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Coppell Health-SY 890515TO GINN, INC. Consulting Engineers ~ ].7103 Preston Road Suite 100, LB-]*18 DALLAS, TEXAS 75248 (214) 248-4900 WE ARE SENDING YOU ~ Attached [] Under separate cover via [] Shop drawings [] Prints [] Plans fications Copy of letter [] Change order [] COPIES DATE NO. DESCRIPTION THESE ARE TRANSMITrED as checked below: [] For approval ~For your use [] As requested ~ For review and comment [] FOR BIDS DUE [] Approved as submitted [] Approved as noted [] Returned for corrections [] 19.__ [] Resubmit [] Submit [] Return__ copies for approval copies for distribution .corrected prints [] PRINTS RETURNED AFTER LOAN TO US ROBERTS & DOWDEY CIVIL ENGINEERS 16200 Dallas Parkway, Suite200 -- Dallas, Texas 75248 -- (214) 93L0694 Rober! E..~crey. P.E. Dan M. Dowdey, RE. David E. Pierson, P.E. Buddy & Roberts, P.E. May 10, 1989 NAY II 1989 Mr. Kevin Peiffer, P.E. Ginn, Inc. 17103 Preston Rd. Suite 100, LB 118 Dallas, Texas 75248 RE: Lake, Coppell Health Care Center Dear Kevin: We have been asked to address the lake aeration situation for subject project. Since odor is the main concern of a lake without aeration, we feel that the nature of the water, primarily storm water runoff, will justify waiting until a need for an aerator is evident. The parties involved in the development in the Town Center and Coppell Health Care Center have a mutual interest in having the lake at its best level of appearance and condition at all times. They will be able to respond to the actual need in the event it is apparent that an aerator is required for the lake. Their agreement is such that the installation will be handled between them if needed. The unusual expense required for the development of this first phase of the Health Care Center makes it extremely desirable to postpone any expenses that can be postponed as long as possible. We feel that this delay to see how the lake functions through at least one complete cycle of r~infall and hot weather is reasonable under the circumstances. The enclosed portion of the soils report which relates to the clays which are available for lining the lake is included for your use. The report indicates that the soils which are present will be sufficient to maintain a high degree of impermeability. ACRE¥, ROBERTS & PIERSON, INC. THflEADGILL-00WOEY & ASSOCIATBS Mr. Kevin Peiffer, P.E. May 10, 1989 Page 2 We will be submitting the trench safety plan in the next few days and hopefully getting the plans approved very shortly thereafter. The owner is opening bids on May 24, 1989. It is their desire that construction begins as soon as possible thereafter. uly yours, Dan ~ DMD/dkb Enclosure CC: Mr. Otto Bejcek, Metrocrest Hospital Authority Mr. Grant Hensley, Mediplex Medical Bldg. Corp. Mr. Mike Allen, Univest Development SOUTHWESTERN I.ASORATORIES -- SUBSURFACE EXPLORATION FOR COPPELL HEALTHCARE CENTER COPPELL, TEXAS Prepared For Metrocrest Hospital Authority Dallas, Texas March 13, 1989 SWL Report No. 89-106 SOUTHWESTERN LABORATORIES North Texas Geotechmcal niwalon a geotech~tcal enomeer~ng, no~dest~tive, metall~rgkal ami a~dyt~al serv~es 2S75 Lone Star Drive · I~,O. Box 224227 · Dallas. Texas 75222 · March 13, 1989 Metrocrest Hospital Authority c/o Mediplex Medical Building Corporation . 12225 Greenville Avenue Suite 830, LB 115 Dallas, Texas 75243 Attention: Mr. Philllp' H. Taylor Re: Subsurface Exploration ' Coppell Healthcare Center Coppell, Texas - SWL Report No. 89 106 Gentlemen: Attached is our geotechnical report for the above referenced project. I.t .has been a pleasure to perform this work for you. If, uurlng the course of this project we can be of further assistance, please do not hesitate to call on us. Sincerely, SO~Y~HWESTERN LABORATORIES, INC. /Garrett E. Williams, P.E. ~; ;~m_Z'? .... &; ;..~l. ~'- WILLIAMS Geo.tec~nical Division ~ · ~.'~' ....... Kenneth D. Bain, P.E. Senior Geotechnical Consultant Geotechnical Division GEW/KDB/mh Attachment cc: Mr. John Garcia ProDosed Lake Excavations of up to eight (S) to ten (10) feet ere anticipated for the proposed lake. The bottom and sides will be situated in the reddish brown'and reddish tan and gray sandy clays. Deeper excavations will encounter relatively permeable sands and clayey sands. These sandy and silty clays are considered relatively impervious and would normally be considered to provide adequate protection against large seepage losses. When final grades have been established in the excavation, the upper six (6) inches of the exposed subgrade should be scarified to a depth of six (6) inches, and compacted to a minimum of ninety-five (95) percent of Standard Proctor Density (ASTM D-698) at/or slightly above (-1 to +5 percent) optimum moisture content as determined by that test. Excavations into the sands or clayey sands could require some type of liner to minimize seepage losses in these materials unless the shallow water levels measured in Borings 1,2, and 3 are present in the area of Boring 6. Since such a water level can be subject to seasonal fluctuations such a liner may be desirable if excavations extend into the permeable sands and clayey sands. A clay 09 10,5 -lb- $OUTHWESTE .. LABORATORIES ~ SOUTHWESTERN LABORATORI~.= liner (2 to 3 feet thick) would be a suitable liner. The on-site sandy silty clays would be a suitable,liner material. The clay fills should be spread in relatively horizontal lifts less than ten (10) inches thick, and uniformly compacted to a minimum of ninety-five (95)' percent of ASTM D-698 near (-1 to +5' percent) their optimum moisture content. Periodic watering of liners or other exposed clays in the excavation is advisable to minimize cracks until the lake is filled. Area Pavinq The surficial clays present at this site are subject to losses in shear strength with the increases in moisture content which normally occur beneath area paving. They react with hydrated lime which serves to improve their support value at higher moisture levels and provides a firm, uniform subgrade beneath the paving. We recommend that consideration be given to stabilizing the subgrade beneath flexible (asphalt) paving. Based on the Atterberg Limits Series, a minimum of six (6) percent hydrated lime (THD Item 264) should be used. This lime should be thoroughly mixed and blended with the top six (6) inches of the subgrade (THD Item 260) and the mixture compacted to a minimum of ninety-five (95)