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HomeMy WebLinkAboutIII (B) Approval and Authorization for Mayor and City Clerk to execute Addendum 96-01 to L.J. Nodarse Contract for Geotechnical Work on Starke Lake Boat Ramp AGENDA 6-4-96 OcoeeItem III B s n *or coo.,`>4%.* JAMES W SH RA,P.E. CITY ENGINEER/UTILITIES DIRECTOR 150 N.LAKESHORE DRIVE•OCOEE,FLORIDA 34761 PHONE(407)656-2322 EXT.142•FAX(407)656-7835 MEMORANDUM DATE: May 30, 1996 TO: The Honorable Mayor and Board of City Commissioners FROM: James W. Shira, P.E. City Engineer/Utilities ector SUBJECT: Starke Lake Boat Ramp The contractor for this project, Premier Dredge and Marine, Inc. has begun work on the project by installing 30 foot long pieces of sheet piling in order to dewater the work area. The first half of the sheet piling installation went well, but the lake bottom condition changed drastically at approximately the mid-line of the floating dock. At that point, they were unable to find acceptable soil to bed the piling in as far down as 72 feet. This condition was not apparent when we did our initial soils work. Prior to beginning design work on the docks, L.J. Nodarse performed 80 local soil density tests around each of the two fixed docks and the floating dock structure to determine the nature of the existing lake bottom soils. Since the existing boat ramps had not settled noticeably over the many years that they have been in place and since the local soil density tests indicated reasonably consistent lake bottom conditions, we did not feel that it was necessary to perform additional expensive testing. The conditions predicted by the initial soils work proved to be correct in the area north of the mid-line, but even though the hand probes did not indicate a differing bottom condition, the muck layer south of the mid-line is as much as six times greater. In this area, there appears to be a semi-solid soil layer below a few feet of muck, but below that, instead of more solid soil, there is another layer of muck that continues to a depth of at least 72 feet. We need to have soil borings performed in this area to determine the nature and extent of this unexpected soil condition so that an alternate dewatering scheme can be developed. These soil borings will give us a much more comprehensive analysis of the lake bottom in the area in which the contractor is now having trouble. We will not do similar work in the area that has already been successfully sheeted unless the results of these tests indicate that the installed sheet piling may be bedded in unstable soil. It is imperative that the sheet piling be bedded in a stable soil layer so that when the enclosed area is dewatered the area within the sheet piling will be safe for -L__ THE PRIDE OF WEST ORANGE I 5C The Honorable Mayor and Board of City Commissioners May 31, 1996 Page Two the workmen. We have received a quote from L.J. Nodarse for the required work in the amount of $14,771.25. Attached for your review is a copy of their quote as well as a proposed Addendum to their continuing contract based on this quote. This firm was initially selected due to their familiarity with the general soil conditions in this area as they were the soils consultant for the City Hall project. I recommend that the City Commission authorize and Mayor and City Clerk to execute Addendum No. 96-01 in the not-to-exceed amount of$14,771.25, with funding to be from General Fund Contingency, which has a current balance of$75,850.21.. JWS/jbw Attachments fie LI Nodarse & Associates, Inc. May 29, 1996 Project No. 94-G-0624.1 TO: CITY OF OCOEE • 150 North Lake Shore Drive OCOEE, Florida 34761 ATTN: Mr. Jim Shira, P.E. City Engineer RE: Lake Starke Boat Ramp and Dock Improvements Additional Study Lake Starke, OCOEE, Florida Dear Mr. Shira: L.J. Nodarse & Associates, Inc. (LIN) is pleased to present this proposal for completing an additional subsurface exploration and geotechnical engineering evaluation for the above-referenced project. A previous study was performed at this site by LJN which was dated February 24, 1995. During construction of the planned improvements at the site, the contractor began driving sheet pile to assist in dewatering the site. Driving of piles at the northeast corner of the area encountered soft soils in excess of 85 feet. The purpose of this study is to develop additional subsurface data to help design a method for constructing the desired improvements. SITE AND PROJECT DESCRIPTION The site is located adjacent to the OCOEE City Hall on the bank of Lake Starke. An existing complex of 3 docks and 2 boat ramps exist at the site. Continued use of the ramps has caused erosion at the toe of the ramps. The project includes repairs to the existing ramps, repairs to the eroded areas, protection of the restored areas from prop wash and dock improvements. Initial plans were to dewater the entire area to accomplish these tasks. Additional subsurface data is now required to assist in design of the dewatering system. Geotechnical, Environmental, & Materials Engineers 807 South Orlando Avenue♦ Suite A ♦Winter Park, Florida 32789♦Telephone 407.740.61 10♦ Facsimile 407.740.6112 Project No. 94-G-0624.1 Page 2 PROPOSED SCOPE OF SERVICES The proposed scope of services is based on our understanding of the project and our experience in the area with sites and projects similar to this one. Our exploration is planned to contain the following: • Mobilize barge mounted drilling equipment to the site. • Perform one Standard Penetration Test (SPT) boring to a depth of 125' at the proposed northeast corner of the bulkhead area. • Perform one SPT boring to a depth of 75' at the end of the existing east ramp. • Perform one Standard Penetration Test (SPT) borings to a depth of 50 feet at the end of the existing west ramp. • Terminate borings at a shallow depth