid differential settlement (see section 5.2). Based on the Dynamic Cone Penetration test values, drilled piers can be designed with the following values, after excluding the top 5 feet of material for skin friction: Table 4.2: Pier DesiL-n Parameters Skin Friction 800 psf Point Bearing 4700 psf Center Lift Edge Lift em, feet 8.0 4.1 ym, inches (equilibrium) 0.59 0.58 y., inches (extreme) 1.26 1.83 The Potential Vertical Rise PVR (from TEX 124-E) for the first 10 feet of this soil was determined to be 2.3 inches. Please see Section 1.3 for a description of this calculation. 4.2 Soil Bearing Capacity The allowable bearing capacity of the site soil was determined from Dynamic Cone Penetrometer readings taken in the field. Using these values, provided in the Boring Logs in Appendix A, the allowable bearing capacity that should be used for the subsurface soil in the first 5 feet is 1740 PSF. Due to the potential for organic material decay within the soil (it was located in a wooded area), we recommend using piers to avoid differential settlement (see section 5.2). Based on the Dynamic Cone Penetration test values, drilled piers can be designed with the following values, after excluding the top 5 feet of material for skin friction: Table 4.2: Pier DesiL-n Parameters Skin Friction 800 psf Point Bearing 4700 psf 5.0 Design Recommendations S.1 Building Foundation Foundation options include structurally suspended slabs, Post- Tensioned Slab on Grade PTSOG (aka waffle slab), conventionally reinforced waffle slabs, pier and beam, and others. A structurally suspended slab will provide the least risk of differential movement; as such, it is always a good recommendation in areas with active soils. As soils become more active, the structurally suspended slab becomes more cost effective. ST17-0079 Page 10 of 14 The design soil has a high plasticity index of 37, which may result in large movements in the soil when moisture conditions change. A suspended slab, as mentioned above is one option for this site, as the slab and grade beams are isolated from soil movements. The use of soil modification might also be considered by the design engineer. Soil modification is a means by which the properties of the soil can be improved significantly using one of the following methods: 1. Removal of the clay soils to a depth of 4 feet and reducing it with a select fill of clayey sand soil having a PI between 4 and 15 and maximum particle size of I inch. The fill soils would need to be compacted to at least the minimum of 95% standard proctor (ASTM D698) at a moisture content of -2% to +4% of optimum moisture. 2. Through injections of water into the soil to depths of approximately 10 feet usually requiring at least 4 passes in two directions. This pre -swells the clay soils. Clay soils have low permeability, requiring multiple passes to uniformly cover the area. 3. Through injections of a chemical solution containing potassium, in a similar method as water injection, to depths of approximately 10 feet. Chemical injection changes the properties of the soil, reducing the plasticity. The most popular foundation constructed in the north central Texas region is the waffle slab (and especially the Post Tensioned Slab on Grade). PTSOG foundations have an increased risk of movement and distress caused by the swelling and shrinking of active soils related to changes in moisture content. They rely on the builder and owner to follow soil moisture maintenance guidelines during and after construction. Typical moisture maintenance guidelines are as presented in Section 5.3. Additionally, it is of utmost importance that the grade beams for this type of slab be embedded a minimum of 12 inches into undisturbed subgrade or be supported by piers. As the PTSOG foundation has a lower initial cost and the associated risk level is typically considered reasonable, experience with foundations throughout the North Central Texas region suggests that PTSOGs are capable of supporting most residential and light commercial structures with minimal effects from the supporting soils. If this type of foundation is chosen, the PTSOG should be designed by a professional engineer who has experience with post -tensioned concrete foundations and should follow the guidelines set forth in the "Design of Post -Tensioned Slabs -on - Grade, Third Edition" (including Addendum #1), as published by the Post, Tensioning Institute (PTI). Under special conditions such as low plasticity and without piers, a uniform thickness slab may be used. Other foundation options may also be evaluated by the foundation engineer and the final selection should be made based on the sound engineering principles in conjunction with the risk factor acceptable to the owner and builder. ST17-0079 Page 11 of 14 5.2 Drilled Piers Cast -in-place concrete piers are an excellent way to supplement the structural properties of a building foundation. Drilled piers can be installed to structurally suspend a building foundation to prevent contact with an unstable soil, as in the case of the Structurally Suspended Foundation. Piers can also be used to supplement a PTSOG that has been constructed on unstable soil by preventing the downward settlement that occurs when a slab experiences edge drop. Experience suggests that unless an unstable soil is present, such as inadequately compacted fill material, most PTSOGs behave similarly with or without drilled piers. However, the use of piers for supplemental support will never be discouraged if the owner chooses to construct them. If site conditions show considerable organics or warrant fill in excess of 18 inches in the foundation area which prevents the bottom of grade beams to be founded into at least 12 inches of undisturbed soil, drilled piers should be considered. Said piers should be designed by the foundation engineer. 