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HomeMy WebLinkAboutBURGER KING AT THE MARKET PLACE PUD - FINAL - 21-89B - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTA Geotechnical Consultants, Inc. Play 25, 1989 Rosenbaum -Dean 101 North Cascade, #400 Colorado Springs, CO 80903 Attn: Mr. Steve Boyette Re: The Market Place Fort Collins, Colorado Pavement Thickness Recommendations Dear Steve: We have examined two different areas of this project with respect to pavement thickness design. Examined were the acceleration/ deceleration lanes off_ of South College Avenue, as well as the interior parking lots themselves. Each of the areas examined will be discussed in turn. I. SOUTH COLLEGE AVENUE Site development (_3rawings indicate that an acceleration and deceleration lane off of South College Avenue will be required for this project. The acceleration/deceleration lanes will he built near the northwest corner of the project. A Site Access Study was completed for this project by Mathew J. Delich. His report _indicates that the average daily traffic (ADT) on South College Avenue'in the area of the Market Place should be on the order of 40,000 vehicles per day on a long-term basis. It is the responsibility of the City of Fort Collins, Engineering Division to provide design data for city streets. The appropriate traffic loading (18 kip EDLA) for this construc- tion was provided by Mr. Dave Klockeman. Mr. Klockeman has estimated that the lone -term EnLA for design purposes should be taken as 360. No test borings were specifically drilled within the area of turn lane construction. However, it is observed that some of the test borings drilled for the original geotechnical study were drilled quite close to the area of turn lane construction. It is further observed that the surface soils are uniform in terms of their classification and other engineering characteristics. Based upon these facts, therefore, we believe that the soil which will be encountered during turn lane construction should be nearly iden- tical to that encountered by the test borings drilled during our foundation study. Previous soil testinq on the site indicates that the surface soils should classify as AASHTO A-6(7) to A-6(8). They should 775o N. Union Blvd., Suite 205 Colorado Springs, Colorado 80920 (jig) 5-S-1331 The Market Place May 25, 1989 Paqe -2- possess between 61% and 66% passing the #200 sieve with a liquid limit of 30 and a plasticity index ranging from 15 to 17. A Hveem-Carmany R value of 10 is deemed appropriate for materials of this classification type. Attached are calculations support- inq the thickness design recommendations provided in this summary report. We believe that these thickness calculations have been completed in accordance with the City of Fort Collins regula- tions, as well as those of the Colorado Department of Highways (CDOH). Using the data from the design nomographs which are attached, as well as the appropriate structural coefficients recognized by the City and the State, our calculations indicate that a full depth asphalt layer of at least 10 inches will he required to carry the superimposed traffic loading. This assumes that a hot bituminous pavement would be placed directly upon the subgrade without an intermediate base course layer. Further calculations indicate that, if a combination of hot bituminous pavement and plant mix bituminous base is used, a layer 6 inches in thickness of each of these materials would be appropriate (total pavement section 12 inches). During this pavement construction, we recommend that GCI be given the opportunity to examine the rough -cut subgrade to determine whether or not the soil conditions present conform with those assumed during completion of this design. All work completed on the acceleration/deceleration laneage must comply with the standards of the City of Fort Collins, as well as the CDOH. II. PARKING LOTS _ 01 The Delich Site Access Study indicates that The Market Place development should generate on the order of 6400 vehicles per day. For purposes of design, all. of this traffic is assumed to enter or leave the site via one of the three main entrances shown on the site development plan. Further, the Delich study indi- cates that the traffic stream would contain on the order of 30 delivery trucks per day. Using this data and appropriate equi- valency factors for the