Chicago Harbor Lock Chamber Wall All Resurfacing Project, Chicago Harbor Lock, Chicago, IL

As the Contracting Chief for the Chicago District Office, I am advancing the USACE's responses to Contractor's questions. Please be mindful, the below questions and responses will be captured via an impending amendment that will be issued today, 23 Sept 2019. The amendment will also extend the Bid Opening date to 26 Sep 2019. Regina G. Blair Contracting Chief - USACE, Chicago District Question 1: Drawing S-102 Elevation A1 has a note for an expanded detail A1 on drawing S-509. There is not a drawing S-509 in the set. I think the intent might be drawing S-503 , please clarify. USACE RESPONSE 1: "The correct detail number is A1 on S-503. " 2. Question 2: Drawing S-503 shows the elevation of a typical Armor Plate / Ladder elevation and details. However no details are provided for the connection between the existing ladder and the proposed ladder. Please provide details for how this connection is to be made. USACE RESPONSE 2: "As shown on Sheet S-503, there is no special connection requirement for the existing ladder to the new steel ladder and armor plate. The armor plate of the ladder is to rest on the seat concrete as shown in detail B6, S-503. " QUESTION 3: Will shop and field welds need to be scanned ? USACE RESPONSE 3: "All weld inspection is per specification section 05 50 15 and AWS D1.1." FQUESTION 4:The Lock Wall Steel Ladder is noted as a separate pay item. Is the intent that the ladder steel be fabricated and grouted separately from the adjoining armor plates ? USACE RESPONSE 4: "Please see detail E6, sheet S-503, which indicates that the ladder steel and adjoining armor plates are connected and can be grouted together." QUESTION 5: Page 6 in Section 01 22 00 .00 10 paragraph 1.1 . 9 . 1 description for Cast In Place Concrete directs us to section 05 50 15 but there is no cast in place information in that specification. Please provide a cast in place specification. USACE RESPONSE 5: "Cast in place concrete is provided in specification section 03 30 53. Grouting for the armor plate is provided in specification section 05 50 15." QUESTION 6: How is the existing top of lock corner armor anchored / embedded into the concrete? This has to be removed under this contract however the reference drawings appear to only show radiused concrete. USACE RESPONSE 6: "Please see reference sheet R-106 for armor plate anchorage." QUESTION 7: "Priority Option Items" in 52.217-7 state that we cannot commence work for Priority X items until its full completion of Priority X-1 Option work. Does this include armor plate fabrication? USACE RESPONSE 7: SEE AMENDMENT NO. 0002 QUESTION 8: 01 57 20.01 03 3.3.1 states that the effluent from cofferdam dewatering operations cannot be discharged into Lake Michigan. Please confirm that the lock chamber is not "Lake Michigan" in this instance. USACE RESPONE 8: "The Contractor shall discharge the effluent to the Chicago River side of the lock chamber. The effluent is NOT to be discharged to Lake Michigan or the lock chamber. By way of amendment 3, section 01 57 20.01 03 and paragraph 3.3.1 will include a statement for clarification" QUESTION 9: Will cofferdam dewatering effluent be allowed to be pumped directly into the river / lock chamber or does a settling basing need to be constructed? If there is a need for this basin, will it be allowed to be constructed on shore in the immediate facility of the work being performed? USACE RESPONSE 9: "In accordance to Section 01 57 20.01 03, paragraph 1.7.3 -p, the Contractor needs to submit a detailed waste water management plan that shows the details (such as the design, size, and location) of the proposed settling basin". QUESTION 10: SD-301 Note #2 states that "all cofferdams must be designed, as a minimum, for an ice load of 5k/lf". Due to specified ice flushing, there will not be any instance where the cofferdam is subject to an ice load of this magnitude. Please delete this requirement and insert verbiage stating that any ice loading will either be designed for by the Contractor or preventative measures taken to prevent ice loading. Structural USACE RESPONSE 10: "The cofferdam is to be designed for a 5 kip/ft ice load as indicated in note 2 on sheet SD-301." QUESTION 11: If care is taken to preserve the existing finish of the existing bollards, will the USACE not require them to be painted (called for in 09 97 02)? Structural USACE RESPONSE 11: "All bollards are to be painted yellow IAW Specification section 09 97 02" QUESTION 12: 6. S-504 states to paint the exposed hook concrete safety yellow. Will each of the coats of System 5-E-Z be applicable to coating this concrete? Structural USACE RESPONSE 12: "As indicated in the table in paragraph 3.5 of Specification 09 97 02, the concrete only is to receive yellow top coats." QUESTION 13: Can the horizontal portions of the lock wall be removed and replace in one continuous operation or is this horizontal portion governed by the "1 at a time" or "hopscotch" requirement of the vertical portions of the wall? Structural USACE RESPONSE 13: "Please see note 5 on sheet SD-301. The "Hop scotch" requirement applies only to the lock wall concrete." QUESTION 14: If no active heating is in process, will the Contractor still be required to inspect the cold weather protection "once per day on non-work days"? Structural USACE RESPONSE 14: "As per paragraph 3.2.1 of Specification section 03 30 53, the Contractor must inspect cold weather protection systems once per shift and once per day. This include any cold weather protection systems and heating systems." QUESTION 15: It does not appear to be required to field paint the reused cleats. Is this accurate? Structural USACE RESPONSE 15: "Correct, no requirement exists to paint re-used cleats." QUESTION 16: Will additional holes be allowed in the armor plates to anchor the strongbacks required by 05 50 15 3.3 ? USACE RESPONSE 16: "Please see SD-301, note 10. Anchoring to the newly installed armor panels is not allowed." QUESTION 17: It appears that the existing handrail is both of the anchored flange and grouted in a cored hole variety. Please provide as-builts or denotation where each section starts / ends. Structural USACE RESPONSE 17: "The as-built quantity of the types of handrails is not available but should be replaced in kind as shown on S-102 to S-105." QUESTION 18: It appears that there are locations in the scope of work where the horizontal portion of the lock wall ramps up to be higher than the top of armor plate. Will this ramp need to be removed prior to the 6" of removal required on A3 of S-501 or does the 6" start from the top of the existing surface - whether it is a ramp or not? Further, provide concurrence that the armor is installed horizontal and not ramped up to meet this ramp. Structural USACE RESPONSE 18: "The ramp in front of the control building is not to be removed or replaced. The 6" removal line for the horizontal concrete is from Elevation 586.0 as shown on SD-301."