5.3 Site Preparation and Maintenance The building foundation for the proposed structure should be constructed as previously described. However, there are several additional precautions that should be considered when developing a residential or light commercial property. The foundation soil can be influenced by indirect methods such as, but not limited to, fill compaction, site drainage, existing trees, removed trees, landscape beds, leaking pipes and climatic conditions. The objective of a proper maintenance program is to maintain as near constant moisture content as possible for the soil under the foundation. The following is a list of items to be considered when planning proper foundation maintenance: 1.Drainage: • Never allow water to pond near or against foundation slabs. • Maintain positive drainage away from the foundation. The minimum slope shall be S% for a distance of 10 feet from the edge of the foundation. (S% equals a 6 -inch drop in 10 feet) • Where a horizontal distance of 10 feet is not possible, a berm or swale shall be constructed which provides a minimum 2% slope conveying the water to an acceptable outfall. • The installation and maintenance of gutters and downspouts are highly recommended; they should be kept clear and discharge water away from the foundation. 2.Landscaping: • There should be a minimum distance of 6 inches between the top of the slab and the ground. • Landscape beds must also maintain the minimum positive slope of S% away from the foundation. • Where landscape beds are placed adjacent to the foundation, they should be equipped with a moisture barrier and/or area drains which convey water by means of buried pipe to an acceptable outfall. ST17-0079 Page 12 of 14 • Area drains must be checked periodically to ensure that they remain functional. • Trees remove moisture from the ground in order to survive, and should therefore be watered regularly. • Trees should be placed at a distance no closer to the foundation than the full height of the mature tree. • If existing tree removal is not an acceptable option, a root guard system should be constructed around the foundation in the area of the tree(s). Replace and compact any loose fill adjacent to the foundation with native soil. Water is conveyed quickly through sand or granular materials; these materials should not be used adjacent to the foundation unless accompanied by an appropriate drain system. 3.Seasonal Changes: • Avoid excessive drying around the perimeter of the foundation; when soil pulls away from foundation it is too dry. • Excessive moisture is also a problem; therefore, avoid overwatering, even during dry seasons. 4 -Swimming pools, pipe systems and sprinkler lines: • Routinely check for leaks. All property owners should conduct a yearly survey of their foundation and perform any maintenance necessary to improve drainage and prevent the ponding of water adjacent to these structures. This is especially important dining the fust five (S) years after construction because this is usually the time when the most severe adjustment between the new foundation and its supporting soil occurs. S.4 Inspections and Testing The most carefully prepared plans have no value if they are not followed. Even if all major components are present, the results can be a disaster if they are not assembled in the proper order and fashion. Therefore, it is recommended that the foundation be inspected before any major concrete pour to verify the dimensions of the structural members of the slab and to verify the placement of the reinforcing steel or cable. If the residence is to be constructed within a city's ETJ, the city will typically require a city inspection. Whitworth Engineering can provide inspection services for residential or light commercial foundations at the owner's request. Testing of the concrete mix is only required by a few local municipalities. Whitworth Engineering can also provide said testing service. 6.0 Report Qualifications and Limitations This investigation was conducted in accordance with generally accepted geotechnical practices and procedures. The opinions expressed in this report are based on the engineering properties of the referenced samples in association with the values developed from recognized empirical formulas and any other information provided to Whitworth Engineering by the owner or his representatives. ST17-0079 Page 13 of 14 The recommendations provided in this report are only applicable to the specific property for which the investigation was conducted for the conditions as they have been reported herein. The engineering properties of soil are not constant; they are influenced by moisture and a number of other factors as previously discussed. Because of this, the recommendations made in this report are only valid for six (6) months from the date of this report. Any major deviations from the site conditions as they have been reported should be forwarded to Whitworth Engineering for further review. ST17-0079 Page 14 of 14 Log of Boring B 1 WHITWORTH Project #: ST17.0079 Date: 2/16/2017 III Client: E. . G 1 . IIS IIS l 1 I°1 City of Grapevine Elevation: 0 Address: 608 South Dooley Street GPS North: 32.93526 City: Grapevine GPS West: -97.07372 Sa=le LeVen S - Shelby Tube D - Dynamic Cone Penetration Test 1111Stratum Description LEAN CLAY - mosit, stiff, black and brown. ONE MEN MEN FAT CLAY - moist, stiff, yellowish brown and gray. MEN MEN MEN MEN IMMIMEMIMIMISIMIMIMIMMIM! MEN NONE 18'EOB (No Water F NONE NONE IMMIMEMIMIMISIMIMIMIMMIM! NONE NONE NONE MEME KEY TO SYMBOLS AND TERMINOLOGY SYMBOL USCS DECRIPTION Q ALLOW. PSF CONSISTENCY FAT CLAY 0-167 CH VERY SOFT CL LEAN CLAY 167-333 SOFT MH ELASTIC SILT 333-666 FIRM ML SILT 666-1333 STIFF CL -ML SILTY CLAY 1333-2666 VERY STIFF SW or SP SAND 2666+ HARD SM SILTY SAND C CLAYEY SAND - LIMESTONE - SANDSTONE - SHALE EAST COLLEGE STREET '.. PICTURE 2 u R W- ° -E id r�I � O O O C 2 I w O +" m B-1 501-011 PICTURE 1 BORING LOCATION PLANS 608 SOUTH DOOLEY STREET BORING LOCATION LOT 2; BLOCK 23 -CITY OF GRAPEVINE GRAPEVINE, TEXAS -20 0 10 20 "AwN Er. zP WHITWORTH SCALE: 111-201 011 lum E N G I N E E R I N G DIAMOND JW INC PROJECT# T7 -0n n ST 079 4100 NORTH MAIN, SUITE 150 FORT a6. TH,TX 7-T&l FAX F3 RT`N�RTH, Tk10184 (817)2 3 onTE. February 16, 2017