various vehicle classes anticipated, an 18 kip FDLA of 19 is deemed appropriate for the main traffic lanes within the parking lot and entry drives. Using this 18 kip FDLA value, and the appropriate CDOH design relationships, we believe that the following thicknesses would he appropriate for this development. For the main travelled lanes, the pavement should consist of 3 inches of asphalt over 12 inches of aggregate base course. If desired, a full depth asphalt design could he used for these areas with calculations indicating that it should be at least 7 inches in thickness. The Market Place May 25, 1989 PaQe -3- A lesser thickness of pavement may be used in those areas where lighter traffic is expected. For the auto parking areas, the pavement section may be reduced to 2 inches of asphalt over 6 inches of aggregate base, if you so desire. However, experience has shown that thin parking lot sections oftentimes require abnormal amounts of maintenance, particularly where noor subgrade soil conditions are present. For this reason, you may consider using a 3-inch surface asphalt layer even though it is not war- ranted based strictly upon the structural calculations. The use of a thicker surface asphalt will result in lesser amounts of parking lot maintenance. With the 3-inch surface, the base may be reduced to 4 inches in thickness for these light traffic areas. Any landscaped islands which will he irrigated can cause some amount of pavement deterioration. It is observed that the sub - grade soils are clay and as such, should be of relatively low permeability. Irrigation water in the .landscaped areas has a tendency to saturate the soil below the vegetation and enter the pavement area from behind and beneath the curb line. This type of phenomenon results in softening of the subgrade and premature pavement failure immediately against such landscaped features. Obviously, if irrigation can he eliminated, it would be the best course of action to prevent pavement deterioration. However, if irrigation must occur, then all soil used within the landscaped areas must he tightly compacted to lower its permeability and water traps behind the curb line must be eliminated. The use of some form of relief_ drain system could also be investigated as could the complete sealing of the landscaped area with an imper- meable membrane. As with the acceleration/deceleration lanes, we recommend that all parkinq lot construction be in strict compliance with the City of Fort Collins Standards. The subgrade preparation must be proper and compaction specifications as given in the original foundation report for this site, issued by GCI, should he follow- ed. Tf you have any questions concerning our recommendations or the calculations which have been presented, feel free to contact us. Respectfully submitted, GEOTECHNICAL CONSULTANTS, INC. By: Martin F. Essigmann, P. E. MFE/heh GCI Job No. 3389-1 cc: Yerqensen, Obering, & Whittaker All? )Z/V77:�l o4�X- 7) 7Z) Or X0 /0 // CCCC'77,1 i ,817'J/✓i/A/OOJ N M %r in tD U3©wnN IviinlonUts 031HO13M-NSIA rn O O O O N vi I I 111 Uo13V3 TON01038 o v, r_ n• F- N z „ Li rr Cr w � 0 7 LA tD rn V M _ N - 3 > u3ownN 'ivuni:)nbis-NS J o m CL w Q F- ' _U Z > p W w W O wLn iv LO m O O Q Z p O \O O _ t!1 Ln O rn 7 Z w LQ V103 wQl Z m X r-a � W w U- 0 3n'1VA 114Oddns lIOS-s O LD rn 4 M N T'Tl'iTrT-r�"Tr`t' l"'�'+r`T'14"'TiT"1'4. irT'-AT-T- O O O O O O O O Di rp r- rD In V M N - Noi1VOnx3 ISd 00IZ '3n-1VA 3ONV1SIS3U-8 41 % Z or-- <11 Geotechnical Consultants, Inc. JOB NO. 3. DRAWN BY DATE �� CHECKED BY SCALE FIGU F N . Test Specimen I 2 3 4 R-Value (300 psi) Moisture Content (%o) 11.0 10.0 9.0 Density (pcf) 121 .6 122.0 1 23. 6 L R-Value by Exudation Pressure S 11 17 11 100 90 80 70 60 m 50 0 D: 40 30 20 10 0 100 200 300 400 500 600 700 800 Exudation Pres-3ure ( psi ) Soil Type Clayey Sand Location Sample I Gravel 1 0/0 Liquid Limit 33 0/6 Sand 66 % Silt and Clay 33 Plasticity index 16 % f JOh'. d 4 of 6 ca4z3x L'.- All I" m 0 M N M Q ,f1 tD 83©wnN 3vun1Onuis 031H013M- NSM to ' 0 0 O 0 N »O1OV.4 hvNO103U tD L K M N 83ownN lv8n1On8is-NS CL Q � F- a% 7- W O W O O O O _ W VlOJ z wQl Cn X (n C j Cl W W PAS z W K U r-4 :,. :in-ivA 11JOddnS -iIOS-S O M pp ti lD N K M N Ot CD r (D V) V M N — NOI1vOnX3 ISd 00C '3n1VA 3ONV1SIS3U-8 �•. jN Geotechnical Consultants, Inc. } c� JOB NO. DRAWN BY ' ' GATE CIIECKED BY SCALE FIGU F NO. "'