if 15 to 20 feet of suitable bearing soil is encountered at the ramp locations. • Perform visual classification and required laboratory testing of the soil samples obtained from the SPT borings. Laboratory testing will include six grain size analysis, Atterberg limits analysis, and organic content tests on appropriate samples. • Analyze the field and laboratory data to develop engineering recommendations for bulkhead design and construction of the proposed improvements. The exploration will be supervised by a qualified Geotechnical Engineer registered in the state of Florida and the results of the exploration will be presented in a geotechnical engineering report. This report will specifically offer recommendations on the following items: • Existing site conditions. • Exploration, testing and sampling methods. • Subsurface soil conditions encountered and soil classifications. • Geotechnical design recommendations for the bulkhead, ramp and dock construction. PROJECT SCHEDULE Based on our present schedule, we are prepared to mobilize to begin the field operations for this project within about 10 days of your authorization to proceed. We anticipate the field portion of Project No. 94-G-0624.1 Page 3 the study to be completed in approximately 3 days. Engineering analysis, necessary laboratory work, and report preparation should be completed within approximately 10 days after the completion of field work. ESTIMATED COSTS For budgetary planning, we estimate the total cost of services for the described study will be approximately $14,771.25. A detailed breakdown of this cost is attached for your convenience. In computing this budget figure we have assumed the site is accessible to our barge mounted drilling equipment, that we have right of entry to the site, and that we will not experience excessive delays due to rubble at borehole locations or for other reasons beyond our control. If such conditions are encountered that could cause the cost of the exploration to exceed the budget figure, we will notify the client and obtain approval for the additional work before we proceed. AUTHORIZATION To authorize us to proceed with this project, please execute and return a copy of the attached Agreement for Services. Authorization should be indicated by the person or firm responsible for payment of our invoice. Please note the attached Agreement for Services forms a part of this proposal and that our terms are "Net 30 Days." CLOSURE LJN appreciates the opportunity to submit this proposal and we look forward to working with you on this project. If you have any questions or if we can provide any additional information, please feel free to call us at your convenience. Sincerely, L.J. NODARSE & ASSOCIATES, INC. • Michael J. Preim, P.E. Vice President/Chief Engineer Attachment: Agreement for Services 94-6-0624.1.PRO:1W Pfjm BREAKDOWN OF SERVICES ADDITIONAL STUDY LAKE STARKE BOAT RAMP AND DOCK IMPROVEMENTS LJN PROJECT NO. 94-G-0624.1 1.0 Field Exploration 1.1 Mobilization of Men & Equipment (Barge Rig) Lump Sum $5,000.00 1.2 Standard Penetration Test Borings (1 @ 125', 1 @ 75', 1 @ 50' ) 0-50'; 150' @ $12.00/ft $1,800.00 50' - 100'; 75' @ $15.00/ft $1,125.00 100' - 150'; 25' @ $26.25/ft $656.25 1.3 Casing(1 @ 100', 1 @ 50', 1 @ 30') 0-50'; 130' @ $8.25/ft $1,072.50 50' - 100'; 50' @ $9.75/ft $487.50 1.4 Grouting(1 @ 125', 1 @ 75', 1 @ 50' ) 0-50'; 150' @ $4.50/ft $675.00 50' - 100'; 75' @ $6.00/ft $450.00 100' - 150'; 25' @ $9.00/ft $225.00 TOTAL FIELD $11,491.25 2.0 Laboratory Services 2.1 Organic Content 6 @ $30.00/test $180.00 2.2 Grain Size Analysis 6 @ $50.00/test $300.00 2.3 Atterberg Limits Analysis 6 @ $60.00/test $360.00 TOTAL LABORATORY $840.00 4.0 Engineering & Report 4.1 Senior Engineer; 8 hrs @ $90.00/hr $720.00 4.3 Project Engineer; 20 hrs @ $ 65.00/hr $1,300.00 4.4 Secretarial; 6 hrs @ $30.00/hr $180.00 4.5 Drafting; 8 hrs @ $30.00/hr $240.00 TOTAL ENGINEERING $2,440.00 TOTAL PROJECT $14,771.25 96 -0i ADDENDUM NO. 0TO GEOTECHNICAL CONSULTING ENGINEERING SERVICES GEOTECHNICAL TESTING SERVICES LAKE STARKE BOAT RAMP AND DOCK IMPROVEMENTS LAKE STARKE OCOEE,FLORIDA 96 -0/ This Addendum No.gihereinafter called the Addendum as of this 30th day of May, 1996,shall constitute an Addendum to the Agreement for Professional Geotechnical Engineering &Testing Services between the City of Ocoee,Florida(the CITY)and L.J.Nodarse&Associates,Inc. (LJN) (the CONSULTANT)dated the 4th of January, 1994. WHEREAS, the CITY and CONSULTANT entered into an AGREEMENT whereby the CITY retained the CONSULTANT to provide professional engineering services as required from time to time,and WHEREAS the CONSULTANT will perform consulting engineering services for the CITY as herein defined. NOW THEREFORE,in consideration of the mutual covenants and promises hereinafter set forth on the part of both parties to be kept and performed,the parties do mutually agree as follows: Section 1 -Services of the Consultant 1.1 The CONSULTANT shall perform the engineering services as outlined in the attached proposal#94- G-0624.1 dated May 29, 1996 relative to the provision of consulting services to the CITY. Section 2 - Compensation 2.1 Compensation by CITY for engineering services provided under this Addendum shall be computed under Section II of the AGREEMENT with the compensation for this additional authorization not to exceed$14,771.25 as outlined in the attached proposal,without further authorization from the CITY. Section 3 -Time of Completion 3.1 The CONSULTANT shall provide the services as outlined in the attached proposal. 46 .01 IN WITNESS WHEREOF,the parties have executed this Addendum No.the day and year hereinafter set forth. CITY CONSULTANT CITY OF OCOEE L.J.NODARSE&ASSOCIATES,INC. BY: BY: �'C'ZZst� /S. Scott Vandergrift,Mayor Michael . 'reim,P.E. A11iST: Al LEST: Jean Grafton, City Clerk