Attachment 010 RFP 12805B24R0010 QandA v1.0.pdf

RFP 12805B24R0010 Colonnade Repair – Las Cruces NM

Amendment 0001 Q&A Document Version 1.0

1. Can the full set of as-built drawings for the existing building please be shared?

Only as-designed drawings are available. See “Attachment 008 As Designed Wooten Hall.pdf” added as part of Amendment 0001.

2. Can the geotechnical report please be shared?

See “Attachment 009 4223117-NMSU Wooten Hall Improvements Geotech Report.pdf” added as part of Amendment 0001.

3. Please clarify the underpinning pile depth requirements on A200. What is the basis and true meaning of the design depth of 100 feet?

A: Soil borings were terminated at 25 ft., the load capacity of the soil at 25 ft. was minimal.

Based on soils information in the Las Cruces, New Mexico area an adequate load bearing material may not be encountered until the piles have been advanced to near 100 ft. Base bid

CLIN 0001 pricing shall include cost to install piles up to 100 ft. depth.

***Please add a per foot estimate beyond 100 ft to Technical Proposal only. This estimate shall

NOT be included in the overall proposal pricing and is for technical evaluation purposes only***

Is that depth an absolute minimum requirement?

A: No, piles should be advanced individually to a depth that provides enough resistance to create a manageable lift and provide permanent support. Once each pile is driven to a depth that provides enough resistance to gently flex the footing pad and colonnade structure above the pad

(which will be considered refusal) advancement of the pile should be terminated. The actual pile depths, drive resistance and hydraulic force required to achieve refusal at that point should be recorded and provided on the required pile log. Each pile will be driven individually and all 4 piles at each column load will be linked together and utilized to provide a simultaneous lift of all columns, at each colonnade section. The south colonnade section will have 48 piles that should be lifted simultaneous in an attempt to lift and rotate the colonnade back to near its original position.

The specifications include details regarding requirement to perform a simultaneously lift at 48 piles.

What is the definition of “right of refusal” on A200?

A: Right of refusal was a typographical error. You should substitute right of refusal for depth of refusal, however it is our intent that the foundation contractor provide their standard form for logging pile depths, pressures and other pertinent information which provides specific information about each pile including the exact location of the pile, each pile should be numbered and identified on the pile log with refusal depths, final drive pressures, amount of lift at pile location and drive pressures required to perform the lift.

The existing colonnade structure does not appear to have the mass to allow for the 80-kip maximum load specified in project specifications 0018 Division 31 - 314116 Steel Pile

Foundation Underpinning & Leveling Systems section 3.4

RFP 12805B24R0010 Colonnade Repair – Las Cruces NM

Amendment 0001 Q&A Document Version 1.0

A: The 80-kip load capability is specified to ensure equipment with adequate capacity is used to achieve the requirements of this job. The piling contractors driving and lifting system will need to be capable of achieving an 80-kip load.

The colonnade loads and resistance will only be determined once final piling depths have been achieved as described above. The colonnade structure should be heavy enough to advance each pile to an adequate load bearing strata that will provide permanent support and lift resistance. The colonnade structure has reinforced concrete above the columns and arches that will create enough additional load resistance to prove a hydraulically advanced steel pile to an adequate depth.

and undesired uplift will likely occur prior to 30 kips.

A: Piles should be driven to refusal and up lift of the structure should be monitored closely so undesired up lift does not occur. If the colonnade is over flexed at any pier location it could cause the colonnade structure to break or crack.

If the 100-foot design depth is a minimum requirement will a change to other underpinning pile types such as helical piers or drilled and grouted micropiles be accepted as bid alternates or course-of-construction change orders? It is our opinion that only micropiles can confidently be installed with a guarantee of 100 foot depth.

A: Should for any reason the proposed pile proves to be inadequate when the first piles are driven, we can discuss alternate methods at that time. Helical piles were considered but due to the soil conditions and access around the columns it was determined that the hydraulically advanced push pile would be our first choice.